title: Suppression of human immunodeficiency virus type 1 (HIV-1) replication by an HIV-1-dependent double locked vector with the Cre/loxP system.
abstract: We previously demonstrated the function of an HIV-1-dependent ribozyme expression vector, with which the site-specific excision of loxP sequences can be achieved by using the Cre-loxP system (ON/OFF) as a molecular switch in an acute HIV-1 infection. However, this expression system also revealed the lower, non-specific expression of the anti-H1V-1 ribozyme in the absence of tat. To circumvent this problem, we used the more efficient HIV-1-dependent Cre recombinase gene expression vector, encoding the LTR-gag-p17 (extending from the 5'-LTR to the middle of the gag gene (pLTR-gag-p17-Cre)). Comparatively, the pLTR-gag-p17-Cre induces a higher Cre-protein expression level in an HIV-1 infection-dependent manner than the minimal pLTR-Cre. Furthermore, we constructed the ploxP-Rz-U5 and pLTR-gag-p17-Cre plasmids and also combined them into a single vector, pLTR-gag-p17-Cre/loxP-Rz-U5, for a comparison of their anti-HIV-1 activities. The resultant simultaneous expression of the Cre protein and the homologous recombination of the two loxP sequences induced a high level of HIV-1 replication inhibition (95%). Significantly, a high steady-state of ribozyme expression was observed in the RT-PCR analysis. These data imply that targeting the HIV-1 genes with the pLTR-gag-p17-Cre/loxP-Rz-U5 vector, which mediates HIV-1-dependent ribozyme expression, would be a useful tool for HIV-1 gene therapy applications.
authors.affiliation: Department of Life and Environmental Sciences, Chiba Institute of Technoloy, Narashino, Chiba, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Habu
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagawa
authors.forename: Norihiko
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Naoko
authors.initials: N
authors.lastname: Miyano-Kurosaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takaku
mesh_terms: D015870:Gene Expression / Q000235:genetics; D015683:Gene Products, gag / Q000235:genetics*; D015316:Genetic Therapy; D005822:Genetic Vectors; D015658:HIV Infections / Q000235:genetics* / Q000628:therapy; D015497:HIV-1 / Q000235:genetics* / Q000254:growth & development; D006367:HeLa Cells; D006801:Humans; D019426:Integrases / Q000235:genetics*; D016337:RNA, Catalytic / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication / Q000235:genetics*
chemical_list: D015683:Gene Products, gag; D016337:RNA, Catalytic; D014764:Viral Proteins; C045073:Cre recombinase; D019426:Integrases