The B cell is the initiating antigen-presenting cell in peripheral lymph nodes.
We have examined the role of B cells in antigen presentation in lymph nodes in several ways. We found that mice depleted of B lymphocytes via chronic injection of anti-mu-chain antibody do not mount peripheral lymph node T cell proliferative responses to normally immunogenic doses of antigen. Depletion of B cells by passage of immune lymph node cells over anti-immunoglobulin columns early after immunization depletes antigen-presenting function from draining lymph nodes, and this function can be restored by using B cells or splenic adherent cells to allow the remaining T cells to proliferate. Lymph node B cells present antigen very effectively to lines of antigen-specific T cells. However, unfractionated lymph node cells from anti-mu-treated mice present very poorly, if at all, whereas unfractionated spleen cells from the same mice do present antigen. This is in keeping with our previous finding that helper T cell function in the spleen is normal in B cell-deprived mice. Finally, when mice homozygous for the lymphoproliferative gene lpr are treated chronically with anti-mu-chain antibody, lymphadenopathy is greatly retarded, suggesting a role for B cells in the massive proliferation of T cells in this syndrome. From this analysis, it would appear that the initiating antigen-presenting cell in the lymph node is a B lymphocyte, and that B lymphocytes in lymph nodes may be distinct from those in the spleen. It is of interest that these results also suggest that the lymph node lacks an antigen-presenting cell that is found in the spleen, perhaps the dendritic cell.
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002458:Cell Fractionation; D002460:Cell Line; D007148:Immunoglobulin mu-Chains / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology* / Q000276:immunology; D008213:Lymphocyte Activation; D008212:Lymphocyte Depletion; D008232:Lymphoproliferative Disorders / Q000235:genetics / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains / Q000276:immunology; D008817:Mice, Mutant Strains / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D000888:Antibodies, Anti-Idiotypic; D007148:Immunoglobulin mu-Chains