title: CD80 expression is induced on activated B cells following stimulation by CD86.
abstract: We examined the effects of CD86 ligation on surface densities of CD80 on activated B cells. For this, splenic B cells where CD86 levels had been enhanced upon anti-immunoglobulin M (IgM) treatment were employed. Incubation of such CD86-expressing B cells with anti-CD86 monoclonal antibody (MoAb) resulted in a marked upregulation in cell surface levels of CD80. Such an enhancement in surface levels was also accompanied by a marked increase in CD80 mRNA, suggesting that the effects of CD86-triggering are exerted at the level of CD80 message. Furthermore, coculture of CD86-upregulated B cells with CD28-expressing fibroblasts also led to the enhancement of CD80 levels, which was not obtained upon incubation with cells expressing cytotoxic T-lymphocyte-associated molecule (CTLA)-4-Ig. Finally, we also demonstrate that CD86-induced CD80 is fully competent to function as a costimulatory molecule, as revealed by its ability to enhance cytokine secretion by allogeneic T cells. Thus, these results reveal the existence of another pathway that regulates the expression of CD80, at least on activated B cells, which could have important implications in directing the course of an immune response.
authors.affiliation: Immunology group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: N C
authors.initials: NC
authors.lastname: Sahoo
authors.forename: K V S
authors.initials: KV
authors.lastname: Rao
authors.forename: K
authors.initials: K
authors.lastname: Natarajan
mesh_terms: D016475:3T3 Cells; D000069594:Abatacept; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen / Q000032:analysis / Q000096:biosynthesis*; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000276:immunology; D060908:CTLA-4 Antigen; D018920:Coculture Techniques; D005260:Female; D005434:Flow Cytometry; D018796:Immunoconjugates; D008213:Lymphocyte Activation / Q000276:immunology; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013047:Specific Pathogen-Free Organisms; D018417:Th1 Cells / Q000276:immunology; D014162:Transfection; D015854:Up-Regulation
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C497965:Cd86 protein, mouse; C556707:Ctla4 protein, mouse; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D000069594:Abatacept