title: Clonal analysis and in situ characterization of lymphocytes infiltrating human breast carcinomas.
abstract: T lymphocytes were isolated from tumor biopsies in 13 patients with breast carcinomas. Immunohistology with monoclonal antibodies confirmed the presence of mononuclear cell infiltrates composed primarily of T lymphocytes in all tumors studied. While the proportion of T lymphocytes expressing the T4 or the T8 surface marker varied from tumor to tumor as determined by morphometric analysis, T8+ cells were more numerous than T4+ cells in 8/12 breast tumors studied. Relatively few T cells (less than 10% in 11/12 tumors) were in an activated state as judged by the surface expression of HLA-DR antigens or the receptor for interleukin-2 (IL-2). In 1 case 20% of the infiltrating mononuclear cells were expressing the IL-2 receptor. The tumor infiltrating lymphocytes (TIL) recovered from 10 tumors were cloned in a microculture system that permits proliferation of nearly 100% of normal peripheral blood T lymphocytes (PBL-T). In contrast to normal and autologous PBL-T, frequencies of proliferating T lymphocyte precursors (PTL-P) were depressed (less than 0.01) in 7/10 TIL preparations indicating a decreased responsiveness of TIL to phytohemagglutinin at the single-cell level. The frequency of PTL-P was noticeably higher in 2 cases (0.03 and 0.09) and close to normal in 1 case (0.39). A total of 170 clones were expanded in vitro and analyzed for different functional capabilities. Most of these clones expressed the T4+/T8-phenotype (73%) and strikingly 53% of these T4+/T8- clones were cytolytic in a lectin-dependent assay, a functional subset which is uncommon among normal PBL-T. Some clones (10%) lysed allogeneic breast tumor cells (MCF7). Only 15% of the clones displayed natural killer activity. Among the cytolytic clones, 17 of 31 tested were also IL-2 producers irrespective of the T4 or T8 phenotype. Our results show that human mammary carcinomas contain many infiltrating T cells with cytolytic potential. Interestingly, among the proliferating cytolytic T cell clones (56% of the microcultures), many expressed the T4+/T8- phenotype. These findings may indicate that the in situ cytolytic reaction (against unknown antigens) is associated preferentially with class II antigens.
mesh_terms: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D001943:Breast Neoplasms / Q000276:immunology / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000276:immunology / Q000473:pathology; D002999:Clone Cells / Q000032:analysis; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007124:Immunoenzyme Techniques; D007958:Leukocyte Count; D008207:Lymphatic Metastasis; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000145:classification* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface