title: Lentiviral vectors encoding human MUC1-specific, MHC-unrestricted single-chain TCR and a fusion suicide gene: potential for universal and safe cancer immunotherapy.
abstract: MUC1 tumor antigen is a target for immunotherapy of most human adenocarcinomas and some hematological malignancies. Expression of a MUC1-specific, MHC-unrestricted single-chain T cell receptor (scTCR) on cells of both innate and adaptive immune system through reconstitution of lethally irradiated mice by retroviral vector-transduced bone marrow cells, had been shown to effectively control the growth of MUC1(+) tumors independent of their MHC type, suggesting that this receptor is a good candidate for broadly applicable gene therapy/immunotherapy. However, the translational application of this immuno-gene therapy modality was discouraged by the progressive transgene silencing in reconstituted T and B cells, as well as the potential of tumorogenesis intrinsic to oncoretroviral vectors. To overcome these problems and facilitate the future clinical use of this receptor, we have constructed a panel of novel self-inactivating lentiviral vectors (LVs) which harbor two independent internal promoters, one driving expression of the scTCR gene and the other of a fusion suicide gene, the HSV-TK-EGFP fusion gene, allowing the transduced cells to be destroyable by the pro-drug ganciclovir. Despite the large size of insert, these vectors were efficiently packaged into high titer virus that transferred the expression of transgene in both T cell lines and primary T cells. Sustained expression was maintained in a T cell line for over 4 months in vitro, suggesting its efficient resistance to transgene silencing. Both scTCR and HSV-TK-EGFP genes were functional in the transduced cells, as evidenced by their specific recognition of MUC1(+) tumors and efficient eradication by ganciclovir.
authors.affiliation: Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Chen
authors.forename: Wentao
authors.initials: W
authors.lastname: Gao
authors.forename: Andrea
authors.initials: A
authors.lastname: Gambotto
authors.forename: Olivera J
authors.initials: OJ
authors.lastname: Finn
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects*; D005434:Flow Cytometry; D015774:Ganciclovir / Q000494:pharmacology; D041722:Genes, Transgenic, Suicide; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D018396:Mucin-1 / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D012190:Retroviridae / Q000235:genetics; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology; D013937:Thymidine Kinase / Q000235:genetics; D014161:Transduction, Genetic
chemical_list: D000998:Antiviral Agents; C060192:MUC1 protein, human; D018396:Mucin-1; D011948:Receptors, Antigen, T-Cell; D049452:Green Fluorescent Proteins; D013937:Thymidine Kinase; D015774:Ganciclovir