A selective effect upon IgG synthesis by T gamma lymphocytes and their products in man

Depletion of T lymphocytes possessing receptors for IgG (T gamma cells) from peripheral blood lymphocytes (PBL) results in enhanced pokeweed mitogen (PWM)-induced IgG synthesis and secretion as compared to IgM. Concanavalin A (Con A) stimulation of T gamma cells causes release of soluble mediators able to suppress immunoglobulin synthesis by PWM-activated PBL. Such factors cause concentration-dependent selective suppression of IgG synthesis. The mediators act upon T gamma cell-depleted lymphocyte populations, also preferentially suppressing the IgG PFC response while leaving the IgM response relatively intact. Thus T gamma cells and their products selectively affect IgG synthesis in vitro.