190,

VIROLOGY

616-623

(1992)

Canine MARTIN

Distemper

BRUGGER,*r’

Virus Increases

THOMAS

*Department tDepartment

Procoagulant

W. JUNGI,1- ANDREAS

Activity

ZURBRIGGEN,”

of Macrophages AND

MARC VANDEVELDE*

of Animal Neurology, University of Berne, 30 12 Berne, Switzerland; and of Veterinary Virology, University of Berne, 30 12 Berne, Switzerland Received

May

28,

1992; accepted

June

19, 1992

Inflammatory demyelination in canine distemper has been proposed to be due to a “bystander” mechanism, in which macrophages play an important role. In the present work we studied whether infection of macrophages by canine distemper virus (CDV) results in changes of macrophage functions, including Fc receptor-dependent and -independent phagocytosis, release of reactive oxygen species (ROS), and procoagulant activity (PCA). As a source of macrophages, dog bone marrow cells were seeded in teflon bags and grown for l-2 weeks, at which time a marked enrichment of macrophages was noted. These cells were infected with the A75/17 strain of CDV. We could not detect any significant difference between uninfected and CDV-infected macrophages with respect to Fc receptor-dependent or -independent phagocytosis or with respect to the release of ROS. However, from Day 4 p.i. to the end of our observation period (10 days p.i.), PCA was up to 1 O-fold higher in CDV-infected unstimulated macrophage cultures than in uninfected unstimulated cultures of the same age. Increase in PCA was not due to the inoculation procedure by itself nor to components of the inoculum other than CDV; in particular, PCA was not due to contaminating endotoxin. Thus, several important macrophage functions do not appear to be impaired by CDV infection. The marked increase of macrophage PCA expression suggests that certain macrophage functions may even be enhanced as a result of infection. Such macrophage activation might contribute to the pathogenesis of the disease. o 1992 Academic PMS, IK.

INTRODUCTION

inflammatory demyelination, their destructive potential should remain unimpaired or, alternatively, be enhanced as a result of the infection. Little is known about macrophage functions in CDV infection. Macrophages have been used in studies of CDV persistence and virulence (Poste, 1971; Ter Meulen and Martin, 1976; Metzler er al., 1980a,b, 1981, 1984; Ter Meulen and Carter, 1982; Friedlander et al., 1985). Macrophage Fc receptors have been shown to be important in CDV neutralization (Appel et al., 1984) and CDV-infected mononuclear phagocytes secrete more prostaglandin E, and less interleukin-1 (IL-l) than uninfected cells (Krakowka et al., 1987). In the present study we examined the effect of CDV on macrophage functions such as Fc receptor-mediated and Fc receptor-independent phagocytosis, production of reactive oxygen species (ROS), and expression of procoagulant activity (PCA). These cellular functions are markers of activation and/or are potentially important in tissue destruction.

Canine distemper virus, a morbillivirus immunologically related to measles virus, causes demyelination in the central nervous system (CNS) of dogs. The initial demyelinating lesions result from viral replication in the glial cells of the white matter (Vandevelde et al., 1985) and become progressively worse as a result of inflammatory reactions in the chronic stage of the disease. Inflammatory demyelination in distemper has been proposed to be due to a “bystander” mechanism, in which macrophages play an important role (Wisniewski et a/., 1972). Chronic progressive inflammatory lesions in distemper contain many macrophages and plasma cells producing CDV-specific antibodies (Vandevelde et a/., 1980, 1986). In vitro studies have shown that macrophages produce toxic factors after stimulation with antiviral antibodies binding to virus-infected ceils (Blirge et a/., 1989; Griot et al., 1989). This observation suggests that “bystander” demyelination is a result of the antiviral immune response. Macrophages themselves are a prime target for CDV (Appel, 1970; Ter Meulen and Hall, 1978). Since viral infections generally tend to impair cell functions (Rolle and Mayr, 1984), a causal relationship between the presence of macrophages and demyelination appears uncertain. However, if macrophages are responsible for CDV-induced ’ To whom 0042-6822/92 Copyright All rights

reprint

requests

should

$5.00

0 1992 by Academic Press, Inc. of reproduction I” any form reserved.

MATERIALS Isolation

and culture

AND

METHODS

of mononuclear

cells (MNC)

A total of 20 dogs of both sexes and of various breeds, 3 months to 8 years of age, were used as bone marrow donors in our experiments. All dogs were anesthetized by i/v injection of pentobarbital (Veterinaria,

be addressed. 616

CANINE

DISTEMPER

VIRUS

Zurich). Bone marrow was obtained from the tuber sacrale or the femur via needle aspiration using a sterile 20-ml syringe, rinsed before use with heparin (5000 U/ml, Hoffmann-La Roche, Basel, Switzerland), and a bone marrow biopsy needle (Hausmann, St. Gallen, Switzerland). Five to forty milliliters of bone marrow were collected, filled up with serum-free medium (RPMI-1640, Cat. No. 074-01800, GIBCO) to 50 ml and the mononuclear cells (MNC) were isolated by isopycnit density gradient centrifugation over Ficoll-Hypaque (density: 1.077 g/ml). The cells were then washed two times with serum-free medium and resuspended in RPMI-1640 supplemented with 20% FCS, penicillin (250 U/ml, Hoechst-Pharma AG, Zurich), streptomycin (100 pg/ml, GrUnenthal, GmbH, Stolberg, Germany), and fungizone (GIBCO, BRL). One to 2 X lo5 cells/ml were seeded in Teflon bags (DuPont, Geneva; 100A) and incubated for at least 7 days at 37” in a humified atmosphere of 5% CO, before use. In some experiments the isolated MNC were seeded in culture flasks (Costar, Cat. No. 3375) at a concentration of l-2 X lo6 cells/ml, and incubated under the same conditions as the Teflon bags, but half of the culture medium was removed and replaced by new medium once a week. These cells were nonspecific esterase-positive but rarely bound opsonized erythrocytes. The infection rate of these cells with A75/17CDV was very weak (~1%). Therefore we used only MNC cultured in Teflon bags for our functional tests. Identification

of macrophages

Macrophages were identified by the expression of nonspecific esterase and the ability to bind opsonized erythrocytes. /Vonspecific esterase. Cells positive for a-naphthylbutyrate esterase were determined as described (Koski et a/., 1976). Briefly, after centrifugation, the cells were fixed with formalin (3.7%, Merck, Darmstadt, Germany) for 15 min, stained with a-naphthylbutyrate (Fluka, Buchs, Switzerland) for at least 30 min, and counterstained with methyl green (Fluka) for 30 sec. All cells of the macrophage lineage exhibited redbrown colored granules in their cell membrane. Rosette assay. Bovine erythrocytes were opsonized with rabbit IgG antibodies against the erythrocyte stroma (Nordic Immunological Laboratories, Lausanne, Switzerland) as described for sheep erythrocytes (Jungi and Peterhans, 1988). Erythrocytes (1 O”/ ml) coated with this antibody were added to unfixed dog bone marrow cultures (500,000 cells/ml) and incubated for 30 min at 37”. The unbound erythrocytes were washed away before fixation and counterstaining.

AND

MACROPHAGES

617

Canine distemper

virus (CDV)

For all experiments we used A75/17 CDV, a virulent strain (kindly donated by Dr. M. Appel, Cornell University, Ithaca, NY) which had been propagated in puppies, as described previously (Zurbriggen et al., 1987). Virus containing lymphoid tissue from the puppies was frozen in aliquots at -70”. Virus titration was done by limiting dilutions in macrophages grown in microtiter plates as described. Infection of the macrophages was monitored after staining with peroxidase-antiperoxidase (PAP) (Sternberger, 1979) using a monoclonal antibody against the nucleoprotein of CDV (Zurbriggen et al., 1987). In the chemiluminescence (CL) assay we used the A75/17 CDV strain grown in Vero cell lines and purified by sucrose gradient centrifugation (Wechsler, 1985). Aliquots were stored at -70” until use. Infection

of the macrophages

The cultured macrophages were removed from the Teflon bags and centrifuged (10 min, 140 g). They were then incubated with the A75/17CDV for 1 hr in a minimal amount of serum-free RPMI-1640 at 37”. Then the cells were resuspended in serum-containing medium and reseeded in Teflon bags or in petri dishes (3003, Falcon) containing glass cover slips (1000, 18 X 18 mm, Karl Hecht Assistent, GmbH, Altnau, Switzerland). Infection of cultured macrophages was monitored with PAP staining (Sternberger, 1979) or indirect immunofluorescence as described previously (Zurbriggen et a/., 1987). The control cultures were treated similarly. Phagocytosis Fc-receptor-independent phagocytosis was tested with latex beads. Ingestion of latex was determined by offering latex beads (LB-30, Sigma, St. Louis, MO) to macrophages on cover slips for 30-45 min. Noningested beads were removed by washing and xylene treatment (Van Furth and Diesselhoff-den Dulk, 1980). Fc-receptor-dependent phagocytosis was determined by ingestion of opsonized erythrocytes as described above (rosette assay). In each of four different areas per slide, 200 macrophages were scored, 3 particles (latex or opsonized erythrocytes) ingested being considered as phagocytosis-positive. The macrophages were stained either with hematoxyline or for CDV expression by immunocytochemistry. Procoagulant

activity

(PCA)

A recently developed microtiter-plate-based PCA assay (Jungi, 1990) was used to determine PCA induction under different stimulation conditions. The turbidimet-

618

BRijGGER ET AL.

ric PCA test was performed with macrophages (2 to 10 days p.i.), washed, and resuspended in physiologic saline and adjusted to the desired macrophage concentration (500,00O/ml). A flat-bottom 96-well microtiter plate (Nunc, Roskliede, Denmark) was placed in a water bath containing a custom-made thermoblock for microtiter plates. This block was perfused by and immersed in water, allowing the adjustment of the well content to 37” in the inner 60 wells of the plate. Each well received 100 ~1of fresh-frozen pooled titrated human plasma. After sufficient time allowing temperature adjustment, 100 ~1 of cell suspension were added. Control wells received 100 ~1of a thromboplastin from human placenta (Thromborel-S, Behringwerke, Marburg, Germany), dilution ranging from lo- to 106-fold. After temperature adjustment, 100 ~1of a 25 mM CaCI, solution, prewarmed to 37”, were dispensed in each well. Then the kinetic measurement by the use of an ELISA-reader photometer (Molecular Devices, Palo Alto, NM) under thermostated (37”) conditions was started. Measurements were routinely performed over 20 min at a wavelength of 365 nm. Dose response curves with thromboplastin showed a double-logarithmic correlation between recalcification time and thromboplastin concentration. PCA of experimental groups were transformed into thromboplastin units according to this dose response curve, one unit being a 1O6dilution of Thromborel-S. All tests were done with macrophage preparations of up to 10 individual donors. Each group was tested in triplicate. Limulus amebocyte lysate assay (LAL) To determine the lipopolysaccharide (LPS) content of our virus suspension, as a common source of contaminating stimulation, we used the kinetic turbidimetric LAL assay as described by Ditter eta/., 1982. In this test the gelation of Limulus amebocyte lysate induced by gram-negative endotoxin is measured. The sensitivity of the test was 0.02 endotoxin units per milliliter (Schalch et al., 1991). Chemiluminescence assay (CL) The ability of macrophages to produce ROS was determined by measurement of luminol-enhanced chemiluminescence (BUrge et a/., 1989). Eight- to twentyday-old cultured macrophages, uninfected and infected with A75/17 were harvested, washed and resuspended in Hanks’ balanced salt solution (HBSS) and transferred into siliconized glass vials (Tewis, Berne CH). To a 0.75-ml cell suspension containing 105 macrophages, 10 PI/ml of a bovine serum albumin solution saturated with luminol (5-amino-2,3-dihydro1,4-phthalazinedione; Cat. No. A 851 1, Sigma) were

added. The mixture contained also sodium azide (100 p.M), and microperoxidase (MP-11, Cat. No. 6756, Sigma; final concentration 10 pg/ml). After dark adaptation at 37” for 1O-20 min, vials were transferred into a modified, thermostatically controlled (37”) Betamatic 1 liquid scintillation spectrometer (Kontron, Zurich), and the background of all samples was measured in a twocycle prerun. The settings for tritium in the out-of-coincidence mode was used. Then, different stimuli were manually pipetted into the samples and light emission was counted repeatedly for 6-set periods 10 to 40 times for each vial. As stimuli we used phorbol myristate acetate (PMA, P-81 39, Sigma) at a concentration of 1O-8 M, zymosan (Z-4250, Sigma; 100 pg/ml) opsonized with fresh bovine serum (Burge et a/., 1989) and a suspension of purified A75/17-CDV. Each test included a negative control (HBSS). Plots of temporal CL traces, recorded on line with a HP981 6 desk computer, contained the means and standard deviations of light emission in each group of three replicates. RESULTS Isolation, culture, and infection of MNC from dog bone marrow Up to 2 X 10’ MNC per dog were harvested after Ficoll-Hypaque treatment of bone marrow. The addition of 20% fetal calf serum (FCS) was found to provide the best conditions for the growth of the collected cells. Supplementation with a mouse fibroblastoid cell line (L-929) conditioned medium containing macrophage colony-stimulating factor (M-CSF) did not increase the cell yield. The cultivation of purified bone marrow cells in teflon bags resulted, after l-2 weeks, in loosely adherent cells with cell processes. More than 98% of these cells were positive for nonspecific esterase and had Fc receptors as determined by the erythrocyte rosette binding assay. After infection with A75/17-CDV, a cytopathic effect became apparent after 4-6 days and progressed during the following days. The cytopathic effect consisted of cell fusion in which up to 20 macrophages were involved. There was no apparent cytolysis. On Day 2 p.i. 100/oof the cells were strongly positive for CDV on immunocytochemical staining; on Days 4-6 the infection rate was 40-50% (Fig. 1). Phagocytosis When assayed for ingestion of latex, uninfected, as well as CDV-infected, dog macrophages contained up to 50 latex beads in their cytoplasm (Fig. 1). We found no difference in numbers of macrophages having pha-

CANINE

FIG. 1. Dog anti-CDV PAP. cultures, latex macrophages,

DISTEMPER

VIRUS

AND

MACROPHAGES

619

bone marrow-derived macrophage cultures. (a) 1 l-day-old infected (,) and uninfected (+) macrophages, 4 days p.i., 375x, (b) Cell fusion between more than 20 2-week-old macrophages, 6 days p.~., 625X, anti-CDV PAP. (c) One-week-old macrophage beads treated and stained with haematoxiline. 375X. (d) Erythrocyte-binding assay, 2-week-old infected (b-) and uninfected (+) 7 days p.i., 375X, anti-CDV PAP

gocytized latex particles between infected and uninfected macrophage cultures. 79 + 16.49% of the uninfected and 85 f 5.72% of the infected cells bound opsonized erythrocytes, which were subsequently ingested (no significant difference, P < 0.05). There was no apparent difference in the quantity of the phagocytized material between infected and uninfected MNC cultures (Fig. 1). Reactive oxygen species There was no difference in light emission after stimulation with PMA or opsonized zymosan between CDVinfected or uninfected MNC. Both groups exhibited a similar reaction pattern independent of the stimulus

used (Fig. 2). We could not detect production of ROS after exposing macrophages to purified A75/17CDV particles at any concentration in a measurement period of 30-60 min (Fig. 2). Procoagulant activity The basal level of PCA expressed by uninfected, unstimulated (not exposed to LPS) cultures after 2 days of growth was 200 t 24.4 units/l 0” cells. At this time, no difference of PCA between uninfected and infected macrophage cultures was detected. However, at Day 4 and later, PCA was lo- to 20-fold higher in CDV-infected unstimulated macrophage cultures (2336 f 228%) than in uninfected, unstimulated cultures

620

BRijGGER

x a0

5

Ia

E

TIME (min.)

20 IE TIME (min.1

FIG. 2. (a) Induction of luminol-dependent chemiluminescence in 2-week-old macrophages. Stimulation with purified CDV particles at any concentration (1 OM6 presented, ~. - e) resulted in no detectable light emmission, compared to zymosan (-) and HBSS (- -) as control stimulation. (b) Induction of luminol-dependent chemiluminescence in 2-week-old CDV-infected (-) or uninfected (- -) macrophages. No difference in reactivity pattern was observed between the two groups. Background control with infected macrophages, stimulated with HBSS (-. -e).

(1 OO”/o). The difference remained at this level up to the end of our observation period (10 days of culture). Infected macrophages were still responsive to LPS stimulation. The increase in PCA in CDV-infected macrophages was comparable to PCA in uninfected cultures after LPS stimulation (for 6 hr). When CDV-infected macrophages were stimulated with LPS, the resulting PCA was again up to fivefold higher (7675 k 333%) than after stimulation with LPS or CDV infection alone (Fig. 3). The differences among uninfected, unstimulated and infected, unstimulated cultures on the one hand, and among infected, unstimulated and infected, LPSstimulated cultures on the other hand were significant (P < 0.05) as shown by a paired t test. The observed increase in PCA was not due to LPS contamination of the virus suspension, as determined by a highly sensitive LAL assay. The LPS concentration contained in the virus inoculum resulted in a LPS concentration corresponding to 0.1 units/ml endotoxin activity or less, which is below the minimal amount required to induce detectable PCA, as demonstrated in parallel experiments. DISCUSSION In viva and in vitro observations support the concept of “bystander” demyelination in distemper encephalitis, probably resulting from the antiviral immune response, in which macrophages play an important effector role (BUrge et a/., 1989; Griot et a/., 1989). Since

ET AL

macrophages themselves are a prime target for CDV (Appel, 1970; Ter Meulen and Hall, 1978), we studied the question whether infection of macrophages by CDV results in changes of macrophage functions, including Fc-receptor-dependent and -independent phagocytosis, release of ROS and PCA. We used macrophage cultures derived from bone marrow, which, besides providing good cell yields in high purity, include a spectrum of monocytic cells at various stages of maturation, as it occurs in inflammatory lesions. In contrast to the cells used in our study, macrophage cultures obtained by bronchial or peritoneal lavages consist largely of differentiated end-stage cells (Brown and Ananaba, 1988; Ogunbiyi et al,, 1988). Our cells were cultivated in teflon bags, preventing cell adhesion, which by itself can be stimulatory for macrophages. Peterhans (1987) showed that interaction between Sendai virus, a paramyxovirus, and the surface of macrophages stimulated these cells to produce highly toxic ROS. Such direct interactions between macrophages and viruses are thought to be important in acute tissue damage in certain infections such as hemorrhagic fevers (Peterhans et al., 1988). Since we were unable to find such an immediate effect of CDV on macrophages, it is unlikely that demyelination in distemper could be explained by such a mechanism. However, in previous studies we have shown that a combi-

8000

-

6000

-

5000

6

LPS-treated

cultures

q

CDV-infected

cultures

CDV-infected

and LPS-treated

cultures

-

% 4000-

3000

-

2000

-

lOOO-

o-’ 4

6

10

days FIG. 3. Procoagulant activity of CDV-infected or uninfected macrophages, unstimulated or stimulated with lipopolysaccharide at different days postinfectionem, compared to control cultures (1000/o). lnfected, LPS stimulated macrophages were not tested on day 2 and 4 p.i. PCA is expressed in relative terms, controls being 100%.

CANINE

DISTEMPER

VIRUS

nation of CDV and antiviral antibodies is capable of stimulating macrophages to release toxic ROS, suggesting that inflammatory demyelination in distemper could be the indirect result (bystander) of the antiviral immune response (Burge et a/., 1989; Griot et al., 1989). The present experiments show that macrophages retain their ability to secrete ROS despite CDV infection. Furthermore, the expression of Fc receptors by macrophages is not altered by the infection, since we found that Fc receptor-dependent (as well as Fc receptor-independent) phagocytosis was not altered after CDV infection. Therefore, our results are consistent with the concept that tissue destruction in distemper is mediated, in part, by an interaction of antiviral antibodies and maciophage Fc receptors (Burge et al., 1989; Griot et al., 1989). Whereas several macrophage functions did not appear to be altered by CDV infection, we consistently found a clear-cut (up to 20-fold) increase in PCA in CDV-infected macrophage cultures. We concluded that this increase in PCA or acceleration of coagulation was induced by infection with CDV. It is highly unlikely that the effects resulted from the inoculation procedure itself, because corresponding control cultures were treated similarly. It is equally improbable that components of the inoculum other than CDV had an effect, since enhanced PCA occurred at the earliest 4 days p.i. (a time at which 40-50% of the macrophages contained viral antigen). Furthermore, increased PCA was sustained for the observation period (10 days p.i.). In particular, LPS, the most common source of contamination in the PCA assay, was excluded by the LAL assay and by the kinetics, as LPS-induced PCA peaks at 6 hr (Miserez and Jungi, 1992). Enhancement of PCA could be a direct effect of the infection or a secondary event mediated by cytokines. These could be derived from antigen-stimulated T cells which produce PCA-inducing factors such as interferon-y (Miserez and Jungi, 1992) and monocyte/macrophage procoagulant-inducing factor (Ryan and Geczy, 1988; Gregory eta/., 1986). In our bone marrow cell culture model, no evidence for the presence of functional T cells exists, let alone for T cells specific for the viral antigen. Thus, in apparent contrast to CDV, and in contrast to bacterial constituents (Sinclair et a/., 1990) viruses are known to induce mononuclear phagocyte PCA in a T-cell-mediated manner. Well-studied examples are murine hepatitis virus 3 (MHV-3) (Sinclair et al., 1990; Levy and Abecassis, 1989) and influenza virus (Schiltknecht et a/., 1984). In MHV-3-infected mice, two genetic traits associated with resistance to infection but not with H2 haplotypes were described. An inability to express MHV-3-induced PCA, which was associated with genetic resistance to MHV-

AND

MACROPHAGES

621

3 infection, is due to a restriction of macrophages responding to T-cell-derived PCA-inducing factors. Another trait resulting in decreased susceptibility to infection promotes the generation of suppressive Thy 1.2+ cells counteracting the PCA-inducing activity of L3T4+ cells (Chung et a/., 1991). These viruses, therefore, differ in their mechanism of PCA induction from CDV which appears to influence macrophage function directly. Whether mononuclear phagocyte-derived cytokines such as tumor necrosis factor (TNF) and interleukin-l (ILl) are involved as intermediary mediators is still not clear. These cytokines were shown to increase PCA in human monocytes (Conkling et a/., 1988; Carlsen et al., 1988) as well as in endothelial cells (Bevilacqua et a/., 1984; Nawroth and Stern, 1985), whereas PGE2 abrogates the induction of PCA (Abecassis et al,, 1987; Levy and Abecassis, 1989). In our system the measured levels of IL1 and TNF were too low to be detected in bioassays performed in heterologous (murine) systems (unpublished results). The infection of endothelial cells with herpes simplex virus also promotes the expression of PCA, a phenomenon due to several mechanisms including the downregulation of anticoagulatoty protein C, up-regulation of thromboplastin, and de nova synthesis of adhesive molecules such as P-selection (GMP140) (Etingin et al., 1990; Key et a/., 1990). Herpes simplex infections are associated with coagulopathy/atherosclerosis. It may be worth investigating other viral infections for induction of procoagulant activity in mononuclear phagocytes and other host cells. An increasing body of evidence demonstrates the importance of monocyte and macrophage coagulation factors in the pathogenesis of a variety of diseases (Lyberg, 1984) and the intimate relationship between clotting pathways and mechanisms of inflammation lend support to the hypothesis that increased PCA in CDV-infected macrophages represents virus-induced alterations of macrophage functions which may be involved in inflammatory damage to the white matter in distemper. Further experiments are necessary to determine the precise nature of the factors released by macrophages and to establish their link to inflammatory tissue destruction. In conclusion, our results further support the concept of bystander demyelination in distemper (Biirge et al., 1989; Griot et al., 1989). First, several important macrophage functions do not appear to be impaired by CDV infection, and second, by markedly increasing macrophage PCA, CDV infection may even enhance the destructive potential of these cells. ACKNOWLEDGMENTS This work was supported by Swiss National Grants 32-28614.90 (M.V.), 31-29332.90

Science Foundation (A.Z.), 31-26248.89

622

BRijGGER

(T.W.J.), and the Swiss Multiple Sclerosis Society. The authors Mrss. B. Glaus and A. Richard for their excellent technical tance.

thank assis-

REFERENCES ABECASSIS, M., FALK, J. A., MAKOWKA, L., DINDZANS, V. J., FALK, R. E., and LEVY, G. A. (1987). 16,16 Dimethyl prostaglandin E2 prevents the development of fulminant hepatitis and blocks the induction of monocyte/macrophage procoagulant activity after murine hepatitis virus strain 3 infection. /. C/in. invest. 80, 881-889. APPEL, J. G. (1970). Distemper pathogenesis in dogs. /. Am. Vet. Med. Assoc. 156, 1681-1683. APPEL, M. J., MENDELSON, S. G.. and HALL, W. W. (1984). Macrophage Fc receptors control infectivity and neutralization of canine distemper virus-antibody complexes. J. \/ire/. 51, 643-649. BEVILACQUA, M. O., POBER, J. S., MAJEAU, G. R., COTRAN, R. S., and GIMBRONE, M. A. JR. (1984) Interleukin 1 (IL-l) induces biosynthesis and cell surface expression of procoagulant activity in human vascular endothelial cells. J. Exp. Med. 160, 618-623. BROWN, T. T., JR., and ANANABA, G. (1988). Effect of respiratory infections caused by bovine herpesvirus-l or parainfluenza-3 virus on bovine alveolar macrophage functions. Am. /. Vet. Res. 49, 14471451. BORGE, T., GRIOT, C., VANDEVELDE, M., and PETERHANS, E. (1989). Antiviral antibodies stimulate production of reactive oxygen species in cultured canine brain cells infected with canine distemper virus. J. Viral. 63, 2790-2797. CARLSEN, E., FLATMARK, A., and PRYDZ, H. (1988). Cytokine-induced procoagulant activity in monocytes and endothelial cells. Further enhancement by cyclosporine. Transplantation 46, 575-580. CHUNG, S., SINCLAIR, S., LEIBOWITZ, J., SKAMENE, E., FUNG, L. S., LEVY, G. (1991). Cellular and metabolic requirements for induction of macrophage procoagulant activity by murine hepatitis virus strain 3 in vitro. J. immunol. 146, 271-278. CONKLING, P. R., GREENBERG, C. S., and WEINBERG, J. B. (1988). Tumor necrosis factor induces tissue factor-like activity in human leukemia cell line U937 and peripheral blood monocytes. Blood 72, 128-133. DITTER, B., BECKER, K.-P.. URBASCHEK, R., and URBASCHEK, B. (1982). Detection of endotoxin in blood and other specimens by evaluation of photometrically registered LAL-reaction kinetics in microtiter plate. Prog. C/in. Biol. Res. 93, 385-392. EDWARDS, R. L., and PERLA, D. (1984). The effect of serum on monocyte tissue factor generation. Blood 64, 707-714. ETINGIN, 0. R., SILVERSTEIN, R. L., FRIEDMAN, H. M., HAIJAR, D. F. (1990). Viral activation of the coagulation cascade: Molecular interactions at the surface of infected endothelial cells. Cell 61, 657-662. FRIEDLANDER, J. M., SUMMERS, B. A., and APPEL, J. G. (1985). Persistence of virulent canine distemper virus in lymphoblastoid cell lines. Arch. Viral. 86, 47-62. GECZY, C. L. (1984). Induction of macrophage PCA by products of activated lymphocytes. Haemostasis 14, 400. GREGORY, S. A., KORNBLUTH, R. S., HELIN, H., REMOLD, H. G., and EDGINGTON, T. S. (1986). Monocyte procoagulant inducing factor: A lymphokine involved in the T cell-instructed monocyte procoagulant response to antigen. /. Immunol. 137, 3231-3239. GRIOT, C., BORGE, T., VANDEVELDE, M., and PETERHANS, E. (1989). Antibody-induced generation of reactive oxygen radicals by brain macrophages in canine distemper encephalitis: A mechanism for bystander demyelination. Acta Neuropathol. 78, 396-403. JUNGI, T. W. (1990). A turbidimetric assay in an ELISA reader for the

ET AL. determination of mononuclear phagocytic procoagulant activity. /. Immunoi. Methods 133, 21-29. JUNGI, T. W., and PETERHANS, E. (1988). Change in the chemiluminescence reactivity pattern during in vitro differentiation of human monocytes to macrophages. Blut 56, 213-220. KEY, N. S., VERCELLO~I, G. M., WINKELMANN, J. C., MOLDOW, C. F., GOODMAN, J. L., ESMON, N. L., ESMON, C. T., JACOB, H. S. (1990). Infection of vascular endothelial cells with herpes simplex virus enhances tissue factor activity and reduces thrombomodulin expression. Proc. Nat/. Acad. Sci. USA 87, 7095-7099. KOSKI, I. R., POPLACK, D. G., and BLAESE, R. M. (1976). In In Vitro Methods in Cell-Mediated and Tumor Immunity (B. R. Bleon and J. R. David, Eds.), pp. 359-362. Academic Press, New York. KRAKOWKA, S., RINGLER, S., LEWIS, M., OLSEN, R., and A~THELM, M. (1987). lmmunosuppression by canine distemper virus: modulation of in vitro immunoglobulin synthesis, interleukin release and prostaglandin E production. Vet. Immunol. Immunopathol. 15, 181-201. LEVY, G., and ABECASSIS, M. (1989). Activation of the immune coagulation system by murine hepatitis virus strain 3. Rev. lnf Dis. 11, S712-S721. LYBERG, T. (1984). Clinical significance of increased thromboplaslln activity on the monocyte surface-A brief review. Haemostasis 14,430-439. METZLER, A. E., HIGGINS, R. J., KRAKOWKA, S., and KOESTNER, A. (1980a). Persistent in vitro interaction of virulent and attenuated canine distemper virus with bovine cells. Arch. Viral. 66,329-339. METZLER, A. E., HIGGINS, R. J., KRAKOWKA, S., and KOESTNER, A. (1980b). Virulence of tissue culture-propagated canine distemper virus. Inf. Immun. 29, 940-944. METZLER, A. E., HIGGINS, R. J., KRAKOWKA, S., and KOESTNER, A. (1981). Characterization of bovine cells, supporting in vitro growth of virulent and attenuated canine distemper virus. Am. /. Vet. Res. 42, 1257-l 262. METZLER, A. E., KRAKOWKA, S., AXTHELM, M. K., and GORHAM, J. R. (1984). In vitro persistence of canine distemper virus: establishment of persistent infection in Vero cells. Am. j. Vet. Res. 45, 2211-2215. MISEREZ, R., and JUNGI, T. W. (1992). LPS-induced, but not interferongamma-induced procoagulant activity of suspended human macrophages is followed by a refractory state of low procoagulant expression. Thromb. Res. 65, 733-744. NAWROTH, P. P., and STERN, D. M. (1985). Modulation of endothelial cell hemostatic properties by tumor necrosis factor. 1. Exp. Med. 163,740-745. OGUNBIYI, P. O., CONLON, P. D., BLACK, W. D., and EYRE, P. (1988). Levamisole-induced attenuation of alveolar macrophage dysfunction in respiratory virus-infected calves. Int. /. Immunopharmacol. 10, 377-385. PETERHANS, E. (1987). In “Cellular Chemiluminescence” (K. Van Dyke and V. Castranova, Eds.), pp. 59-91. CRC Press, Boca Raton. PETERHANS, E., JUNGI, T. W., and STOCKER, R. (1988). “Oxy-Radicals in Molecular Biology and Pathology,” pp. 543-562. A. R. Liss, New York. POSTE, G. (1971). The growth and cytopathogenicity of virulent and attenuated strains of canine distemper virus in dog and ferret macrophages. J. Comp. Pathol. 81, 49-54. ROLLE, M., and MAYR, A. (1984). “Medizinische Mikrobiologie, Infektions- und Seuchenlehre.” Enke Verlag, Stuttgart, Germany. RYAN, J., and GECZY, C. L. (1988). Macrophage procoagulant-inducing factor. In vivo properties and chemotactic activity for phagocytic cells. f. lmmunoi. 141, 21 1 O-21 17. SCHALCH, L., RORDORF-ADAM, C., DASCH, J. R., and JUNGI, T. W.

CANINE

DISTEMPER

(1991). IgG-stimulated and LPS-stimulated monocytes elaborate transforming growthfactor type p (TGF-@) in active form. Biochem. Biophys. Res. Commun. 174,885~89 1. SCHILT-KNECHT, E., ADA, G. L., and BRACIALE, T. J. (1984). Macrophage procoagulant-inducing activity of influenza-specific effector T cells. Cell. Immunol. 89, 342-354. SHANDS, J. W. (I 983). The endotoxininduced PCA of mouse exsudate macrophages: A factor-X activator. Blood 62, 333-340. SINCLAIR, S., ROTSTEIN, 0. D., and LEVY, G. A. (1990). Disparate mechanisms of induction of procoagulant activity by live and inactivated bacteria and viruses. Inf. lmmun. 58, 1821-l 827. STERNBERGER, L. A. (1979) “lmmunocytochemistryy.” pp. 122-l 29. Wiley, Chichester, NY. TER MEULEN, V., and CARTER, M. J. (1982). Morbillivirus persistent infections in animals and man. Virus Persistence Symp. 33, 97132. TER MEULEN, V., and HALL, W. W. (1978). Slow virus infections of the nervoussystem: Virological, immunological and pathogeneticconsiderations. J. Gen. Vkol. 41, l-25. TER MEULEN, V., and MARTIN, S. J. (1976). Genesis and maintenance of a persistent infection by canine distemper virus. /. Gen. Viral. 32,43 l-440. TRACY, P. B., ROHRBACH, M. S., MANN, K. G. (1983). Functional

VIRUS

AND

MACROPHAGES

623

prothrombinase complex assembly on isolated monocytes and lymphocytes. J. Biol. Chem. 258, 7264-7267. VAN FURTH, R., and DIESSELHOFF-DEN DULK, M. M. (1980). Methods to prove ingestion of particles by macrophages with light microscopy. Stand. J. Immunol. 12, 265. VANDEVELDE, M., KRISTENSEN, B., BRAUND, K. G., GREENE, C. E., SWANGO, L. J., and HOERLEIN, B. F. (1980). Chronic canine distemper virus encephalitis in mature dogs. Vet. Pathol. 17, 17-29. VANDEVELDE, M., ZURBRIGGEN, A., HIGGINS, R. J., and PALMER, D. (1985). Spread and distribution of viral antigen in nervous canine distemper. Acta Neuropathol. (Berlin) 67, 2 1 1-2 18. VANDEVELDE, M., ZURBRIGGEN, A., STECK, A., and BICHSEL, P. (1986). Studies on the intrathecal humoral immune response in canine distemper encephalitis. /. Neuroimmunol. 11, 41-51. WECHSLER, S. L. (1985). A simple method for increased recovery of purified paramyxovirus virions. f. tirol. Methods 12, 179-l 82. WISNIEWSKI, H., RAINE, C. S., and KAY, W. J. (1972). Observations on viral demyelinating encephalomyelitis. Canine distemper. Lab. lnvest 26, 589-599. ZUREIRIGGEN, A., VANDEVELDE, M., and BOLLO, E. (1987). Demyelinating, nondemyelinating and attenuated canine distemper virus strains induce oligodendroglial cytolysis in vitro. /. Neuroi. SC;. 79, 33-41.

Canine distemper virus increases procoagulant activity of macrophages.

Inflammatory demyelination in canine distemper has been proposed to be due to a "bystander" mechanism, in which macrophages play an important role. In...
2MB Sizes 0 Downloads 0 Views