Maximising the global health impact of future HIV cure-related interventions through advance planning

Ethics of HIV and hepatitis B cure research

PURPOSE OF REVIEW

Achieving a cure for HIV or hepatitis B virus (HBV) is expected to have a range of salutary effects including eliminating the need for continued treatments, minimizing risk to sexual and injecting partners, reducing prevalence, and decreasing stigma. Nevertheless, conducting research to achieve such laudable goals is necessarily associated with a broad set of ethical challenges. This review aims at describing key findings from selected peer-reviewed literature published in the last 2 years (2018-2019) that enhance understanding of some of these issues.

RECENT FINDINGS

A variety of ethical issues in HIV cure research have been informed by recent conceptual and empirical scholarship. These include: analytical treatment interruptions; attitudes towards participation; responsibilities to nonparticipants; consent and terminology; and selected other issues.

SUMMARY

Understanding of the ethical issues in HIV cure research has been enhanced by sustained normative and empirical scholarship with a range of stakeholders. This work has crucial implications for HBV cure research, but there is also a pressing need for directed work on HBV cure research. In both HIV and HBV cure research, such scholarship promises to help ensure that critically important research efforts are ethically sound.

Activation of Latent HIV-1 T Cell Reservoirs with a Combination of Innate Immune and Epigenetic Regulators

The presence of T cell reservoirs in which human immunodeficiency virus (HIV) establishes latency by integrating into the host genome represents a major obstacle to an HIV cure and has prompted the development of strategies aimed at the eradication of HIV from latently infected cells. The "shock-and-kill" strategy is one of the most pursued approaches to the elimination of viral reservoirs. Although several latency-reversing agents (LRAs) have shown promising reactivation activity, they have failed to eliminate the cellular reservoir. In this study, we evaluated a novel immune system-mediated approach to clearing the HIV reservoir, based on a combination of innate immune stimulation and epigenetic reprogramming. The combination of the STING agonist cGAMP (cyclic GMP-AMP) and the FDA-approved histone deacetylase inhibitor resminostat resulted in a significant increase in HIV proviral reactivation and specific apoptosis in HIV-infected cells in vitro Reductions in the proportion of HIV-harboring cells and the total amount of HIV DNA were also observed in CD4+ central memory T (TCM) cells, a primary cell model of latency, where resminostat alone or together with cGAMP induced high levels of selective cell death. Finally, high levels of cell-associated HIV RNA were detected ex vivo in peripheral blood mononuclear cells (PBMCs) and CD4+ T cells from individuals on suppressive antiretroviral therapy (ART). Although synergism was not detected in PBMCs with the combination, viral RNA expression was significantly increased in CD4+ T cells. Collectively, these results represent a promising step toward HIV eradication by demonstrating the potential of innate immune activation and epigenetic modulation for reducing the viral reservoir and inducing specific death of HIV-infected cells.IMPORTANCE One of the challenges associated with HIV-1 infection is that despite antiretroviral therapies that reduce HIV-1 loads to undetectable levels, proviral DNA remains dormant in a subpopulation of T lymphocytes. Numerous strategies to clear residual virus by reactivating latent virus and eliminating the reservoir of HIV-1 (so-called "shock-and-kill" strategies) have been proposed. In the present study, we use a combination of small molecules that activate the cGAS-STING antiviral innate immune response (the di-cyclic nucleotide cGAMP) and epigenetic modulators (histone deacetylase inhibitors) that induce reactivation and HIV-infected T cell killing in cell lines, primary T lymphocytes, and patient samples. These studies represent a novel strategy for HIV eradication by reducing the viral reservoir and inducing specific death of HIV-infected cells.