title: Multigene lentiviral vectors based on differential splicing and translational control.
abstract: Lentiviral vectors, so far, have been optimized for the expression of a single open reading frame. Certain practical applications of gene therapy will, however, require expression of multiple genes. The goal of this study was to explore the feasibility of directing expression of two marker genes from a lentiviral vector. We designed two types of multigene lentiviral vectors. First, we used a strategy based on the natural splicing signals of HIV-1, by which multiple mRNAs are generated from a single transcriptional unit. A second strategy was construction of a polycistronic mRNA using a translational cis-acting element, the encephalomyocarditis virus internal ribosome entry site (IRES). Our studies show that the inclusion of multiple genes in lentiviral vectors does not result in reduction in virus titers or in the loss of ability to infect nondividing cells. We introduced mutations in tat and/or rev to test whether splicing modulates the relative levels of expression of reporter genes. We also developed a truncated version of tat, which is devoid of the apoptosis-associated domain. Inclusion of this tat mutant in a lentiviral vector resulted in the generation of virus with titers similar to those of lentivirus vectors expressing wild-type tat.
authors.affiliation: Department of Microbiology & Immunology, University of Rochester Cancer Center, 601 Elmwood Avenue, Rochester, New York 14642, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: G
authors.initials: G
authors.lastname: Feuer
authors.forename: S L
authors.initials: SL
authors.lastname: Day
authors.forename: S
authors.initials: S
authors.lastname: Wrzesinski
authors.forename: V
authors.initials: V
authors.lastname: Planelles
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D002455:Cell Division; D004686:Encephalomyocarditis virus / Q000235:genetics; D005434:Flow Cytometry; D015967:Gene Expression Regulation, Viral; D015696:Gene Products, tat / Q000737:chemistry / Q000235:genetics; D005796:Genes / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D015757:Genes, rev / Q000235:genetics; D015756:Genes, tat / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D016086:Lentivirus / Q000235:genetics* / Q000502:physiology; D008856:Microscopy, Fluorescence; D009154:Mutation / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012270:Ribosomes / Q000378:metabolism; D015533:Transcriptional Activation; D014161:Transduction, Genetic / Q000379:methods*; D019076:Transgenes / Q000235:genetics*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D015696:Gene Products, tat; D012333:RNA, Messenger; D054322:tat Gene Products, Human Immunodeficiency Virus