LCMV-specific, class II-restricted cytotoxic T cells in beta 2-microglobulin-deficient mice.

Intracranial infection of normal mice with lymphocytic choriomeningitis virus (LCMV) causes meningitis and death mediated by CD8+ major histocompatibility complex (MHC) class I-restricted cytotoxic T lymphocytes (CTLs). beta 2-Microglobulin-deficient mice (beta 2M-/-) do not express functional MHC class I proteins and do not produce significant numbers of CD8+ T cells. When beta 2M-/- mice were infected with LCMV, many died from LCMV disease and produced a specific response to LCMV mediated by CD4+ CTLs that were class II-restricted. In these mice, CD4+ CTLs may compensate for the lack of CD8+ CTLs.