title: Induction of melanoma antigen-specific cytotoxic T lymphocytes in vitro by stimulation with B7-expressing human melanoma cell lines.
abstract: Crosslinking of CD28 receptors on resting T lymphocytes by B7 costimulatory molecules expressed by antigen-presenting cells (APCs) plays a critical role in T-cell activation. Human melanomas express major histocompatibility complex (MHC)-restricted tumor-associated antigens that can be recognized by cytotoxic T lymphocytes (CTL), yet they remain poorly immunogenic. One mechanism for the failure of T-cell response is the lack of expression of costimulatory molecules by human melanoma cells. We have transfected the B7-1 gene into three HLA-A2-expressing human melanoma cell lines, and studied their capacity to stimulate primary human T cells. B7-expressing melanoma cells were excellent inducers of T-cell proliferation, cytokine production, and cytolytic activity in allogeneic mixed lymphocyte cultures through a process dependent on the function of the T-cell receptor as well as interactions between B7:CD28, CD2:LFA-3, and LFA-1:ICAM-1. Subset analysis demonstrated that CD4+ T cells or addition of exogenous interleukin-2 was required for the induction of CD8+ CTL. Untransfected parental melanoma cells were inert as APCs in these cultures. Rotating stimulation of T cells with the three B7-expressing cell lines led to the generation of T-cell lines that were cytolytic for HLA-A2+ melanoma cells and other HLA-A2+ targets that were pulsed with HLA-A2-restricted MART-1 peptides. These data demonstrate that expression of B7-1 by human melanoma cells converts them into effective APCs for the in vitro induction of MHC-restricted, melanoma-specific CTL.
authors.affiliation: NCI-Frederick Cancer Research and Development Center, Division of Clinical Sciences, Maryland 21702, USA.
authors.forename: R G
authors.initials: RG
authors.lastname: Fenton
authors.forename: S M
authors.initials: SM
authors.lastname: Turcovski-Corrales
authors.forename: D D
authors.initials: DD
authors.lastname: Taub
mesh_terms: D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D018122:B7-1 Antigen / Q000235:genetics / Q000276:immunology*; D002450:Cell Communication; D002462:Cell Membrane; D002478:Cells, Cultured / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D015789:HLA-A2 Antigen / Q000276:immunology; D015793:HLA-B7 Antigen / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D058965:MART-1 Antigen; D008545:Melanoma / Q000276:immunology*; D009363:Neoplasm Proteins / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology* / Q000276:immunology*; D013997:Time Factors; D014162:Transfection / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D018122:B7-1 Antigen; D016207:Cytokines; D015789:HLA-A2 Antigen; D015793:HLA-B7 Antigen; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins; D011948:Receptors, Antigen, T-Cell