Robert Kaplan - US grants

DESCRIPTION (provided by applicant): Innate immune system activation is a recognized feature of chronic HIV infection that may contribute to HIV disease progression as well increasingly important non-classic HIV complications such as cardiovascular disease (CVD). This proposal will a) identify mechanisms linking innate immunity with CVD in the setting of chronic, treated HIV infection; b) develop novel serum biomarkers for monocyte/macrophage related inflammation and coagulation that may stratify CVD risk in the HIV-infected population; c) use global sequencing of RNAs (RNA-Seq) to define HIV- and CVD-associated gain and/or loss of function of specific signaling pathways by studying CD14++ and CD14+CD16+ monocyte subsets from well-characterized HIV+ and HIV- patient groups. Extensively characterized HIV infected and HIV uninfected enrollees from the WIHS and MACS NIH cohorts are brought to bear in this interdisciplinary, multi-site investigation. This project will thereby provide insight into the observed links of HIV infection and related comorbidities (e.g., HCV coinfection) with CVD risk, identifying the innate immune system as a novel and modifiable explanatory pathway. This is of high clinical relevance given the need for improved CVD risk stratification, as well as the feasibility of intervening on mechanisms mediated by monocyte/macrophage activity.

The Hispanic/Latino population is the fasting growing segment of the US population. Diabetes disproportionately affects this group. National US 2007-09 data found that >20 yr old Hispanics (11.8%) have a 66% higher rate of diabetes compared to non-Hispanic whites (7.1%). In the population-based Hispanic Community Health Study (HCHS)/Study of Latinos (SOL), diabetes had a baseline prevalence of approximately 17%. Very recent data implicates the gut microbiome (GMB) as a key determinant of diabetes. Since different ancestral populations harbor different diabetes-associated sets of GMBs, it is necessary to study Hispanic/Latino populations with high rates of diabetes to determine the relationship between the GMB and diabetes. Understanding the relationship of the GMB to diabetes is anticipated to lead to a new era of prevention and treatment options, especially since therapeutic interventions are available that target the GMB. Nevertheless, there are major gaps in understanding the epidemiology of the GMB in the population and its role in the development of diabetes. The proposed study will leverage the HCHS/SOL study that will re-examine the participants in 2014-2017. This study has a major focus on diabetes including a fasting 2h glucose tolerance test (GTT), a standardized and universally accepted metric of glucose metabolism, in addition to specific other laboratory and clinical measurements. This proposed ancillary study will test the hypothesis that specific patterns of the gut microbiome will be significantly associated with pre-diabetes and diabetes, building upon recent advances in understanding the importance of the GMB in human health and metabolic diseases. This project will collect and determine the genetic composition of the fecal microbiome from 2,000 cohort members. The proposed study has developed a unique multidisciplinary team to address the following specific aims: (1) to investigate epidemiological factors affecting the gut microbiome in the sample of Hispanic/Latino individuals of diverse background who have normal indices of carbohydrate metabolism. We will test the association of geographic/ancestral background (e.g., Mexican, Puerto Rican), US birth status, gender, age, BMI, shared household and relatedness, and other variables with the GBM composition; (2) to utilize a cross-sectional design to evaluate the association of the gut microbiome (GMB) with the presence of disorders of carbohydrate metabolism including diabetes and prediabetes; and (3) to examine the longitudinal association of the GMB with risk of developing diabetes. We will use the active follow-up in the entire cohort to identify individuals who develop diabetes and estimate the relative risk of disease associated with different microbiomes. We hypothesize that the microbiomes found to be cross-sectionally associated with diabetes in Aim 2 will be predictive of the development of diabetes among initially pre-diabetic and normoglycemic individuals. 1

? DESCRIPTION (provided by applicant): The advent of combination antiretroviral therapy (cART) has led to marked decreases in AIDS- related mortality in people with HIV infection. Although this has been accompanied by reduction of severe dilated cardiomyopathy associated with late-stage HIV, echocardiographic studies of HIV-infected cohorts in the cART era have highlighted pronounced increases in the prevalence of milder forms of LV systolic dysfunction and, particularly, diastolic dysfunction. Given the young age of such cohorts, and the advancing age of people living with HIV, these echo findings herald a potential upsurge of HF in this population. Moreover, novel cardiac magnetic resonance (CMR) techniques have shown interstitial fibrosis and intramyocardial triglyceride (TG) content to be increased in the setting f cardiovascular and metabolic risk factors, and to correlate with impaired LV function. Such risk factors are well-known to be associated with HIV and its treatment, and modest-sized CMR studies of HIV-infected patients have recently demonstrated increased myocardial fibrosis and TG content, along with depressed myocardial mechanics. Like the majority of available echo studies, these CMR studies did not focus on women, and are limited both by inclusion of healthy volunteers as controls, and by lack of detailed longitudinal assessment of HIV-related factors or treatment. Meanwhile, the development of speckle-tracking echo assessment of myocardial deformation now permits more accurate evaluation of subclinical cardiac dysfunction using a widely applicable non-invasive technique. We propose to leverage the largest and longest prospective cohort of HIV-infected and well-matched uninfected women, the Women's Interagency HIV Study, to build on our previous echo study among Bronx and Brooklyn participants, and perform repeat echoes approximately 12 years later. This will allow the first long-term longitudinal assessment of LV dysfunction in HIV-infected and uninfected women, and a well-sized evaluation of myocardial deformation in such individuals. This will be complemented by CMR assessment of interstitial fibrosis and myocardial TG content, as well as infarct. Using repeated measures of HIV-specific exposures and ART, and added biomarkers of cardiac stress, inflammation and lipid dysregulation, this proposal stands to provide important new knowledge concerning the role of HIV infection and related factors in subclinical myocardial dysfunction and disease. In so doing, the proposed project will identify strategies and future research to avert the potential rise in symptomatic HF that threatens the HIV-infected population in the cART era.

The Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a multi-center epidemiologic study in Hispanic/Latino populations designed to describe the prevalence of cardiovascular and pulmonary disease and other select chronic diseases, their protective or harmful factors, and changes in health over time, including incidence of fatal and non-fatal cardiovascular disease events, exacerbation of pulmonary disease and all-cause mortality. In addition, the role of sociocultural factors (including acculturation) on Hispanic/Latino health is of interest. The initial study period was funded between October 2006 and May 2013. Over 16,400 Hispanics/Latinos, aged 18-74 years at enrollment, and representing different groups of origin (Central Americans, Cubans, Dominicans, Mexicans, Puerto Ricans and South Americans) were recruited and examined between March 2008 and June 2011, and are currently followed at four centers affiliated with San Diego State University, University of Illinois at Chicago, Albert Einstein College of Medicine in the Bronx area of New York, and the University of Miami. A research Coordinating Center at the University of North Carolina in Chapel Hill provides additional scientific and logistical support, and an Echocardiography Reading Center at Brigham and Women's Hospital at Harvard University will provide the reading and interpretation of echocardiograms to be performed during this cycle. In this second study period, study participants will undergo a second examination, and will continue to be followed annually to determine changes in health and health outcomes of interest. Baseline study findings are being analyzed, and publication of the results in scientific journals, and their dissemination to the communities involved in the study is ongoing. The study is currently funded by the National Heart, Lung, and Blood Institute and the National Institute Diabetes, and Digestive, and Kidney Diseases.

Summary/Abstract Our prior work in HIV cohort studies provides insights into the viral, inflammation, immune activation and antiretroviral therapy related risk factors for HIV-related CVD risk. Yet, an understanding of its pathophysiology remains incomplete. Emerging evidence suggests that gut microbiota (GMB) altered during HIV infection correlates with increased immune activation and disrupted metabolite profiles, but the role of GMB in HIV- related CVD is unknown. Our preliminary data show that in HIV infection, progression of atherosclerosis is associated with higher circulating sCD14, a marker of monocyte activation, and increased tryptophan catabolism. This preliminary work presents two promising candidates linking GMB and CVD risk in HIV infection which we propose to study using integrated ?Omics? approaches. In addition to these hypothesis- driven study aims, we will also generate novel hypotheses linking GMB, host immune activation and metabolomics profiles associated with CVD risk. We will leverage the Women?s Interagency HIV Study (WIHS) and Multicenter AIDS Cohort Study (MACS) >20 year follow-up for biospecimens, atherosclerosis and other CVD measures, and HIV parameters. Our longitudinal semi-annual measures allow us to subset individuals according to long-term HIV treatment, disease progression markers (CD4+ T-cell count, viral load), and comorbidity, with inclusion of matched HIV-uninfected participants. In this project, We will extend our established collaborations with leading labs to gather multi-dimensional data among 400 women and men (~65% of whom are HIV+), including stool GMB metagenomics, serum and cellular inflammation and immunologic markers (sCD14, monocyte transcriptomics), metabolomics, and measures (carotid artery ultrasound imaging over 4 year follow-up). Findings from this intensively studied group will then be extended to a larger sample of 746 women and men with metabolomics and longitudinal atherosclerosis data. In this project, we will have the opportunity to identify immune activation and metabolites underlying the role of GMB in CVD, which may be specific to HIV+ individuals, or accentuated in the setting of HIV.

US Hispanics/Latinos are the largest US minority group, constituting over 15% of the US population and growing to one-third of the US population by 2050. Hispanics match or exceed any other race-ethnicity group in having a high burden of diabetes and pre-diabetes. Especially given the relatively young age of US Hispanics, the group with prediabetes (e.g.,fasting plasma glucose 100-125 mg/dl) are of immense public health importance because 15-30% of people with prediabetes will develop diabetes within five years. Physical activity (PA) is an effective preventive behavior in the battle to prevent diabetes as suggested by the Diabetes Prevention Program. In this context, the Hispanic population presents a paradox. Particularly among males, Hispanics have higher moderate-to-vigorous activity levels than non-Hispanics and light intensity PA is higher and sedentary behavior (SB) is lower among Hispanics than other groups. There is also an apparent contradiction (Hispanic paradox) between a high risk of prediabetes/diabetes among Hispanics, while at the same time Hispanics have favorable mortality rates vs. others and may also have lower incidence of cardiovascular disease (CVD). The present application will leverage the Hispanic Community Health Study/Study of Latino Hispanics as well as the Framingham Heart Study (FHS) Third Generation and Omni Gen 2 (FHS Gen3/Omni2) cohorts of multiple race/ethnic groups. This approach not only increases generalizability of our findings to the US mainstream population, but also helps us understand what is unique about Hispanics. In all, 5500 individuals with confirmed prediabetes will be studied, all of whom had 7-day baseline Actical accelerometry measurements (2008-2011) which will be repeated during 2017-2020. This approach will allow us to understand the relationship among PA, SB, onset of diabetes and CVD in a large, representative population study of prediabetics.

Due to the advancing age and high cardiovascular disease (CVD) risk of the HIV infected population, it is predicted that 78% of people living with HIV will be diagnosed with CVD by 2030. Among participants in the Women?s Interagency HIV Study (WIHS), we propose to study an extensively characterized cohort that will be extended from a women-only study to include men with and without clinical and subclinical CVD. We propose these specific aims: 1. In persons living with HIV, to address the hypothesis that specific innate and adaptive immune cell subsets will show defined transcriptomic changes associated with CVD. We have found that both HIV and CVD produce pro-inflammatory gene expression signatures in classical monocytes that partially overlap. However, human blood (PBMCs) contains at least 30 subsets of known immune cell types, which only now can be interrogated using Ab-Seq and scRNA-Seq of PBMCs. Preliminary data demonstrate feasibility. 2. To identify the expression of genes relating to tissue factor (TF) and other coagulation-related pathways in relation to HIV, CVD, inflammation, dyslipidemia and statin use. 3. To test the hypothesis that CD4+ T cells specific for the atherosclerosis antigen apolipoprotein B (APOB) lose their regulatory T cell (Treg) phenotype and to understand the mechanisms by which this promotes CVD in persons living with HIV. A critical tool is the validated tetramer reagent we use to find rare APOB-specific CD4 T cells in participants who express the DRB1*0701 allele of major histocompatibility complex (MHC)-II, comprising about 8% of all subjects. We identified 69 DRB1*0701 positive WIHS participants. The APOB-specific cells will be sorted into single wells by DRB1*0701-APOB-p18 tetramers. Deep scRNA-Seq and Ab-Seq by SMART-Seq2 will yield the first T cell receptor (TCR) sequences and matched transcriptomes for atherosclerosis-specific CD4 T cells. The proposed work has the potential to discover new targets addressable by existing or new drugs, which may improve cardiovascular outcomes in people with HIV. The project will leverage a 20+ year WIHS archive of specimens and data, new participant enrollment and CVD event collection enabled by a future commitment of NHLBI to underwrite the primary HIV cohort infrastructure support.

Lower extremity peripheral artery disease (PAD) affects 10 million adults in the US and increases the risk of mortality and leg amputation. Since it has broad implications for quality of life and maintenance of independent living, the impact of PAD on physical activity and function is of great interest. To characterize the impact of PAD on free-living daily physical activity and examine the value of objective assessment of daily physical activity for PAD management, diagnosis and risk stratification, we propose to evaluate enrollees of the Hispanic Community Cohort Study/Study of Latinos (HCHS/SOL). Participants who were originally studied during 2008-2011 will complete a return in person visit during 2019-2021. Through comprehensive clinical assessment of lower extremity blood vessels, multi-day accelerometry and physical function testing, we address the hypothesis that PAD will be identifiable by suboptimal usual activity patterns including longer sedentary time, higher activity fragmentation and diurnal patterns of activity. The study will also determine the prognostic value of 7-day physical activity, above and beyond self-reported leg symptoms and clinic-based physical function, to predict PAD-associated major health outcomes. Finally, duplex ultrasound of leg arteries in combination with other study assessments will be used to better resolve the population with indeterminant results on peripheral arterial disease clinical test. Results will help to guide the application of both clinical screening protocols and mobile technologies to identify, predict and intervene upon major health sequalae associated with PAD.