Prospective antiretroviral treatment of asymptomatic, HIV-1 infected controllers

Ongoing HIV-1 evolution and reservoir reseeding in two elite controllers with genetically diverse peripheral proviral quasispecies

BACKGROUND

Elite controllers (EC) are human immunodeficiency virus (HIV)-positive individuals who can maintain low viral loads for extended periods without antiretroviral therapy due to multifactorial and individual characteristics. Most have a small HIV-1 reservoir composed of identical proviral sequences maintained by clonal expansion of infected CD4+ T cells. However, some have a more diverse peripheral blood mononuclear cell (PBMC)-associated HIV-1 reservoir with unique sequences.

OBJECTIVES

To understand the turnover dynamics of the PBMC-associated viral quasispecies in ECs with relatively diverse circulating proviral reservoirs.

METHODS

We performed single genome amplification of the env gene at three time points during six years in two EC with high intra-host HIV DNA diversity.

FINDINGS

Both EC displayed quite diverse PBMCs-associated viral quasispecies (mean env diversity = 1.9-4.1%) across all time-points comprising both identical proviruses that are probably clonally expanded and unique proviruses with evidence of ongoing evolution. HIV-1 env glycosylation pattern suggests that ancestral and evolving proviruses may display different phenotypes of resistance to broadly neutralising antibodies consistent with persistent immune pressure. Evolving viruses may progressively replace the ancestral ones or may remain as minor variants in the circulating proviral population.

MAIN CONCLUSIONS

These findings support that the high intra-host HIV-1 diversity of some EC resulted from long-term persistence of archival proviruses combined with the continuous reservoir's reseeding and low, but measurable, viral evolution despite undetectable viremia.

Slow progression of pediatric HIV associates with early CD8+ T cell PD-1 expression and a stem-like phenotype

HIV nonprogression despite persistent viremia is rare among adults who are naive to antiretroviral therapy (ART) but relatively common among ART-naive children. Previous studies indicate that ART-naive pediatric slow progressors (PSPs) adopt immune evasion strategies similar to those described in natural hosts of SIV. However, the mechanisms underlying this immunophenotype are not well understood. In a cohort of early-treated infants who underwent analytical treatment interruption (ATI) after 12 months of ART, expression of PD-1 on CD8+ T cells immediately before ATI was the main predictor of slow progression during ATI. PD-1+CD8+ T cell frequency was also negatively correlated with CCR5 and HLA-DR expression on CD4+ T cells and predicted stronger HIV-specific T lymphocyte responses. In the CD8+ T cell compartment of PSPs, we identified an enrichment of stem-like TCF-1+PD-1+ memory cells, whereas pediatric progressors and viremic adults had a terminally exhausted PD-1+CD39+ population. TCF-1+PD-1+ expression on CD8+ T cells was associated with higher proliferative activity and stronger Gag-specific effector functionality. These data prompted the hypothesis that the proliferative burst potential of stem-like HIV-specific cytotoxic cells could be exploited in therapeutic strategies to boost the antiviral response and facilitate remission in infants who received early ART with a preserved and nonexhausted T cell compartment.

Non-AIDS-Defining Events in Human Immunodeficiency Virus Controllers Versus Antiretroviral Therapy-Controlled Patients: A Cohort Collaboration From the French National Agency for Research on AIDS CO21 (CODEX) and CO06 (PRIMO) Cohorts

Background

Low-grade chronic inflammation may persist in spontaneous human immunodeficiency virus controllers (HICs), leading to non-AIDS-defining events (nADEs).

Methods

Two hundred twenty-seven antiretroviral therapy (ART)-naive HICs (known human immunodeficiency virus type 1 [HIV-1] infection ≥5 years and at least 5 consecutive viral loads [VLs] <400 HIV RNA copies/mL) were compared with 328 patients who initiated ART ≤1 month after primary HIV infection diagnosis and had undetectable VL within 12 months following ART initiation for at least 5 years. Incidence rates of first nADEs were compared between HICs and ART-treated patients. Determinants of nADEs were assessed by using Cox regression models.

Results

All-cause nADEs incidence rates were 7.8 (95% confidence interval [CI], 5.9-9.6) and 5.2 (95% CI, 3.9-6.4) per 100 person-months among HICs and ART patients, respectively (incidence rate ratio [IRR], 1.5 [95% CI, 1.1-2.2]; adjusted IRR, 1.93 [95% CI, 1.16-3.20]). After adjustment for the cohort, demographic, and immunological characteristics, the only other factor associated with all-cause nADE occurrence was age ≥43 (vs <43) years at the beginning of viral control (IRR, 1.69 [95% CI, 1.11-2.56]). The most frequent events observed in the 2 cohorts were non-AIDS-related benign infections (54.6% and 32.9% of all nADEs, respectively, for HICs and ART patients). No differences in cardiovascular or psychiatric events were observed.

Conclusions

HICs experienced 2 times more nADEs than virologically suppressed patients on ART, mainly non-AIDS-related benign infections. Older age was associated with nADE occurrence, independent of immune or virologic parameters. These results do not argue in favor of expanding the ART indication for HICs but rather a case-by-case approach considering clinical outcomes such as nADEs besides immune activation.

Bibliometric and visualized analysis of elite controllers based on CiteSpace: landscapes, hotspots, and frontiers

Background

A unique subset of people living with HIV, known as elite controllers, possess spontaneous and consistent control over viral replication and disease progression in the absence of antiviral intervention. In-depth research on elite controllers is conducive to designing better treatment strategies for HIV. However, comprehensive and illuminating bibliometric reports on elite controllers are rare.

Methods

Articles on elite controllers were retrieved from the Web of Science Core Collection. A visualized analysis of this domain was conducted by CiteSpace software. Taking count, betweenness centrality, and burst value as criteria, we interpreted the visualization results and predicted future new directions and emerging trends.

Results

By December 31, 2022, 843 articles related to elite controllers had been published. The largest contributors in terms of country, institution, and author were the United States (485), Univ Calif San Francisco (87), and Walker B.D. (65), respectively. Migueles S.A. (325) and Journal of Virology (770) were the most cocited author and journal, respectively. Additionally, by summarizing the results of our CiteSpace software analysis on references and keywords, we considered that the research hotspots and frontiers on elite controllers mainly focus on three aspects: deciphering the mechanisms of durable control, delineating the implications for the development of treatments for HIV infection, and highlighting the clinical risks faced by elite controllers and coping strategies.

Conclusion

This study performed a bibliometric and visual analysis of elite controllers, identified the main characteristics and emerging trends, and provided insightful references for further development of this rapidly evolving and complex field.

CD8 lymphocytes mitigate HIV-1 persistence in lymph node follicular helper T cells during hyperacute-treated infection

HIV persistence in tissue sites despite ART is a major barrier to HIV cure. Detailed studies of HIV-infected cells and immune responses in native lymph node tissue environment is critical for gaining insight into immune mechanisms impacting HIV persistence and clearance in tissue sanctuary sites. We compared HIV persistence and HIV-specific T cell responses in lymph node biopsies obtained from 14 individuals who initiated therapy in Fiebig stages I/II, 5 persons treated in Fiebig stages III-V and 17 late treated individuals who initiated ART in Fiebig VI and beyond. Using multicolor immunofluorescence staining and in situ hybridization, we detect HIV RNA and/or protein in 12 of 14 Fiebig I/II treated persons on suppressive therapy for 1 to 55 months, and in late treated persons with persistent antigens. CXCR3+ T follicular helper cells harbor the greatest amounts of gag mRNA transcripts. Notably, HIV-specific CD8+ T cells responses are associated with lower HIV antigen burden, suggesting that these responses may contribute to HIV suppression in lymph nodes during therapy. These results reveal HIV persistence despite the initiation of ART in hyperacute infection and highlight the contribution of virus-specific responses to HIV suppression in tissue sanctuaries during suppressive ART.

Increased biomarkers of cardiovascular risk in HIV-1 viremic controllers and low persistent inflammation in elite controllers and art-suppressed individuals

HIV controllers (HICs) are models of HIV functional cure, although some studies have shown persistent inflammation and increased rates of atherosclerosis in HICs. Since immune activation/inflammation contributes to the pathogenesis of cardiovascular diseases (CVD), we evaluated clinical data and inflammation markers in HIV-1 viremic controllers (VC), elite controllers (EC), and control groups (HIV positive individuals with virological suppression by antiretroviral therapy—cART; HIV negative individuals—HIVneg) to assess whether they presented elevated levels of inflammation markers also associated with CVD. We observed the highest frequencies of activated CD8⁺ T cells in VCs, while EC and cART groups presented similar but slightly altered frequencies of this marker when compared to the HIVneg group. Regarding platelet activation, both HICs groups presented higher expression of P-selectin in platelets when compared to control groups. Monocyte subset analyses revealed lower frequencies of classical monocytes and increased frequencies of non-classical and intermediate monocytes among cART individuals and in EC when compared to HIV negative individuals, but none of the differences were significant. For VC, however, significant decreases in frequencies of classical monocytes and increases in the frequency of intermediate monocytes were observed in comparison to HIV negative individuals. The frequency of monocytes expressing tissue factor was similar among the groups on all subsets. In terms of plasma markers, VC had higher levels of many inflammatory markers, while EC had higher levels of VCAM-1 and ICAM-1 compared to control groups. Our data showed that VCs display increased levels of inflammation markers that have been associated with CVD risk. Meanwhile, ECs show signals of lower but persistent inflammation, comparable to the cART group, indicating the potential benefits of alternative therapies to decrease inflammation in this group.

Challenges and Promise of Human Immunodeficiency Virus Remission

Antiretroviral therapy effectively controls human immunodeficiency virus (HIV) replication but it is unable to fully eradicate the HIV reservoir and treatment must be life-long. Progress toward a strategy for HIV remission will require overcoming key hurdles to fill gaps in our understanding of HIV persistence, but the identification of individuals who have attained sterilizing or functional HIV cure show that such a goal is achievable. In this review, we first outline challenges in targeting the HIV reservoir, including difficulties identifying HIV-infected cells, ongoing work elucidating the complex intracellular environment that contribute to HIV latency, and barriers to reactivating and clearing the HIV reservoir. We then review reported cases of HIV sterilizing cure and explore natural models of HIV remission and the promise that such HIV spontaneous and posttreatment controllers may hold in our search for a broadly-applicable strategy for the millions of patients living with HIV.

Naive infection predicts reservoir diversity and is a formidable hurdle to HIV eradication

Historically, naive cells have been considered inconsequential to HIV persistence. Here, we compared the contributions of naive and memory cells to the reservoirs of individuals with a spectrum of reservoir sizes and variable immunological control. We performed proviral sequencing of approximately 6000 proviruses from cellular subsets of 5 elite controllers (ECs) off antiretroviral therapy (ART) and 5 chronic progressors (CPs) on ART. The levels of naive infection were barely detectable in ECs and approximately 300-fold lower compared with those in CPs. Moreover, the ratio of infected naive to memory cells was significantly lower in ECs. Overall, the naive infection level increased as reservoir size increased, such that naive cells were a major contributor to the intact reservoir of CPs, whose reservoirs were generally very diverse. In contrast, the reservoirs of ECs were dominated by proviral clones. Critically, the fraction of proviral clones increased with cell differentiation, with naive infection predicting reservoir diversity. Longitudinal sequencing revealed that the reservoir of ECs was less dynamic compared with that of CPs. Naive cells play a critical role in HIV persistence. Their infection level predicts reservoir size and diversity. Moreover, the diminishing diversity of the reservoir as cellular subsets mature suggests that naive T cells repopulate the memory compartment and that direct infection of naive T cells occurs in vivo.

Antiretroviral therapy for HIV controllers: Reasons for initiation and outcomes in the French ANRS-CO21 CODEX cohort

BACKGROUND

Less than 1% of Human Immunodeficiency Virus (HIV)-infected individuals are able to achieve spontaneous viral control without requiring antiretroviral therapy (ART). Whether these HIV controllers (HIC) are at risk of HIV-associated comorbidities and could benefit from ART is debated, but recent studies reported decreased T-cell activation upon ART initiation. We report the frequency of ART initiation, reasons to treat, treatment outcome on immunovirological parameters, and rate of side-effects and treatment discontinuation in the French cohort of HIC.

METHODS

Participants included in the French multicenter Agence Nationale de Recherche sur le SIDA et les Hépatites (ANRS) Cohorte des extremes (CODEX) cohort of HIC between July 6, 2007 and January 3, 2018 were prospectively followed. ART initiation, indication, discontinuation, non-Acquired ImmunoDeficiency Syndrome (AIDS)-defining events, side-effects, and immunovirological parameters were recorded. Undetectable HIC (u-HIC) were defined as participants with strictly undetectable viral loads based on routinely used assays throughout the follow-up and blipper HIC (b-HIC) as participants with possible detectable viral loads above the detection threshold during follow-up.

FINDINGS

Among 302 HIC followed for a median of 14.8 years [10.3-20.2], 90 (30%) received ART (7 u-HIC and 83 b-HIC). The main reasons for ART initiation were decreased CD4 T-cell counts (n = 36, 40%), loss of virological control (n = 13, 14%), and non-AIDS-defining events (n = 12, 13%). Sixteen (18%) participants experienced 17 grade 1-2 adverse events. In b-HIC, ART slightly increased the CD4/CD8 ratio (median +0.19, p < 0.0001) and decreased the frequency of circulating CD38⁺ HLA-DR.⁺ CD4 and CD8 lymphocytes (median -0.75%, p = 0.003, and -2%, p < 0.0001, respectively), but these changes were not observed for treated u-HIC. Thirteen (14%) participants discontinued ART (5 (38%) because of side-effects, and 10 remained HIC after treatment cessation (median follow-up: 305 days [235-728]).

INTERPRETATION

Only 30% of participants in this large cohort of HIC required ART during a median follow-up of 14.8 years. These results show that HIC status is very stable and vouch for a patient-centered treatment decision based on the individual benefit/risk balance.

Senotherapeutics for HIV and aging

PURPOSE OF REVIEW

To summarize the state of chronic, treated HIV infection and its contribution to accelerated aging, and to evaluate recent research relevant to the study and treatment of aging and senescence.

RECENT FINDINGS

Chronic treated HIV-1 infection is associated with significant risk of end-organ impairment, non-AIDS-associated malignancies, and accelerated physiologic aging. Coupled with the chronologic aging of the HIV-1-positive population, the development of therapies that target these processes is of great clinical importance. Age-related diseases are partly the result of cellular senescence. Both immune and nonimmune cell subsets are thought to mediate this senescent phenotype, a state of stable cell cycle arrest characterized by sustained release of pro-inflammatory mediators. Recent research in the field of aging has identified a number of 'senotherapeutics' to combat aging-related diseases, pharmacologic agents that act either by selectively promoting the death of senescent cells ('senolytics') or modifying senescent phenotype ('senomorphics').

SUMMARY

Senescence is a hallmark of aging-related diseases that is characterized by stable cell cycle arrest and chronic inflammation. Chronic HIV-1 infection predisposes patients to aging-related illnesses and is similarly marked by a senescence-like phenotype. A better understanding of the role of HIV-1 in aging will inform the development of therapeutics aimed at eliminating senescent cells that drive accelerated physiologic aging.

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.

Maintenance of Viral Suppression in Human Immunodeficiency Virus Controllers Despite Waning T-Cell Responses During Antiretroviral Therapy

AIDS Clinical Trials Group study A5308 found reduced T-cell activation and exhaustion in human immunodeficiency virus (HIV) controllers start antiretroviral therapy (ART). We further assessed HIV-specific T-cell responses and post-ART viral loads. Before ART, the 31% of participants with persistently undetectable viremia had more robust HIV-specific T-cell responses. During ART, significant decreases were observed in a broad range of T-cell responses. Eight controllers in A5308 and the Study of the Consequences of the Protease Inhibitor Era (SCOPE) cohort showed no viremia above the level of quantification in the first 12 weeks after ART discontinuation. ART significantly reduced HIV-specific T-cell responses in HIV controllers but did not adversely affect controller status after ART discontinuation.

Gag p24 is a Marker of HIV Expression in Tissues and Correlates with Immune Response

We demonstrate that HIV gag p24 protein is more readily detected in gut and lymph node tissues than in blood CD4+ T-cells and correlates better with CD4 count during antiretroviral therapy (ART). Gut p24 levels also measurably decline with ART in natural controllers. During ART, gut p24 expression is more strongly associated both with HIV-specific CD8+ T-cell frequency and plasma sCD14 levels than gut HIV RNA expression. This study supports using gag p24 as a marker of HIV expression in HIV+ tissues to study effects of viral persistence and to monitor efficacy of treatment in HIV-based clearance studies.

HIV-DNA content in pTfh cells is associated with residual viremia in elite controllers

OBJECTIVE

The source of residual HIV viremia is highly debated and its potential relationship with the HIV reservoir has not been clarified. Herein, we analysed the cell-associated HIV-DNA content in two important cell compartments of the HIV reservoir, resting CD4+ T memory (Trm) and peripheral T follicular helper (pTfh) cells, and the association with the residual HIV viremia in individuals with spontaneous HIV replication control (elite controllers, EC group) and in individuals with antiretroviral therapy (ART)-mediated HIV replication control (cART group).

DESIGN

A cross-sectional study.

METHODS

Seventeen chronically HIV-infected patients with suppressed HIV replication were included. Cell-associated HIV-DNA was measured by ultrasensitive digital-droplet-PCR in purified Trm and pTfh cells. Residual HIV plasma viremia was quantified using a single-copy assay with a sensitivity of 0.3 HIV-RNA copies/ml.

RESULTS

A significant and positive correlation was demonstrated between HIV-DNA levels in pTfh cells and residual plasma viral load (rpVL) (rho = 0.928, P = 0.008) in HIV-positive elite controllers, but not in HIV-positive treated patients, despite the lower levels of cell-associated HIV-DNA found in elite controllers compared with cART patients in pTfh cells [176 (77-882) vs. 608 (361-860) copies/million cells, respectively; P = 0.05].

CONCLUSION

This association suggests that pTfh cells could have an important contribution to persistent viremia in elite controllers. This could be the consequence of a more limited control of HIV replication in elite controllers with higher transcriptional activity of HIV in pTfh cells of elite controllers than that in cART patients.

Antiretroviral Therapy Reduces T-cell Activation and Immune Exhaustion Markers in Human Immunodeficiency Virus Controllers

BACKGROUND

Despite low plasma human immunodeficiency virus (HIV) RNA, HIV controllers have evidence of viral replication and elevated inflammation. We assessed the effect of antiretroviral therapy (ART) on HIV suppression, immune activation, and quality of life (QoL).

METHODS

A5308 was a prospective, open-label study of rilpivirine/emtricitabine/tenofovir disoproxil fumarate in ART-naive HIV controllers (N = 35), defined as having HIV RNA <500 copies/mL for ≥12 months. The primary outcome measured change in %CD38+HLA-DR+ CD8+ T cells. Residual plasma viremia was measured using the integrase single-copy assay. QoL was measured using the EQ-5D questionnaire. Outcomes were evaluated using repeated measures general estimating equations models.

RESULTS

Before ART, HIV controllers with undetectable residual viremia <0.6 HIV-1 RNA copies/mL had higher CD4+ counts and lower levels of T-cell activation than those with detectable residual viremia. ART use was effective in further increasing the proportion of individuals with undetectable residual viremia (pre-ART vs after 24-48 weeks of ART: 19% vs 94%, P < .001). Significant declines were observed in the %CD38+HLA-DR+CD8+ T cells at 24-48 (-4.0%, P = .001) and 72-96 (-7.2%, P < .001) weeks after ART initiation. ART use resulted in decreases of several cellular markers of immune exhaustion and in a modest but significant improvement in self-reported QoL. There were no significant changes in CD4+ counts or HIV DNA.

CONCLUSIONS

ART in HIV controllers reduces T-cell activation and improves markers of immune exhaustion. These results support the possible clinical benefits of ART in this population.

Replicate Aptima Assay for Quantifying Residual Plasma Viremia in Individuals on Antiretroviral Therapy

Detection of residual plasma viremia in antiretroviral therapy (ART)-suppressed HIV-infected individuals is critical for characterizing the latent reservoir and evaluating the impact of cure interventions. Ultracentrifugation-based single-copy assays are sensitive but labor intensive. Fully automated replicate testing using a standard clinical viral load assay was evaluated as a high-throughput alternative for the quantification of low-level viremia. Four plasma samples from blood donors with acute HIV-1 infection and one viral culture supernatant were serially diluted into 25-ml samples to nominal viral loads ranging from 39 to <0.

Detection of residual plasma viremia in antiretroviral therapy (ART)-suppressed HIV-infected individuals is critical for characterizing the latent reservoir and evaluating the impact of cure interventions. Ultracentrifugation-based single-copy assays are sensitive but labor intensive. Fully automated replicate testing using a standard clinical viral load assay was evaluated as a high-throughput alternative for the quantification of low-level viremia. Four plasma samples from blood donors with acute HIV-1 infection and one viral culture supernatant were serially diluted into 25-ml samples to nominal viral loads ranging from 39 to <0.5 copies (cp)/ml. Each dilution was tested with 45 replicates (reps) using 0.5 ml/rep with the Aptima HIV-1 Quant assay. The nominal and estimated viral loads based on the single-hit Poisson model were compared, and a hybrid Poisson digital model for calibrated viral load estimation was derived. Testing performed using 45 reps on longitudinal plasma samples from 50 ART-suppressed individuals in the Reservoir Assay Validation and Evaluation Network (RAVEN) study cohort (range of 1 to 19 years of continuous ART suppression) showed a median viral load of 0.54 cp/ml (interquartile range [IQR], 0.22 to 1.46 cp/ml) and a 14% (95% confidence interval [CI], 9% to 19%) decline in viral load for each additional year in duration suppressed. Within the RAVEN cohort, the expected false-negative rate for detection at lower rep numbers using 9 and 18 reps was 26% and 14%, respectively. Residual plasma viremia levels positively correlated with cell-associated HIV RNA and DNA. The performance characteristics of the replicate Aptima assay support its use for quantifying residual plasma viremia to study the latent HIV reservoir and cure interventions.

Automated Multireplicate Quantification of Persistent HIV-1 Viremia in Individuals on Antiretroviral Therapy

Clearance of low-level viremia that persists in most HIV-1-positive individuals on antiretroviral therapy (ART) is an important milestone for efforts to cure HIV-1 infection. The level of persistent viremia on ART is generally below the lower limit of quantification (LOQ) of current FDA-cleared plasma HIV-1 RNA assays (20 to 40 copies/ml) but can be quantified by reverse transcriptase PCR (RT-PCR) assays with single-copy sensitivity. Such assays require multistep manual methods, and their low throughput limits the capacity to monitor the effects of interventions on persistent viremia.

Clearance of low-level viremia that persists in most HIV-1-positive individuals on antiretroviral therapy (ART) is an important milestone for efforts to cure HIV-1 infection. The level of persistent viremia on ART is generally below the lower limit of quantification (LOQ) of current FDA-cleared plasma HIV-1 RNA assays (20 to 40 copies/ml) but can be quantified by reverse transcriptase PCR (RT-PCR) assays with single-copy sensitivity. Such assays require multistep manual methods, and their low throughput limits the capacity to monitor the effects of interventions on persistent viremia. Recently, S. Bakkour, X. Deng, P. Bacchetti, E. Grebe, et al. (J Clin Microbiol 58:e01400-20, 2020, https://doi.org/10.1128/JCM.01400-20), reported the use of multiple replicates and Poisson statistics to infer HIV-1 RNA concentrations below the commercial LOQ of an automated platform (Hologic Panther Aptima). Here, we evaluate the detection and quantitation of low-level viremia using the following two adaptions of the automated platform: a multireplicate strategy (9×) and a concentrated single-replicate strategy in which 5 ml of plasma is concentrated by centrifugation (1×, concentrated). We compare these new methods to a recently reported manual integrase-targeting single-copy assay version 2 (iSCA v2). Using laboratory-generated HIV-1 RNA plasma samples at known concentrations, all three methods had similar sensitivity for HIV-1 RNA detection, although iSCA v2 was most sensitive (95% LOD, 2.3 copies/ml), 9× was marginally less sensitive (95% LOD, 3.0 copies/ml), and 1×, concentrated was least sensitive (95% LOD, 3.9 copies/ml). In contrast, for clinical plasma samples, 9× had greater sensitivity than iSCA v2 (82% of samples were quantifiable compared with 62% of samples by iSCA v2). These results support 9× as an acceptable high-throughput alternative to iSCA v2 for quantifying low-level viremia in individuals on ART.

Next-Generation Surrogate Wnts Support Organoid Growth and Deconvolute Frizzled Pleiotropy In Vivo

Modulation of Wnt signaling has untapped potential in regenerative medicine due to its essential functions in stem cell homeostasis. However, Wnt lipidation and Wnt-Frizzled (Fzd) cross-reactivity have hindered translational Wnt applications. Here, we designed and engineered water-soluble, Fzd subtype-specific "next-generation surrogate" (NGS) Wnts that hetero-dimerize Fzd and Lrp6. NGS Wnt supports long-term expansion of multiple different types of organoids, including kidney, colon, hepatocyte, ovarian, and breast. NGS Wnts are superior to Wnt3a conditioned media in organoid expansion and single-cell organoid outgrowth. Administration of Fzd subtype-specific NGS Wnt in vivo reveals that adult intestinal crypt proliferation can be promoted by agonism of Fzd5 and/or Fzd8 receptors, while a broad spectrum of Fzd receptors can induce liver zonation. Thus, NGS Wnts offer a unified organoid expansion protocol and a laboratory "tool kit" for dissecting the functions of Fzd subtypes in stem cell biology.

A role for antibodies in natural HIV control

PURPOSE OF REVIEW

Rare patients naturally control HIV replication without antiretroviral therapy. Understanding the mechanisms implicated in natural HIV control will inform the development of immunotherapies against HIV. Elite controllers are known for developing efficient antiviral T-cell responses, but recent findings suggest that antibody responses also play a significant role in HIV control. We review the key studies that uncovered a potent memory B-cell response and highly functional anti-HIV antibodies in elite controllers, and explore the mechanisms that may account for the distinct properties of their humoral response.

RECENT FINDINGS

Elite controllers maintain a large HIV-specific memory B-cell pool that is sustained by efficient T follicular helper function. Neutralizing antibody rarely show high titers in controllers, but seem capable, at least in certain cases, of neutralizing contemporaneous viral strains. In addition, elite controllers display a unique HIV-specific antibody profile in terms of isotype, antigen specificity, and glycosylation pattern, resulting in polyfunctional antibody effector functions that may promote infected cell lysis and prime effectors of the antiviral immune response.

SUMMARY

Lessons from elite controller studies argue for the importance of integrating the many parameters defining a polyfunctional antibody response when evaluating candidate vaccines and immunotherapeutic approaches directed at HIV.

Two-drug vs. three-drug combinations for HIV-1: Do we have enough data to make the switch?

Three-drug combination antiretroviral therapy (ART) became available in 1996, dramatically improving the prognosis of people living with HIV. The clinical benefits of ART are due to the sustained viral load suppression and CD4 T cell gains. Major drawbacks of the first ART regimens were adverse events, and high pill burden, which led to the reduction of drug adherence resulting in frequent treatment discontinuations and the development of drug resistance. Due to increased viral potency of new antiretroviral drugs consideration of a two-drug combination therapy repositioning occurred in an effort to reduce adverse events, drug-drug interactions and cost, while maintaining a sustained antiviral effect. Various combinations of two-drug regimens have been studied, and non-inferiority compared to a three-drug regimen has been shown only for some of them. In addition, a two-drug combination regimen may not be suitable for every patient, especially those who are pregnant, those with tuberculosis or coexisting HBV infection. Furthermore no information has been generated concerning the secondary transmission of HIV from patients who have undetectable plasma viral load on two-drug regimens. Additional studies of two-drug combinations are also necessary to evaluate the debated existence of low viral replication in tissues and on immune activation. While there is no urgent need to routinely switch patients to two-drug combination therapy, due to the availability of drug combinations without significant toxicities, dual regimens represent a suitable option that deserve long-term evaluation before being introduced to clinical practice.

Antiretroviral Treatment for HIV Elite Controllers?

In most HIV-infected persons, the natural history of untreated infection is one of sustained viremia, progressive CD4 T cell depletion with resultant morbidity and mortality. The advent of effective combination antiretroviral therapy (ART) that controls HIV replication has altered this landscape dramatically. Yet a rare population of HIV-infected persons-elite controllers (EC)-can control HIV replication such that plasma levels of virus are "undetectable" without ART. The EC phenotype is heterogeneous, with some subjects durably controlling the virus-persistent elite controllers-and some eventually losing viral control-transient elite controllers. Overall, EC tend to have robust HIV-specific T cell responses and in some cases, mainly in transient elite controllers, elevated activation and inflammation indices that diminish with ART suggesting that endogenous defenses against this persistent pathogen come at the cost of heightened activation/inflammation. A limited data set suggests that cardiovascular disease risk as well as the occur-rence of other morbid events may be greater in the overall EC population than in treated HIV infection. ART in EC decreases activation indices but does not appear to increase circulating CD4 T cell numbers nor do we know if it alters clinical outcomes. Thus, it is difficult to recommend or discourage a decision to start ART in the EC population but the authors lean toward treatment particularly in those EC whose activation indices are high and those who are progressively losing circulating CD4 T cell numbers. Biomarkers that can reliably predict loss of virologic control and immune failure are needed.

HIV controllers: to treat or not to treat? Is that the right question?

The term HIV controller refers to the small proportion of individuals infected with HIV who can spontaneously control viraemia to maintain very low viral loads. One major unresolved question is whether HIV controllers should receive antiretroviral therapy, given that international guidelines recommend treatment for all individuals who are infected with HIV. Differences in the definitions of a controller (in terms of the viral-load cutoff and the duration of viral control) and contrasting reports on CD4 T-cell decline, chronic immune activation, the cardiovascular risk, and loss of viral control in controllers have prevented the development of a consensus view.

Rapid development of HIV elite control in a patient with acute infection

Background

Elite controllers (EC), a small subset of the HIV-positive population (< 1%), suppress HIV viremia below the limit of quantification of clinical viral load assays in the absence of antiretroviral therapy (ART). However, there is a paucity of longitudinal data detailing the viral and immune dynamics or HIV reservoir seeding during acute infection in individuals that go on to become Elite Controllers.

Case presentation

In this report, we describe a case of a 42 year old woman diagnosed during acute infection who rapidly and permanently suppressed her viremia in the absence of antiretroviral therapy (ART). Rapid antibody/antigen testing was either negative or equivocal during acute infection, despite subsequent viral load testing at that time point with 71,550 plasma HIV RNA copies/mL, making initial diagnosis challenging. The patient subsequently developed detectable anti-HIV antibodies and an increase in HIV-specific CD8+ T cell responses to overlapping subtype C HIV gag peptide; very low-level plasma viremia (0.84 RNA copies/mL) was detected by an ultrasensitive assay 2 years following infection. Subsequently, she was started on ART for multifocal furunculosis despite continued suppression of virus and stable CD4+ T cell counts. Following ART initiation, HIV specific antibody levels and CD8+ T cell responses increased, but no HIV DNA or RNA was able to be isolated from large numbers of peripheral blood CD4+ T cells.

Conclusion

This case provides important information regarding the establishment of elite HIV control during acute infection and also demonstrates an increase in HIV-specific immune responses following ART despite undetectable peripheral blood cellular measures of HIV persistence. This case also highlights the challenges in diagnosing acute HIV infection without the use of viral load testing in this rare elite controller phenotype.

HIV-1 elite controllers: an immunovirological review and clinical perspectives

HIV type 1 (HIV-1) elite controllers (ECs) represent a rare group of individuals with an ability to maintain an undetectable HIV-1 viral load overtime in the absence of previous antiretroviral therapy. The mechanisms associated with this paradigm remain not clearly defined. However, loss of virological control, morbidity and mortality persist in these individuals, such as progress to AIDS-defining conditions together with persistent high rate of immune activation. Further insight into potential therapeutic options is therefore warranted. In this review, we discuss recent data on the type of immune responses understood to be associated with chronic virological control, the potential for disease progression and therapeutic options in ECs.

The Clinical-Translational Physician-Scientist: Translating Bedside to Bench

Translational research is often conceptualized with an implicit directionality, taking an idea generated in the laboratory (ie, the "bench") and applying it at the point of care (ie, the "bedside"). This role is often played by physician-scientists who work both in the laboratory and in the clinic. Less well appreciated is the valuable role a physician-scientist can play by using compelling observations from clinical research studies to guide basic scientists toward clinically important problems and even novel scientific concepts. The goal of this editorial is to highlight this often overlooked role that clinical-translational physician-scientists can play in translating observations at the bedside to efforts at the bench, highlighting their importance for scientific progress and discussing the type of research training and scientific environments that can help these individuals flourish. The importance of cohort studies and multidisciplinary team science in this context will also be highlighted.

Problem-Based Learning Could Tackle the Issue of Insufficient Education and Adherence in People Living With HIV/AIDS

Background: Poor medication adherence is still the main cause of antiretroviral therapy (ART) failure among people living with HIV/AIDS (PLWHA). Effective behavioral interventions are needed to improve HIV awareness and medication adherence.

Methods: In this retrospective cohort study, we assessed the effect of problem-based learning (PBL) approaches to HIV-related education and adherence outcomes among PLWHA and a college student sample. In our study, compared with 309 demography-matched control participants using conventional counseling methods (109 PLWHA and 200 college students), 321 subjects (111 PLWHA and 210 college students) chose to learn HIV-related knowledge via PBL-integrated methods. Co-primary outcomes were self-administered questionnaire after HIV-related education by all participants and self-reported medication adherence by newly diagnosed PLWHA, measured in terms of the number of missed doses in the past week at each of the seven visits during a 1-year period. Multivariate regression models adjusting different covariates were used to test the robustness of HIV awareness and adherence association. Mediation model was used to investigate the relationship among PBL training, awareness of HIV, and ART adherence.

Results: The knowledge scores of participants in the PBL group were higher than those in the controls (P = 0.001), especially the subgroup of newly diagnosed PLWHA in the PBL group (P = 0.001). The HIV-related health scores of the PBL college students were also higher than those of subjects exposed to conventional education (P < 0.001). There was no significant difference between the two by newly diagnosed PLWHA groups in the number of missed doses during the past week at each visit except at the first follow-up visit (P = 0.018). The indirect effect of PBL-integrated education on ART adherence at the 2-week visit through HIV awareness had a point estimate of 0.0349 and a 95% bias-corrected bootstrap confidence interval of 0.0061∼0.0874 in newly diagnosed PLWHA.

Conclusions: PLWHA and college students using PBL showed improved awareness of HIV and higher levels of recent ART adherence; however, there was no change in long-term ART adherence in newly diagnosed PLWHA.

ART in HIV-Positive Persons With Low Pretreatment Viremia: Results From the START Trial

BACKGROUND

The benefit of immediate antiretroviral therapy (ART) at CD4 >500 cells/μL was established in the Strategic Timing of Antiretroviral Treatment (START) study. The benefits and risks of immediate ART in participants with low pretreatment viremia, including virologic suppressors, were further assessed.

SETTING

Randomized prospective international study.

METHODS

START participants with enrollment viremia <3000 c/mL were included. We compared clinical outcomes (grade 4 adverse events, hospitalizations, or death), plasma viremia, CD4 counts, and changes in biomarkers in immediate versus deferred ART groups.

RESULTS

Participants (N = 1134 including 93 with viremia ≤50 c/mL) had a median age of 37 years, 40% were women, and median CD4 was 713 cells/µL. Ninety-seven percent in the immediate and 29% in the deferred arm initiated ART at a median of 6 and 699 days, respectively. Clinical outcomes were experienced in 64 versus 61 patients in immediate and deferred arms (hazard ratio 1.10, 95% confidence interval: 0.77 to 1.56). The CD4 count difference was 125 cells/µL at 12 and 235 cells/µL at 36 months higher in the immediate versus deferred groups. D-dimer and VCAM levels decreased, and C-reactive protein increased, in the immediate arm at month 8. No significant changes in CD4 counts or biomarkers were observed in persons who maintained spontaneous virologic suppression.

CONCLUSIONS

START participants with low enrollment viremia experienced higher CD4 counts, greater proportion with suppressed viremia, and decreases in D-dimer levels on immediate ART despite the lack of difference in serious clinical outcomes. These data support immediate ART in people with low viremia, although equipoise remains for suppressors.

Why Everyone (Almost) with HIV Needs to Be on Treatment: A Review of the Critical Data

Since 2014, a consensus of landmark studies has justified starting antiretroviral therapy (ART) regardless of CD4 count. The evidence for immediate and universal ART is strong, clearly showing individual and population-level benefits, and is supported by all major guidelines groups. Altogether, improvements in ART and recognition of its clinical and epidemiologic benefits justify near-universal ART, preferably as soon after the diagnosis of human immunodeficiency virus (HIV) as possible. Case-based discussions provide a framework to explore the evidence behind the current recommendation for ART for all HIV-positive persons and specific scenarios are discussed in which ART initiation may be delayed.

Post-treatment and spontaneous HIV control

PURPOSE OF REVIEW

The aim of the current review is to explore the evidence around virological remission in ART-treated and untreated individuals living with HIV. With increasing evidence and interest in post-treatment control within the HIV-cure field, it is now increasingly important to agree on definitions to allow different 'controller' phenotypes to be clearly distinguished and mechanisms compared.

RECENT FINDINGS

This review explores recent data on potential predictors and mechanisms driving spontaneous and post-treatment control. We explore data on the role of the reservoir as a determinant of control and the challenges associated with its study, including the safety of treatment interruption. We explore options around deriving a consensus on how to define different forms of control and the longer term utility of achieving remission.

SUMMARY

Post-treatment control and remission following treatment interruption are becoming increasingly common measures of intervention efficacy in cure trials. As well as a need to show treatment interruption protocols are well tolerated and acceptable, for these measures to be robust and comparable between studies, clear and consensual definitions need to be agreed.

Longitudinal HIV sequencing reveals reservoir expression leading to decay which is obscured by clonal expansion

After initiating antiretroviral therapy (ART), a rapid decline in HIV viral load is followed by a long period of undetectable viremia. Viral outgrowth assay suggests the reservoir continues to decline slowly. Here, we use full-length sequencing to longitudinally study the proviral landscape of four subjects on ART to investigate the selective pressures influencing the dynamics of the treatment-resistant HIV reservoir. We find intact and defective proviruses that contain genetic elements favoring efficient protein expression decrease over time. Moreover, proviruses that lack these genetic elements, yet contain strong donor splice sequences, increase relatively to other defective proviruses, especially among clones. Our work suggests that HIV expression occurs to a significant extent during ART and results in HIV clearance, but this is obscured by the expansion of proviral clones. Paradoxically, clonal expansion may also be enhanced by HIV expression that leads to splicing between HIV donor splice sites and downstream human exons.

How HIV reservoirs are shaped over time on antiviral therapy is poorly understood. Here, the authors analyze the dynamics of the HIV reservoir by longitudinal proviral sequencing revealing that HIV reservoir expression can contribute to its clearance and paradoxically even to its persistence.

Increased frequency of systemic pro-inflammatory Vδ1+ γδ T cells in HIV elite controllers correlates with gut viral load

γδ T cells predominate in the intestinal mucosa and help maintain gut homeostasis and mucosal immunity. Although HIV infection significantly alters these cells, what drives these perturbations is unclear. Growing evidence suggests that impaired intestinal immune function in HIV leads to chronic immune activation and disease progression. This occurs even in HIV controllers - individuals with undetectable HIV viremia without antiretroviral therapy (ART). We show that Vδ1⁺ cells, a subset of γδ T cells described as being important in intestinal barrier function, increase in frequency in HIV-infected individuals, including HIV controllers. These cells resemble terminally differentiated effector memory cells, producing the pro-inflammatory cytokines IFNγ, TNFα, and MIP-1β upon stimulation. Importantly, pro-inflammatory Vδ1⁺ cell frequency correlates with levels of HIV RNA in intestinal tissue but not in plasma. This study supports a model in which local viral replication in the gut in HIV controllers disrupts the phenotype and function of Vδ1⁺ cells, a cell type involved in the maintenance of epithelial barrier integrity, and may thereby contribute to systemic immune activation and HIV disease progression.

HIV control: Is getting there the same as staying there?

In this brief review and perspective, we address the question of whether the immune responses that bring about immune control of acute HIV infection are the same as, or distinct from, those that maintain long-term viral suppression once control of viremia has been achieved. To this end, we describe the natural history of elite and post-treatment control, noting the lack of data regarding what happens acutely. We review the evidence suggesting that the two clinical phenotypes may differ in terms of the mechanisms required to achieve and maintain control, as well as the level of inflammation that persists once a steady state is achieved. We then describe the evidence from longitudinal studies of controllers who fail and studies of biologic sex (male versus female), age (children versus adults), and simian immunodeficiency virus (SIV) (pathogenic/experimental versus nonpathogenic/natural infection). Collectively, these studies demonstrate that the battle between the inflammatory and anti-inflammatory pathways during acute infection has long-term consequences, both for the degree to which control is maintained and the health of the individual. Potent and stringent control of HIV may be required acutely, but once control is established, the chronic inflammatory response can be detrimental. Interventional approaches designed to bring about HIV cure and/or remission should be nuanced accordingly.

Plasmatic Levels of IL-18, IP-10, and Activated CD8+ T Cells Are Potential Biomarkers to Identify HIV-1 Elite Controllers With a True Functional Cure Profile

Elite controllers (ECs) are rare individuals able to naturally control HIV-1 replication below the detection limit of viral load (VL) commercial assays. It is unclear, however, whether ECs might be considered a natural model of a functional cure because some studies have noted CD4⁺ T cell depletion and disease progression associated with abnormally high levels of immune activation and/or inflammation in this group. Here, we propose the use of immunological parameters to identify HIV-1 ECs that could represent the best model of a functional cure. We compared plasma levels of six inflammatory biomarkers (IP-10, IL-18, sCD163, sCD14, CRP, and IL-6) and percentages of activated CD8⁺ T cells (CD38⁺HLA-DR⁺) between 15 ECs [8 with persistent undetectable viremia (persistent elite controllers) and 7 with occasional viral blips (ebbing elite controllers)], 13 viremic controllers (VCs—plasma VL between 51 and 2,000 RNA copies/mL), and 18 HIV-1 infected patients in combined antiretroviral therapy, with suppressed viremia, and 18 HIV-uninfected controls (HIV-neg). The two groups of ECs presented inflammation and activation profiles similar to HIV-neg individuals, and there was no evidence of CD4⁺ T cell decline over time. VCs, by contrast, had higher levels of IL-18, IP-10, and CRP and a lower CD4/CD8 ratio than that of HIV-neg (P < 0.05). Plasma levels of IL-18 and IP-10 correlated positively with CD8⁺ T cell activation and negatively with both CD4/CD8 and CD4% in HIV-1 controllers. These results suggest that most ECs, defined using stringent criteria in relation to the cutoff level of viremia (≤50 copies/mL) and a minimum follow-up time of >5 years, show no evidence of persistent inflammation or immune activation. This study further suggests that plasmatic levels of IL-18/IP-10 combined with the frequency of CD8⁺CD38⁺HLA-DR⁺ T cells can be important biomarkers to identify models of a functional cure among HIV-1 ECs.

High Plasma Levels of sTNF-R1 and CCL11 Are Related to CD4+ T-Cells Fall in Human Immunodeficiency Virus Elite Controllers With a Sustained Virologic Control

Our aim was to analyze the relationship between plasma inflammatory biomarkers and CD4+ T-cells evolution in human immunodeficiency virus (HIV) elite controllers (HIV-ECs) with a suppressed viremia. We carried out a retrospective study in 30 HIV-ECs classified into two groups: those showing no significant loss of CD4+ T-cells during the observation period (stable CD4+, n = 19) and those showing a significant decrease of CD4+ T-cells (decline CD4+, n = 11). Baseline plasma biomarkers were measured using a multiplex immunoassay: sTNF-R1, TRAIL, sFas (APO), sFasL, TNF-α, TNF-β, IL-8, IL-18, IL-6, IL-10, IP-10, MCP-1, MIP-1α, MIP-1β, RANTES, SDF1α, GRO-α, and CCL11. Baseline levels of sTNF-R1 and CCL11 and sTNF-R1/TNF-α ratio correlated with the slope of CD4+ T-cells (cells/μl/year) during follow-up [r = -0.370 (p = 0.043), r = -0.314 (p = 0.091), and r = -0.381 (p = 0.038); respectively]. HIV-ECs with declining CD4+ T-cells had higher baseline plasma levels of sTNF-R1 [1,500.7 (555.7; 2,060.7) pg/ml vs. 450.8 (227.9; 1,263.9) pg/ml; p = 0.018] and CCL11 [29.8 (23.5; 54.9) vs. 19.2 (17.8; 29.9) pg/ml; p = 0.041], and sTNF-R1/TNF-α ratio [84.7 (33.2; 124.2) vs. 25.9 (16.3; 75.1); p = 0.012] than HIV-1 ECs with stable CD4+ T-cells. The area under the receiver operating characteristic (ROC) curve [area under ROC curve (AUROC)] were 0.758 ± 0.093 (sTNF-R1), 0.727 ± 0.096 (CCL11), and 0.777 ± 0.087 (sTNF-R1/TNF-α). The cut-off of 75th percentile (high values) for these biomarkers had 71.4% positive predictive value and 73.9% negative predictive value for anticipating the evolution of CD4+ T-cells. In conclusion, the loss of CD4+ T-cells in HIV-ECs was associated with higher levels of two plasma inflammatory biomarkers (sTNF-R1 and CCL11), which were also reasonably accurate for the prediction of the CD4+ T-cells loss.

The hidden risk: Incorporating inflammation and HIV serostatus into coronary artery disease screening

CAD is a well-established comorbidity associated with HIV infection. This association is in large part due to ongoing inflammation propagated by viremia and dysregulation of the immune system. Despite this knowledge, evidence to guide clinical management and screening for CAD among HIV-infected patients is lacking. The following editorial discusses recent evidence that HIV-infected patients with abnormal cardiovascular stress testing are more likely to undergo subsequent percutaneous coronary intervention. Importantly, the cardiovascular consequences of HIV infection and potential clinical implications are discussed.

A High Frequency of HIV-Specific Circulating Follicular Helper T Cells Is Associated with Preserved Memory B Cell Responses in HIV Controllers

Follicular helper T cells (Tfh) play an essential role in the affinity maturation of the antibody response by providing help to B cells. To determine whether this CD4⁺ T cell subset may contribute to the spontaneous control of HIV infection, we analyzed the phenotype and function of circulating Tfh (cTfh) in patients from the ANRS CO21 CODEX cohort who naturally controlled HIV-1 replication to undetectable levels and compared them to treated patients with similarly low viral loads. HIV-specific cTfh (Tet⁺), detected by Gag-major histocompatibility complex class II (MHC-II) tetramer labeling in the CD45RA⁻ CXCR5⁺ CD4⁺ T cell population, proved more frequent in the controller group (P = 0.002). The frequency of PD-1 expression in Tet⁺ cTfh was increased in both groups (median, >75%) compared to total cTfh (<30%), but the intensity of PD-1 expression per cell remained higher in the treated patient group (P = 0.02), pointing to the persistence of abnormal immune activation in treated patients. The function of cTfh, analyzed by the capacity to promote IgG secretion in cocultures with autologous memory B cells, did not show major differences between groups in terms of total IgG production but proved significantly more efficient in the controller group when measuring HIV-specific IgG production. The frequency of Tet⁺ cTfh correlated with HIV-specific IgG production (R = 0.71 for Gag-specific and R = 0.79 for Env-specific IgG, respectively). Taken together, our findings indicate that key cTfh-B cell interactions are preserved in controlled HIV infection, resulting in potent memory B cell responses that may play an underappreciated role in HIV control.

The rare patients who spontaneously control HIV replication in the absence of therapy provide a unique model to identify determinants of an effective anti-HIV immune response. HIV controllers show signs of particularly efficient antiviral T cell responses, while their humoral response was until recently considered to play only a minor role in viral control. However, emerging evidence suggests that HIV controllers maintain a significant but “silent” antiviral memory B cell population that can be reactivated upon antigenic stimulation. We report that cTfh help likely contributes to the persistence of controller memory B cell responses, as the frequency of HIV-specific cTfh correlated with the induction of HIV-specific antibodies in functional assays. These findings suggest that T follicular help may contribute to HIV control and highlight the need for inducing such help in HIV vaccine strategies that aim at eliciting persistent B cell responses.

Post-treatment controllers after treatment interruption in chronically HIV-infected patients

OBJECTIVE

Control HIV replication requires continuous combined antiretroviral therapy (cART) as discontinuation of cART results in a rapid viral rebound. However, a few individuals exist who took cART for several years and did not show the expected viral rebound after treatment cessation. Most post-treatment controllers (PTCs) are early treated individuals. We report three cases who started cART during chronic infection.

DESIGN

Patients were treated and monitored according to Italian guidelines. For the description of cases, the percentage of CD8CD38HLA*DR cells, CD8CD38HLA*DR cells, major histocompatibility complex genotyping, total HIV-DNA and plasma levels of anti-retroviral (ARV) drugs were performed.

RESULTS

Patients started therapy during chronic infection. Patient 26636 started her first ARV drug two years after diagnosis and patients 93016 and 50293 started cART with high viral loads and low CD4 cell counts. Time without cART was 13, 11 and 1.5 years, respectively. None presented any of the protective class I HLA alleles and patient 93016 has the HLA-B*35 allele that appears to be enriched in PTCs. Patients 93016 and 50293 had very low levels of CD8CD38HLA*DR cells (<5%) much lower than those of patient 26636 (27%). T-cell-associated HIV-DNA was 3.78, 3.48 and 3.13 log copies/10 CD4, respectively.

CONCLUSION

Patients like ours may advance our understanding of the characteristics for which individuals may be more likely to achieve ART-free remissions. Furthermore, our patients are among the few so far described who started cART during chronic infection extending the hope that a functional cure is possible even in this setting.

From CD4-Based Initiation to Treating All HIV-Infected Adults Immediately: An Evidence-Based Meta-analysis

Background

The World Health Organization (WHO) Consolidated antiretroviral therapy (ART) guidelines set the CD4⁺ T-cell counts threshold to 500 cells/mm³ in 2013, and 2015 guidelines recommend treating all HIV-infected adults regardless of their CD4⁺ T-cell counts. To inform the decision-making around ART guidelines for people living with HIV, we systematically reviewed the literature to estimate differences in clinical benefits between individuals starting treatment with baseline CD4⁺ T-cell counts ≥500 cells/mm³ (early initiation) as compared to <500 cells/mm³ (deferred initiation).

Methods

We systematically searched the electronic databases and abstracts for randomized controlled trials (RCT) and observational studies. Outcomes were mortality, AIDS progression, AIDS or death, immunologic recovery, and virologic suppression. We pooled data across studies and performed analyses of effect sizes.

Results

We identified 13 studies comparing early and deferred treatment. The pooled risk ratio (RR) of mortality of 11 observational studies was 0.90 (95% CI 0.82–0.99), with moderate heterogeneity (I² = 53%). The pooled RR for progression to AIDS from two observational studies was 0.77 (95% CI 0.47–1.24). Five observational studies found a pooled RR of death or AIDS of 0.94 (95% CI 0.93–0.95). For the outcome of immunologic recovery, defined as CD4⁺ T-cell counts reaching at least 800 cells/mm³ after ART, one observational study found early initiation of ART had an HR (hazard ratio) of 2.39 (95% CI 1.93–2.96). The pooled RR of viral suppression (a viral load <50 copies/ml) after 9 months from one cohort was 1.04 (95% CI 0.99–1.09).

Conclusion

Mortality risk and risk for AIDS appear to be reduced among people living with HIV with early initiation of ART, based on current WHO guidelines, as compared to those with deferred initiation of ART (<500 cells/mm³).

Single-molecule techniques to quantify and genetically characterise persistent HIV

Antiretroviral therapy effectively suppresses, but does not eradicate HIV-1 infection. Persistent low-level HIV-1 can still be detected in plasma and cellular reservoirs even after years of effective therapy, and cessation of current treatments invariably results in resumption of viral replication. Efforts to eradicate persistent HIV-1 require a comprehensive examination of the quantity and genetic composition of HIV-1 within the plasma and infected cells located in the peripheral blood and tissues throughout the body. Single-molecule techniques, such as the single-copy assay and single-genome/proviral sequencing assays, have been employed to further our understanding of the source and viral dynamics of persistent HIV-1 during long-term effective therapy. The application of the single-copy assay, which quantifies plasma HIV-1 RNA down to a single copy, has revealed that viremia persists in the plasma and CSF after years of effective therapy. This low-level HIV-1 RNA also persists in the plasma following treatment intensification, treatment with latency reversing agents, cancer-related therapy, and bone marrow transplantation. Single-genome/proviral sequencing assays genetically characterise HIV-1 populations after passing through different selective pressures related to cell type, tissue type, compartment, or therapy. The application of these assays has revealed that the intracellular HIV-1 reservoir is stable and mainly located in CD4+ memory T cells. Moreover, this intracellular HIV-1 reservoir is primarily maintained by cellular proliferation due to homeostasis and antigenic stimulation, although cryptic replication may take place in anatomic sites where treatment is sub-optimal. The employment of single-genome/proviral sequencing showed that latency reversing agents broadly activate quiescent proviruses but do not clear the intracellular reservoir. Recently, full-length individual proviral sequencing assays have been developed and the application of these assays has revealed that the majority of intracellular HIV-1 DNA is genetically defective. In addition, the employment of these assays has shown that genetically intact proviruses are unequally distributed in memory T cell subsets during antiretroviral therapy. The application of single-molecule assays has enhanced the understanding of the source and dynamics of persistent HIV-1 in the plasma and cells of HIV-infected individuals. Future studies of the persistent HIV-1 reservoir and new treatment strategies to eradicate persistent virus will benefit from the utilization of these assays.

Loss of long-term non-progressor and HIV controller status over time in the French Hospital Database on HIV - ANRS CO4

Objectives

We studied the frequency and risk factors for loss of long-term non-progressor (LTNP) and HIV controller (HIC) status among patients identified as such in 2005 in the French Hospital Database on HIV (FHDH-ANRS CO4).

Methods

We selected patients who were treatment-naïve and asymptomatic in 2005 (baseline). Those with ≥8 years of known HIV infection and a CD4 cell nadir ≥500/mm³ were classified as LTNP and those with ≥10 years of known HIV infection and 90% of plasma viral load (VL) values ≤500 copies/ml in the absence of cART as HIC. cART initiation without loss of status and death from non AIDS-defining causes were considered as competing events.

Results

After 5 years of follow-up, 33% (95%CI; 27–42) of 171 LTNP patients and 17% (95%CI; 10–30) of 72 HIC patients had lost their status. In multivariable analyses, loss of LTNP status was associated with lower baseline CD4 cell counts and CD4/CD8 ratios. Only VL was significantly associated with loss of HIC status after adjustment for the baseline CD4 cell count, the CD4/CD8 ratio, and concomitant LTNP status. The hazard ratio for loss of HIC status was 5.5 (95%CI, 1.5–20.1) for baseline VL 50–500 vs ≤50 cp/mL, after adjustment for the baseline CD4 cell count.

Conclusions

One-third of LTNP and one-fifth of HIC patients lost their status after 5 years of follow-up, raising questions as to the possible benefits and timing of ART initiation in these populations.

Persistent HIV-1 replication during antiretroviral therapy

Purpose of review

The present review will highlight some of the recent findings regarding the capacity of HIV-1 to replicate during antiretroviral therapy (ART).

Recent findings

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.

Summary

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.

A Randomized Controlled Trial of Lisinopril to Decrease Lymphoid Fibrosis in Antiretroviral-Treated, HIV-infected Individuals

BACKGROUND

In HIV infection, lymphoid tissue is disrupted by fibrosis. Angiotensin converting enzyme inhibitors have anti-fibrotic properties. We completed a pilot study to assess whether the addition of lisinopril to antiretroviral therapy (ART) reverses fibrosis of gut tissue, and whether this leads to reduction of HIV RNA and DNA levels.

METHODS

Thirty HIV-infected individuals on ART were randomized to lisinopril at 20mg daily or matching placebo for 24 weeks. All participants underwent rectal biopsies prior to starting the study drug and at 22 weeks, and there were regular blood draws. The primary end point was the change in HIV RNA and DNA levels in rectal tissue. Secondary outcomes included the change in 1) HIV levels in blood; 2) Gag-specific T-cell responses; 3) levels of T-cell activation; and 4) collagen deposition.

RESULTS

The addition of lisinopril did not have a significant effect on the levels of HIV RNA or DNA in gut tissue or blood, Gag-specific responses, or levels of T-cell activation. Lisinopril also did not have a significant impact on lymphoid fibrosis in the rectum, as assessed by quantitative histology or heavy water labeling.

CONCLUSIONS

Treatment with lisinopril for 24 weeks in HIV-infected adults did not have an effect on lymphoid fibrosis, immune activation, or gut tissue viral reservoirs. Further study is needed to see if other anti-fibrotic agents may be useful in reversing lymphoid fibrosis and reducing HIV levels.

Mechanisms of Virologic Control and Clinical Characteristics of HIV+ Elite/Viremic Controllers

Human immunodeficiency virus type 1 (HIV-1) disease is pandemic, with approximately 36 million infected individuals world-wide. For the vast majority of these individuals, untreated HIV eventually causes CD4+ T cell depletion and profound immunodeficiency, resulting in morbidity and mortality. But for a remarkable few (0.2 to 0.5 percent), termed elite controllers (ECs), viral loads (VLs) remain suppressed to undetectable levels (< 50 copies/ml) and peripheral CD4+ T cell counts remain high (200 to 1000/μl), all in the absence of antiretroviral therapy (ART). Viremic controllers (VCs) are a similar but larger subset of HIV-1 infected individuals who have the ability to suppress their VLs to low levels. These patients have been intensively studied over the last 10 years in order to determine how they are able to naturally control HIV in the absence of medications, and a variety of mechanisms have been proposed. Defective HIV does not explain the clinical status of most ECs/VCs; rather these individuals appear to somehow control HIV infection, through immune or other unknown mechanisms. Over time, many ECs and VCs eventually lose the ability to control HIV, leading to CD4+ T cell depletion and immunologic dysfunction in the absence of ART. Elucidating novel mechanisms of HIV control in this group of patients will be an important step in understanding HIV infection. This will extend our knowledge of HIV-host interaction and may pave the way for the development of new therapeutic approaches and advance the cure agenda.

Long-term follow-up of elite controllers: Higher risk of complications with HCV coinfection, no association with HIV disease progression

To estimate the effect of hepatitis C virus (HCV) coinfection on the development of complications and progression of human immunodeficiency virus (HIV) disease among HIV-infected elite controllers.Single-center retrospective cohort. Kaplan-Meier methods, prevalence ratios, and Cox proportional-hazards models were used.In all, 55 HIV-infected elite controllers were included in this study. Among them, 45% were HIV/HCV coinfected and 55% were HIV mono-infected. Median follow-up time for the cohort was 11 years. Twenty-five patients experienced a complication and 16 lost elite controller status during the study period. HCV coinfected patients were 4.78 times (95% confidence interval 1.50-15.28) more likely to develop complications compared with HIV mono-infected patients. There was no association between HCV coinfection status and loss of elite control (hazard ratio 0.75, 95% confidence interval 0.27-2.06).Hepatitis C virus coinfection was significantly associated with the risk of complications even after controlling for sex, injecting drug use, and older age. HCV coinfected patients had higher levels of cellular activation while also having similar levels of lipopolysaccharide and soluble CD14. HCV coinfection was not associated with loss of elite controller status. Taken together, this suggests that HCV coinfection does not directly affect HIV replication dynamics or natural history, but that it may act synergistically with HIV to produce a greater number of associated complications. Continued follow-up will be needed to determine whether HCV cure through the use of direct-acting antivirals among HIV/HCV coinfected elite controllers will make the risk for complications among these patients similar to their HIV mono-infected counterparts.

Effect of the Latent Reservoir on the Evolution of HIV at the Within- and Between-Host Levels

The existence of long-lived reservoirs of latently infected CD4+ T cells is the major barrier to curing HIV, and has been extensively studied in this light. However, the effect of these reservoirs on the evolutionary dynamics of the virus has received little attention. Here, we present a within-host quasispecies model that incorporates a long-lived reservoir, which we then nest into an epidemiological model of HIV dynamics. For biologically plausible parameter values, we find that the presence of a latent reservoir can severely delay evolutionary dynamics within a single host, with longer delays associated with larger relative reservoir sizes and/or homeostatic proliferation of cells within the reservoir. These delays can fundamentally change the dynamics of the virus at the epidemiological scale. In particular, the delay in within-host evolutionary dynamics can be sufficient for the virus to evolve intermediate viral loads consistent with maximising transmission, as is observed, and not the very high viral loads that previous models have predicted, an effect that can be further enhanced if viruses similar to those that initiate infection are preferentially transmitted. These results depend strongly on within-host characteristics such as the relative reservoir size, with the evolution of intermediate viral loads observed only when the within-host dynamics are sufficiently delayed. In conclusion, we argue that the latent reservoir has important, and hitherto under-appreciated, roles in both within- and between-host viral evolution.

Post-Treatment Controllers: Role in HIV "Cure" Research

Descriptions of individuals who are able to control viral replication in the absence of antiretroviral therapy after receiving short-term therapy early in infection ("post-treatment controllers") has generated excitement and controversy within the field. As with natural or "elite" controllers, these cases provide hope that a long-term remission or "functional cure" might one day be possible. Here, we review what is known and not known about these cases and discuss the immunologic factors that may allow these unique individuals to be maintain viral control and may be important for future curative strategies.