T-cell proliferative response to hapten-modified self-immunoglobulins: recognition of conjugate-specific determinants.

(4-Hydroxy-3-nitrophenyl)acetyl (NP)-modified BALB/c immunoglobulins were used as the immunogen for induction of a proliferative response in BALB/c mice. As is true for responses to other soluble antigens, proliferation was dependent on Lyt-1 cells and histocompatible radioresistant accessory cells. Lyt-1 cells directed against NP-modified self immunoglobulin are specific for the immunizing hapten NP. However, they do not recognize hapten per se. Rather, they see complex determinants comprised of both the hapten NP and the immunoglobulin self-carrier. Distinct specificities were created by coupling the same hapten to different monoclonal BALB/c antibody molecules or by attaching the hapten to the immunoglobulin self-carrier via a spacer molecule. It is proposed that determinants created by attaching haptens to self-immunoglobulin molecules are similar to those recognized by anti-idiotypic T cells.