Cecilia M. Shikuma

TIGIT Marks Exhausted T Cells, Correlates with Disease Progression, and Serves as a Target for Immune Restoration in HIV and SIV Infection.

HIV infection induces phenotypic and functional changes to CD8+ T cells defined by the coordinated upregulation of a series of negative checkpoint receptors that eventually result in T cell exhaustion and failure to control viral replication. We report that effector CD8+ T cells during HIV infection in blood and SIV infection in lymphoid tissue exhibit higher levels of the negative checkpoint receptor TIGIT. Increased frequencies of TIGIT+ and TIGIT+ PD-1+ CD8+ T cells correlated with parameters of HIV and SIV disease progression. TIGIT remained elevated despite viral suppression in those with either pharmacological antiretroviral control or immunologically in elite controllers. HIV and SIV-specific CD8+ T cells were dysfunctional and expressed high levels of TIGIT and PD-1. Ex-vivo single or combinational antibody blockade of TIGIT and/or PD-L1 restored viral-specific CD8+ T cell effector responses. The frequency of TIGIT+ CD4+ T cells correlated with the CD4+ T cell total HIV DNA. These findings identify TIGIT as a novel marker of dysfunctional HIV-specific T cells and suggest TIGIT along with other checkpoint receptors may be novel curative HIV targets to reverse T cell exhaustion.

Non-Classical Monocytes and Monocyte Chemoattractant Protein-1 (MCP-1) Correlate with Coronary Artery Calcium Progression in Chronically HIV-1 Infected Adults on Stable Antiretroviral Therapy

Background Persistent inflammation and immune activation has been hypothesized to contribute to increased prevalence of subclinical atherosclerosis and cardiovascular disease (CVD) risk in patients with chronic HIV infection. In this study, we examined the correlation of peripheral monocyte subsets and soluble biomarkers of inflammation to coronary artery calcium (CAC) progression, as measured by cardiac computed tomography scan. Methods We conducted a longitudinal analysis utilizing baseline data of 78 participants with HIV infection on stable antiretroviral therapy (ART) in the Hawaii Aging with HIV-Cardiovascular study who had available baseline monocyte subset analysis as well as CAC measurement at baseline and at 2-year follow up. Monocyte phenotypes were assessed from cryopreserved blood by flow cytometry and plasma was assayed for soluble biomarkers using antibody-coated beads in a high sensitivity Milliplex Luminex platform. Change in CAC over 2 years was analyzed as the primary outcome variable. Results Of all monocyte subsets and biomarkers tested, higher non-classical monocyte percentage (ρ = 0.259, p = 0.022), interleukin (IL)-6 (ρ = 0.311, p = 0.012), and monocyte chemoattractant protein (MCP)-1 (ρ = 0.524, p = <0.001) were significantly correlated to higher 2-year CAC progression in unadjusted Spearman’s correlation. Non-classical monocyte percentage (ρ = 0.247, p = 0.039), and MCP-1 (ρ = 0.487, p = <0.001), remained significantly correlated to 2-year CAC progression, while IL-6 was not (ρ = 0.209, p = 0.120) after adjustment for age, hypertension, diabetes mellitus, total/HDL cholesterol ratio, smoking history, and BMI. Conclusion The percentage of non-classical monocytes and plasma MCP-1 levels were independently associated with CAC progression and may be related to the progression of atherosclerosis and increased CVD risk associated with chronic HIV infection on stable ART.

Human Galectin-9 Is a Potent Mediator of HIV Transcription and Reactivation.

Identifying host immune determinants governing HIV transcription, latency and infectivity in vivo is critical to developing an HIV cure. Based on our recent finding that the host factor p21 regulates HIV transcription during antiretroviral therapy (ART), and published data demonstrating that the human carbohydrate-binding immunomodulatory protein galectin-9 regulates p21, we hypothesized that galectin-9 modulates HIV transcription. We report that the administration of a recombinant, stable form of galectin-9 (rGal-9) potently reverses HIV latency in vitro in the J-Lat HIV latency model. Furthermore, rGal-9 reverses HIV latency ex vivo in primary CD4+ T cells from HIV-infected, ART-suppressed individuals (p = 0.002), more potently than vorinostat (p = 0.02). rGal-9 co-administration with the latency reversal agent JQ1, a bromodomain inhibitor, exhibits synergistic activity (p<0.05). rGal-9 signals through N-linked oligosaccharides and O-linked hexasaccharides on the T cell surface, modulating the gene expression levels of key transcription initiation, promoter proximal-pausing, and chromatin remodeling factors that regulate HIV latency. Beyond latent viral reactivation, rGal-9 induces robust expression of the host antiviral deaminase APOBEC3G in vitro and ex vivo (FDR<0.006) and significantly reduces infectivity of progeny virus, decreasing the probability that the HIV reservoir will be replenished when latency is reversed therapeutically. Lastly, endogenous levels of soluble galectin-9 in the plasma of 72 HIV-infected ART-suppressed individuals were associated with levels of HIV RNA in CD4+ T cells (p<0.02) and with the quantity and binding avidity of circulating anti-HIV antibodies (p<0.009), suggesting a role of galectin-9 in regulating HIV transcription and viral production in vivo during therapy. Our data suggest that galectin-9 and the host glycosylation machinery should be explored as foundations for novel HIV cure strategies.

Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients

Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51years; 81% with HIV RNA ≤50copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets.

High prevalence of PI resistance in patients failing second-line ART in Vietnam

Background There are limited data from resource-limited settings on antiretroviral resistance mutations that develop in patients failing second-line PI ART. Methods We performed a cross-sectional virological assessment of adults on second-line ART for ≥6 months between November 2006 and December 2011, followed by a prospective follow-up over 2 years of patients with virological failure (VF) at the Hospital for Tropical Diseases, Vietnam. VF was defined as HIV RNA concentrations ≥1000 copies/mL. Resistance mutations were identified by population sequencing of the pol gene and interpreted using the 2014 IAS-USA mutation list and the Stanford algorithm. Logistic regression modelling was performed to identify predictors of VF. Results Two hundred and thirty-one patients were enrolled in the study. The median age was 32 years; 81.0% were male, 95.7% were on a lopinavir/ritonavir-containing regimen and 22 (9.5%) patients had VF. Of the patients with VF, 14 (64%) carried at least one major protease mutation [median: 2 (IQR: 1–3)]; 13 (59%) had multiple protease mutations conferring intermediate- to high-level resistance to lopinavir/ritonavir. Mutations conferring cross-resistance to etravirine, rilpivirine, tipranavir and darunavir were identified in 55%, 55%, 45% and 27% of patients, respectively. Higher viral load, adherence <95% and previous indinavir use were independent predictors of VF. The 2 year outcomes of the patients maintained on lopinavir/ritonavir included: death, 7 (35%); worsening virological/immunological control, 6 (30%); and virological re-suppression, 5 (25%). Two patients were switched to raltegravir and darunavir/ritonavir with good HIV control. Conclusions High-prevalence PI resistance was associated with previous indinavir exposure. Darunavir plus an integrase inhibitor and lamivudine might be a promising third-line regimen in Vietnam.

HIV Infection and Carotid Artery Intima-media Thickness: Pooled Analyses Across 5 Cohorts of the NHLBI HIV-CVD Collaborative

BACKGROUNDnAge and human immunodeficiency virus (HIV) treatment may affect the association of HIV infection with atherosclerosis.nnnMETHODSnWe used identical carotid artery B-mode ultrasonographic methods in 5 cohorts participating in the National Heart, Lung, and Blood Institute HIV-CVD Collaborative to measure intima-media thickness of the right far wall of the common carotid artery (CCA-IMT) and carotid artery bifurcation (BIF-IMT) between 2010 and 2013. Participants aged 6-75 years were either HIV infected or uninfected. Linear regression assessed associations of CCA-IMT and BIF-IMT with HIV infection and cardiovascular disease risk factors, within age and HIV treatment groups. Adjustment variables included sex, race/ethnicity, smoking, height, weight, and use of antihypertensive and lipid-lowering drugs.nnnRESULTSnWe studied 867 HIV-infected and 338 HIV-uninfected male and 696 HIV-infected and 246 HIV-uninfected female participants. Among both middle-aged (30-49 years) and older adults (50-75 years), HIV-infected participants had CCA-IMT and BIF-IMT values that were similar to or lower than those in HIV-uninfected participants. In contrast, among those aged 6-29 years, HIV infection was associated with higher CCA-IMT and BIF-IMT values. Among HIV-infected participants, associations of higher systolic blood pressure and lower high-density lipoprotein cholesterol with Carotid artery intima-media thickness strengthened with age.nnnCONCLUSIONSnThe effects of HIV on carotid artery structure may differ across the lifespan, with traditional determinants of cardiovascular disease burden playing a larger role and HIV playing a lesser role in older adults than in young adults and children.

Non-classical monocytes predict progression of carotid artery bifurcation intima-media thickness in HIV-infected individuals on stable antiretroviral therapy

Background: Inflammation may contribute to cardiovascular disease (CVD) among antiretrovirally suppressed HIV-infected individuals. We assessed relationships of monocyte, CD8 T-cell activation and plasma biomarkers to changes in carotid artery intima-media thickness (CIMT). Methods: Longitudinal study of HIV-infected subjects ≥40 years and on stable antiretroviral therapy (ART) ≥3 months. Peripheral blood mononuclear cells were immunophenotyped by multiparameteric flow cytometry to quantify classical (CD14++CD16–), intermediate (CD14++CD16+), non-classical (CD14low/+CD16++) and transitional (CD14+CD16–) monocyte subsets and activated (CD38+HLA-DR+) CD8+ T-cells at baseline. Plasma biomarkers were assessed by multiplex Luminex assay. High-resolution B-mode ultrasounds of right carotid arteries were obtained. Changes in CIMT over two years at the right common carotid artery (CIMTCCA) and right bifurcation (CIMTBIF) were outcome variables. Results: We studied 50 subjects: 84% male, median age 49 (Q1, Q3; 46, 56) years, median CD4 count 461 (317, 578) cells/mm3, and with HIV RNA ≤ 50 copies/mL in 84%. Change in CIMTBIF correlated with log values of baseline absolute count of non-classical monocytes (r = 0.37, p = 0.020), and with MCP-1 (r = 0.42, p = 0.0024) and TNF-α (r = 0.30, p = 0.036) levels. In multivariable linear regression, only non-classical monocytes and MCP-1 predicted the change in CIMTBIF, independent of Framingham Risk Score and baseline CIMTBIF. No correlation was noted between CD8 T-cell activation and CIMTBIF change. Monocyte subsets, CD8 T-cell activation, and biomarker concentrations were not correlated with changes in CIMTCCA. Conclusions: Our findings highlight the role of non-classical monocytes and MCP-1 in the progression of CIMTBIF in HIV-infected individuals on stable ART independent of traditional cardio-metabolic risk factors.

Development and evaluation of a real-time polymerase chain reaction assay for the rapid detection of Talaromyces marneffei MP1 gene in human plasma

Penicilliosis caused by Talaromyces marneffei is a common AIDS‐defining illness in South and Southeast Asia. Diagnosis is based on culture which can take up to 14 days for identification, leading to treatment delay and increased mortality. We developed a TaqMan real‐time PCR assay targeting the MP1 gene encoding an abundant cell wall protein specific to T. marneffei. The assays performance was evaluated in MP1‐containing plasmids, clinical isolates, and plasma from HIV‐infected patients with and without penicilliosis. The assay consistently detected 10 copies of MP1‐containing plasmids per reaction and 100 T. marneffei yeast cells per millilitre plasma. There were no amplification with seven other Penicillium species and six other HIV‐associated fungal pathogens tested. The assay was evaluated in 70 patients with AIDS: 50 patients with culture‐confirmed penicilliosis and 20 patients with opportunistic infections other than penicilliosis. The diagnostic sensitivity was 70.4% (19/27, 95% CI: 51.5–84.1%) and 52.2% (12/23, 95% CI: 33.0–70.8%) in plasma samples collected prior to and within 48 h of antifungal therapy respectively. The diagnostic specificity was 100% (20/20, 95% CI: 83.9–100%). This assay provides a useful tool for the rapid diagnosis of T. marneffei infection and has the potential to improve the management of patients with penicilliosis.

Elevation of Non-Classical (CD14+/lowCD16++) Monocytes Is Associated with Increased Albuminuria and Urine TGF-β1 in HIV-Infected Individuals on Stable Antiretroviral Therapy.

Objective High rates of albuminuria are observed among HIV-infected individuals on stable antiretroviral therapy (ART). Though pro-inflammatory and pro-fibrotic responses are described as components of albuminuria in the general population, it is unclear how these responses are associated to albuminuria in ART-treated chronic HIV. We investigated the relationship of monocyte subsets and urine inflammatory and fibrotic biomarkers to albuminuria in ART-treated HIV-infected participants. Design and Methods Cross-sectional analyses were performed on Hawaii Aging with HIV-cardiovascular disease study cohort participants who were required at entry to be ≥40 years old and on ART ≥3 months. Monocyte subpopulations were determined in banked peripheral blood mononuclear cells (PBMC) using multi-parametric flow-cytometry. Entry random urine samples were assessed for albumin-to-creatinine ratios (UACR). Urine samples were measured for inflammatory and fibrotic biomarkers using Luminex technology. Results Among 96 HIV-infected subjects with measured UACR (87% male, 59% Caucasian, and 89% undetectable HIV RNA with median CD4 of 495.5 cells/μL), 18 patients (19%) had albuminuria. Non-classical (CD14low/+CD16++) monocytes were significantly elevated in subjects with albuminuria (p = 0.034) and were correlated to UACR (r = 0.238, p = 0.019). Elevated non-classical monocyte counts were significant predictors of worsening albuminuria, independent of traditional- and ART-associated risk factors (β = 0.539, p = 0.007). Urine TGF-β1 and collagen-IV were significantly higher in albuminuric compared to non-albuminuric participants (TGF-β1; p = 0.039 and collagen-IV; p = 0.042). Urine TGF-β1 was significantly correlated with non-classical monocyte counts (r = 0.464, p = 0.017). Conclusion Alterations in monocyte subpopulations and urine pro-fibrotic factors may play a role in kidney dysfunction during chronic HIV infection and warrants further study.

CD4/CD8 Ratio Predicts Peripheral Fat in HIV-Infected Population.

New Haven, CT kPhiladelphia VA Medical Center, Philadelphia, PA ¶Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA #Washington DC VA Medical Center, Washington, DC **George Washington University Medical Center, Washington, DC ††Hamad Healthcare Quality Institute and Hamad Medical Corporation, Doha, Qatar ‡‡VA Pittsburgh Healthcare System, Pittsburgh, PA §§James J. Peters VA Medical Center, Bronx, NY kkIcahn School of Medicine at Mt. Sinai, New York, NY ¶¶Michael E. DeBakey VA Medical Center, Houston, TX ##Baylor College of Medicine, Houston, TX ***Atlanta VA Medical Center, Atlanta, GA †††Emory University School of Medicine, Atlanta, GA ‡‡‡Saint Louis University School of Medicine, Saint Louis, MO