Cellular and lipopolysaccharide subunit requirements for the caprine lymphoblastogenic response to endotoxin.
Caprine B lymphocytes were established as the cell type that divided when cultured with lipopolysaccharide (LPS), and lipid A was defined as the in vitro mitogenic component of LPS. The conclusion that the caprine B lymphocyte was stimulated by LPS was based on 3 observations: (i) Numbers of B lymphocytes increased in cultures containing LPS, but not in unstimulated or concanavalin A-stimulated cultures, (ii) mixtures of T lymphocytes and monocytes did not incorporate tritiated thymidine when LPS was added, and (iii) removal of monocytes from mixtures of T and B lymphocytes did not reduce the LPS-stimulated reaction. Stimulation of B lymphocytes by LPS occurred when less than 1% monocytes were present and was augmented by greater than 5% monocytes. The lipid A subunit of LPS was most likely responsible for mitogenesis, since purified lipid A stimulated lymphocytes and the addition of polymyxin B, a specific inhibitor of lipid A activity, blocked the lymphocyte reaction.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D004926:Escherichia coli; D005260:Female; D006041:Goats / Q000276:immunology*; D008050:Lipid A / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008297:Male; D008934:Mitogens / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology; D011112:Polymyxin B / Q000494:pharmacology; D012475:Salmonella; D013601:T-Lymphocytes / Q000276:immunology
D008050:Lipid A; D008070:Lipopolysaccharides; D008934:Mitogens; D011112:Polymyxin B