TTGG-A-L-specific memory B cells induced in low responder strains.

The immune response to TTGG-A--L, a defined-sequence, branched-chain polypeptide, is regulated by MHC-linked Ir genes. TTGG-A--L-specific B cells can be demonstrated in low responder strains by activation to specific antibody secretion after immunization with TTGGAA-F gamma G, a conjugate of the hexapeptide TTGGAA and the immunogenic carrier fowl gamma-globulin. It is shown that immunization with TTGG-A--L induces specific memory B cells with equal efficiency in low and high responder strains. This finding demonstrates that memory formation in a B cell subpopulation represented by TTGG-A--L-specific precursors is independent of carrier-specific, MHC-restricted helper T cells. This conclusion is further supported by the demonstration in an adoptive transfer model that immunization with TTGG-A--L induces equivalent levels of TTGG-A--L-specific memory B cells in T cell-deficient nude mice and their normal heterozygous littermates.