HIV-1-infected T cell clones are shared across cerebrospinal fluid and blood during ART.

The central nervous system HIV reservoir is incompletely understood and is a major barrier to HIV cure. We profiled people with HIV (PWH) and uninfected controls through single-cell transcriptomic and T cell receptor (TCR) sequencing to understand the dynamics of HIV persistence in the CNS. In PWH on ART, we found that most participants had single cells containing HIV-1 RNA, which was found predominantly in CD4 central memory T cells, in both cerebrospinal fluid (CSF) and blood. HIV-1 RNA-containing cells were found more frequently in CSF than blood, indicating a higher burden of reservoir cells in the CNS than blood for some PWH. Most CD4 T cell clones containing infected cells were compartment specific, while some (22%) - including rare clones with members of the clone containing detectable HIV RNA in both blood and CSF - were found in both CSF and blood. These results suggest that infected T cells trafficked between tissue compartments and that maintenance and expansion of infected T cell clones contributed to the CNS reservoir in PWH on ART.

Impact of antiretroviral therapy during acute or early HIV infection on virologic and immunologic outcomes: results from a multinational clinical trial.

OBJECTIVE: To assess how antiretroviral therapy (ART) initiation during acute or early HIV infection (AEHI) affects the viral reservoir and host immune responses. DESIGN: Single-arm trial of ART initiation during AEHI at 30 sites in the Americas, Africa, and Asia. METHODS: HIV DNA was measured at week 48 of ART in 5 million CD4+ T cells by sensitive qPCR assays targeting HIV gag and pol. Peripheral blood mononuclear cells were stimulated with potential HIV T cell epitope peptide pools consisting of env, gag, nef, and pol peptides and stained for expression of CD3, CD4, CD8, and intracellular cytokines/chemokines. RESULTS: From 2017 to 2019, 188 participants initiated ART during Fiebig stages I (n = 6), II (n = 43), III (n = 56), IV (n = 23), and V (n = 60). Median age was 27 years (interquartile range 23-38), 27 (14%) participants were female, and 180 (97%) cisgender. Among 154 virally suppressed participants at week 48, 100% had detectable HIV gag or pol DNA. Participants treated during Fiebig I had the lowest HIV DNA levels (P < 0.001). Week 48 HIV DNA mostly did not correlate with concurrent CD4+ or CD8+ T cell HIV-specific immune responses (rho range -0.11 to +0.19, all P > 0.025). At week 48, the magnitude, but not polyfunctionality, of HIV-specific T cell responses was moderately reduced among participants who initiated ART earliest. CONCLUSION: Earlier ART initiation during AEHI reduced but did not eliminate the persistence of HIV-infected cells in blood. These findings explain the rapid viral rebound observed after ART cessation in early-treated individuals with undetectable HIV DNA by less sensitive methods.

HIV-1 envelope diversity and sensitivity to broadly neutralizing antibodies across stages of acute HIV-1 infection.

We studied the relationship between viral diversity and susceptibility to broadly neutralizing antibodies (bNAbs) in longitudinal plasma and peripheral blood mononuclear cells from 89 people with HIV who initiated antiretroviral therapy (ART) during acute and early HIV-1 infection (AEHI). HIV-1 diversity and predicted bNAb susceptibility were comparable across AEHI. Diversity evolution was not observed during ART, suggesting (pro)viruses at initiation or during treatment may identify individuals with susceptible virus for bNAb interventional trials.

The immunogenicity of an HIV-1 gag conserved element DNA vaccine in people with HIV and receiving antiretroviral therapy.

OBJECTIVE: The primary objective of the study was to assess the immunogenicity of an HIV-1 Gag conserved element DNA vaccine (p24CE DNA) in people with HIV (PWH) receiving suppressive antiretroviral therapy (ART). DESIGN: AIDS Clinical Trials Group A5369 was a phase I/IIa, randomized, double-blind, placebo-controlled study of PWH receiving ART with plasma HIV-1 RNA less than 50 copies/ml, current CD4+ T-cell counts greater than 500 cells/µl, and nadir CD4+ T-cell counts greater than 350 cells/µl. METHODS: The study enrolled 45 participants randomized 2 : 1 : 1 to receive p24CE DNA vaccine at weeks 0 and 4, followed by p24CE DNA admixed with full-length p55Gag DNA vaccine at weeks 12 and 24 (arm A); full-length p55Gag DNA vaccine at weeks 0, 4, 12, and 24 (arm B); or placebo at weeks 0, 4, 12, and 24 (arm c). The active and placebo vaccines were administered by intramuscular electroporation. RESULTS: There was a modest, but significantly greater increase in the number of conserved elements recognized by CD4+ and/or CD8+ T cells in arm A compared with arm C (P = 0.014). The percentage of participants with an increased number of conserved elements recognized by T cells was also highest in arm A (8/18, 44.4%) vs. arm C (0/10, 0.0%) (P = 0.025). There were no significant differences between treatment groups in the change in magnitude of responses to total conserved elements. CONCLUSION: A DNA-delivered HIV-1 Gag conserved element vaccine boosted by a combination of this vaccine with a full-length p55Gag DNA vaccine induced a new conserved element-directed cellular immune response in approximately half the treated PWH on ART.

The latency-reversing agent HODHBt synergizes with IL-15 to enhance cytotoxic function of HIV-specific T cells.

IL-15 is under clinical investigation toward the goal of curing HIV infection because of its abilities to reverse HIV latency and enhance immune effector function. However, increased potency through combination with other agents may be needed. 3-Hydroxy-1,2,3-benzotriazin-4(3H)-one (HODHBt) enhances IL-15-mediated latency reversal and NK cell function by increasing STAT5 activation. We hypothesized that HODHBt would also synergize with IL-15, via STAT5, to directly enhance HIV-specific cytotoxic T cell responses. We showed that ex vivo IL-15 + HODHBt treatment markedly enhanced HIV-specific granzyme B-releasing T cell responses in PBMCs from antiretroviral therapy-suppressed (ART-suppressed) donors. We also observed upregulation of antigen processing and presentation in CD4+ T cells and increased surface MHC-I. In ex vivo PBMCs, IL-15 + HODHBt was sufficient to reduce intact proviruses in 1 of 3 ART-suppressed donors. Our findings reveal the potential for second-generation IL-15 studies incorporating HODHBt-like therapeutics. Iterative studies layering on additional latency reversal or other agents are needed to achieve consistent ex vivo reservoir reductions.

Varied Patterns of Decay of Intact Human Immunodeficiency Virus Type 1 Proviruses Over 2 Decades of Antiretroviral Therapy.

Fourteen people with human immunodeficiency virus type 1 had longitudinal measurements of intact, defective, and total proviral DNA over the course of two decades of antiretroviral therapy. Three patterns of intact proviral DNA decay were revealed: (1) biphasic decline with markedly slower second-phase decline, (2) initial decline that transitions to a zero-slope plateau, and (3) initial decline followed by later increases in intact proviral DNA. Defective proviral DNA levels were essentially stable. Mechanisms of slowing or reversal of second-phase decay of intact proviral DNA may include the inability to clear cells with intact but transcriptionally silent proviruses and clonal expansion of cells with intact proviruses.

Comparative sensitivity of automated (Abbott M2000) and manual plasma HIV-1 RNA PCR assays for the detection of persistent viremia after long-term antiretroviral therapy.

Background: The ability of automated, FDA-cleared plasma HIV-1 RNA assays to detect low-level viremia, compared to manual, highly sensitive research-only methods, is not well-defined. We therefore tested paired plasma samples from people with HIV-1 (PWH) on long-term antiretroviral therapy (ART) with both the Abbott M2000 RealTime HIV-1 Viral Load assay (Abbott) and a quantitative reverse transcriptase (RT)-initiated PCR assay that has a reported 95% detection limit of 1 HIV-1 RNA copy/ml (single copy assay, SCA). Methods: Plasma samples from 309 participants in the AIDS Clinical Trials Group study A5321 were tested by both Abbott and SCA. Participants were mostly men (82%). All were on stable ART for a median of 7 years with HIV-1 RNA <40 copies/mL by Abbott. Pooled plasma from each donor was divided and tested. Abbott results were reported as target detected <40 copies/mL but not quantifiable (target detected <40) or target not detected (TND), and SCA results were classified as HIV-1 RNA detected or not detected. Results: By Abbott, 17% (51/309) of sample results were target detected <40, whereas 83% (258/309) were TND. Of the samples that were target detected <40 by Abbott, 73% (37/51) had HIV-1 RNA detected by SCA. By contrast, 43% of samples that were TND by Abbott (110/258) had HIV-1 RNA detected by SCA (p < 0.001). Conclusion: Plasma samples from PWH with HIV-1 RNA detected but <40 copies/ml by the automated Abbott M2000 assay are likely (73% of 51 samples) to have HIV-1 RNA detected by an optimized manual assay with single copy sensitivity. An Abbott HIV-1 RNA result of target not detected did not exclude low-level viremia: 43% of 258 samples had HIV-1 RNA detected by the single copy assay. These findings indicate that the Abbott M2000 assay cannot exclude the persistence of viremia on ART and thus may have less utility, compared to a manual single copy assay, for assessing the impact of experimental interventions designed to eliminate low-level viremia as a step towards achieving ART-free HIV-1 remission.

Advances in HIV-1-specific chimeric antigen receptor cells to target the HIV-1 reservoir.

Antiretroviral therapy (ART) for HIV-1 has dramatically improved outcomes for people living with HIV-1 but requires life-long adherence and can be associated with short and long-term toxicity. Numerous pre-clinical and clinical investigations are underway to develop therapies for immune control of HIV-1 in the absence of ART. The success of chimeric antigen receptor (CAR) cell therapy for hematological malignancy has renewed efforts to develop and investigate CAR cells as strategies to enhance HIV-1 immunity, enable virus control or elimination, and allow ART-free HIV-1 remission. Here, we review the improvements in anti-HIV-1 CAR cell therapy in the two decades since their initial clinical trials were conducted, describe the additional engineering required to protect CAR cells from HIV-1 infection, and preview the current landscape of CAR cell therapies advancing to HIV-1 clinical trials.

Associations of HIV persistence, cigarette smoking, inflammation, and pulmonary dysfunction in people with HIV on antiretroviral therapy.

We aimed to investigate the relationship between measures of HIV persistence with antiretroviral therapy (ART) and cigarette smoking, systemic markers of inflammation, and pulmonary function. Retrospective study of 82 people with HIV (PWH) on ART for a median of 6.9 years (5.6-7.8) and plasma HIV RNA levels <50 copies/mL. HIV DNA and cell-associated HIV RNA (CA-RNA) were measured in peripheral blood mononuclear cells (PBMC) and plasma HIV RNA was measured by single-copy assay (SCA). Plasma levels of 17 inflammatory mediators were measured by Bio-Plex, and standard pulmonary function tests (PFT) were performed in all participants. Median age was 52 years and 41% were women. Most had preserved CD4+ T cell counts (median (IQR) 580 (361-895) cells/mm3). Median plasma HIV RNA was 1.3 (0.7-4.6) copies/mL, and median levels of HIV DNA and CA-RNA in PBMC were 346 (140-541) copies and 19 (3.7-49) copies per 1 million PBMC, respectively. HIV DNA was higher in smokers than in nonsmokers (R = 0.3, P < 0.05), and smoking pack-years positively correlated with HIV DNA and CA-RNA (R = 0.3, P < 0.05 and R = 0.4, P < 0.01, respectively). HIV DNA, CA-RNA, and plasma HIV RNA were not significantly associated with any measure of pulmonary function or inflammation. Cigarette smoking was associated with HIV DNA and CA-RNA levels in blood, but measures of HIV persistence were not associated with pulmonary function or inflammation.

No evidence that circulating HIV-specific immune responses contribute to persistent inflammation and immune activation in persons on long-term ART.

OBJECTIVE: People with HIV (PWH) have persistently elevated levels of inflammation and immune activation despite suppressive antiretroviral therapy (ART), with specific biomarkers showing associations with non-AIDS-defining morbidities and mortality. We investigated the potential role of the HIV-specific adaptive immune response, which also persists under ART, in driving levels of these clinically relevant biomarkers. DESIGN: Cohort-based study. METHODS: HIV-specific IFN-γ-producing T-cell responses and antibody concentrations were measured in blood at study entry in the ACTG A5321 cohort, following a median of 7 years of suppressive ART. HIV persistence measures including cell-associated (CA)-DNA, CA-RNA, and plasma HIV RNA (single-copy assay) were also assessed at study entry. Plasma inflammatory biomarkers and T-cell activation and cycling were measured at a pre-ART time point and at study entry. RESULTS: Neither the magnitudes of HIV-specific T-cell responses nor HIV antibody levels were correlated with levels of the inflammatory or immune activation biomarkers, including hs-CRP, IL-6, neopterin, sCD14, sCD163, TNF-α, %CD38 + HLA-DR + CD8 + and CD4 + cells, and %Ki67 + CD8 + and CD4 + cells - including after adjustment for pre-ART biomarker level. Plasma HIV RNA levels were modestly correlated with CD8 + T-cell activation ( r  = 0.25, P  = 0.027), but other HIV persistence parameters were not associated with these biomarkers. In mediation analysis, relationships between HIV persistence parameters and inflammatory biomarkers were not influenced by either HIV-specific T-cell responses or antibody levels. CONCLUSION: Adaptive HIV-specific immune responses do not appear to contribute to the elevated inflammatory and immune activation profile in persons on long-term ART.

Natural Killer Cell Receptors and Ligands Are Associated With Markers of HIV-1 Persistence in Chronically Infected ART Suppressed Patients.

The latent HIV-1 reservoir represents a major barrier to achieving a long-term antiretroviral therapy (ART)-free remission or cure for HIV-1. Natural Killer (NK) cells are innate immune cells that play a critical role in controlling viral infections and have been shown to be involved in preventing HIV-1 infection and, in those who are infected, delaying time to progression to AIDS. However, their role in limiting HIV-1 persistence on long term ART is still uncharacterized. To identify associations between markers of HIV-1 persistence and the NK cell receptor-ligand repertoire, we used twin mass cytometry panels to characterize the peripheral blood NK receptor-ligand repertoire in individuals with long-term antiretroviral suppression enrolled in the AIDS Clinical Trial Group A5321 study. At the time of testing, participants had been on ART for a median of 7 years, with virological suppression <50 copies/mL since at most 48 weeks on ART. We found that the NK cell receptor and ligand repertoires did not change across three longitudinal samples over one year-a median of 25 weeks and 50 weeks after the initial sampling. To determine the features of the receptor-ligand repertoire that associate with markers of HIV-1 persistence, we performed a LASSO normalized regression. This analysis revealed that the NK cell ligands CD58, HLA-B, and CRACC, as well as the killer cell immunoglobulin-like receptors (KIRs) KIR2DL1, KIR2DL3, and KIR2DS4 were robustly predictive of markers of HIV-1 persistence, as measured by total HIV-1 cell-associated DNA, HIV-1 cell-associated RNA, and single copy HIV-RNA assays. To characterize the roles of cell populations defined by multiple markers, we augmented the LASSO analysis with FlowSOM clustering. This analysis found that a less mature NK cell phenotype (CD16+CD56dimCD57-LILRB1-NKG2C-) was associated with lower HIV-1 cell associated DNA. Finally, we found that surface expression of HLA-Bw6 measured by CyTOF was associated with lower HIV-1 persistence. Genetic analysis revealed that this was driven by lower HIV-1 persistence in HLA-Bw4/6 heterozygotes. These findings suggest that there may be a role for NK cells in controlling HIV-1 persistence in individuals on long-term ART, which must be corroborated by future studies.

Associations Between Multiple Measures of HIV-1 Persistence in Persons on Suppressive Antiretroviral Therapy.

Clinical research to achieve antiretroviral therapy-free remission requires quantitative assays of the HIV-1 reservoir. Intact proviral DNA (IPD) measurement has greater throughput than the quantitative viral outgrowth assay (QVOA). In 25 individuals with well-documented long-term viral suppression, IPD levels and infectious units per million CD4+ T cells by QVOA strongly correlated (r = 0.59, P = .002), and IPD correlated with total cell-associated HIV-1 DNA and cell-associated HIV-1 RNA (r = 0.62 and r = 0.59, P ≤ .002). IPD may provide an accessible marker of inducible replication-competent virus, total numbers of infected cells, and cellular expression of HIV-1 RNA.

A Phase 1/2 Randomized, Placebo-Controlled Trial of Romidespin in Persons With HIV-1 on Suppressive Antiretroviral Therapy.

BACKGROUND: Romidepsin (RMD) is a histone deacetylase inhibitor reported to reverse HIV-1 latency. We sought to identify doses of RMD that were safe and induced HIV-1 expression. METHODS: Enrollees had HIV-1 RNA <40 copies/mL on antiretroviral therapy. Measurements included RMD levels, plasma viremia by single-copy HIV-1 RNA assay, HIV-1 DNA, cell-associated unspliced HIV-1 RNA (CA-RNA), acetylation of histone H3-lysine-9 (H3K9ac+), and phosphorylation of transcription factor P-TEFb. Wilcoxon tests were used for comparison. RESULTS: In the single-dose cohorts 1-3, 43 participants enrolled (36 participants 0.5, 2, 5 mg/m 2 RMD; 7 placebo) and 16 enrolled in the multidose cohort 4 (13 participants 5 mg/m 2 RMD; 3 placebo). One grade 3 event (neutropenia) was possibly treatment related. No significant changes in viremia were observed in cohorts 1-4 compared to placebo. In cohort 4, pharmacodynamic effects of RMD were reduced proportions of CD4+ T cells 24 hours after infusions 2-4 (median, -3.5% to -4.5%) vs placebo (median, 0.5% to 1%; P ≤ .022), and increased H3K9ac+ and phosphorylated P-TEFb in CD4 + T cells vs placebo (P ≤ .02). CONCLUSIONS: RMD infusions were safe but did not increase plasma viremia or unspliced CA-RNA despite pharmacodynamic effects on CD4 + T cells. CLINICAL TRIALS REGISTRATION: NCT01933594.

Early Emergence and Long-Term Persistence of HIV-Infected T-Cell Clones in Children.

Little is known about the emergence and persistence of human immunodeficiency virus (HIV)-infected T-cell clones in perinatally infected children. We analyzed peripheral blood mononuclear cells (PBMCs) for clonal expansion in 11 children who initiated antiretroviral therapy (ART) between 1.8 and 17.4 months of age and with viremia suppressed for 6 to 9 years. We obtained 8,662 HIV type 1 (HIV-1) integration sites from pre-ART samples and 1,861 sites from on-ART samples. Expanded clones of infected cells were detected pre-ART in 10/11 children. In 8 children, infected cell clones detected pre-ART persisted for 6 to 9 years on ART. A comparison of integration sites in the samples obtained on ART with healthy donor PBMCs infected ex vivo showed selection for cells with proviruses integrated in BACH2 and STAT5B Our analyses indicate that, despite marked differences in T-cell composition and dynamics between children and adults, HIV-infected cell clones are established early in children, persist for up to 9 years on ART, and can be driven by proviral integration in proto-oncogenes.IMPORTANCE HIV-1 integrates its genome into the DNA of host cells. Consequently, HIV-1 genomes are copied with the host cell DNA during cellular division. Pediatric immune systems differ significantly from adults, consisting primarily of naive T cells, which have low expression of the HIV-1 coreceptor CCR5. This difference may result in variances in the number or size of infected cell clones that persist in children on ART. Here, we provide the most extensive analysis of the integration landscape of HIV-1 in children. We found that, despite the largely naive cell populations in neonatal immune systems, patterns of HIV-1 integration and the size of infected cell clones are as large and widespread as those in adults. Furthermore, selection for integration events in proto-oncogenes were observed in children despite early ART. If such cell clones persist for the life span of these individuals, there may be long-term consequences that have yet to be realized.

HIV-specific T cell responses reflect substantive in vivo interactions with antigen despite long-term therapy.

Antiretroviral therapies (ARTs) abrogate HIV replication; however, infection persists as long-lived reservoirs of infected cells with integrated proviruses, which reseed replication if ART is interrupted. A central tenet of our current understanding of this persistence is that infected cells are shielded from immune recognition and elimination through a lack of antigen expression from proviruses. Efforts to cure HIV infection have therefore focused on reactivating latent proviruses to enable immune-mediated clearance, but these have yet to succeed in reducing viral reservoirs. Here, we revisited the question of whether HIV reservoirs are predominately immunologically silent from a new angle: by querying the dynamics of HIV-specific T cell responses over long-term ART for evidence of ongoing recognition of HIV-infected cells. In longitudinal assessments, we show that the rates of change in persisting HIV Nef-specific responses, but not responses to other HIV gene products, were associated with residual frequencies of infected cells. These Nef-specific responses were highly stable over time and disproportionately exhibited a cytotoxic, effector functional profile, indicative of recent in vivo recognition of HIV antigens. These results indicate substantial visibility of the HIV-infected cells to T cells on stable ART, presenting both opportunities and challenges for the development of therapeutic approaches to curing infection.

Selective Decay of Intact HIV-1 Proviral DNA on Antiretroviral Therapy.

BACKGROUND: HIV-1 proviruses persist in people on antiretroviral therapy (ART) but most are defective and do not constitute a replication-competent reservoir. The decay of infected cells carrying intact compared with defective HIV-1 proviruses has not been well defined in people on ART. METHODS: We separately quantified intact and defective proviruses, residual plasma viremia, and markers of inflammation and activation in people on long-term ART. RESULTS: Among 40 participants tested longitudinally from a median of 7.1 years to 12 years after ART initiation, intact provirus levels declined significantly over time (median half-life, 7.1 years; 95% confidence interval [CI], 3.9-18), whereas defective provirus levels did not decrease. The median half-life of total HIV-1 DNA was 41.6 years (95% CI, 13.6-75). The proportion of all proviruses that were intact diminished over time on ART, from about 10% at the first on-ART time point to about 5% at the last. Intact provirus levels on ART correlated with total HIV-1 DNA and residual plasma viremia, but there was no evidence for associations between intact provirus levels and inflammation or immune activation. CONCLUSIONS: Cells containing intact, replication-competent proviruses are selectively lost during suppressive ART. Defining the mechanisms involved should inform strategies to accelerate HIV-1 reservoir depletion.

Vesatolimod, a Toll-like Receptor 7 Agonist, Induces Immune Activation in Virally Suppressed Adults Living With Human Immunodeficiency Virus-1.

BACKGROUND: Treatment with vesatolimod, an investigational, oral, toll-like receptor 7 (TLR7) agonist, leads to sustained viral remission in some non-human primates when combined with anti-envelope antibodies or therapeutic vaccines. We report results of a Phase Ib study evaluating safety, pharmacokinetics, and pharmacodynamics of vesatolimod in adults living with human immunodeficiency virus (HIV)-1. METHODS: In this double-blind, multicenter, placebo-controlled trial, participants on antiretroviral therapy with screening plasma HIV-1 RNA levels <50 copies/mL were randomized (6:2) to receive 6-10 doses of vesatolimod (1-12 mg) or matching placebo orally every other week in sequential dose-escalation cohorts. The primary study objectives included establishing the safety and virologic effects of vesatolimod (change from baseline in plasma HIV-1 RNA). Pharmacokinetics and pharmacodynamic/immunologic activity were assessed as secondary objectives. RESULTS: A total of 48 individuals were randomly assigned to vesatolimod (n = 36) or placebo (n = 12). Vesatolimod was generally well tolerated, with no study drug-related serious adverse events or adverse events leading to study drug discontinuation. There were no statistically significant changes from baseline in plasma HIV-1 RNA in the vesatolimod groups, compared to placebo.Vesatolimod plasma exposures increased dose proportionally; consistent responses in cytokines, interferon-stimulated gene expression, and lymphocyte activation were observed with increasing dose levels above 4 mg. Peak elevations 24 hours after receipt of a 6 mg dose were >3.9-fold higher for interferon gamma-induced protein 10 (IP-10), interleukin-1 receptor antagonist (IL-1RA), interferon-inducible T-cell alpha chemoattractant (ITAC) when compared to baseline values. CONCLUSIONS: Vesatolimod was well tolerated at doses ranging from 1 to 12 mg. Immune stimulation was observed at doses above 4 mg, providing rationale for future combination trials in people living with HIV. CLINICAL TRIALS REGISTRATION: NCT02858401.

Association of Male Sex and Obesity With Residual Plasma Human Immunodeficiency Virus 1 Viremia in Persons on Long-Term Antiretroviral Therapy.

BACKGROUND: Although adipose tissue has been proposed to harbor part of the human immunodeficiency virus 1 (HIV-1) reservoir, the influence of host characteristics, including sex and body mass index (BMI), on measures of HIV-1 persistence during antiretroviral therapy (ART) are incompletely understood. METHODS: We evaluated age, sex, BMI, waist circumference, years on ART, pre-ART HIV-1 RNA, pre-ART CD4+ T-cell count, and initial ART regimen with measures of HIV-1 persistence in blood (residual viremia, cellular HIV-1 DNA and RNA) in a cohort of 295 individuals with well-documented long-term virologic suppression (HIV-1 RNA <50 copies/mL) on ART (AIDS Clinical Trials Group study A5321). RESULTS: Men were more likely than women to have detectable plasma HIV-1 RNA by single-copy assay (52% vs 29%; P = .003), and the proportion of participants with detectable residual viremia increased in a stepwise fashion by BMI category (normal weight or underweight, 38%; overweight, 50%; and obese, 55%). ART regimen type was not associated with measures of HIV-1 persistence after controlling for ART duration. CONCLUSIONS: Sex and obesity are independently associated with residual viremia in people on long-term ART. Additional studies to confirm these relationships and to define the mechanisms by which sex and obesity affect HIV-1 persistence are needed to inform HIV-1 cure strategies.

Brief Report: Dipyridamole Decreases Gut Mucosal Regulatory T-Cell Frequencies Among People With HIV on Antiretroviral Therapy.

BACKGROUND: We had previously conducted a double-blind, randomized placebo-controlled, partial cross-over trial showing that 12 weeks of dipyridamole decreased CD8 T-cell activation among treated HIV(+) individuals by increasing extracellular adenosine levels. METHODS: In this substudy, rectosigmoid biopsies were obtained from 18 participants (9 per arm), to determine whether 12 weeks of dipyridamole affects mucosal immune cells. Participants randomized to placebo were then switched to dipyridamole for 12 weeks while the treatment arm continued dipyridamole for another 12 weeks. We evaluated T-cell frequencies and plasma markers of microbial translocation and intestinal epithelial integrity. Linear regression models on log-transformed outcomes were used for the primary 12-week analysis. RESULTS: Participants receiving dipyridamole had a median 70.2% decrease from baseline in regulatory T cells (P = 0.007) and an 11.3% increase in CD8 T cells (P = 0.05). There was a nonsignificant 10.80% decrease in plasma intestinal fatty acid binding protein levels in the dipyridamole arm compared with a 9.51% increase in the placebo arm. There were no significant differences in plasma levels of ß-D-glucan. In pooled analyses, there continued to be a significant decrease in regulatory T cells (-44%; P = 0.004). There was also a trend for decreased CD4 and CD8 T-cell activation. CONCLUSION: Increasing extracellular adenosine levels using dipyridamole in virally suppressed HIV (+) individuals on antiretroviral therapy can affect regulation of gut mucosal immunity.