Review
Therapeutic vaccines for leishmaniasis
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Ali Khamesipour 1.
Introduction
2.
Clinical manifestation
3.
Diagnosis
4.
Treatments
5.
Immunology of leishmaniasis
6.
Vaccines for prevention
7.
Immunotherapy
8.
Immunotherapy of leishmaniasis
9.
Expert opinion
Tehran University of Medical Sciences, Center for Research and Training in Skin Diseases and Leprosy, Tehran, Iran
Introduction: Numerous therapeutic strategies are used to treat leishmaniasis. The treatment of cutaneous leishmaniasis (CL) is solely depends on antimonate derivatives with safety issues and questionable efficacy and there is no fully effective modality to treat CL caused by Leishmania tropica and Leishmania braziliensis. Areas covered: There is no prophylactic vaccine available against any form of leishmaniasis. Immunotherapy for CL has a long history; immunotherapy trials of first and second generation vaccines showed promising results. The current article briefly covers the prophylactic vaccines and explains different immunotherapy strategies that have been used to treat leishmaniasis. This paper does not include experimental vaccines and only lays emphasis on human trials and those vaccines which reached human trials. Expert opinion: Immunotherapy is currently used to successfully treat several disorders; Low cost, limited side effects and no possibility to develop resistance make immunotherapy a valuable choice especially for infectious disease with chemotherapy problems. Efforts are needed to explore the immunological surrogate marker(s) of cure and protection in leishmaniasis and overcome the difficulties in standardization of crude Leishmania vaccines. One of the reasons for anti-leishmaniasis vaccine failure is lack of an appropriate adjuvant. So far, not enough attention has been paid to develop vaccines for immunotherapy of leishmaniasis. Keywords: leishmaniasis immunotherapy, treatment of leishmaniasis, vaccine against leishmaniasis Expert Opin. Biol. Ther. [Early Online]
1.
Introduction
Leishmaniasis is among the neglected diseases that are reported from 98 countries. According to the World Health Organization estimation, a tenth of the world population is at risk of contracting the disease, and 12 million are affected, the annual incidence rate being 1.5 -- 2 million. Ninety percent of visceral leishmaniasis (VL) is reported from five countries: India, Bangladesh, Brazil, Nepal and Sudan. Ninety percent of cutaneous leishmaniasis (CL) is reported from Afghanistan, Algeria, Brazil, Iran, Peru, Saudi Arabia and Syria. The disease is a major health problem in some of the endemic regions. The available control measures are not fully effective, which results in expansion of the disease to new foci. Leishmaniasis is a vectorborne disease caused by at least 20 different species of intracellular Leishmania parasite, which are transmitted by the bite of at least 30 species of sand flies. Life cycle of Leishmania consists of two parasite forms: the promastigote form, which is flagellated parasite and is seen in sand fly vector and culture media, and the amastigote form, which is present and multiplies in mammalian host cells [1].
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A. Khamesipour
Visceral leishmaniasis VL is a systemic disease caused by L. donovani, L. infantum (also previously known as L. chagasi in the new world but is genetically identical to L. infantum); the incubation period is 2 weeks to 18 months. Clinical manifestation of VL includes fever, cachexia, hepatosplenomegaly and anemia. VL can be 100% lethal within 2 years if left untreated. Untreated patients are the source of parasite for anthroponotic VL [1,5-8]. 2.3
Article highlights. . . . . . .
A brief of leishmaniasis status. A brief in clinical forms of leishmaniasis. Prophylactic vaccines against human leishmaniasis. History of therapeutic vaccines in human leishmaniasis. Progress in the field of leishmaniasis vaccine and immunotherapy. Shortages in the field of leishmaniasis vaccine and immunotherapy.
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This box summarizes key points contained in the article.
2.
Post Kala-azar Dermal Leishmaniasis Post Kala-azar Dermal Leishmaniasis (PKDL) is a dermal disorder and sequel of VL. In Sudan, PKDL develops weeks to months after VL recovery and in the majority about 50 -- 60% of the patients, whereas in India PKDL is seen after months to years following recovery from VL and only in 5 -- 15% of the patients. The exact cause of the lesions is not known. Ultraviolet (UVB) might play a role in the pathogenesis and the host immune response is also a crucial factor as response to chemotherapy in patients is strongly correlated with Leishmanin Skin Test (LST), which becomes positive after cure. However, the difference between the two continents is not known, and improper treatment may be one of the reasons [9]. 2.4
Clinical manifestation
Leishmaniasis depends upon the particular Leishmania species that causes the disease and the host genetic profile, which governs the host’s immune responses. The infection can be subclinical, but the clinical manifestations of the disease mainly include the following four clinical forms.
Cutaneous leishmaniasis CL is a self-healing skin lesion. CL in the old world is induced by Leishmania major, Leishmania tropica, Leishmania aethiopica, Leishmania killicki, Leishmania donovani and Leishmania infantum, although the latter two usually cause VL but can cause CL in some endemic parts. CL is either anthroponotic with an incubation period of 2 -- 8 months or zoonotic with an incubation period of 2 -- 8 weeks. The reservoir of the zoonotic form of CL ranges from small rodents to the canine family. New world CL induces by Leishmania mexicana species complex L. mexicana, Leishmania amazonensis and Leishmania venezuelensis or the subgenus Viannia: Leishmania [V.] braziliensis, Leishmania [V.] guyanensis, Leishmania [V.] panamensis and Leishmania [V.] peruviana. The Viannia subgenus, which originated in the new world, is also referred to as the L. (V.) braziliensis species complex [2,3]. The mechanism(s) of lesion development and healing are not yet well understood. 2.1
3.
Laboratory diagnosis of leishmaniasis is mainly based on detection of Leishmania parasites in the samples collected from around the lesions, bone marrow, lymph node or spleen aspirates. In case of VL, antibody and antigen detection in the blood and even presence of Leishmania antigens in the urine of suspected patients can be helpful. Diagnosis of CL is only based on detection of Leishmania and the sole available tool is to use samples prepared by scrape of the lesion(s) or biopsy; however, the sensitivity of the test is not > 80% and the test is rather primitive, but due to lack of other choices, it is used in the endemic areas [7,10]. 4.
Mucucutaneous leishmaniasis Mucucutaneous leishmaniasis (MCL) occurs as a result of metastasis of Leishmania to nasooropharyngeal mucosa and usually is a sequel of CL-induced especially by L. [V.] braziliensis, but also by L. [V.] panamensis and sometimes by L. [V.] guyanensis and L. (Leishmania) amazonensis. MCL can occur years after cure of initial lesion or can be seen simultaneously at the same time with active cutaneous lesion. Diffuse cutaneous leishmaniasis (DCL) consists of multiple nonulcerative nodules and is usually a sequel of L. amazonensis, L. aethiopica and L. mexicana. Disseminated CL is caused by L. (L.) amazonensis and L. (V.) braziliensis. It is believed that proper treatment reduces the risk of MCL [2-4]. 2.2
2
Diagnosis
Treatments
Standard treatment of leishmaniasis is based on chemotherapy, the first-line treatment is pentavalent antimonials (Glucantime; meglumine antimoniate; MA and Pentostam; sodium stibogluconate [SSG]), which are in use since the 1950s with various efficacy from 10 to 90%. In some endemic areas of India, the efficacy of pentavalent antimonials is very low and as such replaced by other more effective drugs like liposomal form of amphotericin B (Ambisome), miltefosine and paromomycine. Various modalities are used to treat CL, but the treatment for CL is still a dilemma. CL is usually a self-healing lesion and in endemic areas is mostly left at the mercy of nature; the available standard treatment is pentavalent antimonials with various efficacy rates sometimes as low
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Therapeutic vaccines for leishmaniasis
as 10% in case of CL caused by L. tropica. The drug is expensive and needs multiple injections, either systemic or intralesional, which is painful and toxic. Radiowave-induced heat therapy has also been used to treat CL, including with recent trials in Brazil, Afghanistan and India. It is strongly recommended not to use chemotherapy for canine VL [11-15].
lesions, a significantly higher level of Treg cells was shown. The presence and roles of other cytokines and memory cells in CL lesion were also investigated, but regardless of the numerous publications, the surrogate marker(s) of cure and protection in leishmaniasis are not well defined [16-26]. 6.
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5.
Vaccines for prevention
Immunology of leishmaniasis
When the female sand fly takes a blood meal from the vertebrate hosts, flagellate metacyclic forms of Leishmania are inoculated along with sand fly salivary components into the dermis of the vertebrate hosts. Then, the parasites are taken up by different cell types, including neutrophils, monocytes, macrophages and resident dendritic cells. Leishmania parasites bind to C3b, which accelerate phagocytosis and soon after the promastigotes convert to the amastigotes form. The first line of immune response against Leishmania infection are the different components of the innate immune response such as the complement system, natural killer cells, mononuclear cells, polymorphonuclear phagocytic cells and the various inflammatory factors like cytokines. Recently, it was shown that neutrophils, the first-line phagocytic cells, which kill pathogens, are infected with Leishmania parasites and are used as a Trojan horse for Leishmania. Surface Leishmania proteins such as lipophosphoglycan and glycosyl inositol phospholipid act as virulence factors, which inhibit the action of the complement system [16-18]. Immune responses in murine leishmaniasis have been extensively studied. Originally Th1/Th2 dichotomy was described as the reason for resistant and susceptibility of L. major infection, but with advanced knowledge and technology and further studies on the roles of various immune elements, it was revealed that the story is not as simple as it was originally described [16]. Human immune response to Leishmania infection is more complicated than that found in inbred animal models. There are reports of relationship betweenTh1/Th2 balance and outcome of human leishmaniasis. It has been shown that in VL and DCL patients Th2 response is induced, and in comparison to healthy controls or subclinical or asymptomatic individuals, a significantly lower level of IFN-g and higher level of IL-4 production by stimulated CD4+ and CD8+ T cells were observed. It was also shown that a Th1 response with high level of IFN-g is dominant in CL patients. To evaluate immune responses in leishmaniasis, the only in vivo available and reliable test is LST, which is also called Montenegro skin test (MST) in the new world. Various antigens and cytokine profiles were used to check in vitro immune responses in leishmaniasis. It was shown that not only CD4+ T cells but also CD8+ T cells are the source of IFN-g. The exact role of Th1/Th2 in persistence of cutaneous lesion has not been elucidated and a mixture of Th1/ Th2 response seems to deal with both acute and chronic leishmaniasis. In acute CL lesion in comparison with chronic
In endemic areas of the Middle East, it was well known that individuals with CL lesion upon cure are protected against further lesion development and as such for centuries, in some of the hyper-endemic areas of the South Western and South North Central parts of Asia, the exudates from an active lesion were used to inoculate and thereby protect young children against future lesions on the exposed parts of the body especially on the face. During the last 50 years, L. major promastigotes grown in culture media have been used for leishmanization in Israel, Iran as well as in a high-risk population in Uzbekistan [21]. So far leishmanization has been shown to be the most effective control measure against CL, and that the in vitro response to live Leishmania is stronger than killed Leishmania crude antigens. However, the main drawback of leishmanization other than the induction of skin lesion, which do not heal at expected time, is the lack of standardized methods. Leishmanization was practiced in endemic areas with no known HIV, and most of the residence showed a scar of CL by age 15 due to high incidence rate [23,27,28]. There are many reasons to believe that development of vaccine against different forms of leishmaniasis is possible. Usually individuals cured of CL are protected against further lesion development, and leishmanization induces protection against further infection; upon cure of the lesion strong immune responses are induced, which can be shown by in vivo and in vitro tests. Numerous antigens have been used as vaccine candidate in animal models. Protection against leishmaniasis in animal model was achieved using various types of antigens. Killed L. major experimental vaccine plus BCG was shown to be safe and induced cell-mediated immune response demonstrated in vivo and in vitro [8,23,24,28-34]. Efforts to develop an effective vaccine against leishmaniasis resulted in preparation of a few first-generation Leishmania vaccines, which reached Phase III efficacy trials in the old and new worlds. The outcome of the trials showed that Leishmania vaccine was safe in humans and dogs. The vaccines induced immune responses in vaccinees, which was shown by in vivo LST and in vitro tests (high level of IFN-g), but the efficacy in preventing disease was not promising, the main reason possibly being the lack of an affordable appropriate adjuvant that can be used in humans [23,28,33-36]. Leish F1 (formerly called Leish111f) is a fusion of three preserved L. major proteins: thiolspecific antioxidant (TSA), L. major stress-inducible protein 1 (LmSTI1) and Leishmania elongation initiation factor (LeIF) protein; it is the only second-generation vaccine that reached human trials. In a study performed in CL endemic area of Colombia, MST-negative and MST-positive
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volunteers were selected and vaccinated with Leish F1 plus MPLSE or Leish F1 alone or placebo. The follow-up results showed that Leish F1 was safe and well tolerated in both groups and was able to induce immune responses. In another Phase II study, which was done in VL endemic area of India, Leish F1 was tested in DAT-negative and DAT-positive volunteers and the results showed that Leish F1 was safe and able to induce Th1 response in both groups of volunteers with history of exposure to L. donovani or in volunteers without history of exposure [30,37]. 7.
Immunotherapy
Immunotherapy has a long history of success in the treatment of diseases from infectious to noninfectious diseases. Serotherapy of diphtheria and tetanus using animal antiserum was initiated before discovery of antibacterial agents. Serotherapy reduced mortality and morbidity of several diseases such as diphtheria and tetanus. Antivenom serotherapy was introduced in the 19th century and became a real breakthrough in medicine and still is the sole treatment for snakebites. Serotherapy advanced from using animal polyclonal antibodies to intravenous immunoglobulins (IGIV) and monoclonal antibodies and more recently humanized antibodies. Nowadays, regardless of the limitations of passive immunization, pathogen-specific antibodies are approved for prophylactic and therapeutic use for several infectious diseases such as rabies virus, cytomegalovirus, hepatitis viruses, respiratory syncytial virus, pneumococcal pneumonia, meningococcal meningitis and Hemophilus influenzae meningitis. Overall, serotherapy has saved millions of lives [38-40]. A meta-analysis study showed that allergen-specific immunotherapy significantly reduced asthma symptoms. Recently, several monoclonal antibodies have been used for cancer therapy. BCG has been used for immunotherapy of bladder cancer. When chemotherapy is not able to control a disease due to various reasons, a combination of the available tools like chemotherapy, immunotherapy and radiotherapy is justified [41,42]. Treatment of leishmaniasis using passive immunization, however, cannot be considered as anti-Leishmania antibodies do not play any role in the cure or protection, but vaccine therapy and use of immunomodulators, which influence cell-mediated immune response, are potential candidate for immunotherapy in leishmaniasis. 8.
Immunotherapy of leishmaniasis
Immunotherapy of first-generation vaccines Regardless of the problems associated with chemotherapy such as the low efficacy in case of CL caused by L. tropica and L. braziliensis, a limited attention was paid to the use of immunotherapy in leishmaniasis especially in the old world. In experimental models, the injection of killed L. major into protected resistant strain of mice was shown to abrogate the protection [43] , which might imply that injection of killed 8.1
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parasite in patients might induce exacerbation, although this phenomenon was not seen in human clinical trials. Immunotherapy of leishmaniasis was pioneered by Row et al., who treated patients with oriental sore using single or multiple doses of killed Leishmania harvested from culture media. Subsequently, Dubovsky in 1943 treated 38 CL patients with oriental sore using killed promastigotes harvested from NNN media; the results showed that 22 (about 58%) of the patients were cured [44]. In a study completed in Brazil, 117 CL patients mostly (76%) with one lesion were recruited and double-blind randomly divided into two groups, all of the patients received systemic Glucantime, 1 ml per 5 kg body weight, at most 10 ml per day. Then one group was assigned to receive immunotherapy with an escalating dose of L. amazonensis (Leishvaccin) from 24 µg on day 1 to 120 µg on day 5, and after a resting period of 10 days the treatment was repeated until complete healing of the lesion(s). No significant difference was seen between the time of cure in the two groups [45]. In a double-blind placebo-controlled trial, which was completed in Brazil, a vaccine was prepared from L. amazonensis in BioBras, Brazil. Then, 102 parasitologically proven CL patients were recruited and treated with either daily subcutaneous (SC) injections of 0.5 ml of the vaccine plus 8.5 mg/kg (0.5 ml/5 kg body weight) intramuscular (IM) injections of MA for 10 days, followed by 10 days rest, or daily SC injections of 0.5 ml of placebo and 8.5 mg/kg (0.5 ml/5 kg body weight), IM injections of MA for 10 days followed by 10 days of rest. The results showed that 47 (100%) of the patients in the immunochemotherapy group versus 4 of 49 (8.2%) in the chemotherapy group were cured after four series of treatment; the results were significantly (p < 0.0001) in favor of immunochemotherapy [44]. In another study conducted in Minas Gerais, Brazil, 542 patients with CL based on parasitological examination or MT were included in an open study and randomly divided into different groups and treated with either Glucantime, 1 ampoule per 25 kg body weight for 10 days, not > 2 ampoules per day or half of the above dose plus killed L. amazonensis promastigotes mixed with BCG. The results showed that immunotherapy induced 100% cure rate similar to full dose of MA; it was concluded that immunotherapy reduces the dose of Glucantime and the duration of the treatment and therefore the vaccine was registered in Brazil as an adjacent to MA therapy [46]. Convit et al. [47] performed a Phase II clinical trial in which 94 patients with localized CL were treated with either heat-killed L. mexicana amazonensis promastigotes mixed with BCG or with standard treatment of pentavalent antimony. The clinical cure was similar (94%) in the two groups, but the side effects in the immunotherapy group were just limited to the local site of injections due to BCG whereas the systemic side effect was those more severe and common to the chemotherapy groups. In a group of 23 CL and 20 MCL patients along with 10 healthy control volunteers, immune responses were evaluated during and after immunotherapy. CL patients received immunotherapy with
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Therapeutic vaccines for leishmaniasis
heat killed promastigotes of L. amazonensis plus BCG, the dose of BCG determined according to baseline PPD results. Immunotherapy was given 2 -- 4 times, at 6 -- 8 week intervals until clinical cure was achieved. MCL patients were treated with chemotherapy plus up to six doses of immunotherapy until complete cure. The results showed that immunotherapy enhanced Th1 response against Leishmania antigens with a higher in vitro IFN-g production [48]. In a large immunotherapy trial completed during 10-year study in Venezuela, 11,532 CL patients were skin tested with leishmanin and purified protein derivative (PPD), and then the patients were treated with heat-killed L. mexicana amazonensis mixed with BCG. The patients received 1 -- 2 booster injections if the lesion(s) was active. Evaluation of the lesion(s) was done in 5431 of the patients and showed ~ 95% efficacy. The side effects were mostly local and due to BCG [47]. In Venezuela, DCL and MCL are not common, and the response to chemotherapy is not high so a study was carried out with four patients with severe MCL and three patients with early DCL, the duration of the lesions being 1 -- 5 years. All the patients had been refractory to chemotherapy and so were treated with a homemade Leishmania braziliensis promastigotes killed by pasteurization plus BCG, intradermally in the deltoid regions in 4-week interval. Complete remission of the lesions occurred after 5 -- 9 injections for MCL patients and after 7 -- 10 for DCL patients [49]. A polyvalent vaccine composed of L. amazonensis, L. venezuelensis, L. braziliensis and L. L. chagasi was prepared and injected IM, three times, 1 month apart to healthy and CL volunteers. The results showed that the vaccine was safe and time to remission of the lesion of the CL patients was similar to chemotherapy [50]. Treatment of PKDL with chemotherapy is difficult. Alumprecipitated autoclaved L. major (Alum-ALM) was shown to be immunogenic and induced Th1 response in an animal model. Safety and immunogenicity of Alum-ALM mixed with BCG was completed in healthy volunteers and PKDL patients, and the results showed that Alum-ALM mixed with BCG was safe and induced strong immune response in human [51]. Then a double-blind randomized efficacy trial was designed in which 30 Sudanese PKDL patients were treated either with combination of Alum-ALM plus BCG and SSG or vaccine diluent and SSG. By day 60, 13 (87%) of 15 patients in group of combined immunotherapy and chemotherapy showed complete cure and in 2 of the patients improvement was observed, whereas in contrast, the group that received chemotherapy alone, 8 (53%) of 15 patients showed complete cure, and 2 of the patients in this group showed relapse on day 90 and 1 patient subsequently showed improvement. Combined therapy was significantly more effective than chemotherapy alone [52,53]. The interpretation of the results generated in efficacy trials is not always an easy task, partly due to the nature of the disease; there are a variety of clinical pictures; there can be healing of CL lesion(s) by
treatment or self-cure all depending on many factors. The issue has been noticed in chemotherapy trials (13 -- 14) and can be concluded from the above immunotherapy trials. Immunotherapy of second-generation vaccines Six mucosal leishmaniasis (ML) patients with duration of lesion 1 -- 5 years and history of CL long before the development of ML were recruited and received 1 -- 15 courses of 20 mg/kg/day MA for 20 -- 30 days. The patients were injected SC with a mixture of 5 µg of each of TSA, LmSTI1, LeIF, Leishmania heat shock protein 83 (Lbhsp83) and 50 mg of the cytokine granulocyte-macrophage colony-stimulating (Leukine; Amgen) in 0.5 ml, three times, 1 month apart, in the anterior surface of the forearm. At 9-month follow--up, five patients showed complete cure and one patient showed improvement and was further treated with immunotherapy and chemotherapy that eventually showed complete cure; all six patients were free of disease during 5-year follow-up [54]. In a double-blind randomized dose-escalating study, 44 adult CL parasitologically proved patients were treated SC either with Leish-F1plus a clinical grade formulation of monophosphoryl lipid A (MPL-SE) or MPL-SE or normal saline; all the three groups of patients received 1 -- 4 courses of chemotherapy using Glucantime (10 mg Sb5 +/kg/day) for 10 days, followed by 11 days of rest. The results showed that Leish-F1 was safe and cure rate was higher in the vaccine group than the control group that received normal saline or MPL-SE [55]. 8.2
Treatment using immunomodulators Immunomodulators such as cytokines and Toll-like receptors agonists were used to treat experimental leishmaniasis. The results of IFN-g treatment in murine model were promising, but when tested in clinical trials to treat old world CL in Syria, the cure rate was less than that in the patients who received Glucantime. When it was tested in new world CL in Guatemala, there was no significant difference seen between the group that received Glucantime alone with the group that was treated with combination of IFN-g and Glucantime. Cytokines are not used in the treatment of leishmaniasis currently due to the cost and side effects. Imiquimod is an immunomodulator and is shown to be effective in the treatment of murine model of leishmaniasis, but the results of human trials are controversial. A few studies, however, showed some degree of effectiveness in the treatment of CL with imiquimod, but topical imiquimod failed to treat CL caused by L. tropica even when it was combined with Glucantime [13,37]. 8.3
9.
Expert opinion
Leishmaniasis is a major public health problem in some endemic regions and the most neglected disease; CL has been ignored partly due to the fact that it has been defined as a simple self-healing skin disease. Treatment of leishmaniasis, especially CL caused by L. tropica and L. braziliensis, is frustrating for the patients and a dilemma for the physicians
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and health authorities [12,13]. Host immune responses are generated upon exposure to Leishmania parasites, but the exact role of various compartment of immune responses in the pathogenesis and cure is not well defined and the surrogate markers of protection are not known [19-28,56-63]. The most effective control measure against leishmaniasis seems to be an effective vaccine. Historically, leishmanization was showed to be efficacious and it is theoretically feasible to develop an effective vaccines against leishmaniasis, but so far no vaccine is available against any form of leishmaniasis. Different candidate vaccines including live Leishmania, attenuated, suicidal cassettes and gene manipulated Leishmania to firstgeneration, second-generation and third-generation vaccines have been used successfully in experimental models. Immunotherapy has advanced in recent years and monoclonal antibodies, BCG, cytokines and other immunomodulators are in use to treat infectious and noninfectious diseases [8,23,30,35,37,38,40-42,64]. When chemotherapy is not available, or has serious side effects, or its efficacy not high enough to control the disease, the use of immunotherapy or combination with chemotherapy is justified. As is mentioned before, numerous prophylactic trials and several trials of immunotherapy using whole crude or well-defined antigens have been completed; each study showed that the different preparations of the vaccines were safe and the results of immunotherapy trials showed the vaccines were beneficial. Although various degrees of efficacy were shown, the results are promising. Moreover, immunotherapy was shown to be relatively safe, the side effects were always limited to the site of vaccine injection and mainly due to the combination with BCG. An effective prophylactic vaccine against leishmaniasis should be able to induce Th1 response with a limited Th2 response. However, designing therapeutic vaccines against leishmaniasis is more difficult than the development of prophylactic vaccine, and unlike prophylactic vaccines, a unique strategy might not be effective. One problem is that the various immune responses generated in different clinical forms and the wide spectrum of the severity of leishmaniasis are not similar. In some circumstances, a Th1 type of immune response is required to initiate cure, whereas in some a strong Th1 response is already induced that needs to be suppressed or modulated. In some types of the disease such as in MCL, and in recidivans CL patients, a strong Th1 response is already induced (shown by in vivo LST and in vitro production of a high level of IFN-g and no IL-4/IL-5 in response to Leishmania antigens and a very low level of anti-Leishmania antibodies), In these groups of patients, immunotherapy should modulate Th1, whereas in VL and DCL patients, a Th2 response is dominant, so immunotherapy needs to switch the immune response to Th1 type of response. Immunotherapy using vaccine is affordable for endemic areas, and there is no possibility of the development of
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resistant. To develop an effective immunotherapy strategy, several tools are needed; immune responses development in different clinical forms of leishmaniasis must be explored to define the immune surrogate marker(s) of cure and protection. First-generation vaccines are cheap and could be manufactured under good manufacturing practice in endemic areas and for this reason crude antigens mainly were used in vaccine trials for prophylactic and immunotherapy. The disadvantage, however, is that Leishmania crude antigens are not standardized and as such batch-to-batch variation exists so standardization is a must. Also, serum-free media is not available to culture Leishmania. Second-generation vaccines are well defined, reproducible but not affordable for endemic areas [44,48,53,64]. Another complication is that there is no animal model that completely corresponds to human leishmaniasis and thus, sometimes several animal models are used and then the interpretation of the results is difficult. Moreover, there is no guarantee that one will get the same results in humans. In addition, an appropriate adjuvant is required to use with Leishmania antigens either crude or well-defined ones. Currently available adjuvants that can be used with Leishmania vaccines are limited to those in human use if they are affordable. This is one of the reasons that BCG was used in the old world leishmaniasis vaccine trials [28,33,34,36,57]. Failure of developing effective Leishmania vaccines is due to many reasons. Leishmaniasis is a poverty-related disease and is endemic in the poorest regions of the world with limited infrastructure. Although leishmaniasis is a major health problem in some endemic areas, it is not recognized as such. Pharmaceutical industries are not interested to develop vaccine against leishmaniasis as it is not profitable and so health authorities in the endemic countries need to invest in this area, but unfortunately endemic countries are involved in war/sanctions/political crisis. Last but not least, strong collaboration between the well-equipped laboratories and endemic area is required.
Acknowledgement I would like to appreciate Prof John R David for help in editing the manuscript.
Declaration of interest The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
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Therapeutic vaccines for leishmaniasis
Bibliography Papers of special note have been highlighted as either of interest () or of considerable interest () to readers. 1.
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2.
3.
4.
..
5.
..
6.
.
7.
..
8.
..
9.
.
Alvar J, Velez ID, Bern C, et al. Leishmaniasis worldwide and global estimates of its incidence. PLoS One 2012;7(5):e35671
10.
.
11.
Akilov OE, Khachemoune A, Hasan T. Clinical manifestations and classification of Old World cutaneous leishmaniasis. Int J Dermatol 2007;46(2):132-42 Gontijo B, de Carvalho Mde L. American cutaneous leishmaniasis. Rev Soc Bras Med Trop 2003;36(1):71-80 Bonfante-Garrido R, Barroeta S, de Alejos MA, et al. Disseminated American cutaneous leishmaniasis. Int J Dermatol 1996;35(8):561-5 Leishmaniasis status and clinical forms. Das A, Ali N. Vaccine prospects of killed but metabolically active Leishmania against visceral leishmaniasis. Expert Rev Vaccines 2012;11(7):783-5 A review on some of the antiLeishmania candidate vaccines. Goto H, Prianti M. Immunoactivation and immunopathogeny during active visceral leishmaniasis. Rev Inst Med Trop Sao Paulo 2009;51(5):241-6 Immunology of visceral leishmaniasis (VL). Khalil EA, El Hassan AM, Zijlstra EE, et al. Autoclaved Leishmania major vaccine for prevention of visceral leishmaniasis: a randomised, doubleblind, BCG-controlled trial in Sudan. Lancet 2000;356(9241):1565-9 The only Phase III efficacy trial of first-generation vaccine against VL. Nagill R, Kaur S. Vaccine candidates for leishmaniasis: a review. Int Immunopharmacol 2011;11(10):1464-88 List of leishmaniasis candidate vaccines. WHO. Post-kala-azar dermal leishmaniasis: a manual for case management and control. report of a who consultative meeting. Kolkata, India; 2012 Available from: http://apps.who.int/ iris/bitstream/10665/78608/1/ 9789241505215_eng.pdf A review on Post Kala-azar Dermal Leishmaniasis.
..
Goto H, Lindoso JA. Current diagnosis and treatment of cutaneous and mucocutaneous leishmaniasis. Expert Rev Anti Infect Ther 2010;8(4):419-33 Diagnosis and treatment of cutaneous leishmaniasis (CL) and MCL. Barroso PA, Marco JD, Calvopina M, et al. A trial of immunotherapy against Leishmania amazonensis infection in vitro and in vivo with Z-100, a polysaccharide obtained from Mycobacterium tuberculosis, alone or combined with meglumine antimoniate. J Antimicrob Chemother 2007;59(6):1123-9 Immunotherapy of cutaneous leishmaniasis.
12.
Croft SL, Olliaro P. Leishmaniasis chemotherapy-challenges and opportunities. Clin Microbiol Infect 2011;17(10):1478-83
13.
Firooz A, Khamesipour A, Ghoorchi MH, et al. Imiquimod in combination with meglumine antimoniate for cutaneous leishmaniasis: a randomized assessor-blind controlled trial. Arch Dermatol 2006;142(12):1575-9
14.
..
15.
.
Khatami A, Firooz A, Gorouhi F, et al. Systematic review of new world cutaneous leishmaniasis: several points. Int J Dermatol 2009;48(2):201; author reply 201-2 Overview of chemotherapy and weaknesses. Bumb RA, Prasad N, Aara N, et al. Long-term efficacy of a single-dose Radio Frequency Heat therapy versus intralesional antimonials for cutaneous leishmaniasis in India. Br J Dermatol 2013;168(5):1114-19 Chemotherapy and heat therapy.
16.
Sacks D, Noben-Trauth N. The immunology of susceptibility and resistance to Leishmania major in mice. Nat Rev Immunol 2002;2(11):845-58
17.
Bogdan C. Leishmaniasis in rheumatology, haematology and oncology: epidemiological, immunological and clinical aspects and caveats. Ann Rheum Dis 2012;71(Suppl 2):i60-6
18.
Peters NC, Egen JG, Secundino N, et al. In vivo imaging reveals an essential role for neutrophils in leishmaniasis
Expert Opin. Biol. Ther. (2014) 14(11)
transmitted by sand flies. Science 2008;321(5891):970-4 19.
Habibi GR, Khamesipour A, McMaster WR, et al. Cytokine gene expression in healing and non-healing cases of cutaneous leishmaniasis in response to in vitro stimulation with recombinant gp63 using semiquantitative RT-PCR. Scand J Immunol 2001;54(4):414-20
20.
Hejazi SH, Hoseini S, Javanmard SH, et al. Interleukin-10 and transforming growth factor-beta in early and late lesions of patients with leishmania major induced cutaneous leishmaniasis. Iran J Parasitol 2012;7(3):16-23
21.
Hoseini SG, Javanmard SH, Zarkesh SH, et al. Regulatory T-cell profile in early and late lesions of cutaneous leishmaniasis due to Leishmania major. J Res Med Sci 2012;17(6):513-18
22.
Jafari-Shakib R, Ajdary S, Amiri ZM, et al. CD26 expression on CD4+T cells in patients with cutaneous leishmaniasis. Clin Exp Immunol 2008;153(1):31-6 Leishmaniasis immunology.
.
23.
..
24.
.
Khamesipour A, Dowlati Y, Asilian A, et al. Leishmanization: use of an old method for evaluation of candidate vaccines against leishmaniasis. Vaccine 2005;23(28):3642-8 Effectiveness of leishmanization. Mahmoodi M, Khamesipour A, Dowlati Y, et al. Immune response measured in human volunteers vaccinated with autoclaved Leishmania major vaccine mixed with low dose of BCG. Clin Exp Immunol 2003;134(2):303-8 Immune response in vaccines vs CL patients old world.
25.
Nateghi Rostami M, Keshavarz H, Edalat R, et al. CD8+ T cells as a source of IFN-gamma production in human cutaneous leishmaniasis. PLoS Negl Trop Dis 2010;4(10):e845
26.
Tolouei S, Ghaedi K, Khamesipour A, et al. IL-23 and IL-27 levels in macrophages collected from peripheral blood of patients with healing vs nonhealing form of cutaneous leishmaniasis. Iran J Parasitol 2012;7(1):18-25
27.
Nateghi Rostami M, Keshavarz Valian H, Eskandari SE, et al. Differential in vitro CD4+/CD8+ T-cell response to live vs. killed Leishmania
7
A. Khamesipour
.
28.
..
Expert Opin. Biol. Ther. Downloaded from informahealthcare.com by University Of South Australia on 08/11/14 For personal use only.
29.
..
30.
..
31.
32.
.
33.
34.
..
35.
..
36.
8
major. Parasite Immunol 2010;32(2):101-10 Immune responses in CL.
..
Noazin S, Khamesipour A, Moulton LH, et al. Efficacy of killed whole-parasite vaccines in the prevention of leishmaniasis: a meta-analysis. Vaccine 2009;27(35):4747-53 Overview of first-generation vaccines.
37.
Duthie MS, Vanitha RS, Franco PM, et al. The development and clinical evaluation of second-generation leishmaniasis vaccines. Vaccine 2012;30(2):134-41 Overview of second generation vaccines.
38.
Singh B, Sundar S. Leishmaniasis: vaccine candidates and perspectives. Vaccine 2012;30(26):3834-42 A review on leishmaniasis vaccines.
..
.
39.
.
Badiee A, Jaafari MR, Samiei A, et al. Coencapsulation of CpG oligodeoxynucleotides with recombinant Leishmania major stress-inducible protein 1 in liposome enhances immune response and protection against leishmaniasis in immunized BALB/c mice. Clin Vaccine Immunol 2008;15(4):668-74
40.
Firouzmand H, Badiee A, Khamesipour A, et al. Induction of protection against leishmaniasis in susceptible BALB/c mice using simple DOTAP cationic nanoliposomes containing soluble Leishmania antigen (SLA). Acta Trop 2013;128(3):528-35 Induction of protection in animal model.
42.
Momeni AZ, Jalayer T, Emamjomeh M, et al. A randomized, double blind, controlled trial of a killed L. major vaccine plus BCG against ZCL in Iran. Vaccine 1999;17:466-72 Sharifi I, Fekri A, Aflatonian M, et al. Double-blind randomized controlled vaccine trial of a single dose of killed Leishmania major plus Bacillus of Calmette Guerin (BCG) against anthroponotic cutaneous Leishmaniasis Bam, Iran. Lancet 1998 First generation vaccine trials. Alvar J, Croft SL, Kaye P, et al. Case study for a vaccine against leishmaniasis. Vaccine 2013;31(Suppl 2):B244-9 Status of antileishmaniasis vaccines. Badiee A, Heravi Shargh V, Khamesipour A, et al. Micro/nanoparticle adjuvants for antileishmanial vaccines:
.
41.
..
.
43.
.
44.
45.
46.
present and future trends. Vaccine 2013;31(5):735-49 Adjuvant and leishmaniasis vaccines. Okwor I, Uzonna JE. As a strategy for treatment of leishmaniasis: a review of the literature. Immunotherapy 2009;1(5):765-76 Overview of immunotherapy/ chemotherapy.
treatment. Rev Soc Bras Med Trop 2006;39(1):14-21 47.
Convit J, Ulrich M, Zerpa O, et al. Immunotherapy of American cutaneous leishmaniasis in Venezuela during the period 1990--1999. Trans R Soc Trop Med Hyg 2003;97:469-72
48.
Cabrera M, Blackwell JM, Castes M, et al. Immunotherapy with live BCG plus heat killed Leishmania induces a T helper 1-like response in American cutaneous leishmaniasis patients. Parasite Immunol 2000;22(2):73-9
49.
Convit J, Ulrich M, Polegre MA, et al. Therapy of Venezuelan patients with severe mucocutaneous or early lesions of diffuse cutaneous leishmaniasis with a vaccine containing pasteurized Leishmania promastigotes and bacillus Calmette-Guerin: preliminary report. Mem Inst Oswaldo Cruz 2004;99(1):57-62
50.
O’Daly JA, Spinetti HM, Gleason J, et al. Clinical and immunological analysis of cutaneous leishmaniasis before and after different treatments. J Parasitol Res 2013;2013:657016
51.
Khalil EA, Musa AM, Modabber F, et al. Safety and immunogenicity of a candidate vaccine for visceral leishmaniasis (Alum-precipitated autoclaved Leishmania major + BCG) in children: an extended phase II study. Ann Trop Paediatr 2006;26(4):357-61 Immunotherapy trials.
Simon J. Emil Behring’s medical culture: from disinfection to serotherapy. Med Hist 2007;51(2):201-18 Serotherapy. Chakravarty J, Kumar S, Trivedi S, et al. A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1 +MPL-SE vaccine for use in the prevention of visceral leishmaniasis. Vaccine 2011;29(19):3531-7 Second generation phase 1-2 study. Waldmann TA. Immunotherapy: past, present and future. Nat Med 2003;9:269-77 Serotherapy. Pennington JE. Immunotherapy of infectious diseases: past, present and future. Trans Am Clin Climatol Assoc 1988;99:126-35 Overview of immunotherapy. Luke TC, Arturo C, Stanley WJ, et al. Hark back: passive immunotherapy for influenza and other serious infections. Crit Care Med 2010;38:e66-73 Passive immunotherapy. Okwora I, Liua D, Beverley SM, et al. Inoculation of killed Leishmania major into immune mice rapidly disrupts immunity to a secondary challenge via IL-10-mediated process. Proc Natl Acad Sci USA 2009;106(33):13951-6 Experimental immunotherapy. Machado-Pinto J, Pinto J, da Costa CA, et al. Immunochemotherapy for cutaneous leishmaniasis: a controlled trial using killed Leishmania (Leishmanin amazonensis vaccine plus antimonial. Int J Dermatol 2002;41(2):73-8 Toledo VP, Mayrink W, Gollob KJ, et al. Immunochemotherapy in American cutaneous leishmaniasis: immunological aspects before and after treatment. Mem Inst Oswaldo Cruz 2001;96(1):89-98 Mayrink W, Botelho AC, Magalhaes PA, et al. Immunotherapy, immunochemotherapy and chemotherapy for American cutaneous leishmaniasis
Expert Opin. Biol. Ther. (2014) 14(11)
..
52.
..
53.
..
54.
..
55.
.
Musa AM, Khalil EA, Mahgoub FA, et al. Immunochemotherapy of persistent post-kala-azar dermal leishmaniasis: a novel approach to treatment. Trans R Soc Trop Med Hyg 2008;102(1):58-63 The only immunotherapy trial to treat PKDL. Modabber F. Leishmaniasis vaccines: past, present and future. PLoS Negl Trop Dis 2010;36(Suppl 1):S51-61 Overview of leishmaniasis vaccines. Badaro R, Lobo I, Munos A, et al. Immunotherapy for drug-refractory mucosal leishmaniasis. J Infect Dis 2006;194(8):1151-9 Immunotherapy studies. Nascimento E, Fernandes DF, Vieira EP, et al. Vaccination of humans against cutaneous leishmaniasis: cellular and humoral immune responses. Infect Immun 1990;58(7):2198-203 Immune response in vaccinees new world.
Therapeutic vaccines for leishmaniasis
56.
.
57.
Beattie L, Kaye PM. Leishmania-host interactions: what has imaging taught us? Cell Microbiol 2011;13(11):1659-67
58.
Bogdan C. Natural killer cells in experimental and human leishmaniasis. Front Cell Infect Microbiol 2012;2:69
59.
Expert Opin. Biol. Ther. Downloaded from informahealthcare.com by University Of South Australia on 08/11/14 For personal use only.
Awasthi A, Mathur RK, Saha B. Immune response to Leishmania infection. Indian J Med Res 2004;119(6):238-58 Immune responses in VL.
60.
De Almeida Silva L, Romero HD, Prata A, et al. Immunologic tests in patients after clinical cure of visceral leishmaniasis. Am J Trop Med Hyg 2006;75(4):739-43
leishmaniasis due to Leishmania major in Sudan. Am J Trop Med Hyg 1995;52(5):438-42 61.
.
62.
..
Kaye PM, Aebischer T. Visceral leishmaniasis: immunology and prospects for a vaccine. Clin Microbiol Infect 2011;17(10):1462-70 Immune responses in leishmaniasis. Musa AM, Noazin S, Khalil EA, et al. Immunological stimulation for the treatment of leishmaniasis: a modality worthy of serious consideration. Trans R Soc Trop Med Hyg 2010;104(1):1-2 Overview of importance of immunochemotherapy.
63.
.
64.
..
Nylen S, Gautam S. Immunological perspectives of leishmaniasis. J Glob Infect Dis 2010;2(2):135-46 Immune responses in leishmaniasis. Evans KJ, Kedzierski L. Development of vaccines against visceral leishmaniasis. J Trop Med 2012;2012:892817 Review of vaccines against VL.
Affiliation Ali Khamesipour Tehran University of Medical Sciences, Center for Research and Training in Skin Diseases and Leprosy, Tehran, Iran E-mail: [email protected]
Gaafar A, el Kadaro AY, Theander TG, et al. The pathology of cutaneous
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9
Therapeutic vaccines for leishmaniasis
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Ali Khamesipour 1.
Introduction
2.
Clinical manifestation
3.
Diagnosis
4.
Treatments
5.
Immunology of leishmaniasis
6.
Vaccines for prevention
7.
Immunotherapy
8.
Immunotherapy of leishmaniasis
9.
Expert opinion
Tehran University of Medical Sciences, Center for Research and Training in Skin Diseases and Leprosy, Tehran, Iran
Introduction: Numerous therapeutic strategies are used to treat leishmaniasis. The treatment of cutaneous leishmaniasis (CL) is solely depends on antimonate derivatives with safety issues and questionable efficacy and there is no fully effective modality to treat CL caused by Leishmania tropica and Leishmania braziliensis. Areas covered: There is no prophylactic vaccine available against any form of leishmaniasis. Immunotherapy for CL has a long history; immunotherapy trials of first and second generation vaccines showed promising results. The current article briefly covers the prophylactic vaccines and explains different immunotherapy strategies that have been used to treat leishmaniasis. This paper does not include experimental vaccines and only lays emphasis on human trials and those vaccines which reached human trials. Expert opinion: Immunotherapy is currently used to successfully treat several disorders; Low cost, limited side effects and no possibility to develop resistance make immunotherapy a valuable choice especially for infectious disease with chemotherapy problems. Efforts are needed to explore the immunological surrogate marker(s) of cure and protection in leishmaniasis and overcome the difficulties in standardization of crude Leishmania vaccines. One of the reasons for anti-leishmaniasis vaccine failure is lack of an appropriate adjuvant. So far, not enough attention has been paid to develop vaccines for immunotherapy of leishmaniasis. Keywords: leishmaniasis immunotherapy, treatment of leishmaniasis, vaccine against leishmaniasis Expert Opin. Biol. Ther. [Early Online]
1.
Introduction
Leishmaniasis is among the neglected diseases that are reported from 98 countries. According to the World Health Organization estimation, a tenth of the world population is at risk of contracting the disease, and 12 million are affected, the annual incidence rate being 1.5 -- 2 million. Ninety percent of visceral leishmaniasis (VL) is reported from five countries: India, Bangladesh, Brazil, Nepal and Sudan. Ninety percent of cutaneous leishmaniasis (CL) is reported from Afghanistan, Algeria, Brazil, Iran, Peru, Saudi Arabia and Syria. The disease is a major health problem in some of the endemic regions. The available control measures are not fully effective, which results in expansion of the disease to new foci. Leishmaniasis is a vectorborne disease caused by at least 20 different species of intracellular Leishmania parasite, which are transmitted by the bite of at least 30 species of sand flies. Life cycle of Leishmania consists of two parasite forms: the promastigote form, which is flagellated parasite and is seen in sand fly vector and culture media, and the amastigote form, which is present and multiplies in mammalian host cells [1].
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A. Khamesipour
Visceral leishmaniasis VL is a systemic disease caused by L. donovani, L. infantum (also previously known as L. chagasi in the new world but is genetically identical to L. infantum); the incubation period is 2 weeks to 18 months. Clinical manifestation of VL includes fever, cachexia, hepatosplenomegaly and anemia. VL can be 100% lethal within 2 years if left untreated. Untreated patients are the source of parasite for anthroponotic VL [1,5-8]. 2.3
Article highlights. . . . . . .
A brief of leishmaniasis status. A brief in clinical forms of leishmaniasis. Prophylactic vaccines against human leishmaniasis. History of therapeutic vaccines in human leishmaniasis. Progress in the field of leishmaniasis vaccine and immunotherapy. Shortages in the field of leishmaniasis vaccine and immunotherapy.
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This box summarizes key points contained in the article.
2.
Post Kala-azar Dermal Leishmaniasis Post Kala-azar Dermal Leishmaniasis (PKDL) is a dermal disorder and sequel of VL. In Sudan, PKDL develops weeks to months after VL recovery and in the majority about 50 -- 60% of the patients, whereas in India PKDL is seen after months to years following recovery from VL and only in 5 -- 15% of the patients. The exact cause of the lesions is not known. Ultraviolet (UVB) might play a role in the pathogenesis and the host immune response is also a crucial factor as response to chemotherapy in patients is strongly correlated with Leishmanin Skin Test (LST), which becomes positive after cure. However, the difference between the two continents is not known, and improper treatment may be one of the reasons [9]. 2.4
Clinical manifestation
Leishmaniasis depends upon the particular Leishmania species that causes the disease and the host genetic profile, which governs the host’s immune responses. The infection can be subclinical, but the clinical manifestations of the disease mainly include the following four clinical forms.
Cutaneous leishmaniasis CL is a self-healing skin lesion. CL in the old world is induced by Leishmania major, Leishmania tropica, Leishmania aethiopica, Leishmania killicki, Leishmania donovani and Leishmania infantum, although the latter two usually cause VL but can cause CL in some endemic parts. CL is either anthroponotic with an incubation period of 2 -- 8 months or zoonotic with an incubation period of 2 -- 8 weeks. The reservoir of the zoonotic form of CL ranges from small rodents to the canine family. New world CL induces by Leishmania mexicana species complex L. mexicana, Leishmania amazonensis and Leishmania venezuelensis or the subgenus Viannia: Leishmania [V.] braziliensis, Leishmania [V.] guyanensis, Leishmania [V.] panamensis and Leishmania [V.] peruviana. The Viannia subgenus, which originated in the new world, is also referred to as the L. (V.) braziliensis species complex [2,3]. The mechanism(s) of lesion development and healing are not yet well understood. 2.1
3.
Laboratory diagnosis of leishmaniasis is mainly based on detection of Leishmania parasites in the samples collected from around the lesions, bone marrow, lymph node or spleen aspirates. In case of VL, antibody and antigen detection in the blood and even presence of Leishmania antigens in the urine of suspected patients can be helpful. Diagnosis of CL is only based on detection of Leishmania and the sole available tool is to use samples prepared by scrape of the lesion(s) or biopsy; however, the sensitivity of the test is not > 80% and the test is rather primitive, but due to lack of other choices, it is used in the endemic areas [7,10]. 4.
Mucucutaneous leishmaniasis Mucucutaneous leishmaniasis (MCL) occurs as a result of metastasis of Leishmania to nasooropharyngeal mucosa and usually is a sequel of CL-induced especially by L. [V.] braziliensis, but also by L. [V.] panamensis and sometimes by L. [V.] guyanensis and L. (Leishmania) amazonensis. MCL can occur years after cure of initial lesion or can be seen simultaneously at the same time with active cutaneous lesion. Diffuse cutaneous leishmaniasis (DCL) consists of multiple nonulcerative nodules and is usually a sequel of L. amazonensis, L. aethiopica and L. mexicana. Disseminated CL is caused by L. (L.) amazonensis and L. (V.) braziliensis. It is believed that proper treatment reduces the risk of MCL [2-4]. 2.2
2
Diagnosis
Treatments
Standard treatment of leishmaniasis is based on chemotherapy, the first-line treatment is pentavalent antimonials (Glucantime; meglumine antimoniate; MA and Pentostam; sodium stibogluconate [SSG]), which are in use since the 1950s with various efficacy from 10 to 90%. In some endemic areas of India, the efficacy of pentavalent antimonials is very low and as such replaced by other more effective drugs like liposomal form of amphotericin B (Ambisome), miltefosine and paromomycine. Various modalities are used to treat CL, but the treatment for CL is still a dilemma. CL is usually a self-healing lesion and in endemic areas is mostly left at the mercy of nature; the available standard treatment is pentavalent antimonials with various efficacy rates sometimes as low
Expert Opin. Biol. Ther. (2014) 14(11)
Therapeutic vaccines for leishmaniasis
as 10% in case of CL caused by L. tropica. The drug is expensive and needs multiple injections, either systemic or intralesional, which is painful and toxic. Radiowave-induced heat therapy has also been used to treat CL, including with recent trials in Brazil, Afghanistan and India. It is strongly recommended not to use chemotherapy for canine VL [11-15].
lesions, a significantly higher level of Treg cells was shown. The presence and roles of other cytokines and memory cells in CL lesion were also investigated, but regardless of the numerous publications, the surrogate marker(s) of cure and protection in leishmaniasis are not well defined [16-26]. 6.
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5.
Vaccines for prevention
Immunology of leishmaniasis
When the female sand fly takes a blood meal from the vertebrate hosts, flagellate metacyclic forms of Leishmania are inoculated along with sand fly salivary components into the dermis of the vertebrate hosts. Then, the parasites are taken up by different cell types, including neutrophils, monocytes, macrophages and resident dendritic cells. Leishmania parasites bind to C3b, which accelerate phagocytosis and soon after the promastigotes convert to the amastigotes form. The first line of immune response against Leishmania infection are the different components of the innate immune response such as the complement system, natural killer cells, mononuclear cells, polymorphonuclear phagocytic cells and the various inflammatory factors like cytokines. Recently, it was shown that neutrophils, the first-line phagocytic cells, which kill pathogens, are infected with Leishmania parasites and are used as a Trojan horse for Leishmania. Surface Leishmania proteins such as lipophosphoglycan and glycosyl inositol phospholipid act as virulence factors, which inhibit the action of the complement system [16-18]. Immune responses in murine leishmaniasis have been extensively studied. Originally Th1/Th2 dichotomy was described as the reason for resistant and susceptibility of L. major infection, but with advanced knowledge and technology and further studies on the roles of various immune elements, it was revealed that the story is not as simple as it was originally described [16]. Human immune response to Leishmania infection is more complicated than that found in inbred animal models. There are reports of relationship betweenTh1/Th2 balance and outcome of human leishmaniasis. It has been shown that in VL and DCL patients Th2 response is induced, and in comparison to healthy controls or subclinical or asymptomatic individuals, a significantly lower level of IFN-g and higher level of IL-4 production by stimulated CD4+ and CD8+ T cells were observed. It was also shown that a Th1 response with high level of IFN-g is dominant in CL patients. To evaluate immune responses in leishmaniasis, the only in vivo available and reliable test is LST, which is also called Montenegro skin test (MST) in the new world. Various antigens and cytokine profiles were used to check in vitro immune responses in leishmaniasis. It was shown that not only CD4+ T cells but also CD8+ T cells are the source of IFN-g. The exact role of Th1/Th2 in persistence of cutaneous lesion has not been elucidated and a mixture of Th1/ Th2 response seems to deal with both acute and chronic leishmaniasis. In acute CL lesion in comparison with chronic
In endemic areas of the Middle East, it was well known that individuals with CL lesion upon cure are protected against further lesion development and as such for centuries, in some of the hyper-endemic areas of the South Western and South North Central parts of Asia, the exudates from an active lesion were used to inoculate and thereby protect young children against future lesions on the exposed parts of the body especially on the face. During the last 50 years, L. major promastigotes grown in culture media have been used for leishmanization in Israel, Iran as well as in a high-risk population in Uzbekistan [21]. So far leishmanization has been shown to be the most effective control measure against CL, and that the in vitro response to live Leishmania is stronger than killed Leishmania crude antigens. However, the main drawback of leishmanization other than the induction of skin lesion, which do not heal at expected time, is the lack of standardized methods. Leishmanization was practiced in endemic areas with no known HIV, and most of the residence showed a scar of CL by age 15 due to high incidence rate [23,27,28]. There are many reasons to believe that development of vaccine against different forms of leishmaniasis is possible. Usually individuals cured of CL are protected against further lesion development, and leishmanization induces protection against further infection; upon cure of the lesion strong immune responses are induced, which can be shown by in vivo and in vitro tests. Numerous antigens have been used as vaccine candidate in animal models. Protection against leishmaniasis in animal model was achieved using various types of antigens. Killed L. major experimental vaccine plus BCG was shown to be safe and induced cell-mediated immune response demonstrated in vivo and in vitro [8,23,24,28-34]. Efforts to develop an effective vaccine against leishmaniasis resulted in preparation of a few first-generation Leishmania vaccines, which reached Phase III efficacy trials in the old and new worlds. The outcome of the trials showed that Leishmania vaccine was safe in humans and dogs. The vaccines induced immune responses in vaccinees, which was shown by in vivo LST and in vitro tests (high level of IFN-g), but the efficacy in preventing disease was not promising, the main reason possibly being the lack of an affordable appropriate adjuvant that can be used in humans [23,28,33-36]. Leish F1 (formerly called Leish111f) is a fusion of three preserved L. major proteins: thiolspecific antioxidant (TSA), L. major stress-inducible protein 1 (LmSTI1) and Leishmania elongation initiation factor (LeIF) protein; it is the only second-generation vaccine that reached human trials. In a study performed in CL endemic area of Colombia, MST-negative and MST-positive
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volunteers were selected and vaccinated with Leish F1 plus MPLSE or Leish F1 alone or placebo. The follow-up results showed that Leish F1 was safe and well tolerated in both groups and was able to induce immune responses. In another Phase II study, which was done in VL endemic area of India, Leish F1 was tested in DAT-negative and DAT-positive volunteers and the results showed that Leish F1 was safe and able to induce Th1 response in both groups of volunteers with history of exposure to L. donovani or in volunteers without history of exposure [30,37]. 7.
Immunotherapy
Immunotherapy has a long history of success in the treatment of diseases from infectious to noninfectious diseases. Serotherapy of diphtheria and tetanus using animal antiserum was initiated before discovery of antibacterial agents. Serotherapy reduced mortality and morbidity of several diseases such as diphtheria and tetanus. Antivenom serotherapy was introduced in the 19th century and became a real breakthrough in medicine and still is the sole treatment for snakebites. Serotherapy advanced from using animal polyclonal antibodies to intravenous immunoglobulins (IGIV) and monoclonal antibodies and more recently humanized antibodies. Nowadays, regardless of the limitations of passive immunization, pathogen-specific antibodies are approved for prophylactic and therapeutic use for several infectious diseases such as rabies virus, cytomegalovirus, hepatitis viruses, respiratory syncytial virus, pneumococcal pneumonia, meningococcal meningitis and Hemophilus influenzae meningitis. Overall, serotherapy has saved millions of lives [38-40]. A meta-analysis study showed that allergen-specific immunotherapy significantly reduced asthma symptoms. Recently, several monoclonal antibodies have been used for cancer therapy. BCG has been used for immunotherapy of bladder cancer. When chemotherapy is not able to control a disease due to various reasons, a combination of the available tools like chemotherapy, immunotherapy and radiotherapy is justified [41,42]. Treatment of leishmaniasis using passive immunization, however, cannot be considered as anti-Leishmania antibodies do not play any role in the cure or protection, but vaccine therapy and use of immunomodulators, which influence cell-mediated immune response, are potential candidate for immunotherapy in leishmaniasis. 8.
Immunotherapy of leishmaniasis
Immunotherapy of first-generation vaccines Regardless of the problems associated with chemotherapy such as the low efficacy in case of CL caused by L. tropica and L. braziliensis, a limited attention was paid to the use of immunotherapy in leishmaniasis especially in the old world. In experimental models, the injection of killed L. major into protected resistant strain of mice was shown to abrogate the protection [43] , which might imply that injection of killed 8.1
4
parasite in patients might induce exacerbation, although this phenomenon was not seen in human clinical trials. Immunotherapy of leishmaniasis was pioneered by Row et al., who treated patients with oriental sore using single or multiple doses of killed Leishmania harvested from culture media. Subsequently, Dubovsky in 1943 treated 38 CL patients with oriental sore using killed promastigotes harvested from NNN media; the results showed that 22 (about 58%) of the patients were cured [44]. In a study completed in Brazil, 117 CL patients mostly (76%) with one lesion were recruited and double-blind randomly divided into two groups, all of the patients received systemic Glucantime, 1 ml per 5 kg body weight, at most 10 ml per day. Then one group was assigned to receive immunotherapy with an escalating dose of L. amazonensis (Leishvaccin) from 24 µg on day 1 to 120 µg on day 5, and after a resting period of 10 days the treatment was repeated until complete healing of the lesion(s). No significant difference was seen between the time of cure in the two groups [45]. In a double-blind placebo-controlled trial, which was completed in Brazil, a vaccine was prepared from L. amazonensis in BioBras, Brazil. Then, 102 parasitologically proven CL patients were recruited and treated with either daily subcutaneous (SC) injections of 0.5 ml of the vaccine plus 8.5 mg/kg (0.5 ml/5 kg body weight) intramuscular (IM) injections of MA for 10 days, followed by 10 days rest, or daily SC injections of 0.5 ml of placebo and 8.5 mg/kg (0.5 ml/5 kg body weight), IM injections of MA for 10 days followed by 10 days of rest. The results showed that 47 (100%) of the patients in the immunochemotherapy group versus 4 of 49 (8.2%) in the chemotherapy group were cured after four series of treatment; the results were significantly (p < 0.0001) in favor of immunochemotherapy [44]. In another study conducted in Minas Gerais, Brazil, 542 patients with CL based on parasitological examination or MT were included in an open study and randomly divided into different groups and treated with either Glucantime, 1 ampoule per 25 kg body weight for 10 days, not > 2 ampoules per day or half of the above dose plus killed L. amazonensis promastigotes mixed with BCG. The results showed that immunotherapy induced 100% cure rate similar to full dose of MA; it was concluded that immunotherapy reduces the dose of Glucantime and the duration of the treatment and therefore the vaccine was registered in Brazil as an adjacent to MA therapy [46]. Convit et al. [47] performed a Phase II clinical trial in which 94 patients with localized CL were treated with either heat-killed L. mexicana amazonensis promastigotes mixed with BCG or with standard treatment of pentavalent antimony. The clinical cure was similar (94%) in the two groups, but the side effects in the immunotherapy group were just limited to the local site of injections due to BCG whereas the systemic side effect was those more severe and common to the chemotherapy groups. In a group of 23 CL and 20 MCL patients along with 10 healthy control volunteers, immune responses were evaluated during and after immunotherapy. CL patients received immunotherapy with
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Therapeutic vaccines for leishmaniasis
heat killed promastigotes of L. amazonensis plus BCG, the dose of BCG determined according to baseline PPD results. Immunotherapy was given 2 -- 4 times, at 6 -- 8 week intervals until clinical cure was achieved. MCL patients were treated with chemotherapy plus up to six doses of immunotherapy until complete cure. The results showed that immunotherapy enhanced Th1 response against Leishmania antigens with a higher in vitro IFN-g production [48]. In a large immunotherapy trial completed during 10-year study in Venezuela, 11,532 CL patients were skin tested with leishmanin and purified protein derivative (PPD), and then the patients were treated with heat-killed L. mexicana amazonensis mixed with BCG. The patients received 1 -- 2 booster injections if the lesion(s) was active. Evaluation of the lesion(s) was done in 5431 of the patients and showed ~ 95% efficacy. The side effects were mostly local and due to BCG [47]. In Venezuela, DCL and MCL are not common, and the response to chemotherapy is not high so a study was carried out with four patients with severe MCL and three patients with early DCL, the duration of the lesions being 1 -- 5 years. All the patients had been refractory to chemotherapy and so were treated with a homemade Leishmania braziliensis promastigotes killed by pasteurization plus BCG, intradermally in the deltoid regions in 4-week interval. Complete remission of the lesions occurred after 5 -- 9 injections for MCL patients and after 7 -- 10 for DCL patients [49]. A polyvalent vaccine composed of L. amazonensis, L. venezuelensis, L. braziliensis and L. L. chagasi was prepared and injected IM, three times, 1 month apart to healthy and CL volunteers. The results showed that the vaccine was safe and time to remission of the lesion of the CL patients was similar to chemotherapy [50]. Treatment of PKDL with chemotherapy is difficult. Alumprecipitated autoclaved L. major (Alum-ALM) was shown to be immunogenic and induced Th1 response in an animal model. Safety and immunogenicity of Alum-ALM mixed with BCG was completed in healthy volunteers and PKDL patients, and the results showed that Alum-ALM mixed with BCG was safe and induced strong immune response in human [51]. Then a double-blind randomized efficacy trial was designed in which 30 Sudanese PKDL patients were treated either with combination of Alum-ALM plus BCG and SSG or vaccine diluent and SSG. By day 60, 13 (87%) of 15 patients in group of combined immunotherapy and chemotherapy showed complete cure and in 2 of the patients improvement was observed, whereas in contrast, the group that received chemotherapy alone, 8 (53%) of 15 patients showed complete cure, and 2 of the patients in this group showed relapse on day 90 and 1 patient subsequently showed improvement. Combined therapy was significantly more effective than chemotherapy alone [52,53]. The interpretation of the results generated in efficacy trials is not always an easy task, partly due to the nature of the disease; there are a variety of clinical pictures; there can be healing of CL lesion(s) by
treatment or self-cure all depending on many factors. The issue has been noticed in chemotherapy trials (13 -- 14) and can be concluded from the above immunotherapy trials. Immunotherapy of second-generation vaccines Six mucosal leishmaniasis (ML) patients with duration of lesion 1 -- 5 years and history of CL long before the development of ML were recruited and received 1 -- 15 courses of 20 mg/kg/day MA for 20 -- 30 days. The patients were injected SC with a mixture of 5 µg of each of TSA, LmSTI1, LeIF, Leishmania heat shock protein 83 (Lbhsp83) and 50 mg of the cytokine granulocyte-macrophage colony-stimulating (Leukine; Amgen) in 0.5 ml, three times, 1 month apart, in the anterior surface of the forearm. At 9-month follow--up, five patients showed complete cure and one patient showed improvement and was further treated with immunotherapy and chemotherapy that eventually showed complete cure; all six patients were free of disease during 5-year follow-up [54]. In a double-blind randomized dose-escalating study, 44 adult CL parasitologically proved patients were treated SC either with Leish-F1plus a clinical grade formulation of monophosphoryl lipid A (MPL-SE) or MPL-SE or normal saline; all the three groups of patients received 1 -- 4 courses of chemotherapy using Glucantime (10 mg Sb5 +/kg/day) for 10 days, followed by 11 days of rest. The results showed that Leish-F1 was safe and cure rate was higher in the vaccine group than the control group that received normal saline or MPL-SE [55]. 8.2
Treatment using immunomodulators Immunomodulators such as cytokines and Toll-like receptors agonists were used to treat experimental leishmaniasis. The results of IFN-g treatment in murine model were promising, but when tested in clinical trials to treat old world CL in Syria, the cure rate was less than that in the patients who received Glucantime. When it was tested in new world CL in Guatemala, there was no significant difference seen between the group that received Glucantime alone with the group that was treated with combination of IFN-g and Glucantime. Cytokines are not used in the treatment of leishmaniasis currently due to the cost and side effects. Imiquimod is an immunomodulator and is shown to be effective in the treatment of murine model of leishmaniasis, but the results of human trials are controversial. A few studies, however, showed some degree of effectiveness in the treatment of CL with imiquimod, but topical imiquimod failed to treat CL caused by L. tropica even when it was combined with Glucantime [13,37]. 8.3
9.
Expert opinion
Leishmaniasis is a major public health problem in some endemic regions and the most neglected disease; CL has been ignored partly due to the fact that it has been defined as a simple self-healing skin disease. Treatment of leishmaniasis, especially CL caused by L. tropica and L. braziliensis, is frustrating for the patients and a dilemma for the physicians
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A. Khamesipour
and health authorities [12,13]. Host immune responses are generated upon exposure to Leishmania parasites, but the exact role of various compartment of immune responses in the pathogenesis and cure is not well defined and the surrogate markers of protection are not known [19-28,56-63]. The most effective control measure against leishmaniasis seems to be an effective vaccine. Historically, leishmanization was showed to be efficacious and it is theoretically feasible to develop an effective vaccines against leishmaniasis, but so far no vaccine is available against any form of leishmaniasis. Different candidate vaccines including live Leishmania, attenuated, suicidal cassettes and gene manipulated Leishmania to firstgeneration, second-generation and third-generation vaccines have been used successfully in experimental models. Immunotherapy has advanced in recent years and monoclonal antibodies, BCG, cytokines and other immunomodulators are in use to treat infectious and noninfectious diseases [8,23,30,35,37,38,40-42,64]. When chemotherapy is not available, or has serious side effects, or its efficacy not high enough to control the disease, the use of immunotherapy or combination with chemotherapy is justified. As is mentioned before, numerous prophylactic trials and several trials of immunotherapy using whole crude or well-defined antigens have been completed; each study showed that the different preparations of the vaccines were safe and the results of immunotherapy trials showed the vaccines were beneficial. Although various degrees of efficacy were shown, the results are promising. Moreover, immunotherapy was shown to be relatively safe, the side effects were always limited to the site of vaccine injection and mainly due to the combination with BCG. An effective prophylactic vaccine against leishmaniasis should be able to induce Th1 response with a limited Th2 response. However, designing therapeutic vaccines against leishmaniasis is more difficult than the development of prophylactic vaccine, and unlike prophylactic vaccines, a unique strategy might not be effective. One problem is that the various immune responses generated in different clinical forms and the wide spectrum of the severity of leishmaniasis are not similar. In some circumstances, a Th1 type of immune response is required to initiate cure, whereas in some a strong Th1 response is already induced that needs to be suppressed or modulated. In some types of the disease such as in MCL, and in recidivans CL patients, a strong Th1 response is already induced (shown by in vivo LST and in vitro production of a high level of IFN-g and no IL-4/IL-5 in response to Leishmania antigens and a very low level of anti-Leishmania antibodies), In these groups of patients, immunotherapy should modulate Th1, whereas in VL and DCL patients, a Th2 response is dominant, so immunotherapy needs to switch the immune response to Th1 type of response. Immunotherapy using vaccine is affordable for endemic areas, and there is no possibility of the development of
6
resistant. To develop an effective immunotherapy strategy, several tools are needed; immune responses development in different clinical forms of leishmaniasis must be explored to define the immune surrogate marker(s) of cure and protection. First-generation vaccines are cheap and could be manufactured under good manufacturing practice in endemic areas and for this reason crude antigens mainly were used in vaccine trials for prophylactic and immunotherapy. The disadvantage, however, is that Leishmania crude antigens are not standardized and as such batch-to-batch variation exists so standardization is a must. Also, serum-free media is not available to culture Leishmania. Second-generation vaccines are well defined, reproducible but not affordable for endemic areas [44,48,53,64]. Another complication is that there is no animal model that completely corresponds to human leishmaniasis and thus, sometimes several animal models are used and then the interpretation of the results is difficult. Moreover, there is no guarantee that one will get the same results in humans. In addition, an appropriate adjuvant is required to use with Leishmania antigens either crude or well-defined ones. Currently available adjuvants that can be used with Leishmania vaccines are limited to those in human use if they are affordable. This is one of the reasons that BCG was used in the old world leishmaniasis vaccine trials [28,33,34,36,57]. Failure of developing effective Leishmania vaccines is due to many reasons. Leishmaniasis is a poverty-related disease and is endemic in the poorest regions of the world with limited infrastructure. Although leishmaniasis is a major health problem in some endemic areas, it is not recognized as such. Pharmaceutical industries are not interested to develop vaccine against leishmaniasis as it is not profitable and so health authorities in the endemic countries need to invest in this area, but unfortunately endemic countries are involved in war/sanctions/political crisis. Last but not least, strong collaboration between the well-equipped laboratories and endemic area is required.
Acknowledgement I would like to appreciate Prof John R David for help in editing the manuscript.
Declaration of interest The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
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Therapeutic vaccines for leishmaniasis
Bibliography Papers of special note have been highlighted as either of interest () or of considerable interest () to readers. 1.
Expert Opin. Biol. Ther. Downloaded from informahealthcare.com by University Of South Australia on 08/11/14 For personal use only.
2.
3.
4.
..
5.
..
6.
.
7.
..
8.
..
9.
.
Alvar J, Velez ID, Bern C, et al. Leishmaniasis worldwide and global estimates of its incidence. PLoS One 2012;7(5):e35671
10.
.
11.
Akilov OE, Khachemoune A, Hasan T. Clinical manifestations and classification of Old World cutaneous leishmaniasis. Int J Dermatol 2007;46(2):132-42 Gontijo B, de Carvalho Mde L. American cutaneous leishmaniasis. Rev Soc Bras Med Trop 2003;36(1):71-80 Bonfante-Garrido R, Barroeta S, de Alejos MA, et al. Disseminated American cutaneous leishmaniasis. Int J Dermatol 1996;35(8):561-5 Leishmaniasis status and clinical forms. Das A, Ali N. Vaccine prospects of killed but metabolically active Leishmania against visceral leishmaniasis. Expert Rev Vaccines 2012;11(7):783-5 A review on some of the antiLeishmania candidate vaccines. Goto H, Prianti M. Immunoactivation and immunopathogeny during active visceral leishmaniasis. Rev Inst Med Trop Sao Paulo 2009;51(5):241-6 Immunology of visceral leishmaniasis (VL). Khalil EA, El Hassan AM, Zijlstra EE, et al. Autoclaved Leishmania major vaccine for prevention of visceral leishmaniasis: a randomised, doubleblind, BCG-controlled trial in Sudan. Lancet 2000;356(9241):1565-9 The only Phase III efficacy trial of first-generation vaccine against VL. Nagill R, Kaur S. Vaccine candidates for leishmaniasis: a review. Int Immunopharmacol 2011;11(10):1464-88 List of leishmaniasis candidate vaccines. WHO. Post-kala-azar dermal leishmaniasis: a manual for case management and control. report of a who consultative meeting. Kolkata, India; 2012 Available from: http://apps.who.int/ iris/bitstream/10665/78608/1/ 9789241505215_eng.pdf A review on Post Kala-azar Dermal Leishmaniasis.
..
Goto H, Lindoso JA. Current diagnosis and treatment of cutaneous and mucocutaneous leishmaniasis. Expert Rev Anti Infect Ther 2010;8(4):419-33 Diagnosis and treatment of cutaneous leishmaniasis (CL) and MCL. Barroso PA, Marco JD, Calvopina M, et al. A trial of immunotherapy against Leishmania amazonensis infection in vitro and in vivo with Z-100, a polysaccharide obtained from Mycobacterium tuberculosis, alone or combined with meglumine antimoniate. J Antimicrob Chemother 2007;59(6):1123-9 Immunotherapy of cutaneous leishmaniasis.
12.
Croft SL, Olliaro P. Leishmaniasis chemotherapy-challenges and opportunities. Clin Microbiol Infect 2011;17(10):1478-83
13.
Firooz A, Khamesipour A, Ghoorchi MH, et al. Imiquimod in combination with meglumine antimoniate for cutaneous leishmaniasis: a randomized assessor-blind controlled trial. Arch Dermatol 2006;142(12):1575-9
14.
..
15.
.
Khatami A, Firooz A, Gorouhi F, et al. Systematic review of new world cutaneous leishmaniasis: several points. Int J Dermatol 2009;48(2):201; author reply 201-2 Overview of chemotherapy and weaknesses. Bumb RA, Prasad N, Aara N, et al. Long-term efficacy of a single-dose Radio Frequency Heat therapy versus intralesional antimonials for cutaneous leishmaniasis in India. Br J Dermatol 2013;168(5):1114-19 Chemotherapy and heat therapy.
16.
Sacks D, Noben-Trauth N. The immunology of susceptibility and resistance to Leishmania major in mice. Nat Rev Immunol 2002;2(11):845-58
17.
Bogdan C. Leishmaniasis in rheumatology, haematology and oncology: epidemiological, immunological and clinical aspects and caveats. Ann Rheum Dis 2012;71(Suppl 2):i60-6
18.
Peters NC, Egen JG, Secundino N, et al. In vivo imaging reveals an essential role for neutrophils in leishmaniasis
Expert Opin. Biol. Ther. (2014) 14(11)
transmitted by sand flies. Science 2008;321(5891):970-4 19.
Habibi GR, Khamesipour A, McMaster WR, et al. Cytokine gene expression in healing and non-healing cases of cutaneous leishmaniasis in response to in vitro stimulation with recombinant gp63 using semiquantitative RT-PCR. Scand J Immunol 2001;54(4):414-20
20.
Hejazi SH, Hoseini S, Javanmard SH, et al. Interleukin-10 and transforming growth factor-beta in early and late lesions of patients with leishmania major induced cutaneous leishmaniasis. Iran J Parasitol 2012;7(3):16-23
21.
Hoseini SG, Javanmard SH, Zarkesh SH, et al. Regulatory T-cell profile in early and late lesions of cutaneous leishmaniasis due to Leishmania major. J Res Med Sci 2012;17(6):513-18
22.
Jafari-Shakib R, Ajdary S, Amiri ZM, et al. CD26 expression on CD4+T cells in patients with cutaneous leishmaniasis. Clin Exp Immunol 2008;153(1):31-6 Leishmaniasis immunology.
.
23.
..
24.
.
Khamesipour A, Dowlati Y, Asilian A, et al. Leishmanization: use of an old method for evaluation of candidate vaccines against leishmaniasis. Vaccine 2005;23(28):3642-8 Effectiveness of leishmanization. Mahmoodi M, Khamesipour A, Dowlati Y, et al. Immune response measured in human volunteers vaccinated with autoclaved Leishmania major vaccine mixed with low dose of BCG. Clin Exp Immunol 2003;134(2):303-8 Immune response in vaccines vs CL patients old world.
25.
Nateghi Rostami M, Keshavarz H, Edalat R, et al. CD8+ T cells as a source of IFN-gamma production in human cutaneous leishmaniasis. PLoS Negl Trop Dis 2010;4(10):e845
26.
Tolouei S, Ghaedi K, Khamesipour A, et al. IL-23 and IL-27 levels in macrophages collected from peripheral blood of patients with healing vs nonhealing form of cutaneous leishmaniasis. Iran J Parasitol 2012;7(1):18-25
27.
Nateghi Rostami M, Keshavarz Valian H, Eskandari SE, et al. Differential in vitro CD4+/CD8+ T-cell response to live vs. killed Leishmania
7
A. Khamesipour
.
28.
..
Expert Opin. Biol. Ther. Downloaded from informahealthcare.com by University Of South Australia on 08/11/14 For personal use only.
29.
..
30.
..
31.
32.
.
33.
34.
..
35.
..
36.
8
major. Parasite Immunol 2010;32(2):101-10 Immune responses in CL.
..
Noazin S, Khamesipour A, Moulton LH, et al. Efficacy of killed whole-parasite vaccines in the prevention of leishmaniasis: a meta-analysis. Vaccine 2009;27(35):4747-53 Overview of first-generation vaccines.
37.
Duthie MS, Vanitha RS, Franco PM, et al. The development and clinical evaluation of second-generation leishmaniasis vaccines. Vaccine 2012;30(2):134-41 Overview of second generation vaccines.
38.
Singh B, Sundar S. Leishmaniasis: vaccine candidates and perspectives. Vaccine 2012;30(26):3834-42 A review on leishmaniasis vaccines.
..
.
39.
.
Badiee A, Jaafari MR, Samiei A, et al. Coencapsulation of CpG oligodeoxynucleotides with recombinant Leishmania major stress-inducible protein 1 in liposome enhances immune response and protection against leishmaniasis in immunized BALB/c mice. Clin Vaccine Immunol 2008;15(4):668-74
40.
Firouzmand H, Badiee A, Khamesipour A, et al. Induction of protection against leishmaniasis in susceptible BALB/c mice using simple DOTAP cationic nanoliposomes containing soluble Leishmania antigen (SLA). Acta Trop 2013;128(3):528-35 Induction of protection in animal model.
42.
Momeni AZ, Jalayer T, Emamjomeh M, et al. A randomized, double blind, controlled trial of a killed L. major vaccine plus BCG against ZCL in Iran. Vaccine 1999;17:466-72 Sharifi I, Fekri A, Aflatonian M, et al. Double-blind randomized controlled vaccine trial of a single dose of killed Leishmania major plus Bacillus of Calmette Guerin (BCG) against anthroponotic cutaneous Leishmaniasis Bam, Iran. Lancet 1998 First generation vaccine trials. Alvar J, Croft SL, Kaye P, et al. Case study for a vaccine against leishmaniasis. Vaccine 2013;31(Suppl 2):B244-9 Status of antileishmaniasis vaccines. Badiee A, Heravi Shargh V, Khamesipour A, et al. Micro/nanoparticle adjuvants for antileishmanial vaccines:
.
41.
..
.
43.
.
44.
45.
46.
present and future trends. Vaccine 2013;31(5):735-49 Adjuvant and leishmaniasis vaccines. Okwor I, Uzonna JE. As a strategy for treatment of leishmaniasis: a review of the literature. Immunotherapy 2009;1(5):765-76 Overview of immunotherapy/ chemotherapy.
treatment. Rev Soc Bras Med Trop 2006;39(1):14-21 47.
Convit J, Ulrich M, Zerpa O, et al. Immunotherapy of American cutaneous leishmaniasis in Venezuela during the period 1990--1999. Trans R Soc Trop Med Hyg 2003;97:469-72
48.
Cabrera M, Blackwell JM, Castes M, et al. Immunotherapy with live BCG plus heat killed Leishmania induces a T helper 1-like response in American cutaneous leishmaniasis patients. Parasite Immunol 2000;22(2):73-9
49.
Convit J, Ulrich M, Polegre MA, et al. Therapy of Venezuelan patients with severe mucocutaneous or early lesions of diffuse cutaneous leishmaniasis with a vaccine containing pasteurized Leishmania promastigotes and bacillus Calmette-Guerin: preliminary report. Mem Inst Oswaldo Cruz 2004;99(1):57-62
50.
O’Daly JA, Spinetti HM, Gleason J, et al. Clinical and immunological analysis of cutaneous leishmaniasis before and after different treatments. J Parasitol Res 2013;2013:657016
51.
Khalil EA, Musa AM, Modabber F, et al. Safety and immunogenicity of a candidate vaccine for visceral leishmaniasis (Alum-precipitated autoclaved Leishmania major + BCG) in children: an extended phase II study. Ann Trop Paediatr 2006;26(4):357-61 Immunotherapy trials.
Simon J. Emil Behring’s medical culture: from disinfection to serotherapy. Med Hist 2007;51(2):201-18 Serotherapy. Chakravarty J, Kumar S, Trivedi S, et al. A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1 +MPL-SE vaccine for use in the prevention of visceral leishmaniasis. Vaccine 2011;29(19):3531-7 Second generation phase 1-2 study. Waldmann TA. Immunotherapy: past, present and future. Nat Med 2003;9:269-77 Serotherapy. Pennington JE. Immunotherapy of infectious diseases: past, present and future. Trans Am Clin Climatol Assoc 1988;99:126-35 Overview of immunotherapy. Luke TC, Arturo C, Stanley WJ, et al. Hark back: passive immunotherapy for influenza and other serious infections. Crit Care Med 2010;38:e66-73 Passive immunotherapy. Okwora I, Liua D, Beverley SM, et al. Inoculation of killed Leishmania major into immune mice rapidly disrupts immunity to a secondary challenge via IL-10-mediated process. Proc Natl Acad Sci USA 2009;106(33):13951-6 Experimental immunotherapy. Machado-Pinto J, Pinto J, da Costa CA, et al. Immunochemotherapy for cutaneous leishmaniasis: a controlled trial using killed Leishmania (Leishmanin amazonensis vaccine plus antimonial. Int J Dermatol 2002;41(2):73-8 Toledo VP, Mayrink W, Gollob KJ, et al. Immunochemotherapy in American cutaneous leishmaniasis: immunological aspects before and after treatment. Mem Inst Oswaldo Cruz 2001;96(1):89-98 Mayrink W, Botelho AC, Magalhaes PA, et al. Immunotherapy, immunochemotherapy and chemotherapy for American cutaneous leishmaniasis
Expert Opin. Biol. Ther. (2014) 14(11)
..
52.
..
53.
..
54.
..
55.
.
Musa AM, Khalil EA, Mahgoub FA, et al. Immunochemotherapy of persistent post-kala-azar dermal leishmaniasis: a novel approach to treatment. Trans R Soc Trop Med Hyg 2008;102(1):58-63 The only immunotherapy trial to treat PKDL. Modabber F. Leishmaniasis vaccines: past, present and future. PLoS Negl Trop Dis 2010;36(Suppl 1):S51-61 Overview of leishmaniasis vaccines. Badaro R, Lobo I, Munos A, et al. Immunotherapy for drug-refractory mucosal leishmaniasis. J Infect Dis 2006;194(8):1151-9 Immunotherapy studies. Nascimento E, Fernandes DF, Vieira EP, et al. Vaccination of humans against cutaneous leishmaniasis: cellular and humoral immune responses. Infect Immun 1990;58(7):2198-203 Immune response in vaccinees new world.
Therapeutic vaccines for leishmaniasis
56.
.
57.
Beattie L, Kaye PM. Leishmania-host interactions: what has imaging taught us? Cell Microbiol 2011;13(11):1659-67
58.
Bogdan C. Natural killer cells in experimental and human leishmaniasis. Front Cell Infect Microbiol 2012;2:69
59.
Expert Opin. Biol. Ther. Downloaded from informahealthcare.com by University Of South Australia on 08/11/14 For personal use only.
Awasthi A, Mathur RK, Saha B. Immune response to Leishmania infection. Indian J Med Res 2004;119(6):238-58 Immune responses in VL.
60.
De Almeida Silva L, Romero HD, Prata A, et al. Immunologic tests in patients after clinical cure of visceral leishmaniasis. Am J Trop Med Hyg 2006;75(4):739-43
leishmaniasis due to Leishmania major in Sudan. Am J Trop Med Hyg 1995;52(5):438-42 61.
.
62.
..
Kaye PM, Aebischer T. Visceral leishmaniasis: immunology and prospects for a vaccine. Clin Microbiol Infect 2011;17(10):1462-70 Immune responses in leishmaniasis. Musa AM, Noazin S, Khalil EA, et al. Immunological stimulation for the treatment of leishmaniasis: a modality worthy of serious consideration. Trans R Soc Trop Med Hyg 2010;104(1):1-2 Overview of importance of immunochemotherapy.
63.
.
64.
..
Nylen S, Gautam S. Immunological perspectives of leishmaniasis. J Glob Infect Dis 2010;2(2):135-46 Immune responses in leishmaniasis. Evans KJ, Kedzierski L. Development of vaccines against visceral leishmaniasis. J Trop Med 2012;2012:892817 Review of vaccines against VL.
Affiliation Ali Khamesipour Tehran University of Medical Sciences, Center for Research and Training in Skin Diseases and Leprosy, Tehran, Iran E-mail: [email protected]
Gaafar A, el Kadaro AY, Theander TG, et al. The pathology of cutaneous
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