title: Characterization of mouse and human B7-H3 genes.
abstract: T cell activation and immune function are regulated by costimulatory molecules of the B7 superfamily. Human B7-H3 is a recent addition to this family and has been shown to mediate T cell proliferation and IFN-gamma production. In this work we describe the identification of the mouse B7-H3 homolog, which is ubiquitously expressed in a variety of tissues. Activated CD4 and CD8 T cells express a putative receptor that can be recognized by soluble mouse B7-H3-Ig molecules. While the mouse B7-H3 gene was found to contain a single copy, we discovered a novel isoform of human B7-H3 (named as B7-H3b hereafter) with four Ig-like domains that results from gene duplication and differential splicing. B7-H3b is the major isoform expressed in several tissues. This structural information suggests a genetic variation of the B7-H3 gene in mammalian species.
authors.affiliation: Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195, USA.
authors.forename: Mingyi
authors.initials: M
authors.lastname: Sun
authors.forename: Sabrina
authors.initials: S
authors.lastname: Richards
authors.forename: Durbaka V R
authors.initials: DV
authors.lastname: Prasad
authors.forename: Xoi Muoi
authors.initials: XM
authors.lastname: Mai
authors.forename: Alexander
authors.initials: A
authors.lastname: Rudensky
authors.forename: Chen
authors.initials: C
authors.lastname: Dong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D060887:B7 Antigens; D018122:B7-1 Antigen / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D020440:Gene Duplication; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D020033:Protein Isoforms / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D060887:B7 Antigens; D018122:B7-1 Antigen; C423237:CD276 protein, human; C486038:Cd276 protein, mouse; D020033:Protein Isoforms; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins