Different repertoires of mouse T cells for bovine insulin presented by syngeneic and allogeneic cells

摘要

AbstractSplenic T cells were primed, after removal of alloreactive cells, to beef insulin on allogeneic antigen‐presenting cells (APC). The fine specificity ofin vitrosecondary response was tested in combinations H‐2b(responder) T cell‐H‐2k(nonresponder) APC, andvice versa, using separated chains of beef and pork insulin. The response in both combinations exhibited identical specificity patterns demonstrating that both responder and nonresponder APC could present the same array of insulin epitopes to allogeneic T cells. The determinants presented to allogeneic T cells include the A‐chain loop epitope and the B‐chain determinant(s) that were found to be immunogenic for H‐2band H‐2dT cells, respectively, in the context of syngeneic major histocompatibility complex (HC) molecules. In addition, minor determinants were detected in the A chain outside the loop that are not immunogenic in syngeneic T cell‐APC combinations. Inhibition of T cell proliferation with monoclonal antibodies has shown that class II MHC molecules of the nonresponder (AαkAβk, EαkEβk) as well as those of the responder APC (AαbAβb) are equally capable of presenting virtually all insulin epitopes recognizable by T cells. The data, therefore, demonstrate that the selective recognition of different insulin epitopes observed in syngeneic or semisyngeneic T cell‐APC combinations does not result from determinant sele