Combined ART started during acute HIV infection protects central memory CD4+ T cells and can induce remission

HIV-1 reservoir landscape of post-treatment control

PURPOSE OF REVIEW

This review explores the viral reservoir landscape in individuals who control viral replication after treatment interruption (TI), designated as post-treatment controllers (PTCs). Identifying their virologic features is crucial to inform drug-free HIV remission strategies.

RECENT FINDINGS

Traditionally characterized as small, likely due to early treatment, the viral reservoir of PTCs, after TI, exhibits limited transcriptional activity, residual viral replication and subsequent proviral diversity. Intact proviruses are found to be restricted. In nonhuman primate PTCs, this depletion of intact proviruses is already observed in lymph nodes before TI, suggesting that control mechanisms begin during antiretroviral therapy. Furthermore, recent studies suggest immune-driven proviral deep latency associated with repressive epigenetic features and integration sites in PTCs. While molecular mapping of virological features of PTCs is increasingly precise and coupled with in-depth immunologic assays, robust predictive biomarkers of PTCs are still lacking.

SUMMARY

Despite limited sample sizes and heterogeneous definitions, common virologic features of PTCs include restricted reservoir size and transcriptional activity, fewer intact proviruses and deep proviral latency. Ongoing research using innovative technologies will further elucidate the mechanisms underlying post-treatment control, paving the way for successful HIV cure interventions.

Early antiretroviral therapy favors post-treatment SIV control associated with the expansion of enhanced memory CD8+ T-cells

HIV remission can be achieved in some people, called post-treatment HIV controllers, after antiretroviral treatment discontinuation. Treatment initiation close to the time of infection was suggested to favor post-treatment control, but the circumstances and mechanisms leading to this outcome remain unclear. Here we evaluate the impact of early (week 4) vs. late (week 24 post-infection) treatment initiation in SIVmac251-infected male cynomolgus macaques receiving 2 years of therapy before analytical treatment interruption. We show that early treatment strongly promotes post-treatment control, which is not related to a lower frequency of infected cells at treatment interruption. Rather, early treatment favors the development of long-term memory CD8+ T cells with enhanced proliferative and SIV suppressive capacity that are able to mediate a robust secondary-like response upon viral rebound. Our model allows us to formally demonstrate a link between treatment initiation during primary infection and the promotion of post-treatment control and provides results that may guide the development of new immunotherapies for HIV remission.

The build-up of stock of stable integrated proviruses overtime explains the difficulty in reducing HIV-1 DNA levels when treatment is initiated at the chronic stage of the infection

Background

Understanding factors affecting the size and the evolution of the HIV reservoir is essential for the development of curative strategies. This study aimed to assess the impact of antiretroviral therapy (ART) initiated during primary infection (PHI) vs chronic infection (CHI) on the levels and dynamics of integrated HIV-1 DNA, a biomarker of viral persistence.

Methods

Integrated and total HIV-1-DNA were measured in the blood of 92 patients treated during PHI (early group) and 41 during CHI (deferred group), at diagnosis, ART initiation, and 12-24 months on treatment.

Results

On ART, detectable (>1.78 log10 copies/106 PBMCs) integrated HIV-1 DNA levels were significantly lower in the early vs deferred group (2.99 log10vs 3.29 log10,p = 0.005). The proportion of undetectable integrated HIV-1 DNA tended to be higher in the early group vs deferred group (61 % vs 46 %; p = 0.133).

Conclusion

Treatment initiated at PHI limits the levels of integrated HIV-1 DNA in blood. However, initiating treatment at CHI does not allow reaching such low levels in most patients, probably because the stable proviruses at that stage are present in the less prone to elimination long-lived cells. Thus, early ART could provide an opportunity to preparing for functional cure and eradication strategies.

Upregulation of IFN-stimulated genes persists beyond the transitory broad immunologic changes of acute HIV-1 infection

Chronic immune activation during HIV-1 infection contributes to morbidity and mortality in people living with HIV. To elucidate the underlying biological pathways, we evaluated whole blood gene expression trajectories from before, through acute, and into chronic HIV-1 infection. Interferon-stimulated genes, including MX1, IFI27 and ISG15, were upregulated during acute infection, remained elevated into chronic infection, and were strongly correlated with plasma HIV-1 RNA as well as TNF-α and CXCL10 cytokine levels. In contrast, genes involved in cellular immune responses, such as CD8A, were upregulated during acute infection before reaching a peak and returning to near pre-infection levels in chronic infection. Our results indicate that chronic immune activation during HIV-1 infection is characterized by persistent elevation of a narrow set of interferon-stimulated genes and innate cytokines. These findings raise the prospect of devising a targeted intervention to restore healthy immune homeostasis in people living with HIV-1.

Profound phenotypic and epigenetic heterogeneity of the HIV-1-infected CD4+ T cell reservoir

Understanding the complexity of the long-lived HIV reservoir during antiretroviral therapy (ART) remains a considerable impediment in research towards a cure for HIV. To address this, we developed a single-cell strategy to precisely define the unperturbed peripheral blood HIV-infected memory CD4+ T cell reservoir from ART-treated people living with HIV (ART-PLWH) via the presence of integrated accessible proviral DNA in concert with epigenetic and cell surface protein profiling. We identified profound reservoir heterogeneity within and between ART-PLWH, characterized by new and known surface markers within total and individual memory CD4+ T cell subsets. We further uncovered new epigenetic profiles and transcription factor motifs enriched in HIV-infected cells that suggest infected cells with accessible provirus, irrespective of reservoir distribution, are poised for reactivation during ART treatment. Together, our findings reveal the extensive inter- and intrapersonal cellular heterogeneity of the HIV reservoir, and establish an initial multiomic atlas to develop targeted reservoir elimination strategies.

Real-world data in late presentation of HIV infection in Suzhou, China: Results from four consecutive cross-sectional surveys, 2017-2020

Objectives

This study aimed to examine the real prevalence of late presentation of HIV infection and to identify factors associated with late HIV presentation among patients with newly diagnosed HIV/AIDS in Suzhou, China.

Methods

Patients with newly diagnosed HIV/AIDS who registered in national AIDS surveillance system from 2017 to 2020 were included in this study. Late presentation (LP) of HIV infection was defined as HIV diagnosis with a CD4 count < 350 cells/μL or an AIDS-defining event. Multivariable logistic regression analyses were used to identify factors associated with LP.

Results

A total of 2,300 patients were enrolled. 1,325 were classified as late presenters, showing a high percentage of 57.6% (95% CI: 54.5-60.7%) and a rise (P = 0.004) over the four-year period. Patients with newly diagnosed HIV/AIDS who were older than 24 years of age (aOR = 1.549, P = 0.001 for 25-39 years; aOR = 2.389, P < 0.001 for 40 years and older), were Suzhou registered residents (aOR = 1.259, P = 0.026), and were from inpatient and outpatient (aOR = 1.935, P < 0.001) were more likely to be late presentation.

Conclusions

This study showed a high percentage and a rise of late presentation of HIV infection among patients with newly diagnosed HIV/AIDS in Suzhou, China, which is a challenge for future prevention and control of AIDS. Targeted measures should be urgently implemented to reduce late HIV diagnosis.

Systematic post-mortem analysis of brain tissue from an HIV-1 subtype C viremic decedent revealed a paucity of infection and pathology

Whether the human brain is a robust reservoir for HIV-1 subtype C has yet to be established. We aimed to determine whether HIV-1 subtype C infection can be detected in the brain tissue of a viremic individual at post-mortem and whether the viral burden was differential between different brain regions. This study reports a 38-year-old Zambian female decedent with severe wasting who was on Atripla for antiretroviral therapy. The cause of death was determined to be HIV/AIDS end-stage disease. The QuantStudio 3 Real-Time PCR System analyzed formalin-fixed paraffin-embedded tissue DNA from a systematic sampling of the entire left-brain hemisphere. Plasma and cerebral spinal fluid HIV-1 RNA loads were 576,123 and 14,962 copies/mL, respectively. The lymph node DNA viral load was 2316 copies per 106 cells. Two hundred and six (96.3%) tissue blocks had amplifiable DNA. HIV-1 viral DNA was detected in 35.9% of the blocks, the highest in the basal ganglia (66.7%) and the frontal lobe (46%). Overall, HIV detection was random, with low viral copies detected by quantitative polymerase chain reaction (qPCR); the lowest was observed in the occipital (median, IQR, range) 0.0 [0.0-0.0], 0.0-31.3, and the highest in the basal ganglia (mean ± SD, range, 125.1149.5, 0.0-350.0). Significant differences in HIV-1 DNA distribution were observed between the occipital versus parietal (p = 0.049), occipital versus frontal (p = 0.019), occipital versus basal ganglia (p = 0.005), cerebellum versus frontal (p = 0.021), cerebellum versus basal ganglia (p = 0.007), and temporal versus frontal (p = 0.034).

Substantial uneven proliferation of CD4+ T cells during recovery from acute HIV infection is sufficient to explain the observed expanded clones in the HIV reservoir

The HIV reservoir is a population of 1-10 million anatomically dispersed, latently infected memory CD4+ T cells in which HIV DNA is quiescently integrated into human chromosomal DNA. When antiretroviral therapy (ART) is stopped and HIV replication initiates in one of these cells, systemic viral spread resumes, rekindling progression to AIDS. Therefore, HIV latency prevents cure. The detection of many populations of identical HIV sequences at unique integration sites implicates CD4+ T cell proliferation as the critical driver of reservoir sustainment after a prolonged period of effective ART. Initial reservoir formation occurs during the first week of primary infection usually before ART is started. While empirical data indicates that both de novo infection and cellular proliferation generate latently infected cells during early untreated infection, it is not known which of these mechanisms is predominant. We developed a mathematical model that recapitulates the profound depletion and brisk recovery of CD4+ T cells, reservoir creation, and viral load trajectory during primary HIV infection. We extended the model to stochastically simulate individual HIV reservoir clones. This model predicts the first detection of HIV infected clones approximately 5 weeks after infection as has recently been shown in vivo and suggests that substantial, uneven proliferation among clones during the recovery from CD4+ lymphopenia is the most plausible explanation for the observed clonal reservoir distribution during the first year of infection.

Effective Treatment of Patients Experiencing Primary, Acute HIV Infection Decreases Exhausted/Activated CD4+ T Cells and CD8+ T Memory Stem Cells

Several studies have identified main changes in T- and B-lymphocyte subsets during chronic HIV infection, but few data exist on how these subsets behave during the initial phase of HIV infection. We enrolled 22 HIV-infected patients during the acute stage of infection before the initiation of antiretroviral therapy (ART). Patients had blood samples drawn previous to ART initiation (T0), and at 2 (T1) and 12 (T2) months after ART initiation. We quantified cellular HIV-DNA content in sorted naïve and effector memory CD4 T cells and identified the main subsets of T- and B-lymphocytes using an 18-parameter flow cytometry panel. We identified correlations between the patients’ clinical and immunological data using PCA. Effective HIV treatment reduces integrated HIV DNA in effector memory T cells after 12 months (T2) of ART. The main changes in CD4+ T cells occurred at T2, with a reduction of activated memory, cytolytic and activated/exhausted stem cell memory T (T_SCM) cells. Changes were present among CD8+ T cells since T1, with a reduction of several activated subsets, including activated/exhausted T_SCM. At T2 a reduction of plasmablasts and exhausted B cells was also observed. A negative correlation was found between the total CD4+ T-cell count and IgM-negative plasmablasts. In patients initiating ART immediately following acute/early HIV infection, the fine analysis of T- and B-cell subsets has allowed us to identify and follow main modifications due to effective treatment, and to identify significant changes in CD4+ and CD8+ T memory stem cells.

Genotypic and Phenotypic Diversity of the Replication-Competent HIV Reservoir in Treated Patients

In HIV infection, viral rebound after treatment discontinuation is considered to originate predominantly from viral genomes integrated in resting CD4⁺ T lymphocytes. Replication-competent proviral genomes represent a minority of the total HIV DNA. While the quantification of the HIV reservoir has been extensively studied, the diversity of genomes that compose the reservoir was less explored. Here, we measured the genotypic and phenotypic diversity in eight patients with different treatment histories. Between 4 and 14 (mean, 8) individual viral isolates per patient were obtained using a virus outgrowth assay, and their near-full-length genomes were sequenced. The mean pairwise distance (MPD) observed in different patients correlated with the time before undetectable viremia was achieved (r = 0.864, P = 0.0194), suggesting that the complexity of the replication-competent reservoir mirrors that present at treatment initiation. No correlation was instead observed between MPD and the duration of successful treatment (mean, 8 years; range, 2 to 21 years). For 5 of the 8 patients, genotypically identical viral isolates were observed in independent wells, suggesting clonal expansion of infected cells. Identical viruses represented between 25 and 60% of the isolates (mean, 48%). The proportion of identical viral isolates correlated with the duration of treatment (r = 0.822, P = 0.0190), suggesting progressive clonal expansion of infected cells during ART. A broader range of infectivity was also observed among isolates from patients with delayed viremia control (r = 0.79, P = 0.025). This work unveiled differences in the genotypic and phenotypic features of the replication-competent reservoir from treated patients and suggests that delaying treatment results in increased diversity of the reservoir.

IMPORTANCE In HIV-infected and effectively treated individuals, integrated proviral genomes may persist for decades. The vast majority of the genomes, however, are defective, and only the replication-competent fraction represents a threat of viral reemergence. The quantification of the reservoir has been thoroughly explored, while the diversity of the genomes has been insufficiently studied. Its characterization, however, is relevant for the design of strategies aiming the reduction of the reservoir. Here, we explored the replication-competent near-full-length HIV genomes of eight patients who experienced differences in the delay before viremia control and in treatment duration. We found that delayed effective treatment was associated with increased genetic diversity of the reservoir. The duration of treatment did not impact the diversity but was associated with higher frequency of clonally expanded sequences. Thus, early treatment initiation has the double advantage of reducing both the size and the diversity of the reservoir.

Once-daily dolutegravir versus darunavir plus cobicistat in adults at the time of primary HIV-1 infection: the OPTIPRIM2-ANRS 169 randomized, open-label, Phase 3 trial

BACKGROUND

Whether integrase strand transfer inhibitors (INSTIs) can decrease HIV-1 DNA levels more rapidly than boosted PIs during primary HIV-1 infection (PHI) is unknown. We hypothesized that once-daily dolutegravir/tenofovir/emtricitabine could reduce the viral reservoir through rapid viral replication control further than once-daily darunavir/cobicistat/tenofovir/emtricitabine.

METHODS

The OPTIPRIM2-ANRS 169 study was a randomized (1:1), open-label, multicentre trial in adults with ≤5 or ≤3 HIV antibodies detected, respectively, by western blot or immunoblot in the last 10 days. The primary endpoint was total HIV-1 DNA levels in PBMCs at Week 48 (W48) adjusted for baseline levels. The main secondary endpoint was HIV-1 RNA level decrease.

RESULTS

Between April 2017 and August 2018, 101 patients were included from 31 hospitals. Most patients were men (93%), the median age was 36 years and 17% were Fiebig stage ≤3. The median (IQR) plasma HIV-1 RNA and DNA levels were, respectively, 5.8 (5.0-6.6) and 3.87 (3.52-4.15) log10 copies/million PBMCs. The median (IQR) decreases in HIV-1 DNA levels at W48 were -1.48 (-1.74 to -1.06) and -1.39 (-1.55 to -0.98) log10 copies/million PBMCs in the dolutegravir and darunavir/cobicistat groups, respectively (P = 0.52). Plasma HIV-1 RNA levels were <50 copies/mL in 24% versus 0% of patients in the dolutegravir and darunavir/cobicistat groups at W4, 55% versus 2% at W8, 67% versus 17% at W12, and 94% versus 90% at W48, respectively.

CONCLUSIONS

Dolutegravir-based and darunavir-based regimens initiated during PHI strongly and similarly decreased the blood reservoir size. Considering the rapid viral suppression during a period of high HIV-1 transmission risk, dolutegravir-based regimens are a major first-line option.

Impaired CD4+ T cell differentiation in HIV-1 infected patients receiving early anti-retroviral therapy

Differentiation of CD4+ T naïve (T_N) into central memory (T_CM) cells involves extensive molecular processes. We compared the transcriptomes of CD4+ T_N and T_CM cells from HIV-1 infected patients receiving early anti-retroviral therapy (ART; EA; n = 13) and controls (n = 15). Comparison of protein coding genes between T_CM and T_N revealed 533 and 82 differentially expressed genes (DEGs) in controls and EA, respectively. A high degree of transcriptional complexity was detected during transition of CD4+ T_N to T_CM cells in controls involving 70 TFs, 20 master regulators of T cell differentiation (TBX21, GATA3, RARA, FOXP3, RORC); in EA only 7 TFs were modulated with expression of several master regulators remaining unchanged during differentiation. Analysis of interactions between modulated TFs and target genes revealed important regulatory interactions missing in EA group. We conclude that T cell differentiation in EA patients is impaired due to reduced modulation of genes involved in transition from CD4+ T_N to T_CM cells.

Longitudinal Improvements in Viral Suppression for Persons With New HIV Diagnosis Receiving Care in the Ryan White Program: A 10-Year Experience in New Haven, CT (2009-2018)

Background

The Ryan White (RW) program funds medical and other support services for low-income persons with HIV, significantly improving progress along the HIV care continuum. Although the program has shown overall improvements in achievement of viral suppression, the relative contributions of changes in clinical practice and RW service components to the optimization of the HIV care continuum, particularly for those with new HIV diagnoses, remain unknown.

Methods

The target population was patients with recent HIV diagnoses who received care at RW-funded clinics in the greater New Haven area between 2009 and 2018. Client data were extracted from the RW-funded database, CAREWare, and the electronic medical record. Primary outcomes included time between HIV diagnosis and first HIV primary care (PC) visit, antiretroviral therapy (ART) initiation, and viral suppression (VS).

Results

There were 386 eligible patients. Between 2009 and 2018, the median number of days from HIV diagnosis to first PC visit decreased from 58.5 to 8.5 days, and ART initiation decreased from 155 to 9 days. In 2018, 86% of participants achieved viral suppression within 1 year, compared with 2.5% in 2009. Patients who initiated single-tablet ART and integrase inhibitor-containing regimens were more likely to reach viral suppression within 1 year (P < .001). Receipt of medical case management services was also associated with achieving viral suppression (P < .001).

Conclusions

Longitudinal improvements over 10 years in ART initiation and viral suppression were observed due to clinical advances and their effective implementation through the RW comprehensive care model. Further study of the essential components promoting these outcomes is needed.

Antiretroviral Initiation at ≥800 CD4+ Cells/mm3 Associated With Lower Human Immunodeficiency Virus Reservoir Size

BACKGROUND

Identifying factors that determine the frequency of latently infected CD4+ T cells on antiretroviral therapy (ART) may inform strategies for human immunodeficiency virus (HIV) cure. We investigated the role of CD4+ count at ART initiation for HIV persistence on ART.

METHODS

Among participants of the Strategic Timing of Antiretroviral Treatment Study, we enrolled people with HIV (PWH) who initiated ART with CD4+ T-cell counts of 500-599, 600-799, or ≥ 800 cells/mm3. After 36-44 months on ART, the levels of total HIV-DNA, cell-associated unspliced HIV-RNA (CA-US HIV-RNA), and two-long terminal repeat HIV-DNA in CD4+ T cells were quantified and plasma HIV-RNA was measured by single-copy assay. We measured T-cell expression of Human Leucocyte Antigen-DR Isotype (HLA-DR), programmed death-1, and phosphorylated signal transducer and activator of transcription-5 (pSTAT5). Virological and immunological measures were compared across CD4+ strata.

RESULTS

We enrolled 146 PWH, 36 in the 500-599, 60 in the 600-799, and 50 in the ≥ 800 CD4 strata. After 36-44 months of ART, total HIV-DNA, plasma HIV-RNA, and HLA-DR expression were significantly lower in PWH with CD4+ T-cell count ≥ 800 cells/mm3 at ART initiation compared with 600-799 or 500-599 cells/mm3. The median level of HIV-DNA after 36-44 months of ART was lower by 75% in participants initiating ART with ≥ 800 vs 500-599 cells/mm3 (median [interquartile range]: 16.3 [7.0-117.6] vs 68.4 [13.7-213.1] copies/million cells, respectively). Higher pSTAT5 expression significantly correlated with lower levels of HIV-DNA and CA-US HIV-RNA. Virological measures were significantly lower in females.

CONCLUSIONS

Initiating ART with a CD4+ count ≥ 800 cells/mm3 compared with 600-799 or 500-599 cells/mm3 was associated with achieving a substantially smaller HIV reservoir on ART.

Virological and Immunological Outcomes of an Intensified Four-Drug versus a Standard Three-Drug Antiretroviral Regimen, Both Integrase Strand Transfer Inhibitor-Based, in Primary HIV Infection

The optimal therapeutic approach for primary HIV infection (PHI) is still debated. We aimed to compare the viroimmunological response to a four- versus a three-drug regimen, both INSTI-based, in patients with PHI. This was a monocentric, prospective, observational study including all patients diagnosed with PHI from December 2014 to April 2018. Antiretroviral therapy (ART) was started, before genotype resistance test results, with tenofovir/emtricitabine and either raltegravir plus boosted darunavir or dolutegravir. Cumulative probability of virological suppression [VS] (HIV-1 RNA< 40 cp/mL), low-level HIV-1 DNA [LL-HIVDNA] (HIV-1 DNA < 200 copies/106PBMC), and CD4/CD8 ratio ≥1 were estimated using Kaplan−Meier curves. Factors associated with the achievement of VS, LL-HIVDNA, and CD4/CD8 ≥ 1 were assessed by a Cox regression model. We enrolled 144 patients (95.8% male, median age 34 years): 110 (76%) started a four-drug-based therapy, and 34 (24%) a three-drug regimen. Both treatment groups showed a comparable high probability of achieving VS and a similar probability of reaching LL-HIVDNA and a CD4/CD8 ratio ≥1 after 48 weeks from ART initiation. Higher baseline HIV-1 RNA and HIV-1 DNA levels lowered the chance of VS, whereas a better preserved immunocompetence increased that chance. Not statistically significant factors associated with LL-HIVDNA achievement were found, whereas a higher baseline CD4/CD8 ratio predicted the achievement of immune recovery. In PHI patients, the rapid initiation of either an intensified four-drug or a standard three-drug INSTI-based regimen showed comparable responses in terms of VS, viral reservoir size, and immunological recovery.

Early Diagnosis of HIV-1 and HIV-2 Using Cobas HIV-1/HIV-2 Qualitative Test: A Novel Qualitative Nucleic Acid Amplification Test for Plasma, Serum, and Dried Blood Spot Specimens

BACKGROUND

Nucleic acid amplification tests (NATs) minimize the time from HIV infection to diagnosis, reducing transmission during acute HIV. NATs are especially useful for diagnosing HIV in children younger than 18 months and discriminating between HIV-1 and HIV-2.

METHODS

We evaluated the performance of the cobas HIV-1/HIV-2 qualitative (cobas HIV-1/2 Qual) test for use on cobas 6800/8800 Systems. The results of adult plasma and serum samples and pediatric dried blood spots were compared with those of the recomLine HIV-1 & HIV-2 Immunoglobulin G serological test and COBAS AmpliPrep/COBAS TaqMan HIV-1 qualitative test, v2.0. Genotype inclusivity and limits of detection were determined, and sensitivity on seroconversion panels was compared with that in the Bio-Rad Geenius HIV 1/2 Confirmatory Assay, Abbott ARCHITECT HIV Ag/Ab Combo serological test, and cobas TaqScreen MPX, v2.0.

RESULTS

Concordance of cobas HIV-1/2 Qual test with the comparator serological test and COBAS AmpliPrep/COBAS TaqMan test was ≥99.6% with all sample types. Reactivity with all HIV genotypes was 100%. LOD in plasma samples was 14.8, 12.6, and 27.9 copies/mL for HIV-1 group M, HIV-1 group O, and HIV-2, respectively, with similar results for serum samples. LOD in dried blood spots was 255 copies/mL for HIV-1 and 984 copies/mL for HIV-2. HIV infection was detected 18.9 days and 8.5 days earlier than the confirmatory and serological assays, respectively, and at a similar time to the NAT.

CONCLUSIONS

The cobas HIV-1/2 Qual test enables early and accurate diagnoses of HIV-1 and HIV-2 in adults and children across sample types. The assay could help avert transmission during acute HIV, simplify HIV diagnostic algorithms, and promote the survival of HIV-infected children.

Alteration in Oral Microbiome Among Men Who Have Sex With Men With Acute and Chronic HIV Infection on Antiretroviral Therapy

Despite the antiretroviral therapy (ART), human immunodeficiency virus (HIV)-related oral disease remains a common problem for people living with HIV (PLWH). Evidence suggests that impairment of immune function in HIV infection might lead to the conversion of commensal bacteria to microorganisms with increased pathogenicity. However, limited information is available about alteration in oral microbiome in PLWH on ART. We performed a longitudinal comparative study on men who have sex with men (MSM) with acute HIV infection (n=15), MSM with chronic HIV infection (n=15), and HIV-uninfected MSM controls (n=15). Throat swabs were collected when these subjects were recruited (W0) and 12 weeks after ART treatment (W12) from the patients. Genomic DNAs were extracted and 16S rRNA gene sequencing was performed. Microbiome diversity was significantly decreased in patients with acute and chronic HIV infections compared with those in controls at the sampling time of W0 and the significant difference remained at W12. An increased abundance of unidentified Prevotellaceae was found in patients with acute and chronic HIV infections. Moreover, increased abundances of Prevotella in subjects with acute HIV infection and Streptococcus in subjects with chronic HIV infection were observed. In contrast, greater abundance in Lactobacillus, Rothia, Lautropia, and Bacteroides was found in controls. After effective ART, Bradyrhizobium was enriched in both acute and chronic HIV infections, whereas in controls, Lactobacillus, Rothia, Clostridia, Actinobacteria, and Ruminococcaceae were enriched. In addition, we found that lower CD4⁺ T-cell counts (<200 cells/mm³) were associated with lower relative abundances of Haemophilus, Actinomyces, unidentified Ruminococcaceae, and Rothia. This study has shown alteration in oral microbiome resulting from HIV infection and ART. The results obtained warrant further studies in a large number of subjects with different ethnics. It might contribute to improved oral health in HIV-infected individuals.

Can Broadly Neutralizing HIV-1 Antibodies Help Achieve an ART-Free Remission?

Many broadly neutralizing antibodies (bnAbs) targeting the HIV-1 envelope glycoprotein are being assessed in clinical trials as strategies for HIV-1 prevention, treatment, and antiretroviral-free remission. BnAbs can neutralize HIV-1 and target infected cells for elimination. Concerns about HIV-1 resistance to single bnAbs have led to studies of bnAb combinations with non-overlapping resistance profiles. This review focuses on the potential for bnAbs to induce HIV-1 remission, either alone or in combination with latency reversing agents, therapeutic vaccines or other novel therapeutics. Key topics include preliminary activity of bnAbs in preclinical models and in human studies of HIV-1 remission, clinical trial designs, and antibody design strategies to optimize pharmacokinetics, coverage of rebound-competent virus, and enhancement of cellular immune functions.

How elite controllers and posttreatment controllers inform our search for an HIV-1 cure

A small percentage of people living with HIV-1 can control viral replication without antiretroviral therapy (ART). These patients are called elite controllers (ECs) if they are able to maintain viral suppression without initiating ART and posttreatment controllers (PTCs) if they control HIV replication after ART has been discontinued. Both types of controllers may serve as a model of a functional cure for HIV-1 but the mechanisms responsible for viral control have not been fully elucidated. In this review, we highlight key lessons that have been learned so far in the study of ECs and PTCs and their implications for HIV cure research.

Relationship between CD4 T cell turnover, cellular differentiation and HIV persistence during ART

The precise role of CD4 T cell turnover in maintaining HIV persistence during antiretroviral therapy (ART) has not yet been well characterized. In resting CD4 T cell subpopulations from 24 HIV-infected ART-suppressed and 6 HIV-uninfected individuals, we directly measured cellular turnover by heavy water labeling, HIV reservoir size by integrated HIV-DNA (intDNA) and cell-associated HIV-RNA (caRNA), and HIV reservoir clonality by proviral integration site sequencing. Compared to HIV-negatives, ART-suppressed individuals had similar fractional replacement rates in all subpopulations, but lower absolute proliferation rates of all subpopulations other than effector memory (TEM) cells, and lower plasma IL-7 levels (p = 0.0004). Median CD4 T cell half-lives decreased with cell differentiation from naïve to TEM cells (3 years to 3 months, p<0.001). TEM had the fastest replacement rates, were most highly enriched for intDNA and caRNA, and contained the most clonal proviral expansion. Clonal proviruses detected in less mature subpopulations were more expanded in TEM, suggesting that they were maintained through cell differentiation. Earlier ART initiation was associated with lower levels of intDNA, caRNA and fractional replacement rates. In conclusion, circulating integrated HIV proviruses appear to be maintained both by slow turnover of immature CD4 subpopulations, and by clonal expansion as well as cell differentiation into effector cells with faster replacement rates.

The Biology of the HIV-1 Latent Reservoir and Implications for Cure Strategies

Antiretroviral therapy (ART) inhibits HIV replication but is not curative. During ART, the integrated HIV genome persists indefinitely within CD4⁺ T cells and perhaps other cells. Here, we describe the mechanisms thought to contribute to its persistence during treatment and highlight findings from numerous recent studies describing the importance of cell proliferation in that process. Continued progress elucidating the biology will enhance our ability to develop effective curative interventions.

Initiation of Antiretroviral Therapy during Primary HIV Infection: Effects on the Latent HIV Reservoir, Including on Analytic Treatment Interruptions

Antiretroviral therapy (ART) inhibits HIV replication but does not eradicate the latent reservoir. The previous research suggests that earlier ART initiation provides benefit on limiting reservoir size, but timing and extent of this effect remain unclear. Analytic treatment interruption (ATI) may be used to demonstrate HIV remission, but whether early ART also improves likelihood or duration of even temporary virologic remission is unclear. This review seeks to answer both questions. We performed a systematic review and analysis following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and included 21 interventional or observational studies with sufficient HIV reservoir outcomes. We also aggregated reservoir outcomes and transformed data into approximate measurements of total HIV DNA per million peripheral blood mononuclear cells and analyzed the correlation between timing of ART initiation and reservoir size. People living with HIV who initiate ART in primary infection maintain smaller reservoirs on suppressive ART than those who initiate treatment during chronic infection. The reduction of reservoir is most pronounced when ART is started within 2 weeks of HIV acquisition. Across studies, we found a moderately strong association between longer time to ART initiation and reservoir size, which was strongest when measured after 1 year on ART (Pearson's r = 0.69, p = 0.0003). After ATI, larger pre-ATI reservoir size predicts shorter time to viral rebound. Early ART may also facilitate long-term control of viremia. Although achieving sustained HIV remission will require further interventions, initiating ART very early in infection could limit the extent of the reservoir and also lead to post-ATI control in rare cases.

Implications of Immune Checkpoint Expression During Aging in HIV-Infected People on Antiretroviral Therapy

Immune checkpoint molecules (ICMs) regulate T cell responses. In chronic viral infections and cancer, where antigens can persistently stimulate the immune system, ICMs can serve as a barrier to effective immune responses. The role of ICMs in the setting of systemic low-grade inflammation as in aging and antiretroviral therapy (ART)-suppressed HIV infection is not known. In this study, we made use of stored samples from the FLORAH cohort of HIV-infected ART-suppressed adults (age range 19-77 years.) and age-matched HIV-uninfected controls. We measured the expression levels of ICMs: PD-1, LAG-3, TIGIT, TIM-3, and 2B4 on resting CD4 and CD8 T cells and maturation subsets. To determine how expression of these molecules can affect T cell function, we stimulated peripheral blood mononuclear cell with HIV Gag or p09/H1N1 antigen and performed intracellular cytokine staining by multiparameter flow cytometry. ICMs were expressed at higher levels in CD8 compared with CD4. PD-1 was the only molecule that remained significantly higher in HIV-infected individuals compared with controls. LAG-3 expression increased with age in CD4 and CD8 T cells. 2B4 expression on CD8 T cells was negatively associated with IL-2 production but showed no effect on CD4 T cell function. TIM-3 expression was negatively associated with IL-21 production in CD4 and CD8 T cells and also negatively correlated with flu vaccine responses in HIV-negative individuals. Taken altogether, this study demonstrates the marked variation in ICM expression in T cells among adults and sheds light on the biology of these molecules and their effects on antigen-specific T cell functions. Overall, our results point to TIM-3 as a potential biomarker for immune function in HIV⁺ individuals on ART.

CXCR4-Using HIV Strains Predominate in Naive and Central Memory CD4+ T Cells in People Living with HIV on Antiretroviral Therapy: Implications for How Latency Is Established and Maintained

HIV can persist in people living with HIV (PLWH) on antiretroviral therapy (ART) in multiple CD4⁺ T cell subsets, including naive cells, central memory (CM) cells, transitional (TM) cells, and effector memory (EM) cells. Since these cells express different levels of the viral coreceptors CXCR4 and CCR5 on their surface, we sought to determine whether the HIV envelope protein (Env) was genotypically and phenotypically different between CD4⁺ T cell subsets isolated from PLWH on suppressive ART (n = 8). Single genome amplification for the HIV env gene was performed on genomic DNA extracts from different CD4⁺ T cell subsets. We detected CXCR4-using (X4) strains in five of the eight participants studied, and in these participants, the prevalence of X4 strains was higher in naive CD4⁺ T cells than in the memory subsets. Conversely, R5 strains were mostly found in the TM and EM populations. Identical sets of env sequences, consistent with clonal expansion of some infected cells, were more frequent in EM cells. These expanded identical sequences could also be detected in multiple CD4⁺ T cell subsets, suggesting that infected cells can undergo T cell differentiation. These identical sequences largely encoded intact and functional Env proteins. Our results are consistent with a model in which X4 HIV strains infect and potentially establish latency in naive and CM CD4⁺ T cells through direct infection, in addition to maintenance of the reservoir through differentiation and proliferation of infected cells.IMPORTANCE In people living with HIV (PLWH) on suppressive ART, latent HIV can be found in a diverse range of CD4⁺ T cells, including quiescent naive and central memory cells that are typically difficult to infect in vitro It is currently unclear how latency is established in these cells in vivo We show that in CD4⁺ T cells from PLWH on suppressive ART, the use of the coreceptor CXCR4 was prevalent among viruses amplified from naive and central memory CD4⁺ T cells. Furthermore, we found that expanded numbers of identical viral sequences were most common in the effector memory population, and these identical sequences were also found in multiple different CD4⁺ T cell subsets. Our results help to shed light on how a range of CD4⁺ T cell subsets come to harbor HIV DNA, which is one of the major barriers to eradicating the virus from PLWH.

Impact of Early Antiretroviral Therapy Initiation on HIV-Specific CD4 and CD8 T Cell Function in Perinatally Infected Children

Early initiation of antiretroviral therapy (ART) in vertically HIV-infected children limits the size of the virus reservoir, but whether the time of treatment initiation (TI) can durably impact host immune responses associated with HIV infection is still unknown. This study was conducted in PBMC of 20 HIV-infected virally suppressed children on ART (mean age 9.4 y), classified as early treated (ET; age at ART initiation ≤0.5 y, n = 14) or late treated (LT; age at ART initiation 1-10 y, n = 6). Frequencies and functions of Ag-specific CD4 (CD40L⁺) and CD8 (CD69⁺) T cells were evaluated by intracellular IL-2, IFN-γ, and TNF-α production with IL-21 in CD4 or CD107a, granzyme B and perforin in CD8 T cells following stimulation with HIV gp140 protein (ENV) or GAG peptides by multiparameter flow cytometry. ET showed a higher proportion of cytokine-producing ENV- and GAG-specific CD4 and CD8 T cells compared with LT. In particular, ET were enriched in polyfunctional T cells. RNA sequencing analysis showed upregulation of immune activation pathways in LT compared with ET. Our results suggest that timing of TI in HIV-infected children has a long-term and measurable impact on the quality of the HIV-specific T cell immune responses and transcriptional profiles of PBMC, reinforcing the importance of early TI.

Pharmacological Modulation of the Wnt/β-Catenin Pathway Inhibits Proliferation and Promotes Differentiation of Long-Lived Memory CD4+ T Cells in Antiretroviral Therapy-Suppressed Simian Immunodeficiency Virus-Infected Macaques

The major obstacle to human immunodeficiency type 1 virus (HIV-1) eradication is a reservoir of latently infected cells that persists despite long-term antiretroviral therapy (ART) and is maintained through cellular proliferation. Long-lived memory CD4+ T cells with high self-renewal capacity, such as central memory (CM) T cells and stem cell memory (SCM) T cells, are major contributors to the viral reservoir in HIV-infected individuals on ART. The Wnt/β-catenin signaling pathway regulates the balance between self-renewal and differentiation of SCM and CM T cells, and pharmacological manipulation of this pathway offers an opportunity to interfere with the proliferation of latently infected cells. Here, we evaluated in vivo a novel approach to inhibit self-renewal of SCM and CM CD4+ T cells in the rhesus macaque (RM) model of simian immunodeficiency (SIV) infection. We used an inhibitor of the Wnt/β-catenin pathway, PRI-724, that blocks the interaction between the coactivator CREB-binding protein (CBP) and β-catenin, resulting in the cell fate decision to differentiate rather than proliferate. Our study shows that PRI-724 treatment of ART-suppressed SIVmac251-infected RMs resulted in decreased proliferation of SCM and CM T cells and modified the SCM and CM CD4+ T cell transcriptome toward a profile of more differentiated memory T cells. However, short-term treatment with PRI-724 alone did not significantly reduce the size of the viral reservoir. This work demonstrates for the first time that stemness pathways of long-lived memory CD4+ T cells can be pharmacologically modulated in vivo, thus establishing a novel strategy to target HIV persistence.IMPORTANCE Long-lasting CD4+ T cell subsets, such as central memory and stem cell memory CD4+ T cells, represent critical reservoirs for human immunodeficiency virus (HIV) persistence despite suppressive antiretroviral therapy. These cells possess stem cell-like properties of enhanced self-renewal/proliferation, and proliferation of latently infected memory CD4+ T cells plays a key role in maintaining the reservoir over time. Here, we evaluated an innovative strategy targeting the proliferation of long-lived memory CD4+ T cells to reduce viral reservoir stability. Using the rhesus macaque model, we tested a pharmacological inhibitor of the Wnt/β-catenin signaling pathway that regulates T cell proliferation. Our study shows that administration of the inhibitor PRI-724 decreased the proliferation of SCM and CM CD4+ T cells and promoted a transcriptome enriched in differentiation genes. Although the viral reservoir size was not significantly reduced by PRI-724 treatment alone, we demonstrate the potential to pharmacologically modulate the proliferation of memory CD4+ T cells as a strategy to limit HIV persistence.

Targeting Cellular and Tissue HIV Reservoirs With Toll-Like Receptor Agonists

The elimination of both cellular and tissue latent reservoirs is a challenge toward a successful HIV cure. "Shock and Kill" are among the therapeutic strategies that have been more extensively studied to target these reservoirs. These strategies are aimed toward the reactivation of the latent reservoir using a latency-reversal agent (LRA) with the subsequent killing of the reactivated cell either by the cytotoxic arm of the immune system, including NK and CD8 T cells, or by viral cytopathic mechanisms. Numerous LRAs are currently being investigated in vitro, ex vivo as well as in vivo for their ability to reactivate and reduce latent reservoirs. Among those, several toll-like receptor (TLR) agonists have been shown to reactivate latent HIV. In humans, there are 10 TLRs that recognize different pathogen-associated molecular patterns. TLRs are present in several cell types, including CD4 T cells, the cell compartment that harbors the majority of the latent reservoir. Besides their ability to reactivate latent HIV, TLR agonists also increase immune activation and promote an antiviral response. These combined properties make TLR agonists unique among the different LRAs characterized to date. Additionally, some of these agonists have shown promise toward finding an HIV cure in animal models. When in combination with broadly neutralizing antibodies, TLR-7 agonists have shown to impact the SIV latent reservoir and delay viral rebound. Moreover, there are FDA-approved TLR agonists that are currently being investigated for cancer therapy and other diseases. All these has prompted clinical trials using TLR agonists either alone or in combination toward HIV eradication approaches. In this review, we provide an extensive characterization of the state-of-the-art of the use of TLR agonists toward HIV eradication strategies and the mechanism behind how TLR agonists target both cellular and tissue HIV reservoirs.

Long-term Therapeutic Impact of the Timing of Antiretroviral Therapy in Patients Diagnosed With Primary Human Immunodeficiency Virus Type 1 Infection

Background

We aimed to determine the consequences of delayed human immunodeficiency virus type 1 (HIV-1) infection diagnosis by comparing long-term outcomes depending on the time of combination antiretroviral therapy (cART) initiation in patients diagnosed during primary HIV infection (PHI).

Methods

We selected patients from the French National Agency for Research on AIDS and Viral Hepatitis (ANRS) PRIMO cohort, treated for ≥36 months, with sustained HIV RNA <50 copies/mL: 77 treated within 1 month following PHI diagnosis (immediate ART) and 73 treated >12 months after infection (deferred ART). We measured inflammatory biomarkers from PHI through the last visit on cART, and CD4+ and CD8+ T-cell activation and plasma ultrasensitive HIV RNA at the last visit. Inflammation/activation levels were compared with those of uninfected controls. We modeled CD4+ count, CD4:CD8 ratio, and HIV DNA dynamics on cART.

Results

The decrease of HIV DNA levels was more marked in the immediate than deferred ART group, leading to a sustained mean difference of -0.6 log10 copies/106 peripheral blood mononuclear cells. Immediate ART led to improved CD4+ T-cell counts and CD4:CD8 ratios over the first 4 years of cART. At the last visit (median, 82 months), there was no difference between groups in CD4+ counts, CD4:CD8 ratio, ultrasensitive HIV RNA, or inflammation/activation marker levels. Long-term suppressive cART failed to normalize inflammation levels, which were not associated with immunovirological markers.

Conclusions

Antiretroviral therapy initiated during PHI promotes long-term reduction of HIV reservoir size. In patients with sustained virologic suppression, inflammation may be driven by non-HIV-related factors.

Limited Knowledge and Lack of Screening for Acute HIV Infection at Primary Care Clinics in High-Prevalence Communities of New York City

Diagnosis and treatment of acute HIV infection (AHI) is crucial for ending the HIV epidemic. Individuals with AHI, who have high viral loads and often are unaware of their infection, are more likely to transmit HIV to others than those with chronic infection. In preparation for an educational intervention on AHI in primary health care settings in high HIV-prevalence areas of New York City, 22 clinic directors, 313 clinic providers, and 220 patients were surveyed on their knowledge and awareness of the topic from 2012-2015. Basic HIV knowledge was high among all groups while knowledge of AHI was partial among providers and virtually absent among patients. Inadequate knowledge about this crucial phase of HIV may be impeding timely identification of cases in the primary care setting.

Decreased Seroreactivity in Individuals Initiating Antiretroviral Therapy during Acute HIV Infection

Antiretroviral therapy (ART) during acute HIV infection (AHI) interrupts viral dynamics and may delay the emergence of serological markers targeted by current HIV screening and confirmatory assays, thus creating challenges for correctly classifying HIV infection status. The performance of three HIV antigen/antibody combination (HIV Ag/Ab Combo) assays (the Bio-Rad GS, Abbott Architect, and Bio-Rad BioPlex 2200 assays) was evaluated with samples collected from RV254/South East Asia Research Collaboration in HIV 010 (RV254/SEARCH010) study (Bangkok, Thailand) participants at weeks 12 and 24 following the initiation of ART at Fiebig stage I (FI) (n = 23), FII (n = 39), or FIII/IV (n = 22). Supplemental, confirmatory testing was performed by the Geenius HIV 1/2 and HIV-1 Western blot assays (Bio-Rad). Samples from 30 untreated, HIV-1-infected individuals demonstrated robust HIV Ag/Ab Combo assay reactivity with well-developed HIV-1 Western blotting profiles by 24 weeks after infection. In contrast, 52.2% of samples from individuals initiating ART at FI, 7.7% of samples from individuals initiating ART at FII, and 4.5% of samples from individuals initiating ART at FIII/IV were nonreactive by the HIV Ag/Ab Combo assays, with 36.4 to 39.1% of samples having low signal-to-cutoff (S/CO) results by the Architect and BioPlex assays (S/CO < 10). Seroreversion from a reactive to a nonreactive status was observed in 10 individuals initiating ART at FII and 3 individuals initiating ART at FIII/IV. The Geenius and HIV-1 Western blot assay results were negative or indeterminate for 73.9% and 69.6% of individuals, respectively, treated at FI; 50.0% and 26.3% of individuals, respectively, treated at FII; and 54.5% and 40.9% of individuals, respectively, treated at FIII/IV. Virologic suppression of HIV-1 by ART during AHI impedes seroconversion to biomarkers of infection, limiting the utility of HIV Ag/Ab Combo and supplemental, confirmatory assays for infection status determination.

Sustained Sexual Behavior Change After Acute HIV Diagnosis in Malawi

BACKGROUND

Identification of acute HIV infection (AHI) allows for important opportunities for HIV prevention through behavior change and biomedical intervention. Here, we evaluate changes in sexual risk behaviors among persons with AHI enrolled in a combined behavioral and biomedical intervention designed to reduce onward transmission of HIV.

METHODS

Participants were randomized to standard HIV counseling, a multisession behavioral intervention, or a multisession behavioral intervention plus antiretrovirals. Sexual behaviors were assessed periodically over 1 year.

RESULTS

Four weeks after diagnosis, the predicted probability of reporting multiple sexual partners decreased from 24% to 9%, and the probability of reporting unprotected sex decreased from 71% to 27%. These declines in sexual risk behaviors were sustained over follow-up irrespective of study arm.

CONCLUSIONS

Diagnosis of AHI alone may be sufficient to achieve immediate and sustained behavior change during this highly infectious period.

Learning From the Exceptions: HIV Remission in Post-treatment Controllers

Among the top priorities of the HIV field is the search for therapeutic interventions that can lead to sustained antiretroviral therapy (ART)-free HIV remission. Although the majority of HIV-infected persons will experience rapid viral rebound after ART interruption, there are rare individuals, termed post-treatment controllers (PTCs), who demonstrate sustained virologic suppression for months or years after treatment cessation. These individuals are considered an ideal example of durable HIV control, with direct implications for HIV cure research. However, understanding of the mechanisms behind the capacity of PTCs to control HIV remains incomplete. This is in part due to the scarcity of PTCs identified through any one research center or clinical trial, and in part because of the limited scope of studies that have been performed in these remarkable individuals. In this review, we summarize the results of both clinical and basic research studies of PTCs to date, explore key differences between PTCs and HIV spontaneous controllers, examine potential mechanisms of post-treatment control, and discuss unanswered questions and future research directions in this field.

Longitudinal Changes in Cd4+, Cd8+ T Cell Phenotype and Activation Marker Expression Following Antiretroviral Therapy Initiation among Patients with Cryptococcal Meningitis

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4⁺ and CD8⁺ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4⁺ and CD8⁺ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4⁺ and CD8⁺ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27⁺CD45R0⁺), effector memory (CD45R0⁺CD27^–), immune activation (CD38⁺ and Human Leucocyte Antigen DR (HLA-DR⁺), and exhaustion (Programmed cell death protein one (PD-1) in the CD4⁺ T cell subset. In comparison to the CD4⁺ T cell population, the CD8⁺ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4⁺ and CD8⁺ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4⁺ T cells during ART treatment during CM co-infection.

Dolutegravir reshapes the genetic diversity of HIV-1 reservoirs

Objectives

Better understanding of the dynamics of HIV reservoirs under ART is a critical step to achieve a functional HIV cure. Our objective was to assess the genetic diversity of archived HIV-1 DNA over 48 weeks in blood cells of individuals starting treatment with a dolutegravir-based regimen.

Methods

Eighty blood samples were prospectively and longitudinally collected from 20 individuals (NCT02557997) including: acutely (n = 5) and chronically (n = 5) infected treatment-naive individuals, as well as treatment-experienced individuals who switched to a dolutegravir-based regimen and were either virologically suppressed (n = 5) or had experienced treatment failure (n = 5). The integrase and V3 loop regions of HIV-1 DNA isolated from PBMCs were analysed by pyrosequencing at baseline and weeks 4, 24 and 48. HIV-1 genetic diversity was calculated using Shannon entropy.

Results

All individuals achieved or maintained viral suppression throughout the study. A low and stable genetic diversity of archived HIV quasispecies was observed in individuals starting treatment during acute infection. A dramatic reduction of the genetic diversity was observed at week 4 of treatment in the other individuals. In these patients and despite virological suppression, a recovery of the genetic diversity of the reservoirs was observed up to 48 weeks. Viral variants bearing dolutegravir resistance-associated substitutions at integrase position 50, 124, 230 or 263 were detected in five individuals (n = 5/20, 25%) from all groups except those who were ART-failing at baseline. None of these substitutions led to virological failure.

Conclusions

These data demonstrate that the genetic diversity of the HIV-1 reservoir is reshaped following the initiation of a dolutegravir-based regimen and strongly suggest that HIV-1 can continue to replicate despite successful treatment.

Barriers and strategies to achieve a cure for HIV

9 years since the report of a cure for HIV after C-C chemokine receptor type 5 Δ32 stem cell transplantation, no other case of HIV cure has been reported, despite much research. However, substantial progress has been made in understanding the biology of the latent HIV reservoir, and in measuring the amount of virus that persists after antiretroviral therapy (ART) with increasingly sophisticated approaches. This knowledge is being translated into a long pipeline of clinical trials seeking to reduce viral persistence in participants on suppressive treatment and ultimately to allow safe cessation of ART. In this Review, we discuss the main barriers preventing the development of an HIV cure, methods used to measure HIV persistence in individuals on ART, clinical strategies that aim to cure HIV, and future directions for studies in the field of HIV cure research.

Increasing contribution of integrated forms to total HIV DNA in blood during HIV disease progression from primary infection

BACKGROUND

In the current context of research on HIV reservoirs, offering new insights into the persistence of HIV DNA in infected cells, which prevents viral eradication, may aid in identifying cure strategies. This study aimed to describe the establishment of stable integrated forms among total HIV DNA during primary infection (PHI) and their dynamics during the natural history of infection.

METHODS

Total and integrated HIV DNA were quantified in blood from 74 PHI patients and 97 recent seroconverters (<12 months following infection, "progression cohort"). The evolution of both markers over six years was modelled (mixed-effect linear models). Their predictive values for disease progression were studied (Cox models).

FINDINGS

For most patients during PHI, stable integrated forms were a minority among total HIV DNA (median: 12%) and became predominant thereafter (median at AIDS stage: 100%). Both total and integrated HIV DNA increased over a six-year period. Patients from the progression cohort who reached clinical AIDS during follow-up (n = 34) exhibited higher total and integrated HIV DNA levels at seroconversion and a higher percentage of integrated forms than did slower progressors (n = 63) (median: 100% vs 44%). The integrated HIV DNA load was strongly associated with the risk of developing AIDS (aRR = 2.63, p = 0.002).

INTERPRETATION

The profile of "rapid" or "slower" progression in the natural history of HIV infection appears to be determined early in the course of HIV infection. The strong predominance of unstable unintegrated forms in PHI may explain the great benefit of this early treatment, which induces a sharp decrease in total HIV DNA. FUND: French National Agency for Research on AIDS and Viral Hepatitis.

Harnessing CD8+ T Cells Under HIV Antiretroviral Therapy

Antiretroviral therapy (ART) has transformed HIV from a fatal disease to a chronic condition. In recent years there has been considerable interest in strategies to enable HIV-infected individuals to cease ART without viral rebound, either by purging all cells infected harboring replication-competent virus (HIV eradication), or by boosting immune responses to allow durable suppression of virus without rebound (HIV remission). Both of these approaches may need to harness HIV-specific CD8⁺ T cells to eliminate infected cells and/or prevent viral spread. In untreated infection, both HIV-specific and total CD8⁺ T cells are dysfunctional. Here, we review our current understanding of both global and HIV-specific CD8⁺ T cell immunity in HIV-infected individuals with durably suppressed viral load under ART, and its implications for HIV cure, eradication or remission. Overall, the literature indicates significant normalization of global T cell parameters, including CD4/8 ratio, activation status, and telomere length. Global characteristics of CD8⁺ T cells from HIV⁺ART⁺ individuals align more closely with those of HIV-seronegative individuals than of viremic HIV-infected individuals. However, markers of senescence remain elevated, leading to the hypothesis that immune aging is accelerated in HIV-infected individuals on ART. This phenomenon could have implications for attempts to prime de novo, or boost existing HIV-specific CD8⁺ T cell responses. A major challenge for both HIV cure and remission strategies is to elicit HIV-specific CD8⁺ T cell responses superior to that elicited by natural infection in terms of response kinetics, magnitude, breadth, viral suppressive capacity, and tissue localization. Addressing these issues will be critical to the success of HIV cure and remission attempts.

Cellular Determinants of HIV Persistence on Antiretroviral Therapy

The era of antiretroviral therapy has made HIV-1 infection a manageable chronic disease for those with access to treatment. Despite treatment, virus persists in tissue reservoirs seeded with long-lived infected cells that are resistant to cell death and immune recognition. Which cells contribute to this reservoir and which factors determine their persistence are central questions that need to be answered to achieve viral eradication. In this chapter, we describe how cell susceptibility to infection, resistance to cell death, and immune-mediated killing as well as natural cell life span and turnover potential are central components that allow persistence of different lymphoid and myeloid cell subsets that were recently identified as key players in harboring latent and actively replicating virus. The relative contribution of these subsets to persistence of viral reservoir is described, and the open questions are highlighted.

Socio-demographic and clinical determinants of late presentation among patients newly diagnosed with HIV in the Eastern Cape, South Africa

South Africa recently implemented the 'test and treat' strategy for all HIV-infected individuals receiving diagnosis at the health facility level. However, the impact of this programme in terms of the prevention of HIV transmission, morbidity and mortality associated with HIV can only be maximized if patients are diagnosed early. This study determines the prevalence of late presentation among newly diagnosed HIV-infected individuals and also examines the socio-demographic and clinical determinants for late presentation in health facilities in the Eastern Cape Province, South Africa.In this cross-sectional study, a total of 335 newly diagnosed patients were recruited consecutively between August 2016 and July 2017. Late presenter for HIV care was defined in accordance with the European Late Presenter Consensus working group as a patient who reports for care when the CD4 count is below 350 cells/μL and/or when there is an established AIDS-defining clinical condition, irrespective of CD4 count. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of late HIV diagnosis.Participants' mean age was 33.6 (SD: 10.6). Almost 96% of the participants believed their route of HIV infection was heterosexual sex. Most newly diagnosed HIV-infected patients (60%) were late presenters (CD4+ count ≤350 cells/μL and/or having an AIDS-defining illness in World Health Organisation (WHO)-defined stage III/IV), with 35% presenting with Acquired Immune Deficiency Syndrome (AIDS)-related complications. In the adjusted model, only male sex (AOR: 2.81; CI: 1.51-5.23), no formal education (AOR: 5.63; CI: 1.68-18.85), and overweight body mass category (AOR: 2.45; CI: 1.04-5.75) were independently associated with late HIV diagnosis.The majority of newly diagnosed HIV-infected individuals were late presenters. To maximize the impact of the 'test and treat' policy aimed at reducing new HIV transmissions and preventing the morbidity and mortality associated with HIV, there is a need for programmes to improve early detection of HIV in the study settings. This programme should target males and individuals with no formal education for maximum impact.

Peering into the HIV reservoir

The main obstacle to HIV eradication is the establishment of a long-term persistent HIV reservoir. Although several therapeutic approaches have been developed to reduce and eventually eliminate the HIV reservoir, only a few have achieved promising results. A better knowledge of the mechanisms involved in the establishment and maintenance of HIV reservoir is of utmost relevance for the design of new therapeutic strategies aimed at purging it with the ultimate goal of achieving HIV eradication or alternatively a functional cure. In this regard, it is also important to take a close look into the cellular HIV reservoirs other than resting memory CD4 T-cells with key roles in reservoir maintenance that have been recently described. Unraveling the special characteristics of these HIV cellular compartments could aid us in designing new therapeutic strategies to deplete the latent HIV reservoir.

Distribution and reduction magnitude of HIV-DNA burden in CD4+ T cell subsets depend on art initiation timing

OBJECTIVE

The aim of our study was to analyze the dynamics of HIV-DNA levels in CD4 T-cell subsets in individuals starting successful dolutegravir-based regimens.

DESIGN

Twenty-seven individuals with acute infection (AI, n = 8) or chronic infection (CI, n = 5) and patients in virological success (VS, n = 10) or virological failure (VF, n = 4) on antiretroviral therapy (ART) who initiated a dolutegravir-based regimen were enrolled (NCT02557997).

METHODS

CD4 T-cells from baseline and week 48 of successful treatment were sorted into effector memory (TEM), transitional memory (TTM), central memory (TCM) and naïve (TN) cell groups for total HIV-DNA measurements by qPCR. Bayesian methods were used to estimate the posterior probability of a HIV-DNA decrease more than 0.25 log copies/10 cells at week 48.

RESULTS

All patients achieved HIV-RNA suppression at 48 weeks. At baseline and week 48, the highest contributions to the HIV-DNA-infected pool from CD4 T cells were observed in TTM cells in the AI group (62.4 and 60.2%, respectively), but in TCM cells for the CI, VS and VF groups (54.6 and 59.4%, 58.2 and 62.9%, 62.4 and 67.2%), respectively. HIV-DNA burden declined in all subsets after 48 weeks of treatment in the AI (probability (Pr) > 91%), CI (Pr > 52%) and VF (Pr > 52%) groups, but only in TEM cells in the VS group (Pr = 95%).

CONCLUSION

Our study showed that dolutegravir-based treatment reduced the HIV-DNA cellular burden in individuals from the AI, CI and VF groups, though the reduction levels differed between the patient subgroups. Early treated patients had the highest probability of HIV-DNA reduction. Interestingly, in the aviremic VS group, HIV-DNA reduction was limited to TEM cells.

Total HIV DNA: a global marker of HIV persistence

Among the different markers of HIV persistence in infected cells, total HIV DNA is to date the most widely used. It allows an overall quantification of all viral forms of HIV DNA in infected cells, each playing a different role in HIV replication and pathophysiology. The real-time PCR technology is to date, a precise, sensitive and reproducible technology that allows the description of the distribution of HIV infected cells in blood and tissues. The objective of this review is to present some examples which show the interest to quantify total HIV DNA levels. This marker brought an undeniable and considerable contribution to reservoir studies. Many results, both in clinical and basic research, allowed to get a large overview of the distribution of infected cells in the body, at all stages of HIV disease and during therapy. Future clinical studies aiming at reducing HIV reservoirs will benefit from HIV DNA quantification in blood and tissues, in association with other markers of HIV reservoir activity.

Strength in Amalgamation: Newer Combination Agents for HIV and Implications for Practice

Antiretroviral (ART) therapy for the treatment of human immunodeficiency virus (HIV) infection has undergone significant changes over the past 30 years. Many single-tablet regimens (STRs), including newer fixed-dose combination (FDC) tablets, are available, offering patients several options for choosing a treatment regimen that works best for them. Given these changes, patients are more likely to adhere to treatment, achieve better clinical outcomes, and experience both fewer side effects and drug-drug interactions. Newer STRs include dolutegravir (DTG)/lamivudine (3TC)/abacavir (ABC) (Triumeq; Viiv Healthcare, Research Triangle Park, NC), rilpivirine (RPV)/emtricitabine (FTC)/tenofovir alafenamide (TAF) (Odefsey; Gilead, Foster City, CA), RPV/FTC/tenofovir disoproxil fumarate (TDF) (Complera; Gilead), elvitegravir (EVG)/cobicistat (COBI)/FTC/TDF (Stribild; Gilead), and EVG/COBI/FTC/TAF (Genvoya; Gilead). Recently approved FDCs, such as atazanavir (ATV)/COBI (Evotaz; Bristol-Myers Squibb, Princeton, NJ), darunavir (DRV)/COBI (Prezcobix; Janssen Products, Titusville NJ), and FTC/TAF (Descovy; Gilead), are also now available. The Department of Health and Human Services treatment guidelines for HIV recommend many of these integrase strand transfer inhibitor (INSTI) STRs as a preferred choice for initiation of treatment in both ART-naive and -experienced patients because they offer comparably faster rates of virologic suppression, reduced rates of resistance development (especially with DTG), and overall better adherence than protease inhibitors or NNRTIs. Numerous phase 3 clinical trials support these recommendations including several switch or simplification clinical trials. Notably, the novel pharmacokinetic booster COBI, with its water soluble properties, has enabled the development and coformulation of a few of these STRs and FDCs. Also, a newer tenofovir salt formulation, TAF, has an advantageous pharmacokinetic profile, contributing to better overall renal and bone tolerability compared with TDF. Further simplification regimens comprising dual ART therapies are currently being explored. This review provides an overview of the clinical efficacy and safety data for these coformulated agents, highlighting the relative impact on comparative adverse events, assessing the potential for experiencing fewer drug-drug interactions, and discussing the clinical implications regarding adherence to treatment.

Viral kinetics in untreated versus treated acute HIV infection in prospective cohort studies in Thailand

Introduction: The extent of viral replication during acute HIV infection (AHI) influences HIV disease progression. However, information comparing viral load (VL) kinetics with and without antiretroviral therapy (ART) in AHI is limited. The knowledge gained could inform preventive strategies aimed at reducing VL during AHI and therapeutic strategies to alter the viral kinetics that may enhance the likelihood of achieving HIV remission.

Methods: The analysis utilized VL data captured during the first year of HIV infection from two studies in Thailand: the RV217 study (untreated AHI, 30 participants and 412 visits) and the RV254 study (treated AHI, 235 participants and 2803 visits). Fiebig stages were I/II (HIV RNA+, HIV IgM−) and Fiebig III/IV (HIV IgM+, Western blot-/indeterminate). Data were modelled utilizing spline effects within a linear mixed model, with a random intercept and slope to allow for between-subject variability and adjustment for the differences in variability between studies. The number of knots in the quadratic spline basis functions was determined by comparing models with differing numbers of knots via the Akaike Information Criterion. Models were fit using PROC GLIMMIX in SAS v9.3.

Results: At enrolment, there were 24 Fiebig I/II and 6 Fiebig III/IV individuals in the untreated group and 137 Fiebig I/II and 98 Fiebig III/IV individuals in the treated group. Overall, the median age was 27.5 years old, most were male (89%), and CRF01_AE was the most common HIV clade (76%). By day 12 (4 days after ART in RV254), the untreated group had a 2.7-fold higher predicted mean VL level compared to those treated (predicted log VL 6.19 for RV217 and 5.76 for RV254, p = 0.05). These differences increased to 135-fold by day 30 (predicted log VL 4.89 for RV217 and 2.76 for RV254) and 1148-fold by day 120 (predicted log VL 4.68 for RV217 and 1.63 for RV254) (p < 0.0001 for both) until both curves were similarly flat at about day 150 (p = 0.17 between days 150 and 160). The VL trajectories were significantly different between Fiebig I/II and Fiebig III/IV participants when comparing the two groups and within the treated group (p < 0.001 for both).

Conclusions: Initiating ART in AHI dramatically changed the trajectory of VL very early in the course of infection that could have implications for reducing transmission potential and enhancing responses to future HIV remission strategies. There is an urgency of initiating ART when acute infection is identified. New and inexpensive strategies to engage and test individuals at high risk for HIV as well as immediate treatment access will be needed to improve the treatment of acute infection globally.

Clinical Trial Number: NCT00796146 and NCT00796263

Differentiating Immune Cell Targets in Gut-Associated Lymphoid Tissue for HIV Cure

The single greatest challenge to an HIV cure is the persistence of latently infected cells containing inducible, replication-competent proviral genomes, which constitute only a small fraction of total or infected cells in the body. Although resting CD4+ T cells in the blood are a well-known source of viral rebound, more than 90% of the body's lymphocytes reside elsewhere. Many are in gut tissue, where HIV DNA levels per million CD4+ T cells are considerably higher than in the blood. Despite the significant contribution of gut tissue to viral replication and persistence, little is known about the cell types that support persistence of HIV in the gut; importantly, T cells in the gut have phenotypic, functional, and survival properties that are distinct from T cells in other tissues. The mechanisms by which latency is established and maintained will likely depend on the location and cytokine milieu surrounding the latently infected cells in each compartment. Therefore, successful HIV cure strategies require identification and characterization of the exact cell types that support viral persistence, particularly in the gut. In this review, we describe the seeding of the latent HIV reservoir in the gut mucosa; highlight the evidence for compartmentalization and depletion of T cells; summarize the immunologic consequences of HIV infection within the gut milieu; propose how the damaged gut environment may promote the latent HIV reservoir; and explore several immune cell targets in the gut and their place on the path toward HIV cure.

On the way to find a cure: Purging latent HIV-1 reservoirs

Introduction of cART in 1996 has drastically increased the life expectancy of people living with HIV-1. However, this treatment has not allowed cure as cessation of cART is associated with a rapid viral rebound. The main barrier to the eradication of the virus is related to the persistence of latent HIV reservoirs. Evidence is now accumulating that purging the HIV-1 reservoir might lead to a cure or a remission. The most studied strategy is the so called "shock and kill" therapy. This strategy is based on reactivation of dormant viruses from the latently-infected reservoirs (the shock) followed by the eradication of the reservoirs (the kill). This review focuses mainly on the recent advances made in the "shock and kill" therapy. We believe that a cure or a remission will come from combinatorial approaches i.e. combination of drugs to reactivate the dormant virus from all the reservoirs including the one located in sanctuaries, and combination of strategies boosting the immune system. Alternative strategies based on cell and gene therapy or based in inducing deep latency, which are evoked in this review reinforce the idea that at least a remission is attainable.

Clinical and public health implications of acute and early HIV detection and treatment: a scoping review

INTRODUCTION

The unchanged global HIV incidence may be related to ignoring acute HIV infection (AHI). This scoping review examines diagnostic, clinical, and public health implications of identifying and treating persons with AHI.

METHODS

We searched PubMed, in addition to hand-review of key journals identifying research pertaining to AHI detection and treatment. We focused on the relative contribution of AHI to transmission and the diagnostic, clinical, and public health implications. We prioritized research from low- and middle-income countries (LMICs) published in the last fifteen years.

RESULTS AND DISCUSSION

Extensive AHI research and limited routine AHI detection and treatment have begun in LMIC. Diagnostic challenges include ease-of-use, suitability for application and distribution in LMIC, and throughput for high-volume testing. Risk score algorithms have been used in LMIC to screen for AHI among individuals with behavioural and clinical characteristics more often associated with AHI. However, algorithms have not been implemented outside research settings. From a clinical perspective, there are substantial immunological and virological benefits to identifying and treating persons with AHI - evading the irreversible damage to host immune systems and seeding of viral reservoirs that occurs during untreated acute infection. The therapeutic benefits require rapid initiation of antiretrovirals, a logistical challenge in the absence of point-of-care testing. From a public health perspective, AHI diagnosis and treatment is critical to: decrease transmission via viral load reduction and behavioural interventions; improve pre-exposure prophylaxis outcomes by avoiding treatment initiation for HIV-seronegative persons with AHI; and, enhance partner services via notification for persons recently exposed or likely transmitting.

CONCLUSIONS

There are undeniable clinical and public health benefits to AHI detection and treatment, but also substantial diagnostic and logistical barriers to implementation and scale-up. Effective early ART initiation may be critical for HIV eradication efforts, but widespread use in LMIC requires simple and accurate diagnostic tools. Implementation research is critical to facilitate sustainable integration of AHI detection and treatment into existing health systems and will be essential for prospective evaluation of testing algorithms, point-of-care diagnostics, and efficacious and effective first-line regimens.

Total HIV-1 DNA, a Marker of Viral Reservoir Dynamics with Clinical Implications

HIV-1 DNA persists in infected cells despite combined antiretroviral therapy (cART), forming viral reservoirs. Recent trials of strategies targeting latent HIV reservoirs have rekindled hopes of curing HIV infection, and reliable markers are thus needed to evaluate viral reservoirs. Total HIV DNA quantification is simple, standardized, sensitive, and reproducible. Total HIV DNA load influences the course of the infection and is therefore clinically relevant. In particular, it is predictive of progression to AIDS and death, independently of HIV RNA load and the CD4 cell count. Baseline total HIV DNA load is predictive of the response to cART. It declines during cART but remains quantifiable, at a level that reflects both the history of infection (HIV RNA zenith, CD4 cell count nadir) and treatment efficacy (residual viremia, cumulative viremia, immune restoration, immune cell activation). Total HIV DNA load in blood is also predictive of the presence and severity of some HIV-1-associated end-organ disorders. It can be useful to guide individual treatment, notably, therapeutic de-escalation. Although it does not distinguish between replication-competent and -defective latent viruses, the total HIV DNA load in blood, tissues, and cells provides insights into HIV pathogenesis, probably because all viral forms participate in host cell activation and HIV pathogenesis. Total HIV DNA is thus a biomarker of HIV reservoirs, which can be defined as all infected cells and tissues containing all forms of HIV persistence that participate in pathogenesis. This participation may occur through the production of new virions, creating new cycles of infection and disseminating infected cells; maintenance or amplification of reservoirs by homeostatic cell proliferation; and viral transcription and synthesis of viral proteins without new virion production. These proteins can induce immune activation, thus participating in the vicious circle of HIV pathogenesis.