CD5+ B cell-dependent regulation of the murine T-cell independent immune response against the human blood group A antigen.
The CD5+B lymphocyte (B1a) population is known to be involved in most immune responses to microorganism TI antigens. Moreover, xid mice deficient for immune responses against TI-2 antigens are known to lack the B1a population, suggesting a role for B1a cells in TI-2 immune responses. We previously established that the oligosaccharide human blood group A antigen stimulated murine TI-2 immune responses. In this work, we show that the frequency of anti-A-secreting hybridomas was higher in mice with larger splenic B1a populations and that in vivo anti-CD5 treatment reduced anti-A immune response without affecting the response against TD RBC antigens. A similar effect was observed by in vitro anti-CD5 treatment of splenocytes. The in vivo anti-CD5 treatment also interfered with the immunization-dependent increase in splenocyte numbers. These results are in agreement with an important role for the B-cell CD5 receptor in the regulation of TI-2 immune responses possibly mediated by its interaction with the CD72 ligand.
Néron
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Canadian Red Cross Society, Blood Services, Québec City center, Sainte-Foy, Canada.
Lemieux
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R
D000017:ABO Blood-Group System / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology; D000955:Antigens, T-Independent / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018956:CD5 Antigens / Q000276:immunology*; D005260:Female; D006801:Humans; D006825:Hybridomas; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014407:Tumor Cells, Cultured
D000017:ABO Blood-Group System; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000955:Antigens, T-Independent; D018956:CD5 Antigens; C064228:CD72 protein, human