Persistent HIV-1 replication during antiretroviral therapy

Altres ajuts: We appreciate the help of M.C. Puertas with graphics. Work in JMP group is supported by the Spanish Secretariat of Research (grant SAF2013-49042-R), the Spanish AIDS network 'Red Temática Cooperativa de Investigación en SIDA'(RD12/0017), the American Foundation for AIDS Research (amfAR), the FP7-HEALTH-2013-INNOVATION-1 through the iHIVARNA project, and the Agence Nationale de recherches sur la SIDA et les he'patites virales (ANRS).The present review will highlight some of the recent findings regarding the capacity of HIV-1 to replicate during antiretroviral therapy (ART). Although ART is highly effective at inhibiting HIV replication, it is not curative. Several mechanisms contribute to HIV persistence during ART, including HIV latency, immune dysfunction, and perhaps persistent low-level spread of the virus to uninfected cells (replication). The success in curing HIV will depend on efficiently targeting these three aspects. The degree to which HIV replicates during ART remains controversial. Most studies have failed to find any evidence of HIV evolution in blood, even with samples collected over many years, although a recent very intensive study of three individuals suggested that the virus population does shift, at least during the first few months of therapy. Stronger but still not definitive evidence for replication comes from a series of studies in which standard regimens were intensified with an integration inhibitor, resulting in changes in episomal DNA (blood) and cell-associated RNA (tissue). Limited drug penetration within tissues and the presence of immune sanctuaries have been argued as potential mechanisms allowing HIV to spread during ART. Mathematical models suggest that HIV replication and evolution is possible even without the selection of fully drug-resistant variants. As persistent HIV replication could have clinical consequences and might limit the efficacy of curative interventions, determining if HIV replicates during ART and why, should remain a key focus of the HIV research community. Residual viral replication likely persists in lymphoid tissues, at least in a subset of individuals. Abnormal levels of immune activation might contribute to sustain virus replication

Highlights from the Inaugural HIV Reservoirs and Immune Control Conference, October 1st–4th 2023, Malahide Ireland

The inaugural FASEB HIV Reservoirs and Immune Control Conference brought researchers together from across the globe to discuss reservoir dynamics in clinical cohorts. It extended over 4 days in the seaside town of Malahide, Ireland. The scientific sessions covered a broad range of topics, including: 1) HIV pathogenesis and control, 2) reservoirs and viral expression, 3) pediatric reservoirs, 4) innate immunity and B cell responses, 5) environmental factors affecting pathogenesis, 6) loss of virologic control, and 7) HIV-2. The following article provides a brief summary of the meeting proceedings and includes a supplementary document with the meeting abstracts.

Atlas of the HIV-1 Reservoir in Peripheral CD4 T Cells of Individuals on Successful Antiretroviral Therapy

ADN del VIH-1; Cura del VIH-1; Reservorio de VIH-1HIV-1 DNA; HIV-1 cure; HIV-1 reservoirADN del VIH-1; Cura del VIH-1; Reservori del VIH-1Knowing the mechanisms that govern the persistence of infected CD4+ subpopulations could help us to design new therapies to cure HIV-1 infection. We evaluated the simultaneous distribution of the HIV-1 reservoir in 13 CD4+ subpopulations from 14 HIV-1-infected individuals on antiretroviral therapy to analyze its relationship with HIV-1 transcription, immune activation, and cell proliferation. A unique large blood donation was used to isolate CD4, CD4 resting (CD4r), CD4 activated (CD4a), T naive (TN), T stem cell memory (TSCM), T central memory (TCM), T transitional memory (TTM), T effector memory (TEM), circulating T follicular helper (cTFH), TCD20, TCD32, and resting memory TCD2high (rmTCD2high) cells. HIV-1 DNA measured by droplet digital PCR ranged from 3,636 copies/106 in TTM to 244 in peripheral blood mononuclear cells (PBMCs), with no subpopulation standing out for provirus enrichment. Importantly, all the subpopulations harbored intact provirus by intact provirus DNA assay (IPDA). TCD32, cTFH, and TTM had the highest levels of HIV-1 transcription measured by fluorescent in situ hybridization with flow cytometry (FISH/flow), but without reaching statistical differences. The subpopulations more enriched in provirus had a memory phenotype, were less activated (measured by CD38+/HLA-DR+), and expressed more programmed cell death 1 (PD-1). Conversely, subpopulations transcribing more HIV-1 RNA were not necessarily enriched in provirus and were more activated (measured by CD38+/HLA-DR+) and more proliferative (measured by Ki-67). In conclusion, the HIV reservoir is composed of a mosaic of subpopulations contributing to the HIV-1 persistence through different mechanisms such as susceptibility to infection, provirus intactness, or transcriptional status. The narrow range of reservoir differences between the different blood cell subsets tested suggests limited efficacy in targeting only specific cell subpopulations during HIV-1 cure strategies. IMPORTANCE The main barrier for HIV-1 cure is the presence of latently infected CD4+ T cells. Although various cell subpopulations have been identified as major HIV-1 reservoir cells, the relative contribution of infected CD4 subpopulations in the HIV-1 reservoir remains largely unknown. Here, we evaluated the simultaneous distribution of the HIV-1 reservoir in 13 CD4+ T-cell subpopulations in peripheral blood from HIV-1-infected individuals under suppressive antiretroviral therapy. We found that the HIV-1 reservoir is composed of a mosaic of cell subpopulations, with heterogeneous proviral DNA, HIV-1 transcription, and activation status. Hence, each cell subpopulation contributes to the HIV-1 persistence through different mechanisms such as susceptibility to infection, rates of intact provirus, transcriptional status or half-life. This research provides new insights into the composition of the HIV-1 reservoir, suggesting that, to be effective, eradication strategies must simultaneously target multiple cell subpopulations.This work was sponsored in part by Grifols and by Gilead (GLD17/00204). The funding organizations had no input in the design of the study or in the collection, analyses, and interpretation of the data. Similarly, they played no role in the writing of the manuscript or in the decision to submit the study for publication. J.M.-P. is supported by grant PID2019-109870RB-I00 from the Spanish Ministry of Science and Innovation. J.M.-P. and M.J.B. are supported by the RETIC RD16/0025/0041 and RD16/0025/0007 (cofunded by the European Regional Development Fund/European Social Fund). M.J.B. is supported by grant RTI2018-101082-B-I00 (MINECO/FEDER) and by the Miguel Servet program funded by the Spanish Health Institute Carlos III (CP17/00179). C.G. was supported by the Ph.D. fellowship of the Spanish Ministry of Education, Culture, and Sport (FPU15/03698)

Motivations, barriers and experiences of participants in an HIV reservoir trial

Objectives: We aimed to investigate the motives, barriers and experiences of HIV-STAR study participants. The HIV-STAR study was an analytical HIV treatment interruption trial (ATI) aiming to evaluate the origin of viral rebound, conducted in Ghent, Belgium. Methods: A mixed-method study was performed among 11 participants of the HIV-STAR study. Two self-administered questionnaires with 32 and 23 items, respectively, assessed motives, barriers and experiences of the research participants. In-depth interviews were conducted to further explore and understand topics that had emerged from these surveys. Results: Motives of ATI study participants were primarily related to the improvement of their own health perspectives and to their contribution to find an HIV cure. Barriers for ATI participation mostly related to practical issues, such as difficulty in planning study visits. Ten out of 11 participants reported a very high overall satisfaction and were willing to participate in another ATI. This satisfaction was predominantly linked to clear communication and guidance. Invasive sampling during the ATI was less of a burden than anticipated by participants. However, most participants underestimated the emotional impact of HIV treatment interruption, which was associated with feelings of uncertainty and loss of control. Risk of HIV transmission because of viral rebound was also mentioned as burdensome during this phase. Conclusions: Involvement in an ATI was positively evaluated by HIV-STAR participants. Contributing to HIV cure research outweighed the burden of study participation for most participants. The latter aspects were attenuated by mutual decision making and the experience of empathy from the research team. Still, issues regarding privacy and the psychosocial impact of treatment interruption, including sexuality and HIV transmissibility, should be addressed in a better way

Novel Methodology for the Detection of Enveloped Viruses

Presented at Viruses 2020—Novel Concepts in Virology, Barcelona, Spain, 5–7 February 2020 (abstract)Viral infections in humans cause a huge burden in worldwide healthcare that has increased due to the emergence of new pathogenic viruses, such as in the recent Ebola virus (EBOV) outbreaks. Viral particles in body fluids are often at very low levels, making diagnosis difficult. In order to address this problem, we have developed a new detection platform to isolate and detect different enveloped viruses. We have recently identified that sialic acid-binding Ig‑like lectin 1 (Siglec-1/CD169) is one cellular receptor used by EBOV and HIV-1 to enter myeloid cells, key target cells for infection and pathogenesis. For viral uptake, the V-set domain of this myeloid cell receptor recognizes the gangliosides of viral membranes that were dragged during viral budding from the plasma membrane of infected cells. We took advantage of this specific interaction between Siglec‑1 and viral gangliosides to develop a new detection methodology. We have generated a recombinant protein that contains the V-set domain of Siglec-1 fused to the human IgG Fc domain for anchoring in latex beads. These coated beads allow the isolation of viral particles and their measurement by flow cytometry. We have tested its efficacy to detect HIV-1 and EBOV and its specificity by using anti-Siglec‑1 antibodies that prevent the interaction and serve as a negative control. To test the capacity of our method, we used synthetic liposomes to assess the effect of ganglioside concentration in membranes as well as the size of viral particles. This methodology would facilitate the diagnosis of infections by concentrating viral particles in a fast and direct method. At a time when global human mobility facilitates the dissemination of infectious agents, our approach represents a rapid and effective method to maximize the identification of both known and emerging enveloped viruses as part of public health viral surveillance strategies

HIV-1 Capture and Transmission by Dendritic Cells : The Role of Viral Glycolipids and the Cellular Receptor Siglec-1

Altres ajuts: Work in JMP group is supported by the Spanish AIDS network "Red Temática Cooperativa de Investigación en SIDA" (RD06/0006)Dendritic cells (DCs) are essential in order to combat invading viruses and trigger antiviral responses. Paradoxically, in the case of HIV-1, DCs might contribute to viral pathogenesis through trans -infection, a mechanism that promotes viral capture and transmission to target cells, especially after DC maturation. In this review, we highlight recent evidence identifying sialyllactose-containing gangliosides in the viral membrane and the cellular lectin Siglec-1 as critical determinants for HIV-1 capture and storage by mature DCs and for DC-mediated trans -infection of T cells. In contrast, DC-SIGN, long considered to be the main receptor for DC capture of HIV-1, plays a minor role in mature DC-mediated HIV-1 capture and trans -infection

Role of Human Organic Cation Transporter 1 (hOCT1) Polymorphisms in Lamivudine (3TC) Uptake and Drug-Drug Interactions

Lamivudine (3TC), a drug used in the treatment of HIV infection, needs to cross the plasma membrane to exert its therapeutic action. Human Organic cation transporter 1 (hOCT1), encoded by the SLC22A1 gene, is the transporter responsible for its uptake into target cells. As SLC22A1 is a highly polymorphic gene, the aim of this study was to determine how SNPs in the OCT1-encoding gene affected 3TC internalization and its interaction with other co-administered drugs. HEK293 cells stably transfected with either the wild type form or the polymorphic variants of hOCT1 were used to perform kinetic and drug-drug interaction studies. Protein co-immunoprecipitation was used to assess the impact of selected polymorphic cysteines on the oligomerization of the transporter. Results showed that 3TC transport efficiency was reduced in all polymorphic variants tested (R61C, C88R, S189L, M420del, and G465R). This was not caused by lack of oligomerization in case of variants located at the transporter extracellular loop (R61C and C88R). Drug-drug interaction measurements showed that co-administered drugs [abacavir (ABC), zidovudine (AZT), emtricitabine (FTC), tenofovir diproxil fumarate (TDF), efavirenz (EFV) and raltegravir (RAL)], differently inhibited 3TC uptake depending upon the polymorphic variant analyzed. These data highlight the need for accurate analysis of drug transporter polymorphic variants of clinical relevance, because polymorphisms can impact on substrate (3TC) translocation but even more importantly they can differentially affect drug-drug interactions at the transporter level

Control of HIV-1 Pathogenesis in Viremic Nonprogressors Is Independent of Gag-Specific Cytotoxic T Lymphocyte Responses

Viremic nonprogressors (VNPs) constitute a very scarce group of untreated human immunodeficiency virus type 1 (HIV-1)-infected individuals who maintain stable CD4+ T cell counts despite high levels of HIV-1 replication. The specific factors associated with this atypical control of the HIV infection have been poorly described. Since specific T cell responses seem to be one of the main causes of HIV-1 control in elite controllers, we studied whether HIV-1 Gag-specific cytotoxic T lymphocyte (CTL) responses could also modulate disease control in VNPs. We characterized the immune responses from four VNPs compared to those of five standard progressors (SPs) during the first years of HIV-1 infection. We observed no differences in the breadth and frequency of Gag-specific cellular responses. Furthermore, we obtained 217 HIV-1Gag clonal sequences in which the viral variability of Gag increased over 3 years of infection for synonymous and nonsynonymous mutations in both VNPs and SPs. VNPs evolution rates in gag were comparable to SPs. This observation is in line with a similar accumulation of CTL putative escape mutations in Gag epitopes targeted by CTL responses. Altogether, the absence of viral pathogenesis in VNP individuals seems to be independent of HIV-Gag-specific CTL responses. This novel information guides to the study of alternative mechanism of HIV-1 pathogenesis control.IMPORTANCE Control of HIV infection has been widely studied in elite controllers or long-term nonprogressor models. However, there is a less-known group of individuals, termed viremic nonprogressors (VNPs), who maintain stable CD4+ T cell counts despite high plasma viremia. The mechanisms involved in this remarkable control of HIV-1 pathogenesis clearly have implications for the development of new drugs and vaccines. We show here for the first time that VNPs have immune responses and HIV-gag evolution similar to those of standard progressors. Remarkably, we demonstrate that the mechanism of pathogenesis control in these individuals differs from some elite controllers that are reported to have improved immune control. This is noteworthy since it opens the door to new, as-yet-unknown mechanisms for HIV control. Our novel results advance the understanding of mechanisms involved in viremic nonprogression and suggest that there are alternative mechanisms to the adaptive immune responses for an effective control of viral pathogenesis.We thank the founders for support of this project. We also thank all the centers and investigators involved in CoRIS. M.S. was supported by a Sara Borrell grant (CD11/00286). The RIS cohort (CoRIS) is supported by the Instituto de Salud Carlos III through the Red Temática de Investigación Cooperativa en Sida (RD06/006 RD12/0017/0018, RD16/0025/0041) as part of the Plan Nacional R+D+I and cofinanced by ISCIII-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER). This study was supported by the National Health Institute Carlos III (PI14/01058) and the Gilead Fellowship Program GLD 15/00298. J.G.P. holds a Miguel Servet II contract (CPII15/00014) funded by ISCIII. E.J.-M. is supported by Redes Temáticas de Investigación en SIDA (ISCIII RETIC RD16/0025/0041); Acción Estratégica en Salud; Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008-2011; and Instituto de Salud Carlos III, Fondos FEDER. M.S., A.G.-M., and E.J.-M. performed the experiments. J.D., P.V., and B.A. selected and designed the cohorts. M.S., B.C., J.G.P., and J.M.-P. designed the experiments and drafted the paper. P.V. and B.A. are members of CoRISpe and the HIV HGM BioBank Study Group.S

Understanding the neurological implications of acute and long COVID using brain organoids

As early as in the acute phase of the coronavirus disease 2019 about the long-term implications of infection. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), like many other viruses, can trigger chronic disorders that last months or even years. Long COVID, the chronic and persistent disorder lasting more than 12 weeks after the primary infection with SARS-CoV-2, involves a variable number of neurological manifestations, ranging from mild to severe and even fatal. In vitro and in vivo modeling suggest that SARS-CoV-2 infection drives changes within neurons, glia and the brain vasculature. In this Review, we summarize the current understanding of the neuropathology of acute and long COVID, with particular emphasis on the knowledge derived from brain organoid models. We highlight the advantages and main limitations of brain organoids, leveraging their humanoerived origin, their similarity in cellular and tissue architecture to human tissues, and their potential to decipher the pathophysiology of long COVID