Effects of bacterial lipopolysaccharide on the induction and expression of cell-mediated immunity. I. Depression of the afferent arc.
Bacterial lipopolysaccharide (LPS), being a B cell mitogen, enhances antibody production. When given prior to an injection of sheep red blood cells (SRBC) it caused a premature but not significantly increased production of antibody forming cells in regionally stimulated lymph nodes. There was a corresponding depression of T cell activity, as measured by the relative levels of delayed-type hypersensitivity (DTH) in normal and LPS-treated mice. Although LPS also induced hyperplasia of the reticuloendothelial system, and a consequent reduction in the effective antigenic dose of SRBC, this was not the reason for the reduced level of T cell activity. The opposing effects of LPS on T and B cell responses was due to premature inhibition of the T cell response by an accelerated production of antibody. This caused an earlier onset of the inhibitory mechanism which regulates the T cell response and is specific for the inducing antigen.
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000921:Antibody-Producing Cells; D001402:B-Lymphocytes / Q000276:immunology; D002645:Chickens / Q000276:immunology; D003520:Cyclophosphamide / Q000494:pharmacology; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D005856:Germ-Free Life; D006386:Hemagglutination Tests; D006462:Hemolytic Plaque Technique; D006614:Hindlimb / Q000276:immunology; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular; D007116:Immunization, Passive; D008070:Lipopolysaccharides / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008297:Male; D051379:Mice; D009929:Organ Size; D011135:Polysaccharides, Bacterial; D012477:Salmonella enteritidis / Q000276:immunology; D012756:Sheep / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000473:pathology
D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial; D003520:Cyclophosphamide