Abstract
In the present study we investigated age related effects of inoculum size and cellular immunity on the CNS disease caused by JHM virus (JHMV) in Wistar Lewis (WL) rats. Onset of resistance normally becomes evident by the 10th day when inoculation is made with 106 pfu or less. The resistance could be abrogated in 15 day old animals by increasing the dose two-fold, but with rare exceptions, in 35 day old rats an 80-fold increase in pfu fails to surmount resistance. However, treatment with the immunosuppressant drug cyclosporin A (CsA) abolished resistance, whereby rats challenged at 35 days of age were susceptible to JHMV. The histopathological evidence and disease symptoms in the CsA treated group resembled closely those observed in our previous study with athymic, nude rats. Microscopic examination of the CNS from untreated, infected rats revealed extensive inflammatory responses characterized by perivascular cuffing and mononuclear infiltrates into the neuropile. The parallel CsA treated group showed that inflammatory responses of this type in the CNS were either minimal or absent. From the present evidence, we conclude that JHMV infection, which involves both neuronal and oligodendrocytic elements, is kept in check by the cellular immune system. When cellular immunity is suppressed or absent the disease process is altered from one in which white matter demyelination predominates to another form of disease in which neuronal involvement is prominent.
Keywords: cyclosporin A effects, JHM virus infection, CNS disease, rat
Footnotes
Supported by grants from the Multiple Sclerosis Society of Canada and the Medical Research Council of Canada.
References
- 1.Nagashima K, Wege H, Meyermann R, Ter Meulen V. Coronavirus induced subacute demyelinating encephalomyelitis in rats: A morphological analysis. Acta Neuropathol (Berlin) 1978;44:63–70. doi: 10.1007/BF00691641. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Sorensen O, Percy D, Dales S. In vivo and in vitro models of demyelinating disease. III. JHM virus infection of rats. Arch Neurol. 1980;37:478–484. doi: 10.1001/archneur.1980.00500570026003. [DOI] [PubMed] [Google Scholar]
- 3.Sorensen O, Dugre R, Percy D, Dales S. In vivo and in vitro models of demyelinating disease: endogenous factors influencing demyelinating disease caused by mouse hepatitis virus in rats and mice. Infect Immun. 1982;37:1248–1260. doi: 10.1128/iai.37.3.1248-1260.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Sorensen O, Saravani A, Dales S. In vivo and in vitro models of demyelinating disease. XVII. The infectious process in athymic rats inoculated with JHM virus. Microbial Pathogenesis. 1987;2:79–90. doi: 10.1016/0882-4010(87)90100-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Sorensen O, Beushausen S, Puchalski S, Cheley S, Anderson R, Coulter-Mackie M, Dales S. In vivo and in vitro models of demyelinating diseases—VIII: Genetic immunologic and cellular influences on JHM virus infection of rats. In: Rottier PJM, van der Zeijst BAM, Spaan WJM, Horzinek M, editors. Molecular biology and pathogenesis of coronaviruses. Plenum; New York: 1984. pp. 279–298. [DOI] [PubMed] [Google Scholar]
- 6.Beushausen S, Dales S. In vivo and in vitro models of demyelinating disease. XXI: Relationship between differentiation of rat oligodendrocytes and control of JHMV replication. In: Lai MMC, Stohlman SA, editors. Coronaviruses. Plenum; New York: 1987. pp. 239–254. [DOI] [PubMed] [Google Scholar]
- 7.Sobue G, Pleasure D. Schwann cell galactocerebrodide is induced by derivatives of adenosine 3′: 5′-cyclic monosphosphate. Science. 1984;224:72–74. doi: 10.1126/science.6322307. [DOI] [PubMed] [Google Scholar]
- 8.Abney ER, Bartlett PP, Raff MC. Astrocytes ependymal cells and oligodendrocytes develop on schedule in dissociated cell cultures of embryonic rat brain. Dev Biol. 1981:301–310. doi: 10.1016/0012-1606(81)90476-0. [DOI] [PubMed] [Google Scholar]
- 9.Beushausen S, Dales S. In vivo and in vitro models of demyelinating disease. XI: Tropism and differentiation regulate the infectious process of coronavirus in primary explants of the rat CNS. Virology. 1985;141:89–101. doi: 10.1016/0042-6822(85)90185-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Beushausen S, Narindrasorasak S, Sanwal BD, Dales S. In vivo and in vitro models of demyelinating disease: activation of the adenylate cyclase system influences JHM Virus expression in explanted rat oligodendrocytes. J Virol. 1987;61:3795–3803. doi: 10.1128/jvi.61.12.3795-3803.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Sorensen O, Coulter-Mackie MB, Puchalski S, Dales S. In vivo and in vitro models of demyelinating disease—IX: progression of JHM Virus infection in the central nervous system of the rat during overt and asymptomatic phases. Virology. 1984;137:347–357. doi: 10.1016/0042-6822(84)90227-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Feurer C, Prentice DE, Cammisuli S. Chronic relapsing experimental allergic encephalomyelitis in the Lewis rat. J Neuroimmunol. 1985;10:159–166. doi: 10.1016/0165-5728(85)90006-2. [DOI] [PubMed] [Google Scholar]
- 13.Bolton C, Borel JF, Louise Cuznet M, Davison AN, Turner AM. Immunosuppression by cyclosporin A of experimental allergic encephalomyelitis. J Neurol Sci. 1982;56:147–153. doi: 10.1016/0022-510x(82)90138-1. [DOI] [PubMed] [Google Scholar]
- 14.Morris PJ, Mason DW, Hutchinson IV. The effect of cyclosporin A in animal models of tissue transplantation. Transplant Proc. 1983;15:2287–2292. [Google Scholar]
- 15.Sorensen O, Dales S. In vivo and in vitro models of demyelinating disease: JHM Virus in the rat central nervous system localized by in situ cDNA hybridization and immunofluorescent microscopy. J Virol. 1985;56:434–438. doi: 10.1128/jvi.56.2.434-438.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Watanabe R, Wege H, Ter Meulen V. Adoptive transfer of EAE-like lesions from rats with coronavirusinduced demyelinating encephalomyelitis. Nature. 1983;305:150–153. doi: 10.1038/305150a0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Watanabe R, Wege H, Ter Meulen V. Comparative analysis of coronavirus JHM-induced demyelinating encephalomyelitis in Lewis and Brown Norway rats. Lab Invest. 1987;57:375–384. [PubMed] [Google Scholar]
- 18.Wege H, Watanabe R, Ter Meulen V. Virological and immunological aspects of coronavirus induced subacute demyelinating encephalomyelitis in rats. Adv Exp Med Biol. 1984;173:259–270. doi: 10.1007/978-1-4615-9373-7_26. [DOI] [PubMed] [Google Scholar]
- 19.Levine S, Sowinski R. Allergic encephalomyelitis in the reputedly resistant Brown Norway strain of rats. J Immunol. 1975;114:597–601. [PubMed] [Google Scholar]