Possible role of endotoxin in mediating host resistance

Abstract

Summary. Macrophages activated in a variety of ways in vivo as well as in vitro release a cytotoxic factor upon LPS stimulation. Physicochemical characterization revealed a heat-stable 60,000 D protein with an isoelectric point at pH 4.8. This cytotoxin is one of the efl%ctor molecules in tumor cell killing by activated macrophages since cytolysis can be inhibited by antibodies directed against the cytotoxic factor.