title: The role of H-2-linked genes in helper T-cell function. VI. Expression of Ir genes by helper T cells.
abstract: We examined the expression of (TG)-A--L specific Ir genes in helper T cells using  T cells from low responder leads to (B10, high responder x low responder) F1 chimeric mice. In this paper, the low responder strain studied was B10.M, H-2f. B10.M T cells from these chimeric animals do not help anti-TNP-(TG)-A--L responses, even though they have matured in a high responder thymus and been primed and challenged with antigen on high responder Mphi and B cells. These findings indicate that in the H-2f haplotype an Ir-gene controlling anti-(TG)-A--L activity is expressed in helper T cells. The findings are in contrast to those we have obtained and previously reported with T cells of another low responder haplotype, H-2a. Taken together with our previous findings that (TG)-A--L specific Ir genes are expressed by B cells and Mphi of both the H-2a and H-2f haplotypes, the results indicate two sites of action for Ir genes, and suggest two different gene products acting at different stages of the response, both of which are defective in H-2f cells, and only one of which is defective in H-2a cells.
mesh_terms: D000818:Animals; D005802:Genes, MHC Class II; D008040:Genetic Linkage; D006183:H-2 Antigens / Q000235:genetics*; D008211:Lymphocyte Cooperation; D051379:Mice; D010455:Peptides / Q000276:immunology; D011828:Radiation Chimera; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D006183:H-2 Antigens; D010455:Peptides