title: Specific targeting of EGP-2+ tumor cells by primary lymphocytes modified with chimeric T cell receptors.
abstract: A promising strategy for cancer treatment is adoptive immunotherapy with gene-modified lymphocytes expressing a chimeric T cell receptor (cTCR) that directs tumor targeting and stimulates T cell effector functions. In this study, the activities of two novel cTCR molecules (GAgamma and GAHgamma) were investigated. Both encode a single-chain variable fragment (scFv) derived from the monoclonal antibody (MAb) GA733.2, which binds the epithelial glycoprotein 2 (EGP-2) overexpressed on a variety of human carcinomas. In the GAgamma cTCR, the scFv is directly fused to the transmembrane/cytoplasmic portions of the immunoglobulin Fc receptor (Ig FcRI) gamma subunit, which mediates T cell signaling. GAHgamma possesses an extracellular spacer composed of the CD8alpha immunoglobulin hingelike domain inserted between the scFv and gamma chain. Activated T cells (ATCs), stimulated ex vivo using anti-CD3 MAb, were derived from either healthy donors or patients and transduced with recombinant retrovirus encoding the respective GA cTCR molecules. After culture expansion for 14 days, GAgamma-modified ATCs demonstrated enhanced targeting and lysis of EGP-2+ colon cancer cells and increased cytokine secretion. Cells transduced with the GAHgamma cTCR displayed specific lytic activity that was about twofold greater than that of GAgamma-ATCs and produced significantly more cytokine. In addition, reactivation of GAHgamma-ATC with anti-CD3 MAb prior to addition to EGP-2+ tumor target induced a further increase in lytic activity. Because the activation status influences T cell antitumor functions, our data suggest that reactivation prior to adoptive transfer would improve the clinical efficacy of GAHgamma-modified ATCs.
authors.affiliation: Vince Lombardi Gene Therapy Laboratory, Immunotherapy Research and Treatment Institute, St. Luke's Medical Center, Milwaukee, WI 53215, USA.
authors.forename: L
authors.initials: L
authors.lastname: Ren-Heidenreich
authors.forename: G T
authors.initials: GT
authors.lastname: Hayman
authors.forename: K T
authors.initials: KT
authors.lastname: Trevor
mesh_terms: D000595:Amino Acid Sequence; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D000071858:Epithelial Cell Adhesion Molecule; D006801:Humans; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000166:cytology* / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics*; D011995:Recombination, Genetic; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D017931:DNA Primers; D000071858:Epithelial Cell Adhesion Molecule; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins