Involvement of Tyrosine Kinases and MAP Kinases in the Production of TNF- α and IL-1 β by Macrophages In Vitro on Treatment with Phytohemagglutinin

Abstract

Treatment of murine peritoneal macrophages with various doses of phytohemagglutinin (PHA) for different time intervals enhanced production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Maximum transcription for TNF-α and IL-1β was observed at 16 h, whereas maximum production was observed at 24 h of PHA treatment. The most optimum dose was 1 μg/mL PHA. Pharmacologic inhibitors of tyrosine kinase, p42/44, p38, and JNK downregulate the PHA-induced expression of TNF-α and IL-1β. Maximum protein tyrosine kinase (PTK) activity in macrophages was seen at 5 min of PHA-treatment. PHA-treated macrophages showed maximum expression of phospho-p42/44 and phospho-JNK at 15 min. It was also observed that p38 is activated after 12 h of PHA treatment. Pharmacologic inhibitor of tyrosine kinase, genistein down-regulated the PHA-induced activation of p42/44 and JNK.