title: B cell function in mice transgenic for mCTLA4-H gamma 1: lack of germinal centers correlated with poor affinity maturation and class switching despite normal priming of CD4+ T cells.
abstract: This report outlines the B cell phenotype of transgenic mice that overexpresses the mouse CTLA-4-human gamma 1 (mCTLA4-H gamma 1) protein. Despite the fact that these mice prime CD4+ T cells (Ronchese, F., B. Housemann, S. Hubele, and P. Lane. 1994. J. Exp. Med. 179:809), antibody responses to T-dependent antigens are severely impaired. In contrast, T-independent responses are normal which suggests mCTLA4-H gamma 1 does not act directly on B cells, but acts indirectly by impairing T cell help. The impaired antibody defect is associated with impaired class switching, with low total immunoglobulin (Ig)G and antigen-specific IgG responses, and an absence of germinal center formation in spleen and lymph nodes but not gut-associated tissues. The defective germinal center formation is associated with a reduction in the degree of somatic mutation in hybridomas made from transgenic mice in comparison with those made from normal mice. It seems likely that mCTLA4-H gamma 1 exerts its effect by blocking an interaction between T and B cells that induce T cell help for B cells.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Lane
authors.forename: C
authors.initials: C
authors.lastname: Burdet
authors.forename: S
authors.initials: S
authors.lastname: Hubele
authors.forename: D
authors.initials: D
authors.lastname: Scheidegger
authors.forename: U
authors.initials: U
authors.lastname: Müller
authors.forename: F
authors.initials: F
authors.lastname: McConnell
authors.forename: M
authors.initials: M
authors.lastname: Kosco-Vilbois
mesh_terms: D000069594:Abatacept; D000818:Animals; D000917:Antibody Formation; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D015704:CD4 Antigens / Q000276:immunology*; D060908:CTLA-4 Antigen; D002645:Chickens; D017931:DNA Primers; D006801:Humans; D018796:Immunoconjugates; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification / Q000235:genetics* / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis / Q000235:genetics*; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D010581:Peyer's Patches / Q000276:immunology; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015704:CD4 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556707:Ctla4 protein, mouse; D017931:DNA Primers; D018796:Immunoconjugates; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D011993:Recombinant Fusion Proteins; D005719:gamma-Globulins; D000069594:Abatacept