6533b7cffe1ef96bd1258f13

RESEARCH PRODUCT

Specificity of H-2-linked Ir gene control in mice: recognition of the core structure A--L in defined sequence analogues of (T,G,)-A--L.

subject

description

For further characterization of the processes involved in Ir gene control, the specificity of antibodies and the cross-reaction on the level of helper T cells was studied for a series of polypeptide antigens related to poly-L(Tyr,Glu)-poly-DL-Ala–poly-LLys[(T,G)-A–L] but carrying more defined side chains. Helper cell specificity was assayed in an in vitro secondary anti-dinitrophenyl (DNP) response by cross-stimulation of primed T cells with the various polypeptide carriers. It was established that these polypeptides, although showing the same response pattern, were recognized as distinct entities in the immune response by B and T cells. If this common pattern is due to the effect of the same Ir gene, the latter is unlikely to code directly for the binding site on helper T cells recognizing these antigens. The core structure A–L, although weakly immunogenic itself, is recognized in the response to these antigens concomitantly with the recognition of the tyrosine-containing peptides. Furthermore, it is shown that the antibody response to DNP-A–L is under genetic control and that in the antigen Tyr6-A–L, which has the highest immunogenicity within this group of antigens, the poly-m-alanine side chain is important for the genetic control mechanism. Therefore, it is concluded that the effects of Ir genes are related to recognition of the core structure A–L. The relevance of these experimental findings is discussed.