title: Recruitment of Oligoclonal Viral-Specific T cells to Kill Human Tumor Cells Using Single-Chain Antibody-Peptide-HLA Fusion Molecules.
abstract: Tumor progression is often associated with the development of diverse immune escape mechanisms. One of the main tumor escape mechanism is HLA loss, in which human solid tumors exhibit alterations in HLA expression. Moreover, tumors that present immunogenic peptides via class I MHC molecules are not susceptible to CTL-mediated lysis, because of the relatively low potency of the tumor-specific CLTs. Here, we present a novel cancer immunotherapy approach that overcomes these problems by using the high affinity and specificity of antitumor antibodies to recruit potent antiviral memory CTLs to attack tumor cells. We constructed a recombinant molecule by genetic fusion of a cytomegalovirus (CMV)-derived peptide pp65 (NLVPMVATV) to scHLA-A2 molecules that were genetically fused to a single-chain Fv Ab fragment specific for the tumor cell surface antigen mesothelin. This fully covalent fusion molecule was expressed in E. coli as inclusion bodies and refolded in vitro. The fusion molecules could specifically bind mesothelin-expressing cells and mediate their lysis by NLVPMVATV-specific HLA-A2-restricted human CTLs. More importantly, these molecules exhibited very potent antitumor activity in vivo in a nude mouse model bearing preestablished human tumor xenografts that were adoptively transferred along with human memory CTLs. These results represent a novel and powerful approach to immunotherapy for solid tumors, as demonstrated by the ability of the CMV-scHLA-A2-SS1(scFv) fusion molecule to mediate specific and efficient recruitment of CMV-specific CTLs to kill tumor cells.
authors: Cancer Immunology, Albert Einstein College of Medicine, Bronx, New York.
authors: Roy
authors: R
authors: Noy
authors: Laboratory of Molecular Immunology, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
authors: Maya
authors: M
authors: Haus-Cohen
authors: Laboratory of Molecular Immunology, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
authors: Kfir
authors: K
authors: Oved
authors: Laboratory of Molecular Immunology, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
authors: Tali
authors: T
authors: Voloshin
authors: Laboratory of Molecular Immunology, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel. reiter@tx.technion.ac.il.
authors: Yoram
authors: Y
authors: Reiter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000276:immunology; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D000090204:Mesothelin; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy; D010750:Phosphoproteins / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000637:transplantation; D014763:Viral Matrix Proteins / Q000235:genetics / Q000276:immunology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D015789:HLA-A2 Antigen; C000715528:Msln protein, mouse; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D000090204:Mesothelin