CD8A and infection: This interpretation is consistent with the complete failure to observe any expansion of Vβ4+ CD8+ T cells in MHV68 infected B cell-deficient mice [9], [10] – even though we have previously shown robust MHV68 infection in the spleens of B cell-deficient mice under some experimental conditions (intraperitoneal inoculation of virus) in the absence of any detectable Vβ4+ CD8+ T cell expansion [10], [47].