The latent HIV-1 reservoir represents a major barrier to curing patients with HIV-1 infection, and now in vivo evidence is presented that vorinostat can disrupt proviral latency of HIV-1. A major barrier to achieving a cure in patients infected with HIV-1 is the ability of the HIV genome to integrate into the DNA of resting CD4+ T cells and adopt a state of latency, evading both immune detection and pharmaceutical attack. It was shown previously that induction of virus gene expression in latently HIV-1-infected cells can be achieved in vitro with histone deacetylase inhibitors such as vorinostat, a drug used to treat cutaneous lymphoma. In this study, the authors report the first in vivo evidence that vorinostat can disrupt proviral latency of HIV-1. Vorinostat has some toxic effects that would need to be considered when assessing the risks and benefits of attempts to eradicate HIV infection using this or similar drugs. Despite antiretroviral therapy, proviral latency of human immunodeficiency virus type 1 (HIV-1) remains a principal obstacle to curing the infection1. Inducing the expression of latent genomes within resting CD4+ T cells is the primary strategy to clear this reservoir2,3. Although histone deacetylase inhibitors such as suberoylanilide hydroxamic acid (also known as vorinostat, VOR) can disrupt HIV-1 latency in vitro4,5,6, the utility of this approach has never been directly proven in a translational clinical study of HIV-infected patients. Here we isolated the circulating resting CD4+ T cells of patients in whom viraemia was fully suppressed by antiretroviral therapy, and directly studied the effect of VOR on this latent reservoir. In each of eight patients, a single dose of VOR increased both biomarkers of cellular acetylation, and simultaneously induced an increase in HIV RNA expression in resting CD4+ cells (mean increase, 4.8-fold). This demonstrates that a molecular mechanism known to enforce HIV latency can be therapeutically targeted in humans, provides proof-of-concept for histone deacetylase inhibitors as a therapeutic class, and defines a precise approach to test novel strategies to attack and eradicate latent HIV infection directly.

Changing with the times: Pandemic spread of a virus in naïe populations can select for mutations that alter pathogenesis, virulence, and/or transmissibility. The ancestral form of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged from China has now been largely replaced by strains containing the mutation D614G (Asp ⁶¹⁴ -to-Gly) in the viral spike protein. Hou et al. compared the characteristics of the new variant against the ancestral form in a series of experiments in human cells and animal models. The variant is better at infecting upper-airway epithelial cells and replicates in greater numbers than the ancestral virus. Evidence indicates modest, if any, significant changes to virulence in animal models. Therefore, the virus appears to have evolved for greater transmissibility in humans rather than for greater pathogenicity. The mutation renders the new virus variant more susceptible to neutralizing antisera without altering the efficacy of vaccine candidates currently under development. Science , this issue p. 1464

The serum level of RBD-binding antibodies correlates with SARS-CoV-2 neutralization and can be used for population-level surveillance.

Although combination therapy for HIV infection represents a triumph for modern medicine, chronic suppressive therapy is required to contain persistent infection in reservoirs such as latently infected CD4 ⁺ lymphocytes and cells of the macrophage-monocyte lineage. Despite its success, chronic suppressive therapy is limited by its cost, the requirement of lifelong adherence, and the unknown effects of long-term treatment. This review discusses our current understanding of suppressive antiretroviral therapy, the latent viral reservoir, and the needs for and challenges of attacking this reservoir to achieve a cure.

The International AIDS Society Towards a Cure Working Group lays out its scientific strategy to achieve a cure for HIV. Antiretroviral therapy is not curative. Given the challenges in providing lifelong therapy to a global population of more than 35 million people living with HIV, there is intense interest in developing a cure for HIV infection. The International AIDS Society convened a group of international experts to develop a scientific strategy for research towards an HIV cure. This Perspective summarizes the group's strategy.