Enhancement of the primary cytotoxic response to membrane by a lymphokine costimulator.

Abstract

The primary and secondary cytotoxic T [thymus-derived] cell responses of C57Bl/6(H-2b) mouse spleen cells to P-815 [mastocytoma] membrane fragments (H-2b) were examined. The primary response required the addition of a supernatant from mitogen-stimulated spleen cells (costimulator) to the culture medium. Costimulator had little effect on the secondary response unless the spleen cells were first passed through a nylon wool column. Secondary cultures produced their own costimulator and adherent cells were required for its production. Adherent cells may be needed to activate helper cells.