Anti-gp120 minibody gene transfer to female genital epithelial cells protects against HIV-1 virus challenge in vitro.

Ussama M Abdel-Motal,Quan Zhu,Thomas Han,Jeffery Pudney,Wayne A Marasco,Deborah J Anderson,Phuong T N Sarkis,Luwen Zhang

doi:10.1371/journal.pone.0026473

Ussama M Abdel-Motal, Quan Zhu + Show 6 more

Open Access

https://doi.org/10.1371/journal.pone.0026473

Copy DOI

Abstract

BackgroundAlthough cervico-vaginal epithelial cells of the female lower genital tract provide the initial defense system against HIV-1 infection, the protection is sometimes incomplete. Thus, enhancing anti-HIV-1 humoral immunity at the mucosal cell surface by local expression of anti-HIV-1 broadly neutralizing antibodies (BnAb) that block HIV-1 entry would provide an important new intervention that could slow the spread of HIV/AIDS.Methods and FindingsThis study tested the hypothesis that adeno-associated virus (AAV)-BnAb gene transfer to cervico-vaginal epithelial cells will lead to protection against HIV-1. Accordingly, a recombinant AAV vector that encodes human b12 anti-HIV gp120 BnAb as a single-chain variable fragment Fc fusion (scFvFc), or “minibody” was constructed. The secreted b12 minibody was shown to be biologically functional in binding to virus envelope protein, neutralizing HIV-1 and importantly, blocking transfer and infectivity of HIV-1bal in an organotypic human vaginal epithelial cell (VEC) model. Furthermore, cervico-vaginal epithelial stem cells were found to be efficiently transduced by the optimal AAV serotype mediated expression of GFP.ConclusionThis study provides the foundation for a novel microbicide strategy to protect against sexual transmission of HIV-1 by AAV transfer of broadly neutralizing antibody genes to cervico-vaginal epithelial stem cells that could replenish b12 BnAb secreting cells through multiple menstrual cycles.

Highlights

The mechanisms of HIV-1 transmission through the vaginal route in women are still poorly understood
This study provides the foundation for a novel microbicide strategy to protect against sexual transmission of HIV-1 by associated virus (AAV) transfer of broadly neutralizing antibody genes to cervico-vaginal epithelial stem cells that could replenish b12 broadly neutralizing antibodies (BnAb) secreting cells through multiple menstrual cycles
The findings of this study demonstrate that use of the AAV vector to express neutralizing human anti-gp120 minibodies is a promising strategy for developing an effective durable microbicide against HIV-1 infection

Summary

Introduction

The mechanisms of HIV-1 transmission through the vaginal route in women are still poorly understood. Epithelial cells lining the mucosal surfaces of the female genital tract provide the first line of defense against sexually transmitted pathogens such as HIV-1 [1,2]. The multilayer squamous cell epithelia lining the vagina and ectocervix provide a more substantial barrier against HIV-1 invasion than the single layer columnar epithelium that lines the endocervix [3]. Syndecans (expressed on the vaginal epithelial cells), for example, were found to be exploited by HIV-1 to cross the mucosal epithelium by transcytosis [7,8,9,10]. Cervico-vaginal epithelial cells of the female lower genital tract provide the initial defense system against HIV-1 infection, the protection is sometimes incomplete. Enhancing anti-HIV-1 humoral immunity at the mucosal cell surface by local expression of anti-HIV-1 broadly neutralizing antibodies (BnAb) that block HIV-1 entry would provide an important new intervention that could slow the spread of HIV/AIDS

Methods

Results

Discussion

Conclusion