Abstract
Small portion of normal peripheral blood T cells has Ia-antigen on their surfaces, and these Ia-antigen positive T cells (Ia+ T cells) are thought to be immunologicaly activated T cells in vivo. In this studies we investigated the functional properties on in vitro immune reactions of normal adult lymphocytes.
Ia+ T cell fraction was depleted by negative selection using monoclonal anti-Ia antibody and complement. Ia+ T cells were responder or helper T cells for PHA-induced proliferation, and suppressor T cells for Con A or PWM-induced proliferation of normal peripheral lymphocytes. In autologous mixed lymphocyte reaction (AMLR) Ia+ T cells acted as responder or helper T cells. Moreover, Ia+ T cells had a helper action for PWM-induced production of immunoglobulin by normal peripheral B cells.
These findings showed that Ia-antigen on T cells would not be a single functional subset marker, but differentiating marker for various effector cells of T cells.
