title: Host B7-1 and B7-2 costimulatory molecules contribute to the eradication of B7-1-transfected P815 tumor cells via a CD8+ T cell-dependent mechanism.
abstract: B7-1 (CD80)-transfected P815 tumor cells were previously shown to elicit tumor-eradicating immunity that leads to the regression of B7-1+ P815 tumors after transient growth in normal syngeneic (DBA/2) mice. Here, we show that not only the B7-1 molecule but also the B7-2 (CD86) molecule contributed to the eradication of B7-1+ P815 tumors. The B7-1 molecule that contributed to the eradication of B7-1+ P815 tumors was expressed not only on the tumor cells but also on host APCs, including MAC-1+ cells. The B7-2 molecule that contributed to the eradication of B7-1+ P815 tumors was expressed only on host APCs, such as B220+ cells, and not on the tumor cells. In spite of the fact that B7-expressing host APCs contributed to the eradication of B7-1+ P815 tumors, only CD8+ T cells without help from CD4+ T cells were important for tumor eradication. Taken together, these findings indicate that in addition to the ability of B7-1-transfected tumor cells to stimulate CD8+ T cell-mediated tumor-eradicating immunity directly, such tumor cells can also stimulate CD8+ T cell-mediated tumor-eradicating immunity indirectly as a result of cross-priming through B7-expressing host APCs.
authors: Department of Biochemistry and Molecular Biology, University of Illinois, Chicago 60612, USA.
authors: R N
authors: RN
authors: La Motte
authors: A H
authors: AH
authors: Sharpe
authors: J A
authors: JA
authors: Bluestone
authors: M B
authors: MB
authors: Mokyr
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D015703:Antigens, CD / Q000096:biosynthesis / Q000502:physiology*; D018122:B7-1 Antigen / Q000235:genetics / Q000502:physiology*; D051940:B7-2 Antigen; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D012515:Mast-Cell Sarcoma / Q000235:genetics / Q000276:immunology* / Q000628:therapy*; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D018345:Mice, Knockout; D009368:Neoplasm Transplantation; D014162:Transfection / Q000276:immunology*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000276:immunology
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D008562:Membrane Glycoproteins