DETECTION OF TUMOR-NECROSIS-FACTOR ACTIVITY IN THE SUPERNATANTS OF FELINE MACROPHAGES AND LYMPHOCYTES

Using tumor necrosis factor (TNF)-sensitive L929 cells, TNF-like activity was assayed in the supernatants of feline macrophage and lymphocyte cultures. Macrophages were separated from thioglycollate-elicited peritoneal cells. Lymphocytes were purified from peripheral blood and were then stimulated with calcium ionophore A23187 and phorbol myristate acetate. Lymphocyte stimulators alone did not have cytotoxicity against L929 cells. Based on the facts that cytotoxicity decreased with increasing dilutions of supernatant and that this cytotoxic activity could be blocked by antibody to human TNF, the activity detected in the supernatants of the feline macrophages and lymphocytes was likely due to feline TNF-alpha or -beta.