Exposure to HIV pre-exposure prophylaxis (PrEP) decreases leukocyte mitochondrial function and gene expression profiles in vitro and alters the lipidome
ER Bowman1, C Cameron2, B Richardson2, J Gabriel1, A Kettelhut1, JJ Kwiek1, A Norris Turner1, C Malvestutto1, J Bazan1, SL Koletar1, MM Lederman2, M Cameron2, NR Klatt3, JE Lake4, NT Funderburg1
1The Ohio State University, Columbus, Ohio, USA; 2Case Western Reserve University, Cleveland, OH, USA; 3Department of Surgery, University of Minnesota, Minneapolis, MN, USA; 4The University of Texas Health Science Center, Houston, TX, USA
Objectives: The use of antiretroviral therapy (ART) as pre-exposure prophylaxis (PrEP) is an effective strategy for prevention of HIV acquisition. The cellular and metabolic consequences of PrEP exposure, however, have not been sufficiently described. We explored the in vitro effects of PrEP on immune cell transcriptional profiles and mitochondrial function, and the in vivo longitudinal consequences of PrEP exposure on inflam-matory biomarkers and advanced lipid profiles in a cohort of people initiating PrEP (n=15).
Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from people without HIV and exposed to tenofovir disoproxil fumarate (TDF) or emtricitabine (FTC) overnight. Mitochondrial mass and function were measured by flow cytometry and the Agilent XFp analyzer. Monocyte-derived macrophages (MDMs) were differentiated in 20% autologous serum for 5 days in the presence or absence of TDF or FTC, and surface marker expression, lipid uptake and efferocytosis were measured by flow cytometry. MDM gene expression was profiled using RNAseq. Plasma biomarkers were measured by ELISA and lipids were measured using mass spectrometry and the Lipidyzer platform. For statistical analyses, unpaired t-tests were used for in vitro experiments and paired t-tests were used to compare longitudinal changes in participant plasma biomarker and lipid levels.
Results: PBMCs exposed to TDF or FTC had decreased maximal oxygen consumption rate (OCR) and reduced mitochondrial mass. Exposure to PrEP medications also increased reactive oxygen species (ROS) production from monocyte subsets. Compared with MDMs cultured in medium alone, cells differentiated in the presence of TDF (829 genes) or FTC (888 genes) had significant changes in gene expression. Further, MDMs differentiated in the presence of PrEP medications had decreased mitochondrial mass and displayed increased lipid uptake and reduced efferocytosis. These functional differences were related to changes in gene expression (MerTK, COX5A/B, COX6A1, NDUFB9, STAT2, MYD88, NLRP3, SOCS6, SOD2) and protein expression (for example, CD36, Scavenger receptor A). Plasma lipid levels were also altered in vivo in individuals receiving PrEP (TDF+FTC), including significant increases in hexosylceramide (HCER) species that have been linked to cardiometabolic changes. We observed increased sVCAM-1 levels following initiation of PrEP compared with baseline. We also found that exposure of an endothelial cell line to TDF or FTC resulted in increased mRNA expression of VCAM-1 in vitro.
Conclusions: Exposure of leukocytes to TDF or FTC resulted in decreased mitochondrial function and altered functional and transcriptional profiles. These findings may have important implications for the metabolic and immunological consequences of PrEP in populations at risk for HIV acquisition. Further studies should explore the consequences of newer PrEP medications on in vitro and in vivo immune cell function and the lipidome.
Abstract O14
Antiviral Therapy 2020; 25 Suppl 1:A34
Associations between testosterone usage and electrocardiographic QT interval duration in men living with and without HIV
PG Hiremath1, F Bhondoekhan2, SA Haberlen2, H Ashikaga1, FJ Palella3, G D'Souza2, MJ Budoff4, LA Kingsley5, AS Dobs6, WS Post1,2, EZ Soliman7, TT Brown6, KC Wu1
1Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD; 2Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; 3Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL; 4Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Los Angeles, CA; 5Departments of Infectious Diseases and Microbiology and Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA; 6Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD; 7Division of Public Health Sciences, Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE), Winston-Salem, NC
Objectives: Testosterone usage (T-use) may alter risk factors for sudden cardiac death in men living with HIV (MLWH). Electrocardiographic QT interval prolongation, which could potentiate ventricular arrhythmias, has previously been associated with HIV infection and, separately, associated with low testosterone levels. We investigated whether T-use shortens the QT interval duration in MLWH and HIV-uninfected (HIV-) men.
Methods: We utilized data from the Multicenter AIDS Cohort Study, a prospective, longitudinal study of HIV infection among men who have sex with men. Multi-variable linear regression analyses were used to evaluate associations between T-use and QTc duration.
Results: T-use was more common in MLWH compared with HIV- men (19% versus 9%). In a multivariable regression analysis, T-use was associated with a 5.7 msec shorter QT interval (95% CI -9.5, -1.9; P=0.003); in comparison, HIV infection was associated with a 4.3 msec longer QTc (95% CI 2.1, 6.5; P<0.001). Recent T-use, compared with prior T-use, was also associated with a 6.9 msec shorter QTc (95% CI -13, -1.1; P=0.02). In contrast, there was no significant difference in QTc (beta=0.98 msec; P=0.65) between men with no T-use compared to men with prior T-use. There was no interaction between recent T-use and HIV serostatus (P=0.22).
Conclusions: This study is the first known analysis of T-use and QTc interval in MLWH. Overall, our data demonstrate that recent T-use is associated with a shorter QTc interval. Increased T-use duration above a threshold of ≥50% of visits in the preceding 5 years was associated with a shorter QTc interval while lesser T-use duration was not. Given the association of longer QTc with HIV infection and the increased prevalence of hypogonadism and low T-levels in MLWH, the shorter QTc associated with T-use observed in this study supports a protective effect on ventricular repolarization that may counteract the potentially deleterious prolongation seen with HIV infection. Further research is needed to investigate prognostic implications of T-use on clinical arrhythmic outcomes in MLWH.
Abstract O15
Antiviral Therapy 2020; 25 Suppl 1:A35
Subclinical atherosclerosis in persons with HIV is associated with anti-cytomegalovirus CD4+ T-cel ls
CN Wanjalla1, M Mashayekhi1, S Bailin1, CL Gabriel1, LM Meenderink1,2, T Temu3, DT Fuller4, L Guo4, R Virmani4, C Jenkins1, CO Abana5, CM Warren1, R Gangula1, R Smith1, MS Madhur1, AV Finn4, SA Mallal1, MJ Tyska1, SA Kalams1, JA Beckman1, JR Koethe1,5
1Vanderbilt University Medical Center, Nashville, TN, USA; 2Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA; 3University of Washington, Seattle, WA, USA; 4CVPath Institute, Gaithersburg, MD, USA; 5The University of Texas MD Anderson Cancer Center, Houston, TX, USA
Objectives/aim: Persons with HIV (PWH) have a twofold increased risk of cardiovascular disease (CVD) compared with the general population, which persists despite suppression of plasma viraemia on antiretrovi-ral therapy (ART) and is not explained by traditional cardiovascular risk factors including age, race, obesity, dyslipidaemia and smoking status. Accumulating evidence indicates that chronic innate and adaptive immune activation contribute to the development of CVD in PWH, which may be exacerbated by inflated T-cell responses to cytomegalovirus (CMV). In this study, we assessed relationships between circulating CD4+ T-cell subsets, including anti-CMV CD4+ T-cells, with subclinical atherosclerosis among PWH on long-term ART.
Methods: 70 PWH on a single regimen of efavirenz, emtricitabine and tenofovir with sustained plasma viral suppression and 30 HIV-negative controls, all without known CVD were included in this study. We measured CMV viraemia and CMV IgG titres. We also measured the proportion of CD4+ T-cell subsets by flow cytometry (CD3, CD4, CD8, CD45RO, CCR7, CX3CR1, CD69, CD57). CMV-specific T-cells were measured using the DYSNTHSTRYV-MHC tetramer in 10 participants with HLA-DR7. Brachial artery flow-mediated vasodi-lation (FMD) and carotid plaque burden were measured by ultrasound. We used linear regression models to assess the relationship of immune parameters with cardiovascular end points. Lastly, immunohistochemical and immunofluorescence stains were used to localize immune cells, including CX3CR1+ CD4+ T-cells, within coronary plaques (n=3 per group).
Results: PWH had a higher proportion of circulating CX3CR1+∼GPR56+∼CD57+ (hereafter referred to as C∼G∼C+) CD4+ T-cells (3.9% [IQR 1.7–15.1%] compared with 1.3% [IQR 0.7–4.2%] in HIV-negative controls; P=0.02). A median of 14.4% [IQR 4.7–32.7%] of the C∼G∼C+ CD4+ T-cells in the PWH had antigen receptors that recognized a single CMV glycoprotein-B epitope. A higher number of carotid plaques was positively associated with the percentage of C∼G∼C+ CD4+ T-cells (P<0.05) after adjusting for age, sex, BMI, fasting LDL, hypertension and smoking status in PWH (Figure 1). This relationship was not observed in the HIV-negative individuals. We found no association between C∼G∼C+ CD4+ T-cells and FMD. Notably, CX3CR1+ CD4+ T-cells were present in coronary plaques of PWH who died of sudden cardiac death. While the coronary lesions were at a similar advanced stage, plaques from PWH had higher percentage of CX3CR1+ (0.8 versus 0.13% median cells/mm2; P=0.09), and CD4+ T-cells (0.1 versus 0.01% median cells/mm2; P=0.09).
(Abstract O15)
Conclusion(s)/discussion: Circulating C∼G∼C+ CD4+ T-cells can be CMV-specific, and this subset is significantly higher and associated with greater plaque burden in PWH. Furthermore, CX3CR1+ CD4+ T-cells are present in coronary plaque tissue from PWH and may contribute to atherosclerosis progression. Further studies will determine the functional characteristics and receptor specificity of C∼G∼C+ CD4+ T-cells present in atheroma, and whether anti-CMV therapies may have a role in reducing CVD burden in PWH.
Abstract O16
Antiviral Therapy 2020; 25 Suppl 1:A37
Early ART initiation may preserve influenza vaccine response durability
SR Schnittman1, J Boeck1, G Beck-Engeser1, H Ahn1, N Jones1, A Deitchman1, V York1, H Hartig1, R Hoh1, FM Hecht1, JN Martin1, F Aweeka1, SG Deeks1, J Milush1, PW Hunt1
1University of California San Francisco, San Francisco, CA, USA
Objectives/aims: Ageing and immunosenescence predict poor seasonal influenza vaccine responsiveness. We sought to determine whether treated HIV infection is also associated with poor vaccine responsiveness, and whether delayed antiretroviral therapy (ART) initiation or persistent immune activation affect vaccine response in this setting.
Methods: People with HIV (PWH) maintaining ART-mediated viral suppression >1 year and HIV-negative controls, aged 40–65 years, all CMV-seropositive and enriched for HIV risk factors, received seasonal influenza vaccination between 2014–2018. Total IgG titre against each year's vaccine antigens were assessed at baseline, 1 and 4 months (M1 and M4, respectively). PWH were stratified by timing of ART initiation (within 6 months of HIV infection [early ART] versus later), and among later initiators, by nadir CD4 count (>350, 200–350, <200 cells/mm3). Plasma KT ratio, IP-10, sCD14, sCD163, IL-6, sTNFR2 and suPAR were assessed at baseline. Antibody titre (reported as log-EC50) changes after vaccination were assessed with linear mixed-models, adjusted for demographics and health-related behaviours. Timepoint-by-group and biomarker-by-timepoint interaction terms were used to assess between-group differences and the impact of bio-markers on vaccine response at each timepoint.
Results: Of 164 PWH and 41 HIV-negative participants, median age was 54 years, 91% were men and 61% were White. Of HIV-negatives, 56% were MSM, 34% were current smokers, 15% had distant IDU and 41% had >100 lifetime male sexual partners. Of the PWH, 34 were early ART initiators, and the remainder had a range of nadir CD4 counts: >350 (n=32), 200– 350 (n=43) and <200 cells/mm3 (n=55). Median duration of viral suppression was 8 years (IQR 5–11 years). Flu-specific IgG titres increased from baseline to M1 similarly in all groups. While there was no evidence for a decay in titre between M1 to M4 in HIV- and early ART initiators, later ART initiators experienced signifi-cant declines (P<0.04 for all). The extent of titre decay from M1 to M4 was impacted by ART initiation timing: compared with HIV-, the early ART group had a similar slope of decay (P=0.66), but the combined later ART groups experienced a significantly greater rate of decline (P=0.02). Among all participants, higher sCD14 and IP-10, but not other biomarkers, were associated with greater rates of titre decline M1 to M4 (P=0.05 and P=0.03), but were modest in effect size (9% greater rate of titre decline per 1 IQR increase in either bio-marker). See Figure 1.
(Abstract O16)
Conclusions: Compared with adults without HIV, ART-suppressed PWH have similar early humoral responses to influenza vaccination, but only those who initiate ART within the first 6 months of infection appear to maintain similar response durability at 4 months. While the clinical implications of these findings remain unclear, some pathways of immune activation appear to be associated with shorter response durability.
