Mouse Endogenous Superantigens: Mls and Mls-like Determinants Encoded by MouseRetroviruses

摘要

Mls (minor lymphocyte simulating) determinants were first described byFestenstein (1963) as gene products that cause a strong mixed lymphocyte response (MLR) by unprimed T cells between MHC-compatible mouse strains (Abe Hodes, 1989). Limited dilution experiments have indicated that this strong primary MLR is due to the presence of Mls-receive T cells in naive T cell populations at a high precursor frequency (Janeway et al., 1980). In contrast to conventional antigen recognition, T cell reactivity to Mls determinants is based primarily on the V region of the T cell receptor (TCR) beta chain (V-beta) (Kappler et al., 1988; MacDonald et al, 1988; Abe et al., 1988, 1991; Fry and Matis, 1988; Pullen et al., 1988; Happ et al, 1988; Vacchio et al., 1990); thus most T cells expressing an appropriate V-beta product are reactive to a given Mls determinant. Thus unique V-beta association with T cell recognition explains the high precursor frequency of MLS-reactive T cells in naive T cell populations.