AEGiS-11IAC: Virion-targeted viral inactivation against HIV-1 using Vpr chimeric proteins.

11th International AIDS Conference

Vancouver, British Columbia — July 7-12, 1996

Virion-targeted viral inactivation against HIV-1 using Vpr chimeric proteins.

Int Conf AIDS 1996 Jul 7-12; 11:9 (abstract no. We.A.270)
Cohen EA, Nie Z, Mercier J, Bergeron D, Pignac-Kobinger G; Departement de microbiologie et immunologie Universite de Montreal, Montreal, Quebec. Fax: (514) 343-5995. E-mail: cohenea@ere.umontreal.ca.

OBJECTIVE: Virion-targeted viral inactivation represents a novel approach to interfere with viral replication. In this strategy, a deleterious amino acid (a.a.) sequence is fused to a virion-associated component to prevent production of infectious viral particles and subsequent spread of de novo infection. The HIV-1 Vpr gene product, which is packaged into virions, is an attractive candidate for such strategy. The goal of this study was to develop Vpr-based chimeric proteins that could be specifically targeted into mature HIV-1 virion to affect their structural organization and/or functional integrity.

METHODS: Two mini genes encoding Vpr chimeric proteins were cloned into retroviral vectors (pBabepuro). The CAT gene and the last 18 C-terminal a.a. (IE) of the HIV-1 Vpu protein which contain an immunodominant epitope were fused to the first 88 a.a. of HIV-1 Vpr. These retroviral vectors were used to generate CD4+ T cell lines (Jurkat) expressing constitutively or inducibly Vpr chimeric proteins.

RESULTS: Vpr-based chimeric proteins did not interfere with cellular function as evaluated by cell viability and growth. We have challenged the transduced Jurkat cell lines with laboratory strains of HIV-1 (Vpr+ and Vpr-) and assessed their susceptibility to infection by monitoring RT activity in the supernatant and by measuring syncytium formation and cell viability. Results of these experiments indicate that the Jurkat (IE) exhibited at least a 5 to 10 days delay in virus production when infected with HIV-1 Vpr+ or HIV-1 Vpr-. Using the MAGI assay we have shown that HIV virion containing the VprIE chimeric proteins were 10 times less infectious than the wild type virus.

CONCLUSIONS: Incorporation of Vpr chimeric proteins into virions can modify the structural and/or functional integrity of HIV-1 virions, thus, decreasing their infectivity. Virion-targeted viral inactivation using Vpr chimeric proteins represents a novel gene therapy approach against HIV. (Supported by MRC-PMAC and Theratechnologies Inc.)

Keywords: AEGIS, Gene Products, vpr, Virion, HIV-1, HIV Integrase, Virus Replication, HIV Protease, HIV Antibodies, HIV, HIV Core Protein p24, HIV Antigens, Integrase Inhibitors, HIV-1 Reverse Transcriptase, Gene Products, vpu, Giant Cells, Anti-HIV Agents, Chimeric Proteins, HIV Infections, Cell Line, Cats, Animal, virology, ICA11

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