title: Broad tumor-associated expression and recognition by tumor-derived gamma delta T cells of MICA and MICB.
abstract: Human MHC class I-related molecules, MICA and MICB, are stress-induced antigens that are recognized by a subset of gamma delta T cells expressing the variable region Vdelta1. This functional association has been found to be limited to intestinal epithelium, where these T cells are prevalent and where MICA and, presumably, MICB are mainly expressed. However, increased frequencies of Vdelta1 gamma delta T cells have been observed in various epithelial tumors; moreover, MICA/B are expressed on diverse cultured epithelial tumor cells. With freshly isolated tumor specimens, expression of MICA/B was documented in many, but not all, carcinomas of the lung, breast, kidney, ovary, prostate, and colon. In tumors that were positive for MICA/B, the frequencies of Vdelta1 gamma delta T cells were significantly higher than in those that were negative. Vdelta1 gamma delta T cell lines and clones derived from different tumors recognized MICA/B on autologous and heterologous tumor cells. In accord with previous evidence, no constraints were observed in these interactions, such as those imposed by specific peptide ligands. Thus, MICA/B are tumor-associated antigens that can be recognized, in an apparently unconditional manner, by a subset of tumor-infiltrating gamma delta T cells. These results raise the possibility that an induced expression of MICA/B, by conditions that may be related to tumor homeostasis and growth, could play a role in immune responses against tumors.
authors.affiliation: Fred Hutchinson Cancer Research Center, Clinical Research Division, 1100 Fairview Avenue North, Seattle, WA 98109, USA.
authors.forename: V
authors.initials: V
authors.lastname: Groh
authors.forename: R
authors.initials: R
authors.lastname: Rhinehart
authors.forename: H
authors.initials: H
authors.lastname: Secrist
authors.forename: S
authors.initials: S
authors.lastname: Bauer
authors.forename: K H
authors.initials: KH
authors.lastname: Grabstein
authors.forename: T
authors.initials: T
authors.lastname: Spies
mesh_terms: D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000276:immunology*; D006801:Humans; D009369:Neoplasms / Q000276:immunology* / Q000473:pathology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
chemical_list: D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; C098080:MICB antigen; D016692:Receptors, Antigen, T-Cell, gamma-delta