Abstract
Experiments on the response to sheep erythrocytes (SRC) in vivo indicate that H-2 genes control (i) the induction of T helper (Th) cells (presumed to be a reflection of T-“macrophage” interactions) and (ii) T-B collaboration. Studies on the helper function of normal and chimeric T cells activated to SRC in irradiated syngeneic and allogeneic mice suggest that antigen presentation by “macrophages” of a particular H-2 haplotype generates a population of activated Th cells which collaborate only with specific B cells carrying the same H-2 determinants as the “macrophages”. From this approach it has been concluded that in terms of their helper function (i) normal homozygous T cells of strain a consist of a single population of “anti-self a” (anti-a) Th cells which recognize antigen presented by “macrophages” or specific B cells of strain a but not by strain b cells.