BETA-2-MICROGLOBULIN DEFICIENT MICE LACK CD4-8+ CYTOLYTIC T-CELLS

Mice homozygous for a β2-microglobulin gene disruption do not express any detectable β2-ITL protein. They express little if any functional major histocompatibility complex (MHC) class I antigen on the cell surface yet are fertile and apparently healthy. They show a normal distribution of γδ, CD4+8+ and CD4+8- cells, but have no mature CD4-8+ cells and are defective in CD4-8+ cell-mediated cytotoxicity. Our results strongly support earlier evidence that MHC class I molecules are crucial for positive selection of T cell antigen receptor αβ+ CD4-8+ T cells in the thymus and call into question the non-immune functions that have been ascribed to MHC class I molecules. © 1990 Nature Publishing Group.