Differential effects of antiretroviral treatment on immunity and gut microbiome composition in people living with HIV in rural versus urban Zimbabwe.

BACKGROUND: The widespread availability of antiretroviral therapy (ART) has dramatically reduced mortality and improved life expectancy for people living with HIV (PLWH). However, even with HIV-1 suppression, chronic immune activation and elevated inflammation persist and have been linked to a pro-inflammatory gut microbiome composition and compromised intestinal barrier integrity. PLWH in urban versus rural areas of sub-Saharan Africa experience differences in environmental factors that may impact the gut microbiome and immune system, in response to ART, yet this has not previously been investigated in these groups. To address this, we measured T cell activation/exhaustion/trafficking markers, plasma inflammatory markers, and fecal microbiome composition in PLWH and healthy participants recruited from an urban clinic in the city of Harare, Zimbabwe, and a district hospital that services surrounding rural villages. PLWH were either ART naïve at baseline and sampled again after 24 weeks of first-line ART and the antibiotic cotrimoxazole or were ART-experienced at both timepoints. RESULTS: Although expected reductions in the inflammatory marker IL-6, T-cell activation, and exhaustion were observed with ART-induced viral suppression, these changes were much more pronounced in the urban versus the rural area. Gut microbiome composition was the most highly altered from healthy controls in ART experienced PLWH, and characterized by both reduced alpha diversity and altered composition. However, gut microbiome composition showed a pronounced relationship with T cell activation and exhaustion in ART-naïve PLWH, suggesting a particularly significant role for the gut microbiome in disease progression in uncontrolled infection. Elevated immune exhaustion after 24 weeks of ART did correlate with both living in the rural location and a more Prevotella-rich/Bacteroides-poor microbiome type, suggesting a potential role for rural-associated microbiome differences or their co-variates in the muted improvements in immune exhaustion in the rural area. CONCLUSION: Successful ART was less effective at reducing gut microbiome-associated inflammation and T cell activation in PLWH in rural versus urban Zimbabwe, suggesting that individuals on ART in rural areas of Zimbabwe may be more vulnerable to co-morbidity related to sustained immune dysfunction in treated infection. Video Abstract.

Wilms' tumor 1 (WT1) antigen is overexpressed in Kaposi Sarcoma and is regulated by KSHV vFLIP.

In people living with HIV, Kaposi Sarcoma (KS), a vascular neoplasm caused by KS herpesvirus (KSHV/HHV-8), remains one of the most common malignancies worldwide. Individuals living with HIV, receiving otherwise effective antiretroviral therapy, may present with extensive disease requiring chemotherapy. Hence, new therapeutic approaches are needed. The Wilms' tumor 1 (WT1) protein is overexpressed and associated with poor prognosis in several hematologic and solid malignancies and has shown promise as an immunotherapeutic target. We found that WT1 was overexpressed in >90% of a total 333 KS biopsies, as determined by immunohistochemistry and image analysis. Our largest cohort from ACTG, consisting of 294 cases was further analyzed demonstrating higher WT1 expression was associated with more advanced histopathologic subtypes. There was a positive correlation between the proportion of infected cells within KS tissues, assessed by expression of the KSHV-encoded latency-associated nuclear antigen (LANA), and WT1 positivity. Areas with high WT1 expression showed sparse T-cell infiltrates, consistent with an immune evasive tumor microenvironment. We show that major oncogenic isoforms of WT1 are overexpressed in primary KS tissue and observed WT1 upregulation upon de novo infection of endothelial cells with KSHV. KSHV latent viral FLICE-inhibitory protein (vFLIP) upregulated total and major isoforms of WT1, but upregulation was not seen after expression of mutant vFLIP that is unable to bind IKKÆ´ and induce NFκB. siRNA targeting of WT1 in latent KSHV infection resulted in decreased total cell number and pAKT, BCL2 and LANA protein expression. Finally, we show that ESK-1, a T cell receptor-like monoclonal antibody that recognizes WT1 peptides presented on MHC HLA-A0201, demonstrates increased binding to endothelial cells after KSHV infection or induction of vFLIP expression. We propose that oncogenic isoforms of WT1 are upregulated by KSHV to promote tumorigenesis and immunotherapy directed against WT1 may be an approach for KS treatment.

Monocyte to lymphocyte ratio and hemoglobin level to predict tuberculosis after antiretroviral therapy initiation.

OBJECTIVE: To determine the performance of the baseline monocyte to lymphocyte ratio (MLR), baseline anemia severity and combination of these biomarkers, to predict tuberculosis (TB) incidence in people with HIV (PWH) after antiretroviral therapy (ART) initiation. DESIGN: Multicenter, retrospective cohort study. METHODS: We utilized the data from study A5175 (Prospective Evaluation of Antiretroviral Therapy in Resource-limited Settings: PEARLS). We assessed the utility of MLR, anemia severity and in combination, for predicting TB in the first year after ART. Cox regression was used to assess associations of MLR and anemia with incident TB. Harrell's C index was used to describe single model discrimination. RESULTS: A total of 1455 participants with a median age of 34 [interquartile range (IQR) 29, 41] were included. Fifty-four participants were diagnosed with TB. The hazard ratio (HR) for incident TB was 1.77 [95% confidence interval (CI) 1.01-3.07]; P  = 0.04 for those with MLR ≥0.23. The HR for mild/mod anemia was 3.35 (95% CI 1.78-6.29; P  < 0.001) and 18.16 (95% CI 5.17-63.77; P  < 0.001) for severe anemia. After combining parameters, there were increases in adjusted HR (aHR) for MLR ≥0.23 to 1.83 (95% CI 1.05-3.18), and degrees of anemia to 3.38 (95% CI 1.80-6.35) for mild/mod anemia and 19.09 (95% CI 5.43-67.12) for severe anemia. CONCLUSIONS: MLR and hemoglobin levels which are available in routine HIV care can be used at ART initiation for identifying patients at high risk of developing TB disease to guide diagnostic and management decisions.

Stochastic Interventional Vaccine Efficacy and Principal Surrogate Analyses of Antibody Markers as Correlates of Protection against Symptomatic COVID-19 in the COVE mRNA-1273 Trial.

The COVE trial randomized participants to receive two doses of mRNA-1273 vaccine or placebo on Days 1 and 29 (D1, D29). Anti-SARS-CoV-2 Spike IgG binding antibodies (bAbs), anti-receptor binding domain IgG bAbs, 50% inhibitory dilution neutralizing antibody (nAb) titers, and 80% inhibitory dilution nAb titers were measured at D29 and D57. We assessed these markers as correlates of protection (CoPs) against COVID-19 using stochastic interventional vaccine efficacy (SVE) analysis and principal surrogate (PS) analysis, frameworks not used in our previous COVE immune correlates analyses. By SVE analysis, hypothetical shifts of the D57 Spike IgG distribution from a geometric mean concentration (GMC) of 2737 binding antibody units (BAU)/mL (estimated vaccine efficacy (VE): 92.9% (95% CI: 91.7%, 93.9%)) to 274 BAU/mL or to 27,368 BAU/mL resulted in an overall estimated VE of 84.2% (79.0%, 88.1%) and 97.6% (97.4%, 97.7%), respectively. By binary marker PS analysis of Low and High subgroups (cut-point: 2094 BAU/mL), the ignorance interval (IGI) and estimated uncertainty interval (EUI) for VE were [85%, 90%] and (78%, 93%) for Low compared to [95%, 96%] and (92%, 97%) for High. By continuous marker PS analysis, the IGI and 95% EUI for VE at the 2.5th percentile (519.4 BAU/mL) vs. at the 97.5th percentile (9262.9 BAU/mL) of D57 Spike IgG concentration were [92.6%, 93.4%] and (89.2%, 95.7%) vs. [94.3%, 94.6%] and (89.7%, 97.0%). Results were similar for other D29 and D57 markers. Thus, the SVE and PS analyses additionally support all four markers at both time points as CoPs.

Predictive Value of Serum Biomarkers for Response of Limited-Stage AIDS-Associated Kaposi Sarcoma to Antiretroviral Therapy With or Without Concomitant Chemotherapy in Resource-Limited Settings.

BACKGROUND: Guidelines for limited-stage human immunodeficiency virus-associated Kaposi sarcoma (AIDS/KS) recommend antiretroviral therapy (ART) as initial treatment. However, many such individuals show worsening KS and require additional chemotherapy. Methods to identify such patients are lacking. SETTING: We studied whether serum levels of biomarkers associated with angiogenesis, systemic inflammation, and immune activation, which are elevated in HIV-infected individuals and implicated in the development of KS, could prospectively identify individuals with limited-stage AIDS-KS who would benefit from chemotherapy administered with ART. METHODS: Serum specimens were obtained from participants in a randomized trial evaluating the value of adding oral etoposide chemotherapy to ART in treatment-naïve people with limited-stage AIDS-KS in resource-limited settings. Serum biomarkers of inflammation (C-reactive protein [CRP], interleukin [IL]-6, IL-8, IL-10, granulocyte colony stimulating factor, soluble tumor necrosis factor receptor-2), immune system activation (soluble IL-2 receptor alfa, C-X-C motif chemokine ligand 10/interferon gamma-induced protein 10, C-C motif ligand 2/monocyte chemoattractant protein 1), and angiogenesis (vascular endothelial growth factor, matrix metalloproteinase-2, -9, endoglin, hepatocyte growth factor) were measured at entry to determine whether baseline levels are associated with KS response. On-treatment changes in biomarker levels were determined to assess how etoposide modifies the effects of ART. RESULTS: Pretreatment CRP and IL-10 were higher in those whose KS progressed, and lowest in those who had good clinical responses. Pretreatment CRP, IL-6, and soluble tumor necrosis factor receptor-2 showed significant associations with KS progression at the week-48 primary endpoint. Immediate etoposide led to lower inflammation biomarker levels compared with ART alone. Early KS progression was associated with elevated pretreatment levels of inflammation-associated biomarkers and increasing levels post-treatment. CONCLUSIONS: Quantifying serum biomarkers, especially CRP, may help identify persons with AIDS-KS who would benefit from early introduction of chemotherapy in addition to ART.

Vaccination-Associated Myocarditis and Myocardial Injury.

SARS-CoV-2 vaccine-associated myocarditis/myocardial injury should be evaluated in the contexts of COVID-19 infection, other types of viral myocarditis, and other vaccine-associated cardiac disorders. COVID-19 vaccine-associated myocardial injury can be caused by an inflammatory immune cell infiltrate, but other etiologies such as microvascular thrombosis are also possible. The clinical diagnosis is typically based on symptoms and cardiac magnetic resonance imaging. Endomyocardial biopsy is confirmatory for myocarditis, but may not show an inflammatory infiltrate because of rapid resolution or a non-inflammatory etiology. Myocarditis associated with SARS-COVID-19 vaccines occurs primarily with mRNA platform vaccines, which are also the most effective. In persons aged >16 or >12 years the myocarditis estimated crude incidences after the first 2 doses of BNT162b2 and mRNA-1273 are approximately 1.9 and 3.5 per 100 000 individuals, respectively. These rates equate to excess incidences above control populations of approximately 1.2 (BNT162b2) and 1.9 (mRNA-1273) per 100 000 persons, which are lower than the myocarditis rate for smallpox but higher than that for influenza vaccines. In the studies that have included mRNA vaccine and SARS-COVID-19 myocarditis measured by the same methodology, the incidence rate was increased by 3.5-fold over control in COVID-19 compared with 1.5-fold for BNT162b2 and 6.2-fold for mRNA-1273. However, mortality and major morbidity are less and recovery is faster with mRNA vaccine-associated myocarditis compared to COVID-19 infection. The reasons for this include vaccine-associated myocarditis having a higher incidence in young adults and adolescents, typically no involvement of other organs in vaccine-associated myocarditis, and based on comparisons to non-COVID viral myocarditis an inherently more benign clinical course.

Antiretroviral Therapy Intensification for Neurocognitive Impairment in Human Immunodeficiency Virus.

BACKGROUND: Neurocognitive impairment (NCI) in people with HIV (PWH) on antiretroviral therapy (ART) is common and may result from persistent HIV replication in the central nervous system. METHODS: A5324 was a randomized, double-blind, placebo-controlled, 96-week trial of ART intensification with dolutegravir (DTG) + MVC, DTG + Placebo, or Dual - Placebo in PWH with plasma HIV RNA <50 copies/mL on ART and NCI. The primary outcome was the change on the normalized total z score (ie, the mean of individual NC test z scores) at week 48. RESULTS: Of 357 screened, 191 enrolled: 71% male, 51% Black race, 22% Hispanic ethnicity; mean age 52 years; mean CD4+ T-cells 681 cells/µL. Most (65%) had symptomatic HIV-associated NC disorder. Study drug was discontinued due to an adverse event in 15 (8%) and did not differ between arms (P = .17). Total z score, depressive symptoms, and daily functioning improved over time in all arms with no significant differences between them at week 48 or later. Adjusting for age, sex, race, study site, efavirenz use, or baseline z score did not alter the results. Body mass index modestly increased over 96 weeks (mean increase 0.32 kg/m2, P = .006) and did not differ between arms (P > .10). CONCLUSIONS: This is the largest, randomized, placebo-controlled trial of ART intensification for NCI in PWH. The findings do not support empiric ART intensification as a treatment for NCI in PWH on suppressive ART. They also do not support that DTG adversely affects cognition, mood, or weight.

Cardiotoxicity and pharmacogenetics of doxorubicin in black Zimbabwean breast cancer patients.

AIMS: Doxorubicin-induced cardiotoxicity (DIC) is a significant cause of mortality in cancer care. This study was conducted to establish the frequency of DIC in Zimbabwean breast cancer patients on doxorubicin and to test the DIC predictive power of genetic biomarkers. METHODS: A cohort of 50 Zimbabwean breast cancer patients treated with doxorubicin were followed up for 12 months with serial echocardiography and genotyped for UGTA1A6*4, SLC28A3 and RARG. Eleven per cent of the patients experienced DIC. RESULTS: The frequencies of SLC28A3 (rs7853758), UGT1A6*4 (rs17863783) and RARG (rs2229774) were 60.7%, 17.9% and 14.3%, respectively. No association between DIC and the three variants was observed. CONCLUSIONS: This is the first study on the prevalence of DIC and associated genetic biomarker predictive evaluation in Zimbabwean breast cancer patients. The genetic frequencies observed in our study were different to those reported in other populations. A larger sample size with a longer follow-up time will be necessary in future studies.

Myocardial Injury and Altered Gene Expression Associated With SARS-CoV-2 Infection or mRNA Vaccination.

SARS CoV-2 enters host cells via its Spike protein moiety binding to the essential cardiac enzyme angiotensin-converting enzyme (ACE) 2, followed by internalization. COVID-19 mRNA vaccines are RNA sequences that are translated into Spike protein, which follows the same ACE2-binding route as the intact virion. In model systems, isolated Spike protein can produce cell damage and altered gene expression, and myocardial injury or myocarditis can occur during COVID-19 or after mRNA vaccination. We investigated 7 COVID-19 and 6 post-mRNA vaccination patients with myocardial injury and found nearly identical alterations in gene expression that would predispose to inflammation, coagulopathy, and myocardial dysfunction.

Sex Differences in Subclinical Atherosclerosis and Systemic Immune Activation/Inflammation Among People With Human Immunodeficiency Virus in the United States.

BACKGROUND: Among people with HIV (PWH), sex differences in presentations of atherosclerotic cardiovascular disease (ASCVD) may be influenced by differences in coronary plaque parameters, immune/inflammatory biomarkers, or relationships therein. METHODS: REPRIEVE, a primary ASCVD prevention trial, enrolled antiretroviral therapy (ART)-treated PWH. At entry, a subset of US participants underwent coronary computed tomography angiography (CTA) and immune phenotyping (n = 755 CTA; n = 725 CTA + immune). We characterized sex differences in coronary plaque and immune/inflammatory biomarkers and compared immune-plaque relationships by sex. Unless noted otherwise, analyses adjust for ASCVD risk score. RESULTS: The primary analysis cohort included 631 males and 124 females. ASCVD risk was higher among males (median: 4.9% vs 2.1%), while obesity rates were higher among females (48% vs 21%). Prevalence of any plaque and of plaque with either ≥1 visible noncalcified portion or vulnerable features (NC/V-P) was lower among females overall and controlling for relevant risk factors (RR [95% CI] for any plaque: .67 [.50, .92]; RR for NC/V-P: .71 [.51, 1.00] [adjusted for ASCVD risk score and body mass index]). Females showed higher levels of IL-6, hs-CRP, and D-dimer and lower levels of Lp-PLA2 (P < .001 for all). Higher levels of Lp-PLA2, MCP-1, and oxLDL were associated with higher plaque (P < .02) and NC/V-P prevalence, with no differences by sex. Among females but not males, D-dimer was associated with higher prevalence of NC/V-P (interaction P = .055). CONCLUSIONS: Among US PWH, females had a lower prevalence of plaque and NC/V-P, as well as differences in key immune/inflammatory biomarkers. Immune-plaque relationships differed by sex for D-dimer but not other tested parameters. Clinical Trial Registration. ClinicalTrials.gov; identifier: NCT0234429 (date of initial registration: 22 January 2015).

Metabolic and cardiovascular disease risk for Zimbabwean men with prostate cancer receiving long-term androgen deprivation therapy.

Introduction: Prostate cancer is a leading cause of cancer-related mortality in the majority of sub-Saharan Africa region countries. Androgen deprivation therapy (ADT) is effective treatment, however ADT is associated with complications including metabolic syndrome and cardiovascular disease. Although cardiovascular disease is a leading cause of mortality among prostate cancer patients, there is limited information on ADT impact on metabolic syndrome and cardiovascular disease risk among Africans. An observational prospective cohort study was carried out in Harare, Zimbabwe. Prostate cancer patients due to be initiated on ADT (medical or surgical) were assessed for metabolic syndrome and a 10-year Atherosclerotic Cardiovascular Disease (ASCVD) 10-year risk probability score was done before ADT and followed up to 9 months. Results: 17 black Zimbabwean men were enrolled with a median age 72 years. Most participants (59%) had stage IV disease and 75% opted for surgical castration. At enrolment 23.5% had metabolic syndrome and this increased to 33% after 9 months of ADT. Baseline ASCVD risk was in the high risk category for 68.8% of participants and remained above 50% after 9 months of ADT. In this cohort, there is a 10% absolute increase in metabolic syndrome prevalence amongst African men with prostate cancer within 9 months of ADT initiation.

Evaluation of a training intervention to improve cancer care in Zimbabwe: Strategies to Improve Kaposi Sarcoma Outcomes (SIKO), a prospective community-based stepped-wedge cluster randomized trial.

INTRODUCTION: Most Zimbabweans access medical care through tiered health systems. In 2013, HIV care was decentralized to primary care clinics; while oncology care remained centralized. Most persons in Zimbabwe with Kaposi sarcoma (KS) are diagnosed late in their disease, and the prognosis is poor. Little is known about whether educational interventions could improve KS outcomes in these settings. METHODS: Interventions to improve KS detection and management were evaluated at eight Zimbabwe primary care sites (four rural/four urban) that provided HIV care. Interventions included a standardized KS clinical evaluation tool, palliative care integration, standardized treatment and improved consultative services. Interventions were implemented between February 2013 and January 2016 using a randomized stepped-wedge cluster design. Sites were monitored for KS diagnosis rates and KS outcomes, including early diagnosis (T0 vs. T1 tumour stage), participant retention and mortality. Analyses controlled for within-clinic correlations. RESULTS: A total of 1102 persons with suspected KS (96% HIV positive) were enrolled: 47% incident (new diagnosis), 20% prevalent (previous diagnosis) and 33% determined as not KS. Early (T0) diagnosis increased post-intervention, though not significant statistically (adjusted odds ratio [aOR] = 1.48 [95% confidence interval (95% CI): 0.66-3.79], p = 0.37). New KS diagnosis rates increased 103% (95% CI: 11-273%), p = 0.02) post-intervention; although paired with an increased odds of incorrectly diagnosing KS (aOR = 2.08 [95% CI: 0.33-3.24], p = 0.001). Post-intervention, non-significant decreases in 90-day return rates (adjusted hazard ratio [aHR] = 0.69 [95% CI: 0.38-1.45], p = 0.21) and survival (aHR = 1.36 [95% CI: 0.85-2.20], p = 0.20) were estimated. CONCLUSIONS: KS training interventions at urban and rural Zimbabwe decentralized primary care clinics significantly increased overall and incorrect KS diagnosis rates, but not early KS diagnosis rates, 90-day return rates or survival.

SARS-CoV-2-specific T cells associate with inflammation and reduced lung function in pulmonary post-acute sequalae of SARS-CoV-2.

As of January 2022, at least 60 million individuals are estimated to develop post-acute sequelae of SARS-CoV-2 (PASC) after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While elevated levels of SARS-CoV-2-specific T cells have been observed in non-specific PASC, little is known about their impact on pulmonary function which is compromised in the majority of these individuals. This study compares frequencies of SARS-CoV-2-specific T cells and inflammatory markers with lung function in participants with pulmonary PASC and resolved COVID-19 (RC). Compared to RC, participants with respiratory PASC had between 6- and 105-fold higher frequencies of IFN-γ- and TNF-α-producing SARS-CoV-2-specific CD4+ and CD8+ T cells in peripheral blood, and elevated levels of plasma CRP and IL-6. Importantly, in PASC participants the frequency of TNF-α-producing SARS-CoV-2-specific CD4+ and CD8+ T cells, which exhibited the highest levels of Ki67 indicating they were activity dividing, correlated positively with plasma IL-6 and negatively with measures of lung function, including forced expiratory volume in one second (FEV1), while increased frequencies of IFN-γ-producing SARS-CoV-2-specific T cells associated with prolonged dyspnea. Statistical analyses stratified by age, number of comorbidities and hospitalization status demonstrated that none of these factors affect differences in the frequency of SARS-CoV-2 T cells and plasma IL-6 levels measured between PASC and RC cohorts. Taken together, these findings demonstrate elevated frequencies of SARS-CoV-2-specific T cells in individuals with pulmonary PASC are associated with increased systemic inflammation and decreased lung function, suggesting that SARS-CoV-2-specific T cells contribute to lingering pulmonary symptoms. These findings also provide mechanistic insight on the pathophysiology of PASC that can inform development of potential treatments to reduce symptom burden.

Compartmentalized T cell profile in the lungs of patients with HIV-1-associated pulmonary Kaposi sarcoma.

ABSTRACT: Pulmonary Kaposi sarcoma (pKS) caused by Human herpesvirus 8 (HHV-8) is a devastating form of KS in patients with advanced acquired immunodeficiency syndrome (AIDS) and is associated with increased morbidity and mortality. Blood T cells play a central role in the response of HIV-1 and HHV-8. However, little information is available on T cells in the alveolar space of HIV-1-associated pKS patients.Therefore, we examined CD8+ and CD4+ T cells in the alveolar space in comparison with the blood of patients with pKS. We recruited 26 HIV-1 positive patients with KS, including 15 patients with pKS. Bronchoalveolar lavage (BAL) cells and blood mononuclear cells were analyzed for T cell memory phenotypes, surface markers associated with exhaustion, and intracellular cytokine staining (ICS) using flow cytometry. HIV-1 and HHV-8 viral loads were measured in plasma by quantitative PCR.BAL T cells showed reduced inflammatory capacities and significantly diminished polyfunctionality compared to blood T cells from patients with pKS. This was not accompanied by increased expression of exhaustion markers, such as TIM-3 and PD-1.More importantly, we found a negative correlation between the production of MIP1-ß and TNF-α in T cells in BAL and blood, indicating compartmentalised immune responses to pKS and accentuated chronic HIV-1/HHV-8 pathogenesis via T cells in the lungs of people with pKS.

Intestinal microbial communities and Holdemanella isolated from HIV+/- men who have sex with men increase frequencies of lamina propria CCR5+ CD4+ T cells.

Men who have sex with men (MSM), regardless of HIV infection status, have an intestinal microbiome that is compositionally distinct from men who have sex with women (MSW) and women. We recently showed HIV-negative MSM have elevated levels of intestinal CD4+ T cells expressing CCR5, a critical co-receptor for HIV. Whether elevated expression of CCR5 is driven by the altered gut microbiome composition in MSM has not been explored. Here we used in vitro stimulation of gut Lamina Propria Mononuclear Cells (LPMCs) with whole intact microbial cells isolated from stool to demonstrate that fecal bacterial communities (FBCs) from HIV-positive/negative MSM induced higher frequencies of CCR5+ CD4+ T cells compared to FBCs from HIV-negative MSW and women. To identify potential microbial drivers, we related the frequency of CCR5+ CD4+ T cells to the abundance of individual microbial taxa in rectal biopsy of HIV-positive/negative MSM and controls, and Holdemanella biformis was strongly associated with increased frequency of CCR5+ CD4+ T cells. We used in vitro stimulation of gut LPMCs with the type strain of H. biformis, a second strain of H.biformis and an isolate of the closely related Holdemanella porci , cultured from either a HIV-positive or a HIV-negative MSM stool. H. porci elevated the frequency of both CCR5+ CD4+ T cells and the ratio of TNF-α/IL-10 Genomic comparisons of the 3 Holdemanella isolates revealed unique cell wall and capsular components, which may be responsible for their differences in immunogenicity. These findings describe a novel mechanism potentially linking intestinal dysbiosis in MSM to HIV transmission and mucosal pathogenesis.

Efficacy of the mRNA-1273 SARS-CoV-2 Vaccine at Completion of Blinded Phase.

BACKGROUND: At interim analysis in a phase 3, observer-blinded, placebo-controlled clinical trial, the mRNA-1273 vaccine showed 94.1% efficacy in preventing coronavirus disease 2019 (Covid-19). After emergency use of the vaccine was authorized, the protocol was amended to include an open-label phase. Final analyses of efficacy and safety data from the blinded phase of the trial are reported. METHODS: We enrolled volunteers who were at high risk for Covid-19 or its complications; participants were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 µg) or placebo, 28 days apart, at 99 centers across the United States. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data cutoff date was March 26, 2021. RESULTS: The trial enrolled 30,415 participants; 15,209 were assigned to receive the mRNA-1273 vaccine, and 15,206 to receive placebo. More than 96% of participants received both injections, 2.3% had evidence of SARS-CoV-2 infection at baseline, and the median follow-up was 5.3 months in the blinded phase. Vaccine efficacy in preventing Covid-19 illness was 93.2% (95% confidence interval [CI], 91.0 to 94.8), with 55 confirmed cases in the mRNA-1273 group (9.6 per 1000 person-years; 95% CI, 7.2 to 12.5) and 744 in the placebo group (136.6 per 1000 person-years; 95% CI, 127.0 to 146.8). The efficacy in preventing severe disease was 98.2% (95% CI, 92.8 to 99.6), with 2 cases in the mRNA-1273 group and 106 in the placebo group, and the efficacy in preventing asymptomatic infection starting 14 days after the second injection was 63.0% (95% CI, 56.6 to 68.5), with 214 cases in the mRNA-1273 group and 498 in the placebo group. Vaccine efficacy was consistent across ethnic and racial groups, age groups, and participants with coexisting conditions. No safety concerns were identified. CONCLUSIONS: The mRNA-1273 vaccine continued to be efficacious in preventing Covid-19 illness and severe disease at more than 5 months, with an acceptable safety profile, and protection against asymptomatic infection was observed. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; COVE ClinicalTrials.gov number, NCT04470427.).

Systems Analysis of Gut Microbiome Influence on Metabolic Disease in HIV-Positive and High-Risk Populations.

Poor metabolic health, characterized by insulin resistance and dyslipidemia, is higher in people living with HIV and has been linked with inflammation, antiretroviral therapy (ART) drugs, and ART-associated lipodystrophy (LD). Metabolic disease is associated with gut microbiome composition outside the context of HIV but has not been deeply explored in HIV infection or in high-risk men who have sex with men (HR-MSM), who have a highly altered gut microbiome composition. Furthermore, the contribution of increased bacterial translocation and associated systemic inflammation that has been described in HIV-positive and HR-MSM individuals has not been explored. We used a multiomic approach to explore relationships between impaired metabolic health, defined using fasting blood markers, gut microbes, immune phenotypes, and diet. Our cohort included ART-treated HIV-positive MSM with or without LD, untreated HIV-positive MSM, and HR-MSM. For HIV-positive MSM on ART, we further explored associations with the plasma metabolome. We found that elevated plasma lipopolysaccharide binding protein (LBP) was the most important predictor of impaired metabolic health and network analysis showed that LBP formed a hub joining correlated microbial and immune predictors of metabolic disease. Taken together, our results suggest the role of inflammatory processes linked with bacterial translocation and interaction with the gut microbiome in metabolic disease among HIV-positive and -negative MSM.IMPORTANCE The gut microbiome in people living with HIV (PLWH) is of interest since chronic infection often results in long-term comorbidities. Metabolic disease is prevalent in PLWH even in well-controlled infection and has been linked with the gut microbiome in previous studies, but little attention has been given to PLWH. Furthermore, integrated analyses that consider gut microbiome, together with diet, systemic immune activation, metabolites, and demographics, have been lacking. In a systems-level analysis of predictors of metabolic disease in PLWH and men who are at high risk of acquiring HIV, we found that increased lipopolysaccharide-binding protein, an inflammatory marker indicative of compromised intestinal barrier function, was associated with worse metabolic health. We also found impaired metabolic health associated with specific dietary components, gut microbes, and host and microbial metabolites. This study lays the framework for mechanistic studies aimed at targeting the microbiome to prevent or treat metabolic endotoxemia in HIV-infected individuals.

The Impact of Moderate or High-Intensity Combined Exercise on Systemic Inflammation Among Older Persons With and Without HIV.

BACKGROUND: We investigated whether higher-intensity exercise provided greater decrease in markers of inflammation, and whether responses differed by HIV serostatus. METHODS: People with HIV (PWH; n = 32) and controls (n = 37) aged 50-75 years completed 12 weeks moderate-intensity exercise, then were randomized to moderate- or high-intensity exercise for 12 additional weeks (n = 27 and 29, respectively). Inflammation biomarkers were measured at 0, 12, 24 weeks. Mixed and multiple regression models were adjusted for baseline inflammation, age, and body mass index. RESULTS: Baseline tumor necrosis factor-α (TNF-α), soluble TNF receptor 2 (sTNFR2), and soluble CD14 (sCD14) were significantly higher among PWH than controls (P < .04). From week 0-12, changes in interleukin-6 (IL-6), TNF-α, and sTNFR1 were not significantly different by HIV serostatus. We found no significant interaction between HIV serostatus/exercise intensity on week 12-24 changes in IL-6, TNF-α, and sTNFR1. Among high-intensity exercisers, PWH and controls had significant increases in sCD14 (P ≤ .003), controls significant increases in IL-10 (P = .01), and PWH nonsignificant decrease in highly sensitive C-reactive protein (P = .07). Other markers were not significantly different by serostatus or intensity. CONCLUSIONS: Moderate and high-intensity exercise elicited similar effects on inflammation among PWH and controls, with additional beneficial effects seen among high-intensity exercisers. Increase in sCD14 and attenuated IL-10 increase (PWH only) merit further study. CLINICAL TRIALS REGISTRATION: NCT02404792.

HIV Infection Is Associated with Loss of Anti-Inflammatory Alveolar Macrophages.

HIV type 1 is associated with pulmonary dysfunction that is exacerbated by cigarette smoke. Alveolar macrophages (AM) are the most prominent immune cell in the alveolar space. These cells play an important role in clearing inhaled pathogens and regulating the inflammatory environment; however, how HIV infection impacts AM phenotype and function is not well understood, in part because of their autofluorescence and the absence of well-defined surface markers. The main aim of this study was to evaluate the impact of HIV infection on human AM and to compare the effect of smoking on their phenotype and function. Time-of-flight mass cytometry and RNA sequencing were used to characterize macrophages from human bronchoalveolar lavage of HIV-infected and -uninfected smokers and nonsmokers. We found that the frequency of CD163+ anti-inflammatory AM was decreased, whereas CD163-CCR7+ proinflammatory AM were increased in HIV infection. HIV-mediated proinflammatory polarization was associated with increased levels of inflammatory cytokines and macrophage activation. Conversely, smoking heightened the inflammatory response evident by change in the expression of CXCR4 and TLR4. Altogether, these findings suggest that HIV infection, along with cigarette smoke, favors a proinflammatory macrophage phenotype associated with enhanced expression of inflammatory molecules. Further, this study highlights time-of-flight mass cytometry as a reliable method for immunophenotyping the highly autofluorescent cells present in the bronchoalveolar lavage of cigarette smokers.

Body Composition Changes in Response to Moderate- or High-Intensity Exercise Among Older Adults With or Without HIV Infection.

BACKGROUND: People with HIV (PWH) are at an increased risk for adiposity and sarcopenia, despite effective antiretroviral therapy. Our objective was to compare the effects of prescribed exercise on body composition in older PWH and uninfected controls. SETTING: Academic medical center. METHODS: Sedentary PWH (n = 27) and uninfected controls (n = 28) aged 50-75 years completed 24 weeks of cardiovascular and resistance exercise. Participants completed 12 weeks of moderate-intensity exercise and then were randomized to moderate- or high-intensity exercise for 12 additional weeks. Total lean (LEAN) and fat mass (FAT), and visceral adipose tissue area (VAT) were measured using dual-energy x-ray absorptiometry at baseline and 24 weeks; baseline and intervention differences were compared by HIV serostatus using multivariable regression analyses adjusted for baseline values, age, and exercise adherence. RESULTS: At baseline, PWH had significantly lower FAT (P = 0.003), but no significant differences in LEAN or VAT compared with controls (P > 0.20). Changes over 24 weeks were not significantly different by HIV serostatus, although controls tended to gain more LEAN (0.8 kg; range, 0-1.6 kg; P = 0.04] than PWH (0.6 kg; range, -0.2 to 1.4 kg; P = 0.12) and lose less FAT and VAT (controls: (-0.9 kg; range, -1.8 to 0.0 kg and -10.3 cm; range, -19.6, 1.0) cm; both P = 0.03 vs PWH: -2.0 kg; range, -2.9 to -1.1 kg and -17.7 cm; range, -27.1 to -8.2 cm; both P < 0.001). Exercise intensity differences were not apparent for LEAN, FAT, or VAT. CONCLUSIONS: Exercise reduced total and visceral fat in older PWH and controls. Minimal gains in lean mass suggest that greater emphasis on resistance exercise may be needed to more effectively increase muscle in PWH.