T cell-accessory cell interactions that initiate allospecific cytotoxic T lymphocyte responses: existence of both Ia-restricted and Ia-unrestricted cellular interaction pathways.

摘要: The specificity of the T-accessory cell interactions that initiate primary allospecific cytotoxic T lymphocyte (CTL) responses were found to be surprisingly diverse and three distinct major histocompatibility complex (MHC) specificities, involving responder recognition of: a) self-Ia accessory determinants, b) allo-Ia or c) allo-K/D determinants. Any one these was sufficient CTL responses. It observed when cells did not express foreign class I MHC invariably initiated by Ia-restricted interactions. In contrast, it could Ia-independent specific for allogeneic, but self, K/D determinants involve polymorphic Ia specificities trinitrophenyl (TNP)-self also compared. TNP-self self-Ia-restricted interactions, in both responding recognized as self-specificities on surface those their precursors had encountered radiation-resistant thymic elements differentiation environment. contrast initiation required activation helper (TH) cells, I-restricted Interestingly, such present populations triggered only even modified with TNP. Thus, study demonstrates responses, are cellular interaction pathways. These results raise possibility unprimed TH mediate pathway may predominantly an allospecific, a self + X-specific, receptor repertoire. Possible mechanisms which discuss