title: A mutant Tat protein provides strong protection from HIV-1 infection in human CD4+ T cells.
abstract: Here we show potent inhibition of HIV-1 replication in a human T cell line and primary human CD4(+) cells by expressing a single antiviral protein. Nullbasic is a mutant form of the HIV-1 Tat protein that was previously shown to strongly inhibit HIV-1 replication in nonhematopoietic cell lines by targeting three steps of HIV-1 replication: reverse transcription, transport of viral mRNA, and trans-activation of HIV-1 gene expression. Here we investigated gene delivery of Nullbasic, using lentiviral and retroviral vectors. Although Nullbasic could be delivered by lentiviral vectors to target cells, transduction efficiencies were sharply reduced primarily because of negative effects on reverse transcription mediated by Nullbasic. However, Nullbasic did not inhibit transduction of HEK293T cells by a murine leukemia virus (MLV)-based retroviral vector. Therefore, MLV-based virus-like particles were used to transduce and express Nullbasic-EGFP or EGFP in Jurkat cells, a human leukemia T cell line, and Nullbasic-ZsGreen1 or ZsGreen1 in primary human CD4(+) cells. HIV-1 replication kinetics were similar in parental Jurkat and Jurkat-EGFP cells, but were strongly attenuated in Jurkat-Nullbasic-EGFP cells. Similarly, virus replication in primary CD4(+) cells expressing a Nullbasic-ZsGreen1 fusion protein was inhibited by approximately 8- to 10-fold. These experiments demonstrate the potential of Nullbasic, which has unique inhibitory activity, as an antiviral agent against HIV-1 infection.
authors.affiliation: Queensland Institute of Medical Research, Molecular Virology Laboratory, Herston, Brisbane, Queensland 4006, Australia .
authors.forename: Ann
authors.initials: A
authors.lastname: Apolloni
authors.forename: Min-Husan
authors.initials: MH
authors.lastname: Lin
authors.forename: Haran
authors.initials: H
authors.lastname: Sivakumaran
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Li
authors.forename: Michael H R
authors.initials: MH
authors.lastname: Kershaw
authors.forename: David
authors.initials: D
authors.lastname: Harrich
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D002460:Cell Line; D023061:Gene Order; D005822:Genetic Vectors / Q000235:genetics; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D019169:Jurkat Cells; D016086:Lentivirus / Q000235:genetics; D009052:Leukemia Virus, Murine / Q000235:genetics; D009154:Mutation; D048348:Reverse Transcription; D014161:Transduction, Genetic; D014771:Virion; D014779:Virus Replication; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics*
chemical_list: D054322:tat Gene Products, Human Immunodeficiency Virus