Regulation of plasminogen-activator in mastocytoma cells by lymphokines

Culture supernatants from mitogen-stimulated splenocytes were found to stimulate protease production in P815Y mastocytoma cells. Such supernatants increased cell-associated plasminogen activator levels in a dose-dependent fashion, and under serum-free conditions. In contrast to peritoneal exudate cells, tumor-cell plasminogen activator was not enhanced by the mitogen ConA alone. The tumor cell line P815Y may, thus, be used as a homogeneous cell source for the quantitation of lymphocyte factors which activate or inhibit plasminogen activator activity.