Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules

Jing Wen,Yunfeng Lu,Jie Li,Yang Liu,Irvin S Y Chen,Ming Yan,Yiming Xie,Masakazu Kamata,Derya Unutmaz

doi:10.1371/journal.pone.0151572

Abstract

Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This “shock” approach is then followed by “kill” of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells.

Highlights

Through the use of highly effective anti-retroviral drugs, acquired immune deficiency syndrome (AIDS) has become a manageable chronic disease for many patients [1,2]
Nanocapsules bearing ricin A with nanometer size and positive surface charge Ricin A is the A chain of the ricin toxin, which and irreversibly hydrolyses the Nglycosidic bond of the adenine residue at position 4324 within the rRNA, which is important in binding elongation factors during protein synthesis [37,38]
We engineered a ricin A nanocapsule delivery system designed to release its cargo only within HIV-1 activated cells. This is achieved by encapsulating each ricin A molecule within a polymer shell to form nanocapsules, whose peptide crosslinkers were designed to be cleavable by HIV-1 protease (HIV-PR) [44], an aspartic protease responsible for cleavage of viral gag-pol precursor protein [45]

Summary

Introduction

Through the use of highly effective anti-retroviral drugs, acquired immune deficiency syndrome (AIDS) has become a manageable chronic disease for many patients [1,2]. Latent HIV-1 reservoirs are still present in a small fraction of infected cells, memory T-cells and possibly other cell types [3,4,5]. These reservoirs sustain as silent integrated provirus [6], which can be activated through natural processes or through administration of drugs such as histone. Elimination of Latently HIV-1 Infected Cells by Toxin Nanocapsules

Methods

Results

Conclusion