Murine responses to poly (Phe-Glu-Ala-Gly) and poly (Phe-Ala-Glu-Gly): comparisons between the specificities of the T-cell and B-cell responses.

The murine immune response patterns to (Phe-Glu-Ala-Gly)n and (Phe-Ala-Glu-Gly)n differ from those of the tyrosine analogues (Tyr-Glu-Ala-Gly)n and (Tyr-Ala-Glu-Gly)n. (Phe-Glu-Ala-Gly)n was not immunogenetic in inbred, congenic or recombinant strains of mice. (Phe-Ala-Glu-Gly)n was immunogenic only in mice having f alleles in the IA subregion of the H-2 complex. Reciprocal in vitro cross reactions were noted with T cells from mice of H-2f that respond to either (Phe-Ala-Glu-Gly)n or (Tyr-Ala-Glu-Gly)n. T cells from mice of H-2b, which are responders to (Tyr-Glu-Ala-Gly)n, could not be stimulated with the nonimmunogenic (Phe-Glu-Ala-Gly)n. These results support other studies showing that for any polymer to elicit cross T-cell proliferative responses it must be (a) structurally related to the homologous polymer and (b) immunogenic in the mouse strain whose T cells are being challenged in vitro. Explanations are offered for these statements.