Fact and Speculation on the Function of Immune Response Genes in Antigen Presentation

Abstract

Immune responsiveness of guinea pigs to dinitrophenyl-poly-L-lysine and to the lysine-rich random copolymer of L-glutamic acid and L-lysine are both controlled by a single gene, the poly-L-lysine gene. Recent experiments are reviewed which demonstrate that these 2 antigens specifically compete with one another for presentation to T cells by the same antigen-presenting cells. This finding is interpreted to mean that antigens to which responsiveness is controlled by the same single gene compete for the Ir gene product of antigen-presenting cells. The review discusses if the products of the immune response genes, presumably the Ia antigens, may constitute a 3rd specific antigen recognition system. This idea may help to provide insight into the phenomenon of histocompatibility-restriction and into the nature of the mixed leukocyte reaction.