HIV persists in a small pool of latently infected cells despite antiretroviral therapy (ART). Identifying cellular markers expressed at the surface of these cells may lead to novel therapeutic strategies to reduce the size of the HIV reservoir. We hypothesized that CD4+ T cells expressing immune checkpoint molecules would be enriched in HIV-infected cells in individuals receiving suppressive ART. Expression levels of 7 immune checkpoint molecules (PD-1, CTLA-4, LAG-3, TIGIT, TIM-3, CD160 and 2B4) as well as 4 markers of HIV persistence (integrated and total HIV DNA, 2-LTR circles and cell-associated unspliced HIV RNA) were measured in PBMCs from 48 virally suppressed individuals. Using negative binomial regression models, we identified PD-1, TIGIT and LAG-3 as immune checkpoint molecules positively associated with the frequency of CD4+ T cells harboring integrated HIV DNA. The frequency of CD4+ T cells co-expressing PD-1, TIGIT and LAG-3 independently predicted the frequency of cells harboring integrated HIV DNA. Quantification of HIV genomes in highly purified cell subsets from blood further revealed that expressions of PD-1, TIGIT and LAG-3 were associated with HIV-infected cells in distinct memory CD4+ T cell subsets. CD4+ T cells co-expressing the three markers were highly enriched for integrated viral genomes (median of 8.2 fold compared to total CD4+ T cells). Importantly, most cells carrying inducible HIV genomes expressed at least one of these markers (median contribution of cells expressing LAG-3, PD-1 or TIGIT to the inducible reservoir = 76%). Our data provide evidence that CD4+ T cells expressing PD-1, TIGIT and LAG-3 alone or in combination are enriched for persistent HIV during ART and suggest that immune checkpoint blockers directed against these receptors may represent valuable tools to target latently infected cells in virally suppressed individuals.

Background. CD4(+)/CD8(+) T-cell activation levels often remain elevated in chronic human immunodeficiency virus (HIV) infection despite initiation of antiretroviral therapy (ART). T-cell activation predicts early death and blunted CD4+ T-cell recovery during ART and may affect persistent HIV reservoir size. We investigated whether very early ART initiation is associated with lower on-therapy immune activation and HIV persistence. Methods. From a cohort of patients with early HIV infection (<6 months duration since infection) we identified persons who started ART early (<6 months after infection) or later (≥2 years after infection) and maintained ≥2 years of virologic suppression; at-risk HIV-negative persons were controls. We measured CD4(+)/CD8(+) T-cell activation (percent CD38(+)/HLA-DR(+)) and HIV reservoir size (based on HIV DNA and cell-associated RNA levels). Results. In unadjusted analyses, early ART predicted lower on-therapy CD8(+) T-cell activation (n = 34; mean, 22.1%) than achieved with later ART (n = 32; mean, 28.8%; P = .009), although levels in early ART remained elevated relative to HIV-negative controls (P = .02). Early ART also predicted lower CD4+ T-cell activation than with later ART (5.3% vs 7.5%; P = .06). Early ART predicted 4.8-fold lower DNA levels than achieved with later ART (P = .005), and lower cell-associated RNA levels (difference in signal-to-cutoff ratio (S/Co), 3.2; P = .035). Conclusions. ART initiation <6 months after infection is associated with lower levels of T-cell activation and smaller HIV DNA and RNA reservoir size during long-term therapy.

Background ART is typically begun weeks after HIV diagnosis. We assessed the acceptability, feasibility, safety and efficacy of initiating ART on the same day as diagnosis. Methods We studied a clinic-based cohort consisting of consecutive patients who were referred with new HIV diagnosis between June 2013 and December 2014. A subset of patients with acute or recent infection (<6 months) or CD4<200 were managed according to a “RAPID” care initiation protocol. An intensive, same-day appointment included social needs assessment; medical provider evaluation; and a first ART dose offered after labs were drawn. Patient acceptance of ART, drug toxicities, drug resistance and time to viral suppression outcomes were compared between RAPID participants and contemporaneous patients (who were not offered the program), as well as with an historical cohort. Results Among 86 patients, 39 were eligible and managed on the RAPID protocol. 37 (94.9%) of 39 in RAPID began ART within 24 hours. Minor toxicity with the initial regimen occurred in two (5.1%) of intervention patients versus none in the non-intervention group. Loss to follow-up was similar in intervention (10.3%) and non-intervention patients (14.9%) during the study. Time to virologic suppression (<200 copies HIV RNA/mL) was significantly faster (median 1.8 months) among intervention-managed patients when compared with patients treated in the same clinic under prior recommendations for universal ART (4.3 months; p=0.0001). Conclusions Treatment for HIV infection can be started on the day of diagnosis without impacting the safety or acceptability of ART. Same-day ART may shorten the time to virologic suppression.

Background Disulfiram activates HIV transcription in a primary T-cell model of HIV latency and in a pilot clinical study increased plasma HIV RNA in individuals with adequate diulfiram exposure. Methods We conducted a prospective dose escalation study in order to optimise disulfiram exposure. Thirty people with HIV on suppressive antiretroviral therapy (ART) were enrolled, allocated sequentially to one of three dosing cohorts and received disulfiram daily for three days at a dose of 500mg, 1000mg or 2000mg. The primary endpoint was cell-associated unspliced (CA-US) HIV RNA in CD4+ T-cells. The study is registered with ClinicalTrials.gov, number NCT01944371. Findings The estimated fold increases in CA-US HIV RNA during and post-disulfiram for each cohort were: 500mg: 1·7 (95% confidence interval 1·3 – 2·2) and 2·1 (1·5 – 2·9); 1000mg: 1·9 (1·6 – 2·4) and 2·5 (1·9 – 3·3); and 2000mg: 1·6 (1·2 – 2·1) and 2·1 (1·5 – 3·1) respectively (p<0·003 for all). Disulfiram was well tolerated at all doses. Interpretation Short-term administration of disulfiram resulted in increases in CA-US HIV RNA at all doses, consistent with activating HIV latency. Disulfiram may be suited for future studies of combination and prolonged therapy to activate latent HIV.