title: Tolerance breaking by lymphocyte activating factor induced by Escherichia coli O138 lipopolysaccharide from homologous macrophages.
abstract: Following an antigenic dose of 10 microgram or a tolerogenic dose of 200 microgram of Escherichia coli O138 lipopolysaccharide (LPS), BALB/c mice were examined on day 14 for percentages of theta-bearing cells. A considerable increase in T cells was noticed in lymphocytes from tolerant draining lymph nodes, and furthermore these cells did not possess receptors for LPS when tested for rosette inhibition. However, when the supernatant from 1 X 10(7) macrophages, pretreated with 150 microgram LPS, was given to tolerant mice on day 7, by day 14 tolerance was found to be broken, anti-LPS IgG was present in circulation and the draining lymph node contained T cells specifically committed to LPS. The change from suppressor to helper T cell activity is discussed in relation to enhancement of the immune response.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic; D004926:Escherichia coli / Q000276:immunology*; D007108:Immune Tolerance; D008070:Lipopolysaccharides / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D012397:Rosette Formation
chemical_list: D000942:Antigens, Bacterial; D008070:Lipopolysaccharides