Accession Number:

ADA220028

Title:

CD28 is an Inducible T Cell Surface Antigen that Transduces a Proliferative Signal in CD3(+) Mature Thymocytes

Descriptive Note:

Journal article

Corporate Author:

NAVAL MEDICAL RESEARCH INST BETHESDA MD

Report Date:

1990-03-01

Pagination or Media Count:

9.0

Abstract:

T cells are important regulators of immune surveillance. The antigen specificity of individual T cells is determined by the TCR, a membrane-bound heterodimer that recognizes nominal Silver complexed to self-Major Histocompatibility Complex molecules. The alphabeta subunits which comprise most TCR are expressed on the cell surface in close association with a series of five invariant proteins referred to as CD3 and together they form the TCRCD3 complex. During intrathymic development, most T cells rearrange the TCR alpha and beta-genes to generate the diverse repertoire of T cell specificities that are observed in peripheral lymphoid tissue. However, during this process 99 of T cells die within the thymus and thus never achieve functional maturity. The generation of the mature T cell repertoire is currently believed to be governed by two processes, clonal deletion and positive selection. Clonal detection refers to the elimination of T cells with a specificity for self-silver i.e., those that are potentially autoreactive. Positive selection results in mature T cells be able to recognize silver only in an MHC-restricted fashion. The mechanism by which clonal deletion and positive selection take place are poorly understood, but have been proposed to involve positive and negative signaling through surface molecules on the developing T cell. Keywords T cell Thymocyte CD28 Antigen Reprints.

Subject Categories:

  • Anatomy and Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE