CD32a is a marker of a CD4 T-cell HIV reservoir harbouring replication-competent proviruses.

The persistence of the HIV reservoir in infected individuals is a major obstacle to the development of a cure for HIV. Here, using an in vitro model of HIV-infected quiescent CD4 T cells, we reveal a gene expression signature of 103 upregulated genes that are specific for latently infected cells, including genes for 16 transmembrane proteins. In vitro screening for surface expression in HIV-infected quiescent CD4 T cells shows that the low-affinity receptor for the immunoglobulin G Fc fragment, CD32a, is the most highly induced, with no detectable expression in bystander cells. Notably, productive HIV-1 infection of T-cell-receptor-stimulated CD4 T cells is not associated with CD32a expression, suggesting that a quiescence-dependent mechanism is required for its induction. Using blood samples from HIV-1-positive participants receiving suppressive antiretroviral therapy, we identify a subpopulation of 0.012% of CD4 T cells that express CD32a and host up to three copies of HIV DNA per cell. This CD32a+ reservoir was highly enriched in inducible replication-competent proviruses and can be predominant in some participants. Our discovery that CD32a+ lymphocytes represent the elusive HIV-1 reservoir may lead to insights that will facilitate the specific targeting and elimination of this reservoir.

Corrigendum: CD32a is a marker of a CD4 T-cell HIV reservoir harbouring replication-competent proviruses.

This corrects the article DOI: 10.1038/nature21710.

The two human CXCR4 isoforms display different HIV receptor activities: consequences for the emergence of X4 strains.

CXCR4 is a chemokine receptor that plays key roles with its specific ligand, CXCL12, in stem cell homing and immune trafficking. It is also used as a coreceptor by some HIV-1 strains (X4 strains), whereas other strains (R5 strains) use an alternative coreceptor, CCR5. X4 strains mainly emerge at late stages of the infection and are linked to disease progression. Two isoforms of this coreceptor have been described in humans: CXCR4-A and CXCR4-B, corresponding to an unspliced and a spliced mRNA, respectively. In this study, we show that CXCR4-B, but not CXCR4-A, mediates an efficient HIV-1 X4 entry and productive infection. Yet, the chemotactic activity of CXCL12 on both isoforms was similar. Furthermore, HIV-R5 infection favored CXCR4-B expression over that of CXCR4-A. In vitro infection with an R5 strain increased CXCR4-B/CXCR4-A mRNA ratio in PBMCs, and this ratio correlated with HIV RNA plasma level in R5-infected individuals. In addition, the presence of the CXCR4-B isoform favored R5 to X4 switch more efficiently than did CXCR4-A in vitro. Hence, the predominance of CXCR4-B over CXCR4-A expression in PBMCs was linked to the ability of circulating HIV-1 strains to use CXCR4, as determined by genotyping. These data suggest that R5 to X4 switch could be favored by R5 infection-induced overexpression of CXCR4-B. Finally, we achieved a specific small interfering RNA-mediated knockdown of CXCR4-B. This represents a proof of concept for a possible gene-therapeutic approach aimed at blocking the HIV coreceptor activity of CXCR4 without knocking down its chemotactic activity.

Systematic Review: Strategies for Improving HIV Testing and Detection Rates in European Hospitals.

Undiagnosed HIV infection is a prominent clinical issue throughout Europe that requires the continuous attention of all healthcare professionals and policymakers to prevent missed testing opportunities and late diagnosis. This systematic review aimed to evaluate interventions to increase HIV testing rates and case detection in European hospitals. Out of 4598 articles identified, 29 studies fulfilled the selection criteria. Most of the studies were conducted in single Western European capital cities, and only one study was from Eastern Europe. The main interventions investigated were test-all and indicator-condition-based testing strategies. Overall, the prevalence of undiagnosed HIV was well above 0.1%. The studied interventions increased the HIV testing rate and the case detection rate. The highest prevalence of undiagnosed HIV was found with the indicator-condition-driven testing strategy, whereas the test-all strategy had the most profound impact on the proportion of late diagnoses. Nevertheless, the HIV testing rates and case-finding varied considerably across studies. In conclusion, effective strategies to promote HIV testing in European hospitals are available, but relevant knowledge gaps regarding generalizability and sustainability remain. These gaps require the promotion of adherence to HIV testing guidelines, as well as additional larger studies representing all European regions.

The efficacy and tolerability of latency-reversing agents in reactivating the HIV-1 reservoir in clinical studies: a systematic review.

Introduction: Understanding the clinical potency of latency-reversing agents (LRAs) on the HIV-1 reservoir is useful to deploy future strategies. This systematic review evaluated the effects of LRAs in human intervention studies. Methods: A literature search was performed using medical databases focusing on studies with adults living with HIV-1 receiving LRAs. Eligibility criteria required participants from prospective clinical studies, a studied compound hypothesised as LRA, and reactivation or tolerability assessments. Relevant demographical data, LRA reactivation capacity, reservoir size, and adverse events were extracted. A study quality assessment with analysis of bias was performed by RoB 2 and ROBINS-I tools. The primary endpoints were HIV-1 reservoir reactivation after LRA treatment quantified by cell-associated unspliced HIV-1 RNA, and LRA tolerability defined by adverse events. Secondary outcomes were reservoir size and the effect of LRAs on analytical treatment interruption (ATI) duration. Results: After excluding duplicates, 5182 publications were screened. In total 45 publications fulfilled eligibility criteria including 26 intervention studies and 16 randomised trials. The risk of bias was evaluated as high. Chromatin modulators were the main investigated LRA class in 24 studies. Participants were mostly males (90.1%). Where reported, HIV-1 subtype B was most frequently observed. Reactivation after LRA treatment occurred in 78% of studies and was observed with nearly all chromatin modulators. When measured, reactivation mostly occurred within 24 h after treatment initiation. Combination LRA strategies have been infrequently studied and were without synergistic reactivation. Adverse events, where reported, were mostly low grade, yet occurred frequently. Seven studies had individuals who discontinued LRAs for related adverse events. The reservoir size was assessed by HIV-1 DNA in 80% of studies. A small decrease in reservoir was observed in three studies on immune checkpoint inhibitors and the histone deacetylase inhibitors romidepsin and chidamide. No clear effect of LRAs on ATI duration was observed. Conclusion: This systematic review provides a summary of the reactivation of LRAs used in current clinical trials whilst highlighting the importance of pharmacovigilance. Highly heterogeneous study designs and underrepresentation of relevant patient groups are to be considered when interpreting these results. The observed reactivation did not lead to cure or a significant reduction in the size of the reservoir. Finding more effective LRAs by including well-designed studies are needed to define the required reactivation level to reduce the HIV-1 reservoir.

Anti-spike protein to determine SARS-CoV-2 antibody levels: Is there a specific threshold conferring protection in immunocompromised patients?

BACKGROUND: Identifying a specific threshold level of SARS-CoV-2 antibodies that confers protection in immunocompromised patients has been very challenging. The aim was to assess the threshold of 264 binding antibody units (BAU)/ml using four different SARS-CoV-2 antibody assays (Abbott, Beckman, Roche, and Siemens) and to establish a new optimal threshold of protection for each of the four antibody assays. METHODS: This study was performed on data retrieved from 69 individuals, who received at least one dose of the Pfizer/BioNTech BNT162b2 or Moderna COVID-19 vaccine (Spikevax) at the Alphabio Laboratory in Marseille, France (European Hospital, Alphabio-Biogroup). The results were compared to the percent inhibition calculated using a functional surrogate of a standardized virus neutralization test (Genscript). RESULTS: Samples from 69 patients were analyzed. For a reference cutoff of 264 BAU/ml, assays showed moderate to good overall concordance with Genscript: 87% concordance for Abbott, 78% for Beckman, 75% for Roche, and 88% for Siemens. Overall concordance increased consistently after applying new thresholds, i.e., 148 BAU/ml (Abbott), 48 (Beckman), 559 (Roche), and 270 (Siemens). CONCLUSION: We suggest specific adjusted thresholds (BAU/ml) for the four commercial antibody assays that are used to assess pre-exposure prophylaxis in immunocompromised patients.

A cohort analysis of sexually transmitted infections among different groups of men who have sex with men in the early era of HIV pre-exposure prophylaxis in France.

BACKGROUND: MSM are at particular risk of STIs due to sexual behavior and substance use. HIV PrEP use may increase this risk. DESIGN: Our aim was to comparatively assess incident STIs among different at-risk groups-PLWHIV, HIV-negative PrEP and no-PrEP users-seen at our center early after PrEP implementation. METHODS: Clinical data were retrospectively collected on 636 MSM seen at the Infectious Diseases Department between September 2016 and October 2018. STI incidence rate was assessed among groups for the whole period, as well as separately for each year of the study. RESULTS: Overall STI incidence rate ratio was higher in HIV-neg when compared to PLWHIV. In multivariate analysis, STI risk was significantly higher among HIV-neg no-PrEP users compared to PLWHIV, while not different between PLWHIV and PrEP users.STI incidence globally increased during the first 2 years after PrEP approval among PLWHIV and no-PrEP users, stated by odds ratio (OR = 1.77 [1.23-2.55], p = 0.0020 and OR = 2.29 [0.91-5.73], p = 0.0774 respectively) while it remained rather stable for HIV-neg PrEP users (OR = 1.19 [0.60-2.38], p = 0.6181). The HIV-neg no-PrEP group remained at higher risk of STI than PLWHIV and PrEP users during the two periods. CONCLUSION: These results suggest that a proactive approach of an efficient follow-up of MSM participants since PrEP approval may have prevented an increase of the incidence of STIs among PrEP users.

Polypharmacy Is Associated With Falls in Women With and Without HIV.

BACKGROUND: Aging in people with HIV is associated with increased risk of developing synergistic conditions such as neurocognitive impairment, polypharmacy, and falls. We assessed associations between polypharmacy (use of 5 or more non-ART medications), use of neurocognitive adverse effects (NCAE) medications, and odds of falls in women with HIV (WWH) and without HIV (HIV-). METHODS: Self-reported falls and medication use data were contributed semiannually by 1872 (1315 WWH and 557 HIV-) Women's Interagency HIV Study participants between 2014 and 2016. Polypharmacy and NCAE medication use were evaluated separately and jointly in multivariable models to assess their independent contributions to single and multiple falls risk. RESULTS: The proportion of women who reported any fall was similar by HIV status (19%). WWH reported both greater polypharmacy (51% vs. 41%; P < 0.001) and NCAE medication use (44% vs. 37%; P = 0.01) than HIV- women. Polypharmacy conferred elevated odds of single fall [adjusted odds ratio (aOR) 1.67, 95% CI: 1.36 to 2.06; P < 0.001] and multiple falls (aOR 2.31, 95% CI: 1.83 to 2.93; P < 0.001); the results for NCAE medications and falls were similar. Both polypharmacy and number of NCAE medications remained strongly and independently associated with falls in multivariable models adjusted for HIV serostatus, study site, sociodemographics, clinical characteristics, and substance use. CONCLUSIONS: Polypharmacy and NCAE medication use were greater among WWH compared with HIV-, and both were independently and incrementally related to falls. Deprescribing and avoidance of medications with NCAEs may be an important consideration for reducing fall risk among WWH and sociodemographically similar women without HIV.

Predicting Post-treatment HIV Remission: Does Size of the Viral Reservoir Matter?

Combination antiretroviral therapy (ART) suppresses human immunodeficiency virus (HIV) replication and improves immune function. However, due to the persistence of long-lived HIV reservoirs, therapy interruption almost inevitably leads to a fast viral rebound. A small percentage of individuals who are able to control HIV replication for extended periods after therapy interruption are of particular interest because they may represent a model of long-term HIV remission without ART. These individuals are characterized by a limited viral reservoir and low reservoir measures can predict post-treatment HIV remission. However, most individuals with a low reservoir still experience fast viral rebound. In this Perspective, we discuss the possible reasons behind this and propose to develop an integral profile, composed of viral and host biomarkers, that could allow the accurate prediction of post-treatment HIV remission. We also propose to incorporate information on the chromatin context of the proviral integration sites into the characterization of the HIV reservoir, as this likely influences the reactivation capacity of latent proviruses and, together with the actual number of intact proviruses, contributes to the replication competence of the reservoir.

An optimized stepwise algorithm combining rapid antigen and RT-qPCR for screening of COVID-19 patients.

BACKGROUND & AIM: We investigated the combination of rapid antigen detection (RAD) and RT-qPCR assays in a stepwise procedure to optimize the detection of COVID-19. METHODS: From August 2020 to November 2020, 43,399 patients were screened in our laboratory for COVID-19 diagnostic by RT-qPCR using nasopharyngeal swab. Overall, 4,691 of the 43,399 were found to be positive, and 200 were retrieved for RAD testing allowing comparison of diagnostic accuracy between RAD and RT-qPCR. Cycle threshold (Ct) and time from symptoms onset (TSO) were included as covariates. RESULTS: The overall sensitivity, specificity, PPV, NPV, LR-, and LR+ of RAD compared with RT-qPCR were 72% (95%CI 62%-81%), 99% (95% CI95%-100%), 99% (95%CI 93%-100%), and 78% (95%CI 70%-85%), 0.28 (95%CI 0.21-0.39), and 72 (95%CI 10-208) respectively. Sensitivity was higher for patients with Ct ≤ 25 regardless of TSO: TSO ≤ 4 days 92% (95%CI 75%-99%), TSO > 4 days 100% (95%CI 54%-100%), and asymptomatic 100% (95%CI 78-100%). Overall, combining RAD and RT-qPCR would allow reducing from only 4% the number of RT-qPCR needed. CONCLUSIONS: This study highlights the risk of misdiagnosing COVID-19 in 28% of patients if RAD is used alone. A stepwise analysis that combines RAD and RT-qPCR would be an efficient screening procedure for COVID-19 detection and may facilitate the control of the outbreak.

Residual Viremia Is Linked to a Specific Immune Activation Profile in HIV-1-Infected Adults Under Efficient Antiretroviral Therapy.

Chronic immune activation persists in persons living with HIV-1 even though they are aviremic under antiretroviral therapy, and fuels comorbidities. In previous studies, we have revealed that virologic responders present distinct profiles of immune activation, and that one of these profiles is related to microbial translocation. In the present work, we tested in 140 HIV-1-infected adults under efficient treatment for a mean duration of eight years whether low-level viremia might be another cause of immune activation. We observed that the frequency of viremia between 1 and 20 HIV-1 RNA copies/mL (39.5 ± 24.7% versus 21.1 ± 22.5%, p = 0.033) and transient viremia above 20 HIV-1 RNA copies/mL (15.1 ± 16.9% versus 3.3 ± 7.2%, p = 0.005) over the 2 last years was higher in patients with one profile of immune activation, Profile E, than in the other patients. Profile E, which is different from the profile related to microbial translocation with frequent CD38+ CD8+ T cells, is characterized by a high level of CD4+ T cell (cell surface expression of CD38), monocyte (plasma concentration of soluble CD14), and endothelium (plasma concentration of soluble Endothelial Protein C Receptor) activation, whereas the other profiles presented low CD4:CD8 ratio, elevated proportions of central memory CD8+ T cells or HLA-DR+ CD4+ T cells, respectively. Our data reinforce the hypothesis that various etiological factors shape the form of the immune activation in virologic responders, resulting in specific profiles. Given the type of immune activation of Profile E, a potential causal link between low-level viremia and atherosclerosis should be investigated.

CXCR3 expression on peripheral CD4+ T cells as a predictive marker of response to treatment in chronic hepatitis C.

We monitored in fifty individuals with chronic hepatitis C (CHC) the expression of CCR5 and CXCR3, two chemokine receptors involved in the intra-hepatic recruitment of T cells, at the surface of circulating CD4+ T cells. The percentage of CD4+ T cells expressing CCR5 and/or CXCR3 was increased in patients. The increased percentage of CD4+ CXCR3+ T lymphocytes was linked to serum level of aspartate aminotransferase (AST) and to fibrosis METAVIR score. CD4+ T cell surface CCR5 and CXCR3 densities increased after 6 months of treatment with pegylated interferon-alpha and ribavirin. The pre-therapeutic percentage of CD4+ CXCR3+ T cells was correlated with alanine aminotransferase serum level at 12 months, and viral load at 24 months after treatment initiation. Thus, in CHC we observed a high CXCR3 expression on peripheral blood CD4+ T cells which correlates with AST serum level and liver fibrosis, and is predictive of the response to treatment.

Microbial Translocation Is Linked to a Specific Immune Activation Profile in HIV-1-Infected Adults With Suppressed Viremia.

Persistent immune activation in virologically suppressed HIV-1 patients, which may be the consequence of various factors including microbial translocation, is a major cause of comorbidities. We have previously shown that different profiles of immune activation may be distinguished in virological responders. Here, we tested the hypothesis that a particular profile might be the consequence of microbial translocation. To this aim, we measured 64 soluble and cell surface markers of inflammation and CD4+ and CD8+ T-cell, B cell, monocyte, NK cell, and endothelial activation in 140 adults under efficient antiretroviral therapy, and classified patients and markers using a double hierarchical clustering analysis. We also measured the plasma levels of the microbial translocation markers bacterial DNA, lipopolysaccharide binding protein (LBP), intestinal-fatty acid binding protein, and soluble CD14. We identified five different immune activation profiles. Patients with an immune activation profile characterized by a high percentage of CD38+CD8+ T-cells and a high level of the endothelial activation marker soluble Thrombomodulin, presented with higher LBP mean (± SEM) concentrations (33.3 ± 1.7 vs. 28.7 ± 0.9 µg/mL, p = 0.025) than patients with other profiles. Our data are consistent with the hypothesis that the immune activation profiles we described are the result of different etiological factors. We propose a model, where particular causes of immune activation, as microbial translocation, drive particular immune activation profiles responsible for particular comorbidities.

Highlights from the 8th International Workshop on HIV Persistence during Therapy, 12-15 December 2017, Miami, FL, USA.

Over 4 days, more than 500 scientists involved in HIV persistence research shared their new unpublished data and designed future perspectives towards ART-free HIV remission. This 8th International Workshop on HIV Persistence followed the format of past conferences but further focused on encouraging participation of young investigators, especially through submission of oral and poster presentations. The topic of the workshop was HIV persistence. Consequently, issues of HIV reservoirs and HIV cure were also addressed. In this article, we report the discussions as closely as possible; however, all the workshop abstracts can be found online at www.viruseradication.com.

Highlights from the 22nd International AIDS Conference (AIDS 2018), 22-27 July 2018, Amsterdam, the Netherlands.

Important data on the social, epidemiological and clinical aspects of HIV-1, comorbidities and hepatitis as well as data on novel antiretroviral agents and the cure agenda were presented at AIDS 2018. This report covers some of the highlights.

Highlights from the 20th International Symposium on HIV and Emerging Infectious Diseases (ISHEID) 16-18 May 2018, Marseille, France: from HIV and comorbidities to global health.

The 20th International Symposium on HIV and Emerging Infectious Diseases took place in Marseille, France. It had a refreshing European look with reinforced partnerships with the European AIDS Clinical Society and the British HIV Association and with international speakers and participants. Topics included HIV and global health, HIV and hepatitis cure, the microbiome and immunotherapies, clinical research and methodology, as well as chemsex, pre-exposure prophylaxis, sexually transmitted infections and emerging infectious diseases. Novel areas of research were also described, such as electronic technology in order to improve HIV management, and the expert patient.

Plasma Level of Soluble ST2 in Chronically Infected HIV-1 Patients with Suppressed Viremia.

INTRODUCTION: Interleukin-33 (IL-33) is a cell damage-induced alarmin. The plasma concentration of suppression of tumorogenicity (sST2), a surrogate marker of IL-33 production, is a prognostic marker of cardiovascular disease. OBSERVATION: Recently, we reported that sST2 plasma levels were elevated in early HIV-1 infection and linked to markers of microbial translocation and of T cell activation. RESULTS: Here we show that it is not the case in patients with suppressed viremia. Thus, IL-33 plays its alarmin role only during the early phase of the infection.

Reversing HIV latency via sphingosine-1-phosphate receptor 1 signaling.

OBJECTIVE: In this study, we looked for a new family of latency reversing agents. DESIGN: We searched for G-protein-coupled receptors (GPCR) coexpressed with the C-C chemokine receptor type 5 (CCR5) in primary CD4 T cells that activate infected cells and boost HIV production. METHODS: GPCR coexpression was unveiled by reverse transcriptase-PCR. We used fluorescence resonance energy transfer to analyze the dimerization with CCR5 of the expressed GPCR. Viral entry was measured by flow cytometry, reverse transcription by quantitative PCR, nuclear factor-kappa B translocation by immunofluorescence, long terminal repeat activation using a gene reporter assay and viral production by p24 quantification. RESULTS: Gαi-coupled sphingosine-1-phophate receptor 1 (S1P1) is highly coexpressed with CCR5 on primary CD4 T cells and dimerizes with it. The presence of S1P1 had major effects neither on viral entry nor on reverse transcription. Yet, S1P1 signaling induced NFκB activation, boosting the expression of the HIV LTR. Consequently, in culture medium containing sphingosine-1-phophate, the presence of S1P1 enhanced the replication of a CCR5-, but also of a CXCR4-using HIV-1 strain. The S1P1 ligand FTY720, a drug used in multiple sclerosis treatment, inhibited HIV-1 productive infection of monocyte-derived dendritic cells and of severe combined immunodeficiency mice engrafted with human peripheral blood mononuclear cells. Conversely, S1P1 agonists were able to force latently infected peripheral blood mononuclear cells and lymph node cells to produce virions in vitro. CONCLUSION: Altogether these data indicate that the presence of S1P1 facilitates HIV-1 replicative cycle by boosting viral genome transcription, S1P1 antagonists have anti-HIV effects and S1P1 agonists are HIV latency reversing agents.

Highlights from the 24th Conference on Retroviruses and Opportunistic Infections: 13-16 February 2017, Seattle, Washington, USA.

From the 13th to 16th February 2017, researchers from around the world convened for the 24th annual Conference on Retroviruses and Opportunistic Infections (CROI) at the Washington State Convention Center in Seattle, Washington. The conference was organised by the International Antiviral Society-USA (IAS-USA) in partnership with the CROI Foundation. The conference included over 1000 oral and poster presentations of peer-reviewed original research as well as lectures and symposia featuring insights from leading basic, translational and clinical researchers. Highlighted here are key data presented at the conference.