CD3 Complex

Abstract: Research on the specificities, functions, and maturation of T cells would be greatly aided by a collection of monoclonal antibodies which distinguishes different types of TCR. With this end in mind hamsters were immunized and tested for production of pan-reactive anti-mouse alpha beta TCR antibodies. In this report we describe the properties and uses of a mAb, H57-597, produced from one of these animals. The mAb reacts with surface receptors on all alpha beta TCR-bearing cells and does not react with receptors on gamma delta+ T cells. In an immobilized form, this antibody can directly activate T cells bearing alpha beta TCR. It can be used in immunoprecipitation reactions to precipitate receptor from the appropriate cell types. In combination with anti-CD3, the antibody can be used in cytofluorographic analyses to measure numbers of CD3+, alpha beta+, and CD3+, gamma delta+ cells in the thymus and periphery.

Abstract: The results of several studies demonstrate that activation of resting T-cells requires two stimuli (1–4). One stimulus is represented by the recognition of antigen in conjunction with MHC gene products by the T-cell antigen receptor. The second stimulus is represented by accessory cells and their products. The delineation of the T-cell receptor for antigen and it’s associated molecules, T3, allows a study of how stimuli transmitted through these molecules signal activation. We present here some of these studies. To perform them, we have used the human T-cell line, Jurkat.

Abstract: Although the immunologic role of T cells bearing the conventional alpha beta T cell receptor (TCR) has been well characterized, little is known about the function of the population of T cells bearing the gamma delta TCR Therefore, the role of gamma delta T cells in the immune response to Mycobacterium tuberculosis (MT) was investigated The number of TCR gamma delta cells in the draining lymph nodes of mice immunized with MT was greatly increased in comparison with the number of TCR alpha beta cells Three biochemically distinct gamma delta TCRs were detected Analyses of cell cycle, of interleukin-2 receptor expression, and of interleukin-2 responsiveness showed that a large proportion of the gamma delta T cells were activated in vivo TCR gamma delta cells responded to solubilized MT antigens in vitro but, in contrast to MT-specific alpha beta T cells, the response of gamma delta T cells to MT did not require major histocompatability complex class II recognition These results provide an example of antigen-specific activation of gamma delta T cells in vivo and indicate that gamma delta T cells may have a distinct role in generating a primary immune response to certain microorganisms