Abstract HIV-1 infection greatly alters the NK cell phenotypic and functional repertoire. This is highlighted by the expansion of a rare population of FcRγ– NK cells exhibiting characteristics of traditional immunologic memory in people with HIV (PWH). Although current antiretroviral therapy (ART) effectively controls HIV-1 viremia and disease progression, its impact on HIV-1–associated NK cell abnormalities remains unclear. To address this, we performed a longitudinal analysis detailing conventional and memory-like NK cell characteristics in n = 60 PWH during the first 4 y of ART. Throughout this regimen, a skewed repertoire of cytokine unresponsive FcRγ– memory-like NK cells persisted and accompanied an overall increase in NK surface expression of CD57 and KLRG1, suggestive of progression toward immune senescence. These traits were linked to elevated serum inflammatory biomarkers and increasing Ab titers to human CMV, with human CMV viremia detected in approximately one-third of PWH at years 1–4 of ART. Interestingly, 40% of PWH displayed atypical NK cell subsets, representing intermediate stages of NK-poiesis based on single-cell multiomic trajectory analysis. Our findings indicate that NK cell irregularities persist in PWH despite long-term ART, underscoring the need to better understand the causative mechanisms that prevent full restoration of immune health in PWH.
Abstract Study Objectives Although poor sleep quality is associated with lower CD4+ T cell counts among people living with HIV (PLWH), the association between objective sleep metrics and T lymphocyte subset counts is unknown. We evaluated the association between polysomnography (PSG) derived sleep metrics and T lymphocyte subpopulations in a cohort of men living with HIV. Methods Virally suppressed men living with HIV participating in the Multicenter AIDS Cohort Study underwent home overnight PSG. We assessed the association of PSG parameters with CD4+ and CD8+ T cell counts and the CD4+/CD8+ T cell ratio. Results Overall, 289 men with mean (±SD) age 55.3 ±11.3 years and mean CD4+ T cell count 730 ±308 cells/mm3 were evaluated. Total sleep time (TST) was significantly associated with CD8+ but not CD4+ T cell counts. After adjusting for age, race, depressive symptoms, antidepressant use, and non-nucleoside reverse transcriptase inhibitors use, every hour of shorter TST was associated with an additional 33 circulating CD8+ T cells/mm3 (p=0.05) and a 5.6% (p=0.0007) decline in CD4+/CD8+ T cell ratio. In adjusted models, every hour of shorter REM sleep was associated with an additional 113 CD8+ T cells/mm3 (p=0.02) and a 15.1% lower CD4+/CD8+ T cell ratio (p=0.006). In contrast, measures of sleep efficiency and sleep-disordered breathing were not associated with differences in T lymphocyte subpopulations. Conclusions Our findings suggest that shorter TST and REM sleep durations are associated with differences in T lymphocyte subpopulations among men living with HIV. Addressing sleep may reflect a novel opportunity to improve immune function in PLWH.
Hospitalized patients with severe COVID-19 follow heterogeneous clinical trajectories, requiring different levels of respiratory support and experiencing diverse clinical outcomes. Differences in host immune responses to SARS-CoV-2 infection may account for the heterogeneous clinical course, but we have limited data on the dynamic evolution of systemic biomarkers and related subphenotypes. Improved understanding of the dynamic transitions of host subphenotypes in COVID-19 may allow for improved patient selection for targeted therapies.
Human immunodeficiency virus (HIV)–infected individuals exhibit residual inflammation regardless of virologic suppression. We evaluated whether suboptimal adherence to combination antiretroviral therapy (cART) is associated with greater residual inflammation than optimal adherence, despite virologic suppression. Longitudinal self-reported cART adherence data and serum concentrations of 24 biomarkers of inflammation and immune activation were measured at the same study visit in HIV RNA–suppressed (<50 copies/mL) HIV-infected men in the Multicenter AIDS Cohort Study from 1998 to 2009. Associations between dichotomized 6-month (<100% vs 100%) and categorized 4-day (<85%, 85%–99%, and 100%) cART adherence with biomarker concentrations were evaluated. A total of 912 men provided 2816 person-visits with documented plasma HIV RNA suppression. In adjusted models, person-visits at which <100% cART 6-month adherence was reported had higher concentrations of interleukin 2, 6, and 10, interferon γ, tumor necrosis factor α, and C-reactive protein than person-visits at which 100% cART adherence (P < .05) was reported. These same differences were observed in person-visits reporting <85% versus 100% 4-day cART adherence, but not in visits reporting 85%–99% versus 100% cART adherence. After adjustment for multiple comparisons, tumor necrosis factor α remained significantly higher (11% increase; P < .001) in person-visits at which <100% adherence was reported. Higher concentrations of inflammatory biomarkers were observed among HIV RNA–suppressed men who reported <100% cART adherence than among more adherent men. Residual HIV replication (ie, below the limit of detection), more likely among men with suboptimal adherence, is a plausible mechanism. Whether improving cART adherence could affect residual inflammation and associated morbidity and mortality rates should be investigated.
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.
To the Editors: Reversing T-cell exhaustion using antibodies to immune checkpoint inhibitors (ICIs) has revolutionized cancer therapy. Because T-cell exhaustion, mediated by programmed death-1/programmed death ligand-1 (PD-1/PD-L1), may be a barrier to HIV cure1,2 and CD4+ T cells expressing PD-1 are enriched for latent HIV,2–5 treatment with anti-PD-1 antibodies may provide a strategy for targeting the latent HIV reservoir. Given that elimination of latently infected cells harboring replication-competent provirus will be necessary to cure HIV infection, we initiated a phase I/IIa, double-blind, placebo-controlled, dose-escalating safety and immunotherapeutic study of 2 infusions of an anti-PD-1 antibody (cemiplimab) in virally suppressed persons with HIV (PWH). Although participants were not anticipated to receive direct benefit from this study and ICIs are associated with potentially irreversible immune-related adverse events (irAEs), feedback from PWH and the scientific and HIV communities encouraged the team to pursue this HIV cure intervention. Moreover, preliminary data6,7 provided a reasonable expectation that cemiplimab would improve HIV-specific immune responses, reverse HIV latency, and, thus, advance the field. This risk versus benefit assessment8 led to the incorporation of strict measures to limit risk to participants (eg, history of autoimmune disease was exclusionary). Four of the 5 participants enrolled were randomized to receive 0.3 mg/kg of cemiplimab at weeks 0 and 6; one participant received placebo. Possible irAEs occurred in 2 participants: CASE 1 A 50-year-old man enrolled with baseline CD4+ T-cell count of 1.957 × 109/L and normal thyroid-stimulating hormone (TSH) and free thyroxine (free T4) levels. Four weeks after the first infusion of cemiplimab (0.3 mg/kg), TSH of 0.02 µg/mL and free T4 of 2.73 ng/dL were consistent with hyperthyroidism (Table 1). Mild fatigue was the only symptom reported. Repeat laboratory tests at week 5 and consultation with an endocrinologist confirmed thyroiditis (Table 1), assessed as probably related to cemiplimab. Both TSH and free T4 normalized by week 24 without medical intervention. Fatigue resolved, and no new symptoms were reported. TABLE 1. - Laboratory Values for Participants With Possible Immune-Related AEs After Receipt of 1 Dose of 0.3 mg/kg of Cemiplimab Case 1 Study Week Screen Preentry Entry Wk 4 Wk 5 Wk 6 Wk 12 Wk 16 Wk 24 Wk 36 Wk 38 Wk 48 Study day −70 −43 0 29 36 42 92 120 176 253 267 337 Thyroid laboratory test (reference range) TSH (0.27–4.2 mIU/L) 1.91 3.91 0.02 <0.01 0.01 3.97 2.87 1.55 6.67 1.55 3.5 Thyroxine (4.5–10.9 mcg/dL) 7.1 13.4 16.7 Free T4 (0.93–1.7 ng/dL) 2.73 4.1 3.06 0.81 0.86 1.01 1.20 1.12 1.02 Thyroglobulin antibody (0.0–4.0) 80.4 TSH receptor antibody (≤122) <0.09 Case 2 Study Week Screen Preentry Entry Wk 2 Wk 2.1 Wk 2.2 Wk 4 Wk 5 Wk 6 Wk 12 Wk 16 Wk 20 Wk 24 Wk 28 Wk 36 Wk 48 Study day −64 −48 0 14 17 21 28 35 42 84 116 140 168 204 253 337 Liver laboratory test (reference range) AST (0–40 IU/L) 30 23 53 261 (G3) 192 (G2) 149 (G2) 61 50 39 27 23 82 35 62 54 54 ALT (0–44 IU/L) 23 21 58 287 (G3) 272 (G2) 238 (G2) 93 (G1) 48 31 19 20 66 41 65 49 56 Total bilirubin (0.0–1.2 mg/dL) 0.8 0.3 0.3 0.4 1 0.8 0.5 0.6 0.4 0.2 0.4 0.3 0.4 0.4 0.5 0.7 Prothrombin time (10.2–12.8 s) 11.1 10.7 11 (Bold Type = Outside Reference Range)G, grade. CASE 2 A 57-year-old man with baseline CD4+ T-cell count of 0.911 × 109/L had normal aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels at screening. Just before the first infusion of cemiplimab (0.3 mg/kg), asymptomatic grade 1 elevations in AST and ALT levels were observed (Table 1). Routine safety assessment 2 weeks after the first infusion revealed asymptomatic grade 3 elevations in AST and ALT levels (Table 1). On further questioning, the participant reported acetaminophen (500 mg × 1) and alcohol use (6 beer and 2 whiskey drinks) the evening before the week 2 visit. Hepatology consultation revealed no autoimmune etiology or hepatic synthetic dysfunction but elicited chronic alcohol use. The pattern of the hepatic enzyme elevations and their slow resolution were deemed inconsistent with acute alcohol toxicity and, therefore, judged to be possibly related to cemiplimab. Elevated AST and ALT levels resolved 35 days postinfusion without intervention. Liver biopsy was not pursued, given the participant's asymptomatic course and gradual improvement without intervention. This significantly limited definitive assessment of causality due to drug-induced liver injury versus immune-related hepatitis versus the contribution of acute or chronic alcohol use. Per protocol-specified management of suspected irAEs, the second infusion at week 6 was held for both participants. A detailed, unblinded review of safety data from both cases by the independent Safety Monitoring Committee (SMC) was triggered and all study infusions held. Because of the probability of one irAE and the possibility of a second irAE, the SMC recommended halting accrual of additional study participants and holding further cemiplimab infusions. Of note, 2 participants who received 2 cemiplimab infusions before the occurrence of these events remained asymptomatic without laboratory abnormalities. All 4 cemiplimab-treated participants completed the study with no further irAEs or other safety events through 48 weeks after first cemiplimab infusion. The irAEs similar to these 2 cases are well described with other ICIs and frequently managed in cancer patients receiving this immunotherapy,9,10 although the resolution of the participant's thyroid abnormality in this study has not been commonly described. The irAEs can occur after a single infusion, although typically associated with higher doses, and as early as 14 days postinfusion. Given the lack of anticipated direct benefit to study participants and the frequency of possible/probable irAEs (2 of 4 participants) at the lowest dose of study drug, the study was closed to accrual. Of note, ICIs have shown an acceptable risk–benefit profile in PWH treated for cancer in previous studies.11 Whether well-suppressed HIV infection in otherwise healthy individuals without cancer contributed to risk of irAEs in this study remains unknown. The reduction or elimination of latent HIV reservoirs in PWH receiving suppressive antiretroviral therapy will likely require a combination of multiple therapeutic modalities including interventions that enhance HIV-1–specific immune responses to clear or contain these cells when activated to express replication-competent virus. Strategies to reverse HIV-specific immune exhaustion and target latently infected cells must be tested. These may require more targeted PD-1 blockade than that obtained with systemic administration of antibodies, coupled with a better understanding of risks for immune-mediated adverse events, to pursue studies of ICIs in otherwise healthy, virologically suppressed PWH. Our experience underscores the value of the multiple, carefully considered steps to minimize risk to study participants built into this study. These included engagement with representatives of the PWH community before, during, and after the study, highly restrictive entry criteria, active participation of physician investigators in the informed consent process, written assessment of understanding to document the adequacy of the informed consent process, frequent safety visits and phone contact with participants after each infusion, a 6-week observation period between infusions for safety assessment, and a detailed, predetermined toxicity management plan incorporating rapid review by our SMC in response to suspected irAEs. This study underscores the potential challenges of translating successful immunotherapeutic interventions from the high morbidity/mortality cancer field to otherwise healthy virologically suppressed PWH.
Data on the relationship of antiretroviral exposure to measures of human immunodeficiency virus (HIV) persistence are limited. To address this gap, multiple viral, immunologic, and pharmacologic measures were analyzed from individuals with sustained virologic suppression on therapy (median 7 years) in the AIDS Clinical Trials Group A5321 cohort. Among 110 participants on tenofovir-(TFV)-disoproxil-fumarate (TDF)/emtricitabine (FTC)-containing regimens, we found no significant correlation between hair concentrations of individual antiretrovirals (ARVs) in the regimen and measures of HIV persistence (plasma HIV-1 RNA by single copy assay, cell-associated-DNA, cell-associated RNA) or soluble markers of inflammation. These findings suggest that higher systemic ARV exposure may not impact HIV persistence or inflammation.
Abstract Background 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. Methods HIV-specific T-cell responses and antibody concentrations were measured 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. 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, %CD38 + HLA-DR + CD8 + and CD4 + cells, and %Ki67 + CD8 + and CD4 + cells – including after adjustment for pre-ART biomarker level. Magnitudes of T-cell responses to HIV-Pol were correlated with TNF-α levels, but this was confounded by several factors. Plasma HIV RNA levels were 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. Conclusions Adaptive HIV-specific immune responses do not appear to contribute to the elevated inflammatory and immune activation profile associated with morbidity and mortality under long-term ART. Summary HIV-specific T-cell and antibody responses persist over years of suppressive ART, but there is no evidence that these ongoing immune responses contribute to elevated levels of inflammation and immune activation in people living with HIV on long-term ART.
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.
