title: Improved primate foamy virus vectors and packaging constructs.
abstract: Foamy virus (FV) vectors that have minimal cis-acting sequences and are devoid of residual viral gene expression were constructed and analyzed by using a packaging system based on transient cotransfection of vector and different packaging plasmids. Previous studies indicated (i) that FV gag gene expression requires the presence of the R region of the long terminal repeat and (ii) that RNA from packaging constructs is efficiently incorporated into vector particles. Mutants with changes in major 5' splice donor (SD) site located in the R region identified this sequence element as responsible for regulating gag gene expression by an unidentified mechanism. Replacement of the FV 5' SD with heterologous splice sites enabled expression of the gag and pol genes. The incorporation of nonvector RNA into vector particles could be reduced to barely detectable levels with constructs in which the human immunodeficiency virus 5' SD or an unrelated intron sequence was substituted for the FV 5' untranslated region and in which gag expression and pol expression were separated on two different plasmids. By this strategy, efficient vector transfer was achieved with constructs that have minimal genetic overlap.
authors.affiliation: Institut für Virologie und Immunbiologie, Universität Würzburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Heinkelein
authors.forename: Marco
authors.initials: M
authors.lastname: Dressler
authors.forename: Gergely
authors.initials: G
authors.lastname: Jármy
authors.forename: Matthias
authors.initials: M
authors.lastname: Rammling
authors.forename: Horst
authors.initials: H
authors.lastname: Imrich
authors.forename: Jana
authors.initials: J
authors.lastname: Thurow
authors.forename: Dirk
authors.initials: D
authors.lastname: Lindemann
authors.forename: Axel
authors.initials: A
authors.lastname: Rethwilm
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D000818:Animals; D002460:Cell Line; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D015684:Gene Products, pol / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors; D006801:Humans; D010957:Plasmids / Q000235:genetics; D011323:Primates; D012367:RNA, Viral / Q000378:metabolism; D016092:Spumavirus / Q000235:genetics*; D019065:Virus Assembly
chemical_list: D020121:5' Untranslated Regions; D015683:Gene Products, gag; D015684:Gene Products, pol; D012367:RNA, Viral