INVOLVEMENT OF C-ABL TYROSINE KINASE IN LIPOPOLYSACCHARIDE-INDUCED MACROPHAGE ACTIVATION

LPS endotoxin-induced macrophage activation is recognized to be import ant in both nonspecific immunity and endotoxin-induced sepsis when exc essive macrophage stimulation occurs. In this study, we showed that re duction of c-Abl in macrophages prevented LPS-induced growth arrest, n itric oxide production and TNF-alpha secretion by ANA-1 macrophages. T hese cells continued to grow but later underwent apoptosis, Reduction of c-Abl in these cells led to reduced c-Abl kinase activity associate d with Ran, which recently has been shown to be an LPS-responsive gene product. Our data suggest that c-Abl tyrosine kinase is one of the in termediates downstream of the initial signal transduction event relate d to activation of macrophages by LPS.