Gene Therapy for HIV-1 Using Intracellular Antibodies Against HIV-1 Gag Proteins

ABSTRACT Newcastle disease virus (NDV) avirulent strain LaSota was used to coexpress gp160 Env and p55 Gag from a single vector to enhance both Env-specific and Gag-specific immune responses. The optimal transcription position for both Env and Gag genes in the NDV genome was determined by generating recombinant NDV (rNDV)-Env-Gag (gp160 located between the P and M genes and Gag between the HN and L genes), rNDV-Gag-Env (Gag located between the P and M genes and gp160 between the HN and L genes), rNDV-Env/Gag (gp160 followed by Gag located between the P and M genes), and rNDV-Gag/Env (Gag followed by gp160 located between the P and M genes). All the recombinant viruses replicated at levels similar to those seen with parental NDV in embryonated chicken eggs and in chicken fibroblast cells. Both gp160 and Gag proteins were expressed at high levels in cell culture, with gp160 found to be incorporated into the envelope of NDV. The Gag and Env proteins expressed by all the recombinants except rNDV-Env-Gag self-assembled into human immunodeficiency virus type 1 (HIV-1) virus-like particles (VLPs). Immunization of guinea pigs by the intranasal route with these rNDVs produced long-lasting Env- and Gag-specific humoral immune responses. The Env-specific humoral and mucosal immune responses and Gag-specific humoral immune responses were higher in rNDV-Gag/Env and rNDV-Env/Gag than in the other recombinants. rNDV-Gag/Env and rNDV-Env/Gag were also more efficient in inducing cellular as well as protective immune responses to challenge with vaccinia viruses expressing HIV-1 Env and Gag in mice. These results suggest that vaccination with a single rNDV coexpressing Env and Gag represents a promising strategy to enhance immunogenicity and protective efficacy against HIV. IMPORTANCE A safe and effective vaccine that can induce both systemic and mucosal immune responses is needed to control HIV-1. In this study, we showed that coexpression of Env and Gag proteins of HIV-1 performed using a single Newcastle disease virus (NDV) vector led to the formation of HIV-1 virus-like particles (VLPs). Immunization of guinea pigs with recombinant NDVs (rNDVs) elicited potent long-lasting systemic and mucosal immune responses to HIV. Additionally, the rNDVs were efficient in inducing cellular immune responses to HIV and protective immunity to challenge with vaccinia viruses expressing HIV Env and Gag in mice. These results suggest that the use of a single NDV expressing Env and Gag proteins simultaneously is a novel strategy to develop a safe and effective vaccine against HIV.

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325. Lentiviral Gene Therapy Against HIV-1 Using a Novel TRIM21-Cyclophilin A Fusion Restriction Factor

Molecular Therapy ◽

10.1016/s1525-0016(16)36129-9 ◽

2012 ◽

Vol 20 ◽

pp. S128

Keyword(s):

Gene Therapy ◽

Cyclophilin A ◽

Restriction Factor ◽

Lentiviral Gene Therapy ◽

Hiv 1

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HIV-1 proprotein processing as a target for gene therapy

Gene Therapy ◽

10.1038/sj.gt.3301891 ◽

2003 ◽

Vol 10 (6) ◽

pp. 467-477 ◽

Cited By ~ 21

Author(s):

P Cordelier ◽

M A Zern ◽

D S Strayer

Keyword(s):

Gene Therapy ◽

Proprotein Processing ◽

Hiv 1

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The Retroviral Capsid Domain Dictates Virion Size, Morphology, and Coassembly of Gag into Virus-Like Particles

Journal of Virology ◽

10.1128/jvi.79.21.13463-13472.2005 ◽

2005 ◽

Vol 79 (21) ◽

pp. 13463-13472 ◽

Cited By ~ 69

Author(s):

Danso Ako-Adjei ◽

Marc C. Johnson ◽

Volker M. Vogt

Keyword(s):

Nuclear Export ◽

Leukemia Virus ◽

Particle Diameter ◽

Particle Morphology ◽

Structural Protein ◽

Wild Type ◽

Virus Like Particles ◽

Gag Proteins ◽

Hiv 1

ABSTRACT The retroviral structural protein, Gag, is capable of independently assembling into virus-like particles (VLPs) in living cells and in vitro. Immature VLPs of human immunodeficiency virus type 1 (HIV-1) and of Rous sarcoma virus (RSV) are morphologically distinct when viewed by transmission electron microscopy (TEM). To better understand the nature of the Gag-Gag interactions leading to these distinctions, we constructed vectors encoding several RSV/HIV-1 chimeric Gag proteins for expression in either insect cells or vertebrate cells. We used TEM, confocal fluorescence microscopy, and a novel correlative scanning EM (SEM)-confocal microscopy technique to study the assembly properties of these proteins. Most chimeric proteins assembled into regular VLPs, with the capsid (CA) domain being the primary determinant of overall particle diameter and morphology. The presence of domains between matrix and CA also influenced particle morphology by increasing the spacing between the inner electron-dense ring and the VLP membrane. Fluorescently tagged versions of wild-type RSV, HIV-1, or murine leukemia virus Gag did not colocalize in cells. However, wild-type Gag proteins colocalized extensively with chimeric Gag proteins bearing the same CA domain, implying that Gag interactions are mediated by CA. A dramatic example of this phenomenon was provided by a nuclear export-deficient chimera of RSV Gag carrying the HIV-1 CA domain, which by itself localized to the nucleus but relocalized to the cytoplasm in the presence of wild type HIV-1 Gag. Wild-type and chimeric Gag proteins were capable of coassembly into a single VLP as viewed by correlative fluorescence SEM if, and only if, the CA domain was derived from the same virus. These results imply that the primary selectivity of Gag-Gag interactions is determined by the CA domain.

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