Modulation of immune response by bacterial lipopolysaccharide (LPS): roles of macrophages and T cells in vitro adjuvant effect of LPS on antibody response to T cell-dependent and T cell-independent antigens.
The roles of macrophages and T cells in the adjuvant effect of lipopolysaccharide (LPS) were studied. In vitro anti-trinitrophenyl (anti-TNP) antibody responses to TNP-Ficoll and TNP-keyhole limpet hemocyanine (TNP-KLH) in spleen cells in C57BL/6 mice showed the most enhancement, when LPS was added to cultures at 1 microgram/ml 48 hr after culture was started. The responses to these antigens were enhanced markedly by LPS in whole and macrophage-depleted spleen cells. The enhancement was greater in the latter group than in the former. The adjuvant effect among whole, T cell-depleted, macrophage-depleted and both macrophage- and T cell-depleted spleen cells was compared. The response to TNP-Ficoll was enhanced markedly by LPS in all groups. The enhancement was greater in the latter two groups than in the first two groups. The response to TNP-KLH was enhanced by LPS strongly in macrophage-depleted spleen cells, moderately in whole and both macrophage- and T cel-depleted spleen cells, and only slight in T cell-depleted spleen cells. Enhancement was restored to T cell-depleted spleen cells by adding T cells. The response to TNP-KLH of macrophage-depleted spleen cells of LPS-responsive C3H/HeN mice which was enhanced by LPS was suppressed by adding splenic macrophages of C3H/HeN mice, but not of LPS-nonresponsive C3H/HeJ mice was not enhanced by LPS, irrespective of the addition of macrophages of C3H/HeN mice. The results indicate that B cells are activated directly by LPS, and T cells enhance and macrophages suppress the adjuvant effect of LPS.
D000276:Adjuvants, Immunologic; D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H / Q000276:immunology; D008810:Mice, Inbred C57BL / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology
D000276:Adjuvants, Immunologic; D008070:Lipopolysaccharides; D014301:Trinitrobenzenes