title: Foamy combinatorial anti-HIV vectors with MGMTP140K potently inhibit HIV-1 and SHIV replication and mediate selection in vivo.
abstract: Highly active antiretroviral therapy has greatly reduced the morbidity and mortality from human immunodeficiency virus (HIV) infection, but AIDS continues to be a serious health problem worldwide. Despite enormous efforts to develop a vaccine, there is still no cure, and alternative approaches including gene therapy should be explored. In this study we developed and compared combinatorial foamy virus (FV) anti-HIV vectors that also express a mutant methylguanine methyltransferase (MGMTP140K) transgene to increase the percentage of gene-modified cells after transplantation. These FV vectors inhibit replication of HIV-1 and also the simian immunodeficiency virus/HIV-1 (SHIV) chimera that can be used in monkey AIDS gene therapy studies. We identified a combinatorial FV vector that expresses 3 anti-HIV transgenes and inhibits viral replication by over 4 logs in a viral challenge assay. This FV anti-HIV vector expresses an HIV fusion inhibitor and two short hairpin RNAs (shRNAs) targeted to HIV-1 tat and rev, and can be produced at high titer (3.8 x 10(7) transducing units ml(-1)) using improved helper plasmids suitable for clinical use. Using a competitive repopulation assay, we show that human CD34(+) cells transduced with this combinatorial FV vector efficiently engraft in a mouse xenotransplantation model, and that the percentage of transduced repopulating cells can be increased after transplantation.
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA 98109-1024, USA. hkiem@fhcrc.org
authors.forename: H-P
authors.initials: HP
authors.lastname: Kiem
authors.forename: R A
authors.initials: RA
authors.lastname: Wu
authors.forename: G
authors.initials: G
authors.lastname: Sun
authors.forename: D
authors.initials: D
authors.lastname: von Laer
authors.forename: J J
authors.initials: JJ
authors.lastname: Rossi
authors.forename: G D
authors.initials: GD
authors.lastname: Trobridge
mesh_terms: D000818:Animals; D015254:DNA Modification Methylases / Q000172:deficiency; D045643:DNA Repair Enzymes / Q000172:deficiency; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D015497:HIV-1; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D051379:Mice; D015302:Simian Immunodeficiency Virus; D053150:Simian foamy virus / Q000235:genetics*; D014161:Transduction, Genetic; D019076:Transgenes; D025521:Tumor Suppressor Proteins / Q000172:deficiency; D014779:Virus Replication
chemical_list: D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes