Private and Shared Idiotypic Determinants of the Human T Cell Antigen Receptor

Abstract

T lymphocytes play a crucial role in initiating most immune responses. Not only are T cells, especially antigen-specific helper T cells, necessary to induce functional effector T cell subpopulations but also to initiate development of the B cell response. The complete understanding of this co-ordinated T-B response requires knowledge of both the mechanism of T cell activation and the method by which T cells transmit signals to B cells. Once activated, T lymphocytes appear to function by secreting various soluble factors. These factors have been reported to influence B cell proliferation, differentiation, and immunoglobulin isotype selection (1–3). The nature of the initial events in triggering T lymphocytes to progress from a resting to activated state is poorly understood. Understanding the requirements to initiate this specific T cell activation, however, is crucial to understanding the integration of these two major functional arms of the immune system. The recent definition of the T cell antigen receptor using both monoclonal antibodies (mAbs) and cDNA probes has permitted a new, more precise method for investigating both the cellular events and molecular structures involved in this initial stage of T-B interaction.