Generation of a Dual-Target, Safe, Inexpensive Microbicide that Protects Against HIV-1 and HSV-2 Disease

Christina Farr Zuend,John Smit,Marc S Horwitz,John F Nomellini

doi:10.1038/s41598-018-21134-1

Christina Farr Zuend, John Smit + Show 2 more

Open Access

https://doi.org/10.1038/s41598-018-21134-1

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Journal: Scientific Reports	Publication Date: Feb 12, 2018
Citations: 13	License type: open-access

Affiliation: University of British Columbia

Abstract

HSV-2 infection is a significant health problem and a major co-morbidity factor for HIV-1 acquisition, increasing risk of infection 2–4 fold. Condom based prevention strategies for HSV-2 and HIV-1 have not been effective at stopping the HIV-1 pandemic, indicating that alternative prevention strategies need to be investigated. We have previously developed an inexpensive HIV-1 specific microbicide that utilizes the S-layer mediated display capabilities of Caulobacter crescentus, and have shown that recombinant C. crescentus displaying HIV entry blocking proteins are able to provide significant protection from HIV-1 infection in vitro. Here we demonstrate that recombinant C. crescentus are safe for topical application and describe 5 new recombinant C. crescentus that provide protection from HIV-1 infection in vitro. Further, we demonstrate protection from disease following intravaginal infection with HSV-2 in a murine model using C. crescentus expressing the anti-viral lectins Cyanovirin-N and Griffithsin, as well as α-1-antitrypsin and indolicidin. Interestingly, C. crescentus alone significantly reduced HSV-2 replication in vaginal lavage fluid. Protection from HSV-2 disease was strongly associated with early cytokine production in the vaginal tract. Our data support the potential for a dual-target microbicide that can protect against both HIV-1 and HSV-2, which could have an enormous impact on public health.

Highlights

Microbicides that are topically applied to the vaginal tract or rectum are an excellent option for female-controlled prevention of HIV-1 and HSV-2 infection[12]
Protection from HSV-2 disease by Cc-A1AT seems to be mediated by initiation of an early immune response, as this recombinant C. crescentus led to earlier production of IFNγ, TNF and IL-6 when applied at the time of HSV-2 infection, compared to HSV-2 alone
We describe the creation of five new recombinant C. crescentus and demonstrate that these recombinant bacteria are able to provide

Summary

Introduction

Microbicides that are topically applied to the vaginal tract or rectum are an excellent option for female-controlled prevention of HIV-1 and HSV-2 infection[12]. We have previously demonstrated that recombinant C. crescentus displaying MIP1α, CD4, anti-viral lectins and HIV-1 fusion inhibitors are able to provide 22–85% protection from HIV-1 infection in vitro, likely through direct interaction with either the viral envelope (CD4, anti-viral lectins, fusion inhibitors) or co-receptor blocking on the target cell (MIP1α)[20,22]. In this study we tested C. crescentus expressing these recombinant proteins for their ability to provide protection from HIV-1 infection in vitro using the TZM-bl cell line and human peripheral mononuclear blood cells (PBMCs) and HSV-2 infection in a mouse model. While three of the protective recombinant C. crescentus have previously been suggested to prevent HSV-2 infection by blocking cell-to-cell spread (Griffithsin), preventing entry and membrane fusion (Cyanovirin-N), and disrupting the HSV-2 membrane (Indolicidin), α-1-antitrypsin has not previously been reported to have anti-HSV-2 activity. This work describes the continued development of a safe and effective microbicide to prevent infection with both HIV-1 and HSV-2

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Results

Conclusion