title: B7-1 expression by a non-antigen presenting cell-derived tumor.
abstract: The existence of a naturally occurring immunosurveillance against neoplastic cells is controversial. A difficulty with this concept is that tumor-specific antigen-reactive T cells would not be expected to become activated after encountering tumor cells, since T cells that bind to antigen in the absence of the costimulation provided by antigen-presenting cells may be inactivated. We studied a transgenic model of tumorigenesis where T cells reactive to a particular tumor-specific antigen are lost prior to the development of non-antigen-presenting cell-derived tumors; therefore, the tumors that develop are not subjected to immunosurveillance. We found that a tumor cell line derived from one such tumor expresses the T-cell costimulatory molecule B7-1, the expression of which is normally restricted to antigen-presenting cells. In addition, we found that several immortalized cell lines, which are nontumorigenic and thus have suffered only early genetic events in the tumorigenesis process, express B7. This suggests that a host cell can be induced to express surface B7-1 molecules after suffering an oncogenic insult, which might possibly be a primary mechanism of immunosurveillance against tumors.
authors.affiliation: Section of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Antonia
authors.forename: T
authors.initials: T
authors.lastname: Muñoz-Antonia
authors.forename: G
authors.initials: G
authors.lastname: Soldevila
authors.forename: J
authors.initials: J
authors.lastname: Miller
authors.forename: R A
authors.initials: RA
authors.lastname: Flavell
mesh_terms: D016475:3T3 Cells; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000276:immunology; D000952:Antigens, Polyomavirus Transforming / Q000276:immunology; D018122:B7-1 Antigen / Q000096:biosynthesis* / Q000276:immunology; D001483:Base Sequence; D018267:Carcinoma, Acinar Cell / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D015166:Monitoring, Immunologic; D010190:Pancreatic Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D000952:Antigens, Polyomavirus Transforming; D018122:B7-1 Antigen; D015395:Histocompatibility Antigens Class I