Impact of a decade of successful antiretroviral therapy initiated at HIV-1 seroconversion on blood and mucosal reservoirs

Persistent reservoirs remain the major obstacles to achieve an HIV-1 cure. Prolonged early antiretroviral therapy (ART) may reduce the extent of reservoirs and allow for virological control after ART discontinuation. We compared HIV-1 reservoirs in a cross-sectional study using polymerase chain reaction-based techniques in blood and tissue of early-treated seroconverters, late-treated patients, ART-naïve seroconverters, and long-term non-progressors (LTNPs) who have spontaneous virological control without treatment. A decade of early ART reduced the total and integrated HIV-1 DNA levels compared with later treatment initiation, but not reaching the low levels found in LTNPs. Total HIV-1 DNA in rectal biopsies did not differ between cohorts. Importantly, lower viral transcription (HIV-1 unspliced RNA) and enhanced immune preservation (CD4/CD8), reminiscent of LTNPs, were found in early compared to late-treated patients. This suggests that early treatment is associated with some immunovirological features of LTNPs that may improve the outcome of future interventions aimed at a functional cure

Evolution of experimental design and research techniques in HIV-1 reservoir studies : a systematic review

Although HIV-1 has evolved from a deadly to a chronic disease over the past 20 years, an HIV-1 cure is still lacking due to the presence of persisting cellular viral reservoirs which are spread throughout the body in different anatomical compartments. Hence, the identification and characterization of these HIV-1 reservoirs were the focus of many studies during the past decades. In this review, a systematic literature screening and text mining approach were implemented to assess the evolution in experimental design of these HIV-1 reservoir studies. For this purpose. the online databases PubMed, Web of Science. and ClinicalTrials.gov were consulted and 1768 articles were identified, of which 106 are included in this review. We observed several evolutions that indicate a more structured approach of recent HIV-1 reservoir studies. This includes the use of well-characterized patient cohorts, tissue sampling at several time points and anatomical compartments, the inclusion of patients with different treatment status (on and off antiretroviral therapy), and the implementation of state-of-the-art research techniques such as single genome sequencing. In addition, there is an increased interest and sampling of lymphoid tissues and cerebrospinal fluid together with methods to investigate cellular subsets and HIV-1 sequences. Overall, this review describes an observed shift from detecting and quantifying HIV-1 toward a qualitative in-depth assessment of anatomical reservoirs and cellular subsets playing a role in H1V-1 persistence/latency. These trends coincide with the evolution in focus from controlling HIV-1 replication by currently available antiretroviral therapy toward HIV-1 curative strategies

Host factors and early treatments to restrict paediatric HIV infection and early disease progression

open6noA body of evidence indicates that a threshold level of the virus is required to establish systemic and persistent HIV infection in the host and that this level depends on virus-host interactions. Mother-to-child transmission (MTCT) of HIV is the main source of paediatric HIV infection and occurs when the host's immune system is still developing. Thus, innate resistance and immunity, rather than adaptive immune response, may be the main drivers in restricting the establishment of HIV reservoirs and the long-lived persistence of HIV infection in infants. Genetic variations in HIV co-receptors and their ligands, as well as in Toll-like receptors and defensins, key elements of innate immunity, have been demonstrated to influence the risk of perinatal HIV infection and disease progression in HIV-infected infants. Early treatments with combined antiretroviral therapy (cART) restrict paediatric infection by reducing the level of the transmitted/infecting virus to below the threshold required for the onset of immune response to the virus and also significantly reduce HIV reservoirs. However, despite long periods with no signs and symptoms of HIV infection, all early cART-treated children who later discontinued cART had a rebound of HIV, except for one case in whom a period of viral remission occurred. Which parameters predict viral remission or viral rebound after cART discontinuation? Could early cART prevent rather than just reduce the establishment of viral reservoirs? And, if so, how? Answers to these questions are also important in order to optimise the use of early cART in infants at high risk of HIV infection.openGianesin, Ketty; Petrara, Raffaella; Freguja, Riccardo; Zanchetta, Marisa; Giaquinto, Carlo; DE ROSSI, AnitaGianesin, Ketty; Petrara, Raffaella; Freguja, Riccardo; Zanchetta, Marisa; Giaquinto, Carlo; DE ROSSI, Anit

Combinations of isoform-targeted histone deacetylase inhibitors and bryostatin analogues display remarkable potency to activate latent HIV without global T-cell activation

AbstractCurrent antiretroviral therapy (ART) for HIV/AIDS slows disease progression by reducing viral loads and increasing CD4 counts. Yet ART is not curative due to the persistence of CD4+ T-cell proviral reservoirs that chronically resupply active virus. Elimination of these reservoirs through the administration of synergistic combinations of latency reversing agents (LRAs), such as histone deacetylase (HDAC) inhibitors and protein kinase C (PKC) modulators, provides a promising strategy to reduce if not eradicate the viral reservoir. Here, we demonstrate that largazole and its analogues are isoform-targeted histone deacetylase inhibitors and potent LRAs. Significantly, these isoform-targeted HDAC inhibitors synergize with PKC modulators, namely bryostatin-1 analogues (bryologs). Implementation of this unprecedented LRA combination induces HIV-1 reactivation to unparalleled levels and avoids global T-cell activation within resting CD4+ T-cells.</jats:p

The Long Noncoding RNA HEAL Regulates HIV-1 Replication through Epigenetic Regulation of the HIV-1 Promoter.

A major challenge in finding a cure for HIV-1/AIDS is the difficulty in identifying and eradicating persistent reservoirs of replication-competent provirus. Long noncoding RNAs (lncRNAs, &gt;200 nucleotides) are increasingly recognized to play important roles in pathophysiology. Here, we report the first genome-wide expression analysis of lncRNAs in HIV-1-infected primary monocyte-derived macrophages (MDMs). We identified an lncRNA, which we named HIV-1-enhanced lncRNA (HEAL), that is upregulated by HIV-1 infection of MDMs, microglia, and T lymphocytes. Peripheral blood mononuclear cells of HIV-1-infected individuals show elevated levels of HEAL Importantly, HEAL is a broad enhancer of multiple HIV-1 strains because depletion of HEAL inhibited X4, R5, and dual-tropic HIV replications and the inhibition was rescued by HEAL overexpression. HEAL forms a complex with the RNA-binding protein FUS, which facilitates HIV replication through at least two mechanisms: (i) HEAL-FUS complex binds the HIV promoter and enhances recruitment of the histone acetyltransferase p300, which positively regulates HIV transcription by increasing histone H3K27 acetylation and P-TEFb enrichment on the HIV promoter, and (ii) HEAL-FUS complex is enriched at the promoter of the cyclin-dependent kinase 2 gene, CDK2, to enhance CDK2 expression. Notably, HEAL knockdown and knockout mediated by RNA interference (RNAi) and CRISPR-Cas9, respectively, prevent HIV-1 recrudescence in T cells and microglia upon cessation of azidothymidine treatment in vitro Our results suggest that silencing of HEAL or perturbation of the HEAL-FUS ribonucleoprotein complex could provide a new epigenetic silencing strategy to eradicate viral reservoirs and effect a cure for HIV-1/AIDS.IMPORTANCE Despite our increased understanding of the functions of lncRNAs, their potential to develop HIV/AIDS cure strategies remains unexplored. A genome-wide analysis of lncRNAs in HIV-1-infected primary monocyte-derived macrophages (MDMs) was performed, and 1,145 differentially expressed lncRNAs were identified. An lncRNA named HIV-1-enhanced lncRNA (HEAL) is upregulated by HIV-1 infection and promotes HIV replication in T cells and macrophages. HEAL forms a complex with the RNA-binding protein FUS to enhance transcriptional coactivator p300 recruitment to the HIV promoter. Furthermore, HEAL knockdown and knockout prevent HIV-1 recrudescence in T cells and microglia upon cessation of azidothymidine treatment, suggesting HEAL as a potential therapeutic target to cure HIV-1/AIDS

Pathogenic Role of Type I Interferons in HIV-Induced Immune Impairments in Humanized Mice

Purpose of Review: Recent findings on the critical pathogenic role of type 1 interferons (IFN-I) in HIV-1 persistence in humanized mice suggest that inhibiting IFN-I signaling transiently will reverse HIV-induced inflammatory diseases and rescue anti-HIV immunity to control HIV-1 reservoirs. Recent Findings: In both humanized mice and in monkeys, IFN-I signaling is functionally defined to play an important role in suppressing early HIV-1 and SIV infection. During persistent infection in humanized mice, however, IFN-I signaling is revealed to induce T cell depletion and impairment. Interestingly, in HIV-infected mice with effective combination antiretroviral therapy (cART), blocking IFN-I signaling reverses HIV-induced inflammation, rescues anti-HIV T cells, and reduces HIV-1 reservoirs. Summary: These findings functionally define the role of IFN-I in HIV-1 reservoir persistence and suggest that blocking IFN-I signaling will provide a novel therapeutic strategy to (i) reverse inflammation-associated diseases in HIV patients under cART, (ii) rescue host anti-HIV immunity, and (iii) reduce or control HIV-1 reservoirs

HIV-1 Latency and Viral Reservoirs: Existing Reversal Approaches and Potential Technologies, Targets, and Pathways Involved in HIV Latency Studies

Eradication of latent human immunodeficiency virus (HIV) infection is a global health challenge. Reactivation of HIV latency and killing of virus-infected cells, the so-called “kick and kill” or “shock and kill” approaches, are a popular strategy for HIV cure. While antiretroviral therapy (ART) halts HIV replication by targeting multiple steps in the HIV life cycle, including viral entry, integration, replication, and production, it cannot get rid of the occult provirus incorporated into the host-cell genome. These latent proviruses are replication-competent and can rebound in cases of ART interruption or cessation. In general, a very small population of cells harbor provirus, serve as reservoirs in ART-controlled HIV subjects, and are capable of expressing little to no HIV RNA or proteins. Beyond the canonical resting memory CD4+ T cells, HIV reservoirs also exist within tissue macrophages, myeloid cells, brain microglial cells, gut epithelial cells, and hematopoi-etic stem cells (HSCs). Despite a lack of active viral production, latently HIV-infected subjects con-tinue to exhibit aberrant cellular signaling and metabolic dysfunction, leading to minor to major cellular and systemic complications or comorbidities. These include genomic DNA damage; telo-mere attrition; mitochondrial dysfunction; premature aging; and lymphocytic, cardiac, renal, he-patic, or pulmonary dysfunctions. Therefore, the arcane machineries involved in HIV latency and its reversal warrant further studies to identify the cryptic mechanisms of HIV reservoir formation and clearance. In this review, we discuss several molecules and signaling pathways, some of which have dual roles in maintaining or reversing HIV latency and reservoirs, and describe some evolving strategies and possible approaches to eliminate viral reservoirs and, ultimately, cure/eradicate HIV infection

Molecular Understanding of HIV-1 Latency

The introduction of highly active antiretroviral therapy (HAART) has been an important breakthrough in the treatment of HIV-1 infection and has also a powerful tool to upset the equilibrium of viral production and HIV-1 pathogenesis. Despite the advent of potent combinations of this therapy, the long-lived HIV-1 reservoirs like cells from monocyte-macrophage lineage and resting memory CD4+ T cells which are established early during primary infection constitute a major obstacle to virus eradication. Further HAART interruption leads to immediate rebound viremia from latent reservoirs. This paper focuses on the essentials of the molecular mechanisms for the establishment of HIV-1 latency with special concern to present and future possible treatment strategies to completely purge and target viral persistence in the reservoirs