Concanavalin A-mediated activation of antigen-primed lymphocytes into secondary cytotoxic lymphocytes.

Abstract

A secondary specific cytotoxic response is obtained when lymphocytes primed in vivo to a tumor allograft [mouse leukemia EL-4 cells or mouse Gross virus induced lymphoma G-35 cells] are exposed to Con A [concanavalin A] in culture. The secondary cytotoxic cells generated are specific to target cells bearing antigens of the primary sensitizing cells and are qualitatively indistinguishable from the response obtained upon secondary antigenic stimulation. The cell-mediated cytotoxicity is independent of Con A and is not affected by the Con A-specific inhibitor, .alpha.-methyl-D-mannose pyranoside. Cultures containing a mixture of submitogenic concentrations of Con A and stimulating antigens showed synergy and augmentation of cytotoxic activity. Activation of prekiller cells by Con A into CTL [cytotoxic thymus-derived lymphocytes] may be mediated via the same or similar receptors normally triggered by the stimulating antigens. Functional similarities between Con A and the lymphocyte-defined antigens of the major histocompatibility complex region are discussed.