title: Presentation of native TROP-2 tumor antigens to human cytotoxic T lymphocytes by engineered antigen-presenting cells.
abstract: Professional antigen-presenting cells (APC), e.g. dendritic cells, express immuno-proteasome components and process proteins for MHC presentation differently from non-immune cells. Thus, they induce reactivities against sets of peptides that do not overlap with those generated by non-professional APC, i.e., tumor cells, and stimulate cytotoxic T lymphocytes (CTL) that may not recognize them. The goal of this work was to establish a system for antigen presentation and in vitro stimulation of human CTL using "tumor-cell-like" engineered APC. Murine fibroblasts were transfected with human HLA Class I alleles, together with the B7.1, ICAM-1 and germ-line TROP2 genes. The last encodes a cell surface glycoprotein widely expressed by human cancers. Unseparated peripheral blood mononuclear cells from HLA Class I-matched individuals were stimulated in vitro by the engineered APC. These efficiently induced the activation and proliferation of antigen-specific HLA-restricted CTL lines and clones. The Trop-2-specific CTL demonstrated high specific cytotoxicity against the appropriate transfected target cells. They also efficiently lysed MCF-7 human tumor cells expressing endogenous HLA-A2.1, Trop-2 together with ICAM-1. These results demonstrate that Trop-2 is a target molecule recognized by human CTL. Moreover, they demonstrate that non-immune engineered APC efficiently process and present native tumor-specific proteins in the context of human MHC Class I, and stimulate the growth and cytotoxicity of specific anti-tumor CTL.
authors.affiliation: Laboratory of Experimental Oncology, Department of Cell Biology and Oncology, Istituto di Ricerche Farmacologiche Mario Negri, Consorzio Mario Negri Sud, Chieti, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Mangino
authors.forename: Maria
authors.initials: M
authors.lastname: Grazia Capri
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barnaba
authors.forename: Saverio
authors.initials: S
authors.lastname: Alberti
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D018122:B7-1 Antigen / Q000235:genetics; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology*; D000071858:Epithelial Cell Adhesion Molecule; D005347:Fibroblasts / Q000378:metabolism; D005818:Genetic Engineering; D015789:HLA-A2 Antigen / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology; D006801:Humans; D060945:Inducible T-Cell Co-Stimulator Ligand; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D001613:beta 2-Microglobulin / Q000235:genetics
chemical_list: D000951:Antigens, Neoplasm; D018122:B7-1 Antigen; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; D015789:HLA-A2 Antigen; D015395:Histocompatibility Antigens Class I; D060945:Inducible T-Cell Co-Stimulator Ligand; D001613:beta 2-Microglobulin; D018799:Intercellular Adhesion Molecule-1