Simplified quantitative analysis of spinal cord cells from Theiler's virus-infected mice without the requirement for myelin debris removal.

Flow cytometry is routinely used to analyze mononuclear cell populations in experimental CNS infections and autoimmune diseases in mice and other rodents. Previous analysis of mononuclear cell samples has involved centrifugation of single cell suspensions from minced CNS tissues on discontinuous gradients to separate cells from myelin debris: however, loss of cells that occurs on gradients necessitates pooling of CNS tissues. We have developed a method of analyzing cells in CNS tissues by flow cytometry without removing myelin debris, and applied this method to assess mononuclear cells and oligodendrocytes in SJL mice with Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease.

Susceptibility of peritoneal macrophages to infection by Theiler's virus.

Theiler's murine encephalomyelitis virus (TMEV) strains fall into two groups: high-neurovirulence GDVII virus results in rapidly fatal encephalitis, while low-neurovirulence BeAn and DA viruses produce persistent central nervous system (CNS) infection and inflammatory demyelinating disease. Because macrophages (Mphis) are key components in BeAn virus-induced demyelinating disease, we examined the susceptibility of primary peritoneal macrophages (pMphis) to BeAn infection in vitro. Freshly isolated, thioglycollate-elicited pMphis were resistant to BeAn virus infection even at high multiplicity of infection.

Apoptotic cells, including macrophages, are prominent in Theiler's virus-induced inflammatory, demyelinating lesions.

Theiler's murine encephalomyelitis virus (TMEV) persists in the mouse central nervous system principally in macrophages, and infected macrophages in culture undergo apoptosis. We have detected abundant apoptotic cells in perivascular cuffs and inflammatory, demyelinating lesions of SJL mice chronically infected with TMEV. T cells comprised 74% of apoptotic cells, while 8% were macrophages, 0.

Theiler's murine encephalomyelitis virus induces apoptosis in gamma interferon-activated M1 differentiated myelomonocytic cells through a mechanism involving tumor necrosis factor alpha (TNF-alpha) and TNF-alpha-related apoptosis-inducing ligand.

Infection of susceptible mice with the low-neurovirulence Theiler's murine encephalomyelitis virus strain BeAn results in an inflammatory demyelinating disease similar to multiple sclerosis. While the majority of virus antigen is detected in central nervous system macrophages (Mphis), few infiltrating Mphis are infected. We used the myelomonocytic precursor M1 cell line to study BeAn virus-Mphi interactions in vitro to elucidate mechanisms for restricted virus expression.

Restricted Theiler's murine encephalomyelitis virus infection in murine macrophages induces apoptosis.

Increasing evidence suggests that macrophages (M(phi)s) are necessary for persistence of Theiler's murine encephalomyelitis virus (TMEV) in the mouse central nervous system. Analysis of BeAn virus infection in the Mphi cell lines P388D1, J774A.1 and PU5-1.