T cells recognize both conformational and cryptic determinants on the insulin molecule.

T lymphocytes from strain 2 guinea pigs were studied for recognition of isolated insulin A and B chains. Insulin-immune T cells require intact conformation of the interchain disulfide bond that forms the A chain loop but do not require the B chain. In addition, strain 2 T cells were unexpectedly found to recognize unique epitopes on isolated insulin B chain that are not generated by presentation of native insulin. These data show that the T cell repertoire of strain 2 guinea pig for insulin includes both conformational and cryptic determinants.