Mechanisms of viral clearance in perforin-deficient mice

The roles of CD4+ T cells, IFN-γ and TNF-α in viral clearance from the central nervous system (CNS) were examined in perforin gene deficient (PKO) mice. Depletion of CD4+ T cells from the PKO mice resulted in a significant 1 log₁₀ PFU/gm increase in viral titer over control-treated PKO mice. PKO mice treated with anti-IFN-γ mAb also had a significant 1 log₁₀ increase in infectious virus whereas inhibition of TNF-α did not alter viral clearance or clinical disease in the PKO mice. These data suggest, in addition to perforin-mediated cytolysis, CD4+ T cells and IFN-γ, but not TNF-α could contribute to JHMV clearance from the CNS.