title: B7-CTLA4 interaction promotes cognate destruction of tumor cells by cytotoxic T lymphocytes in vivo.
abstract: Costimulatory molecules B7-1 and B7-2 (hereby collectively called B7) interact with CD28 and CTLA4 on T cells and promote antitumor immunity. The function of B7-CTLA4 interaction in antitumor CTL response remains controversial. Here we used CD28(-/-) and CD28(+/-) or CD28(+/+) transgenic mice that express the T-cell receptor specific for an unmutated tumor antigen, P1A, and for tumor cells expressing a CTLA4-specific B7 mutant to evaluate the function of CD28-B7 and CTLA4-B7 interactions in induction and effector phases of antitumor immunity. We report that B7-CD28 and B7-CTLA4 interactions promote tumor rejection. However, this is achieved by distinct mechanisms. B7-CD28 interaction enhances T-cell clonal expansion, though a role for this interaction in the effector phase cannot be ruled out. In contrast, B7-CTLA4 interaction enhances the CTL-mediated destruction of tumors, but not T-cell clonal expansion.
authors.affiliation: Department of Pathology and the Comprehensive Cancer Center, Ohio State University Medical Center, Columbus 43210, USA.
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Bai
authors.forename: Jinqing
authors.initials: J
authors.lastname: Liu
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: May
authors.forename: Yong
authors.initials: Y
authors.lastname: Guo
authors.forename: Pan
authors.initials: P
authors.lastname: Zheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000069594:Abatacept; D019264:Adoptive Transfer; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000943:Antigens, Differentiation / Q000276:immunology / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000276:immunology*; D018122:B7-1 Antigen / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000235:genetics / Q000378:metabolism; D060908:CTLA-4 Antigen; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D007109:Immunity; D018796:Immunoconjugates; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D009374:Neoplasms, Experimental / Q000628:therapy; D011485:Protein Binding / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000637:transplantation
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; 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; D011948:Receptors, Antigen, T-Cell; C076546:tumor rejection antigen P815A, mouse; D000069594:Abatacept