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HIV-1 proprotein processing as a target for gene therapy
P Cordelier1, M A Zern, D S Strayer
1Department of Pathology, Jefferson Medical College, Philadelphia, PA 19107, USA.
Gene Therapy
|March 7, 2003
Summary
Alpha-1 antitrypsin delivered via SV(AT) vector inhibits HIV-1 replication by blocking proprotein maturation. This gene therapy approach shows promise for controlling HIV by targeting viral processing pathways.
Area of Science:
- Molecular Biology
- Virology
- Gene Therapy
Background:
- HIV-1 protease (HIV-1 PR) and endoconvertases are crucial for processing HIV proproteins.
- Inhibiting these enzymes is a key strategy for anti-HIV gene therapy.
- Alpha-1 antitrypsin (alpha(1)AT) is a native protease inhibitor.
Purpose of the Study:
- To evaluate alpha(1) antitrypsin (alpha(1)AT) delivered by a recombinant simian virus-40-based vector (SV(AT)) as an inhibitor of HIV-1 proprotein maturation.
- To assess the efficacy of SV(AT)-mediated alpha(1)AT delivery in preventing HIV-1 replication and cytopathic effects.
Main Methods:
- Transduction of cell lines and primary human lymphocytes with SV(AT) vector.
- Confirmation of alpha(1)AT expression using Northern blotting, immunoprecipitation, and immunostaining.
- Challenging transduced cells with HIV-1(NL4-3) and measuring viral load (p24 assay), protein processing (Western blot), and virion integrity.
Main Results:
- SV(AT) transduction showed no detectable toxicity.
- SV(AT)-transduced cells were protected from HIV-1(NL4-3) infection, with significantly reduced viral loads.
- Delivered alpha(1)AT inhibited the processing of gp160 to gp120 and p55(Gag), leading to uncleaved Gag proteins in virions.
Conclusions:
- Delivery of alpha(1)AT using the SV(AT) vector effectively inhibits HIV-1 replication in human lymphocytes.
- The mechanism involves inhibiting both cellular serine proteases and HIV-1 PR, blocking essential viral protein maturation.
- SV(AT)-mediated alpha(1)AT delivery represents a novel gene therapy strategy targeting an previously inaccessible stage of the HIV replicative cycle.