[Streptococcal A-induced polyclonal T-cell activation leads to a secondary functional activation of human B-cells]

Human lymphocytes are activated by cell walls or cytoplasma membranes of A-streptococci. Even in health human volunteers lymphocyte proliferation, lymphokine production and immunoglobulin synthesis is induced by high concentrations of streptococcal cell components following a pattern of polyclonal lymphocyte activation. We were interested in the special cellular requirements in this particular model. In cell separation and restitution experiments the observed B-cell activation was identified as the consequence of a primary monocyte-dependent polyclonal T-cell activation. Furthermore, lymphocyte proliferation and lymphokine production proved to be a monocyte- and T-cell-dependent process as well. Thus, lymphocyte activation induced by somatic streptococcal structures in humans depends upon a pattern of cell cooperation of mononuclear subpopulations well-known in a series of classical mitogen-induced lymphocyte activation.