title: Macrophage stimulation by bacterial lipopolysaccharides. III. Selective unresponsiveness of C3H/HeJ macrophages to the lipid A differentiation signal.
abstract: Peritoneal macrophages from the endotoxin-unresponsive C3H/HeJ substrain of mice were entirely refractory to activation in vitro by protein-free LPS, a defect that was not overcome by co-culture of spleen cells from the responder C3H/St substrain with LPS resistant C3H/HeJ macrophages. The defect in responsiveness appears confined to the lipid A activation signal since C3H/HeJ macrophages were fully activated after in vitro treatment by lipid A protein (LAP)--LPS complex, isolated LAP, and BCG. Moreover, after exposure to allogeneic tumor cells in vivo, C3H/HeJ macrophages were cytotoxic for tumor target cells in vitro. By contrast, macrophages from the responder C3H/St strain were fully activated by protein-free LPS to become cytolytic for tumor cells in vitro. C3H/HeJ macrophages, therefore, exhibit a highly selective defect characterized by unresponsiveness to the lipid A activation signal of protein-free LPS and resistance to the toxic effects of high concentrations of LPS that were lethal to the responder C3H/St strain.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D007156:Immunologic Memory; D008050:Lipid A / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H; D009163:Mycobacterium bovis / Q000276:immunology; D010636:Phenols / Q000494:pharmacology; D012641:Selection, Genetic; D013154:Spleen / Q000276:immunology
chemical_list: D008050:Lipid A; D008070:Lipopolysaccharides; D010636:Phenols