THE JOURNAL OF INFECTIOUS DISEASES. VOL. 137, NO.5. MAY 1978 © 1978 by the University of Chicago. 0022-1899/78/3705-0025$00.75
Conditions for Bacille Calmette-Cuerin-Induced Resistance to Infection with Schistosoma mansoni in Mice From the Division of Geographic Medicine, Department of Medicine, and the Department of Pathology, Case Western Reserve University and University Hospitals, Cleveland, Ohio
Richard H. Civil, Kenneth S. Warren, and Adel A. F. Mahmoud
as BCG or T. gondii is rapid in onset and is independent of eosinophils, a finding suggesting that it is mediated via nonspecific defense mechanisms of the host [I 0]. In the present study, we have examined the characteristics of BCG-induced resistance of mice to infection with S. mansoni as assayed by recovery of schistosomula from the lungs and of adult worms from the portal venous circulation. Variables associated with the source and strain of BCG, the dose, route, and timing of mycobacterial administration, and the duration of protection were investigated.
Certain intracellular bacterial infections result in enhanced resistance of mice to other bacterial infections, as well as viral, protozoal, and helminthic infections [1-9]. In our laboratory, resistance to infection with Schistosoma manson i, a multicellular helminthic parasite, has been induced by infection with bacille Calmette-Guerin (BCG) and Toxoplasma gondii [10, II]. Similarly, preparations of heterologous animal proteins or killed bacteria have been reported to induce protective effects against S. mansoni [12, 13]. The resistance induced by these methods differs in many respects from the immunity conferred by a primary infection with the worm [I4]. Specific acquired immunity does not occur in the mouse until many weeks after primary infection, is transferred only with immune serum, and can be abrogated by treatment of immune animals with antiserum to eosinophils [I5]. In contrast, the protection induced by agents such
Materials and Methods
Mice. Female C57BLj6J mice weighing 1822 g were purchased from Jackson Laboratory, Bar Harbor, Maine. Animals were housed in plastic cages and were watered and fed Purina Laboratory Chow (Ralston Purina, St. Louis, Mo.) ad lib. Preparation of BeG vaccines. Two strains of BCG were used. For most experiments a lyophilized preparation of BCG (BCG-Tice, lots no. II 74 (s) 74, 90) containing 1-8 X 108 cfu per ampule was obtained from the Research Foundation, Chicago, Ill. The resistance induced by this preparation of BCG was compared with that induced by a fresh-frozen preparation of BeGPasteur (strain TMC 1011, lot no. HI5; Trudeau
Received for publication August 11, 1977, and in revised form December 9,1977. This study was supported by grants no. AI-08163 from the U.S. Public Health Service and no. GA HS 7704 from the Rockefeller Foundation and by training grant no. 5T32GM07250 from the National Institutes of Health. We thank Pierre Peters and Earlene Moss for technical assistance. Please address requests for reprints to Dr. A. A. F. Mahmoud, Division of Geographic Medicine, Department of Medicine, University Hospitals, Cleveland, Ohio 44106.
550
Downloaded from http://jid.oxfordjournals.org/ at Florida Atlantic University on July 12, 2015
Intravenous administration of a lyophilized preparation of bacille Calmette-Cuerin (BCG-Tice) into mice significantly protected these animals from infection with Schistosoma mansoni. The protective effect depended on the dose of BCG and required the administration of at least 2 X 107 viable organisms. The route of administration of BCG was also crucial, as only intravenous inoculation produced significant protection. The BCG-induced resistance was found to last for eight weeks. Significant inflammation of the lungs was observed in mice receiving either viable or heat-killed BCG; however, protection followed only the administration of viable bacilli. Expression of BCG-induced protection was dependent on the presence of significant numbers of viable organisms and may have been associated with pulmonary inflammation at the time of passage of the schistosomula through the lungs.
BGG-Induced Resistance to S. mansoni
Results
Effect of prior iv treatment with BCG-Tice on recovery of schistosomula from mice. The recovery of schistosomula from the lungs of controls and mice inoculated iv with 2 X 107 cfu of BCG-Tice 14 days prior to challenge with cercariae is shown in figure 1. The number of schis-
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3 5 7 Days After Exposure to Cercariae Figure 1. Recovery of schistosomula from the lungs of bacille Calmette-Guerin (BCG)-treated and control mice three, five, and seven days after exposure to 500 Schistosoma mansoni cercariae. Each point represents the mean ± SE for six mice. The number of schistosomula recovered was significantly lower for BCGtreated groups than for controls at all assay periods
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Conditions for Bacille Calmette-Cuerin-Induced Resistance to Infection with Schistosoma mansoni in Mice From the Division of Geographic Medicine, Department of Medicine, and the Department of Pathology, Case Western Reserve University and University Hospitals, Cleveland, Ohio
Richard H. Civil, Kenneth S. Warren, and Adel A. F. Mahmoud
as BCG or T. gondii is rapid in onset and is independent of eosinophils, a finding suggesting that it is mediated via nonspecific defense mechanisms of the host [I 0]. In the present study, we have examined the characteristics of BCG-induced resistance of mice to infection with S. mansoni as assayed by recovery of schistosomula from the lungs and of adult worms from the portal venous circulation. Variables associated with the source and strain of BCG, the dose, route, and timing of mycobacterial administration, and the duration of protection were investigated.
Certain intracellular bacterial infections result in enhanced resistance of mice to other bacterial infections, as well as viral, protozoal, and helminthic infections [1-9]. In our laboratory, resistance to infection with Schistosoma manson i, a multicellular helminthic parasite, has been induced by infection with bacille Calmette-Guerin (BCG) and Toxoplasma gondii [10, II]. Similarly, preparations of heterologous animal proteins or killed bacteria have been reported to induce protective effects against S. mansoni [12, 13]. The resistance induced by these methods differs in many respects from the immunity conferred by a primary infection with the worm [I4]. Specific acquired immunity does not occur in the mouse until many weeks after primary infection, is transferred only with immune serum, and can be abrogated by treatment of immune animals with antiserum to eosinophils [I5]. In contrast, the protection induced by agents such
Materials and Methods
Mice. Female C57BLj6J mice weighing 1822 g were purchased from Jackson Laboratory, Bar Harbor, Maine. Animals were housed in plastic cages and were watered and fed Purina Laboratory Chow (Ralston Purina, St. Louis, Mo.) ad lib. Preparation of BeG vaccines. Two strains of BCG were used. For most experiments a lyophilized preparation of BCG (BCG-Tice, lots no. II 74 (s) 74, 90) containing 1-8 X 108 cfu per ampule was obtained from the Research Foundation, Chicago, Ill. The resistance induced by this preparation of BCG was compared with that induced by a fresh-frozen preparation of BeGPasteur (strain TMC 1011, lot no. HI5; Trudeau
Received for publication August 11, 1977, and in revised form December 9,1977. This study was supported by grants no. AI-08163 from the U.S. Public Health Service and no. GA HS 7704 from the Rockefeller Foundation and by training grant no. 5T32GM07250 from the National Institutes of Health. We thank Pierre Peters and Earlene Moss for technical assistance. Please address requests for reprints to Dr. A. A. F. Mahmoud, Division of Geographic Medicine, Department of Medicine, University Hospitals, Cleveland, Ohio 44106.
550
Downloaded from http://jid.oxfordjournals.org/ at Florida Atlantic University on July 12, 2015
Intravenous administration of a lyophilized preparation of bacille Calmette-Cuerin (BCG-Tice) into mice significantly protected these animals from infection with Schistosoma mansoni. The protective effect depended on the dose of BCG and required the administration of at least 2 X 107 viable organisms. The route of administration of BCG was also crucial, as only intravenous inoculation produced significant protection. The BCG-induced resistance was found to last for eight weeks. Significant inflammation of the lungs was observed in mice receiving either viable or heat-killed BCG; however, protection followed only the administration of viable bacilli. Expression of BCG-induced protection was dependent on the presence of significant numbers of viable organisms and may have been associated with pulmonary inflammation at the time of passage of the schistosomula through the lungs.
BGG-Induced Resistance to S. mansoni
Results
Effect of prior iv treatment with BCG-Tice on recovery of schistosomula from mice. The recovery of schistosomula from the lungs of controls and mice inoculated iv with 2 X 107 cfu of BCG-Tice 14 days prior to challenge with cercariae is shown in figure 1. The number of schis-
e ~ "'5 ; oE...J ~
Q)
_..c:w .~ - en ..c: E +1
180
140
~ c: 100 .... cQ) ooo:E
eX
....
~
Q)
~ ~
E (,) ~
60 /
:]
Z
20
/}------1
/ / BeG-TREATED
Q)
a:::
/
///
3 5 7 Days After Exposure to Cercariae Figure 1. Recovery of schistosomula from the lungs of bacille Calmette-Guerin (BCG)-treated and control mice three, five, and seven days after exposure to 500 Schistosoma mansoni cercariae. Each point represents the mean ± SE for six mice. The number of schistosomula recovered was significantly lower for BCGtreated groups than for controls at all assay periods
(P
