Proceedings of the National Academy of Sciences of the United States of America
Human T-cell clones and anti-T-cell-receptor antibodies (clonotypic) directed at surface receptors for antigen (T3-Ti molecular complex) as well as anti-interleukin 2 (IL-2) and anti-IL-2-receptor antibodies were utilized to investigate the mechanism by which alloantigens or antigen plus self-major histocompatibility complex (MHC) (i.e., physiologic ligand) trigger specific clonal proliferation. Soluble or Sepharose-bound anti-Ti monoclonal antibodies, like physiologic ligand, enhanced proliferative responses to purified IL-2 by inducing a 6-fold increase in surface IL-2 receptor expression. In contrast, only Sepharose-bound anti-Ti or physiologic ligand triggered endogenous clonal IL-2 production and resulted in subsequent proliferation. The latter was blocked by antibodies directed at either the IL-2 receptor or IL-2 itself. These results suggest that induction of IL-2 receptor expression but not IL-2 release occurs in the absence of T3-Ti receptor cross-linking. Perhaps more importantly, the findings demonstrate that antigen-induced proliferation is mediated through an autocrine pathway involving endogenous IL-2 production, release, and subsequent binding to IL-2 receptors.
Meuer, Stefan C.; Hussey, Rebecca E.; Cantrell, Doreen A.; Hodgdon, James C.; Schlossman, Stuart F.; Smith, Kendall A.; and Reinherz, Ellis L., "Triggering of the T3-Ti antigen-Receptor Complex Results in Clonal T-Cell Proliferation through an Interleukin 2-Dependent Autocrine Pathway." (1984). Open Dartmouth: Faculty Open Access Articles. 1235.