Lymphokine synthesis is induced in human thymocytes by activation of the CD 2 (T11) pathway

This study shows that unfractionated thymocytes can be activated to proliferate in response to activation by the CD 2 pathway, to express interleukin 2 receptors, and to synthesize interleukin 2 and interferon-gamma. Less mature, T3- thymocytes, isolated by negative selection are activated to a lesser extent than are unfractionated thymocytes; activation by the CD 2 pathway, induces proliferation, the expression of the interleukin 2 gene and interferon-gamma synthesis. 12-O-Tetradecanoyl phorbol 13-acetate in combination with the anti-CD 2 antibodies T11(2) + T11(3) increases the response of both unfractionated and T3- thymocytes. In addition we demonstrate that tetradecanoyl phorbol acetate in combination with T11(3) can replace the requirement for T11(2) for thymocyte activation and induce the expression of T11(3).