Publications by authors named "Kenneth C Williams"

60 Publications

Brain tissue transcriptomic analysis of SIV-infected macaques identifies several altered metabolic pathways linked to neuropathogenesis and poly (ADP-ribose) polymerases (PARPs) as potential therapeutic targets.

J Neurovirol 2021 Feb 6;27(1):101-115. Epub 2021 Jan 6.

Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.

Despite improvements in antiretroviral therapy, human immunodeficiency virus type 1 (HIV-1)-associated neurocognitive disorders (HAND) remain prevalent in subjects undergoing therapy. HAND significantly affects individuals' quality of life, as well as adherence to therapy, and, despite the increasing understanding of neuropathogenesis, no definitive diagnostic or prognostic marker has been identified. We investigated transcriptomic profiles in frontal cortex tissues of Simian immunodeficiency virus (SIV)-infected Rhesus macaques sacrificed at different stages of infection. Gene expression was compared among SIV-infected animals (n = 11), with or without CD8+ lymphocyte depletion, based on detectable (n = 6) or non-detectable (n = 5) presence of the virus in frontal cortex tissues. Significant enrichment in activation of monocyte and macrophage cellular pathways was found in animals with detectable brain infection, independently from CD8+ lymphocyte depletion. In addition, transcripts of four poly (ADP-ribose) polymerases (PARPs) were up-regulated in the frontal cortex, which was confirmed by real-time polymerase chain reaction. Our results shed light on involvement of PARPs in SIV infection of the brain and their role in SIV-associated neurodegenerative processes. Inhibition of PARPs may provide an effective novel therapeutic target for HIV-related neuropathology.
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http://dx.doi.org/10.1007/s13365-020-00927-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7786889PMC
February 2021

Phyloanatomic characterization of the distinct T cell and monocyte contributions to the peripheral blood HIV population within the host.

Virus Evol 2020 Jan 27;6(1):veaa005. Epub 2020 Apr 27.

Department of Pathology, Immunology, and Laboratory Medicine, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32601, USA.

Human immunodeficiency virus (HIV) is a rapidly evolving virus, allowing its genetic sequence to act as a fingerprint for epidemiological processes among, as well as within, individual infected hosts. Though primarily infecting the CD4+ T-cell population, HIV can also be found in monocytes, an immune cell population that differs in several aspects from the canonical T-cell viral target. Using single genome viral sequencing and statistical phylogenetic inference, we investigated the viral RNA diversity and relative contribution of each of these immune cell types to the viral population within the peripheral blood. Results provide evidence of an increased prevalence of circulating monocytes harboring virus in individuals with high viral load in the absence of suppressive antiretroviral therapy. Bayesian phyloanatomic analysis of three of these individuals demonstrated a measurable role for these cells, but not the circulating T-cell population, as a source of cell-free virus in the plasma, supporting the hypothesis that these cells can act as an additional conduit of virus spread.
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http://dx.doi.org/10.1093/ve/veaa005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185683PMC
January 2020

Rationale and design of the Mechanistic Substudy of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE): Effects of pitavastatin on coronary artery disease and inflammatory biomarkers.

Am Heart J 2019 06 4;212:1-12. Epub 2019 Mar 4.

MGH Program in Nutritional Metabolism and Harvard Medical School, Boston, MA.

Background: People with HIV (PWH) have increased cardiovascular events, inflammation, and high-risk coronary atherosclerosis. Statin therapy has been shown to lower the risk of cardiovascular disease (CVD) in the general population, but whether this results from reductions in coronary atherosclerosis and is mediated by decreased inflammation remains unknown.

Methods: REPRIEVE is a randomized, placebo-controlled trial of pitavastatin calcium (4 mg/day) vs. placebo enrolling at least 7500 PWH between 40-75 years, on antiretroviral therapy (ART), with low to moderate traditional CVD risk. The Mechanistic Substudy of REPRIEVE (A5333s) is co-enrolling 800 participants from 31 US sites. These participants undergo serial contrast enhanced coronary computed tomography angiography (CCTA) and measurements of biomarkers of inflammation and immune activation at baseline and after 2 years of follow-up. The primary objectives are to determine the effects of pitavastatin on noncalcified coronary atherosclerotic plaque (NCP) volume, low attenuation plaque, and positive remodeling and on changes in immune activation and inflammation and to assess relationships between the two. Changes in CAD will be assessed in a standardized fashion by a core lab with expert readers blinded to time points and participant information; immune activation and inflammation assessment is also performed centrally.

Results: To date the Mechanistic Substudy has completed planned enrollment, with 805 participants.

Conclusion: This study represents the first large, randomized, CCTA-based assessment of the effects of a primary prevention strategy for CVD on high-risk CAD, immune activation and inflammation among PWH. The study will assess pitavastatin's effects on coronary plaque, and the interrelationship of these changes with biomarkers of immune activation and inflammation in PWH to determine mechanisms of CVD prevention and improved outcomes in this population.
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http://dx.doi.org/10.1016/j.ahj.2019.02.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6596304PMC
June 2019

Hydrocephalus after Intrathecal Administration of Dextran to Rhesus Macaques ().

Comp Med 2018 06 18;68(3):227-232. Epub 2018 May 18.

Division of Immunology, Tulane National Primate Research Center, Covington, Louisiana, USA.

Dextrans have been used extensively as medical therapies and labeling agents in biomedical research to investigate the blood-brain barrier and CSF flow and absorption. Adverse effects from dextrans include anaphylactic reaction and dilation of the cerebral ventricles due to administration into the subarachnoid space. This retrospective study describes 51 rhesus macaques (Macaca mulatta) that received dextran intrathecally. The purpose of intrathecal administration was to enable detection of long-lived, dextran-labeled macrophages and to study monocyte-macrophage turnover in the CNS of SIV- or SHIV- infected and uninfected animals by using immunofluorescence. Of the 51 dextran-treated macaques, 8 that received dextran diluted in saline developed hydrocephalus; 6 of these 8 animals exhibited neurologic signs. In contrast, none of the macaques that received intrathecal dextran diluted in PBS developed hydrocephalus. These data suggest the use of saline diluent and the duration of dextran exposure as potential factors contributing to hydrocephalus after intrathecal dextran in rhesus macaques.
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http://dx.doi.org/10.30802/AALAS-CM-17-000096DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6008720PMC
June 2018

Temporal/compartmental changes in viral RNA and neuronal injury in a primate model of NeuroAIDS.

PLoS One 2018 11;13(5):e0196949. Epub 2018 May 11.

Department of Radiology, Neuroradiology Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States of America.

Despite the advent of highly active anti-retroviral therapy HIV-associated neurocognitive disorders (HAND) continue to be a significant problem. Furthermore, the precise pathogenesis of this neurodegeneration is still unclear. The objective of this study was to examine the relationship between infection by the simian immunodeficiency virus (SIV) and neuronal injury in the rhesus macaque using in vivo and postmortem sampling techniques. The effect of SIV infection in 23 adult rhesus macaques was investigated using an accelerated NeuroAIDS model. Disease progression was modulated either with combination anti-retroviral therapy (cART, 4 animals) or minocycline (7 animals). Twelve animals remained untreated. Viral loads were monitored in the blood and cerebral spinal fluid, as were levels of activated monocytes in the blood. Neuronal injury was monitored in vivo using magnetic resonance spectroscopy. Viral RNA was quantified in brain tissue of each animal postmortem using reverse transcription polymerase chain reaction (RT-PCR), and neuronal injury was assessed by immunohistochemistry. Without treatment, viral RNA in plasma, cerebral spinal fluid, and brain tissue appears to reach a plateau. Neuronal injury was highly correlated both to plasma viral levels and a subset of infected/activated monocytes (CD14+CD16+), which are known to traffic the virus into the brain. Treatment with either cART or minocycline decreased brain viral levels and partially reversed alterations in in vivo and immunohistochemical markers for neuronal injury. These findings suggest there is significant turnover of replicating virus within the brain and the severity of neuronal injury is directly related to the brain viral load.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0196949PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5947913PMC
July 2018

Animal models of HIV-associated disease of the central nervous system.

Handb Clin Neurol 2018 ;152:41-53

Department of Biology, Boston College, Chestnut Hill, MA, United States. Electronic address:

It is difficult to study the pathogenesis of human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) in living patients because central nervous system (CNS) tissues are only available post mortem. Rodent and nonhuman primate (NHP) models of HAND allow for longitudinal analysis of HIV-associated CNS pathology and efficacy studies of novel therapeutics. Rodent models of HAND allow for studies with large sample sizes, short duration, and relatively low cost. These models include humanized mice used to study HIV-associated neuropathogenesis and transgenic mice used to study neurotoxic effects of viral proteins without infection. Simian immunodeficiency virus (SIV)-infected NHP are the premier model of neuroAIDS; SIV-associated CNS pathology is similar to HIV-associated CNS pathology with HAND. Additionally, the size, lifespan of NHP, and time to acquired immune deficiency syndrome (AIDS) progression make SIV-infected NHP models optimal for studies of viral latency and reservoirs, and assessing novel therapeutics for neuroAIDS. NHP models of neuroAIDS generally include conventional progressors (AIDS within 2-3 years) and those that have rapid disease (AIDS within 150 days). Rapid AIDS models are achieved by immune modulation and/or infection with neurovirulent and neurosuppressive viral strains and result in a high incidence of SIV-associated encephalitis. In this chapter, we briefly review rodent and NHP models of neuroAIDS, including contributions made using these models to our understanding of HIV-associated CNS disease.
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http://dx.doi.org/10.1016/B978-0-444-63849-6.00004-9DOI Listing
September 2018

Insulin-like growth factor 1 inversely relates to monocyte/macrophage activation markers in HIV.

AIDS 2018 04;32(7):927-932

Program in Nutritional Metabolism, Department of Medicine, Massachusetts General Hospital and Harvard Medical School.

Objective: Monocyte/macrophage activation is increased among people with HIV, and may contribute to the heightened risk of atherosclerosis and neurocognitive dysfunction in this population. Insulin-like growth factor 1 (IGF-1) has been shown to attenuate the innate immune response in animal models of atherosclerosis and inflammatory bowel disease. We investigated, for the first time, relationships of circulating IGF-1 with monocyte/macrophage-specific indices among HIV-infected individuals and uninfected controls.

Design: Observational.

Methods: One hundred and thirty-one HIV-infected patients and 65 well matched controls without known cardiac disease or viral hepatitis were recruited previously. IGF-1, expressed as a z-score relative to the age-adjusted and sex-adjusted population mean, was related to log-transformed inflammatory markers within HIV and non-HIV groups.

Results: In HIV, IGF-1 inversely related to sCD163 (r = -0.28, P = 0.002), sCD14 (r = -0.29, P = 0.002), and high-sensitivity IL-6 (r = -0.27, P = 0.006). There was no association of IGF-1 with high-sensitivity CRP, MCP-1, IL-18, or LPS in HIV, or between IGF-1 and any inflammatory marker in controls. Relationships of IGF-1 with sCD163 and sCD14 remained significant in HIV after controlling for age, sex, smoking, BMI, visceral fat, statin use, viral load, and antiretroviral therapy. For every one-unit decline in IGF-1 z-score, sCD163 and sCD14 increased by 14% (95% CI, 0.23-29%) and 29% (95% CI, 1.4-63%), respectively.

Conclusion: Low IGF-1 was robustly associated with high sCD163 and sCD14 in HIV. Prospective studies are needed to investigate augmentation of IGF-1 as a novel strategy to reduce monocyte/macrophage activation in this population.
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http://dx.doi.org/10.1097/QAD.0000000000001775DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5869172PMC
April 2018

Monocyte subsets exhibit transcriptional plasticity and a shared response to interferon in SIV-infected rhesus macaques.

J Leukoc Biol 2018 01 14;103(1):141-155. Epub 2017 Dec 14.

Department of Biology, Boston College, Chestnut Hill, Massachusetts, USA.

The progression to AIDS is influenced by changes in the biology of heterogeneous monocyte subsets. Classical (CD14++CD16-), intermediate (CD14++CD16+), and nonclassical (CD14+CD16++) monocytes may represent progressive stages of monocyte maturation or disparate myeloid lineages with different turnover rates and function. To investigate the relationship between monocyte subsets and the response to SIV infection, we performed microarray analysis of monocyte subsets in rhesus macaques at three time points: prior to SIV infection, 26 days postinfection, and necropsy with AIDS. Genes with a 2-fold change between monocyte subsets (2023 genes) or infection time points (424 genes) were selected. We identify 172 genes differentially expressed among monocyte subsets in both uninfected and SIV-infected animals. Classical monocytes express genes associated with inflammatory responses and cell proliferation. Nonclassical monocytes express genes associated with activation, immune effector functions, and cell cycle inhibition. The classical and intermediate subsets are most similar at all time points, and transcriptional similarity between intermediate and nonclassical monocytes increases with AIDS. Cytosolic sensors of nucleic acids, restriction factors, and IFN-stimulated genes are induced in all three subsets with AIDS. We conclude that SIV infection alters the transcriptional relationship between monocyte subsets and that the innate immune response to SIV infection is conserved across monocyte subsets.
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http://dx.doi.org/10.1002/JLB.4A0217-047RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6869333PMC
January 2018

HDL Cholesterol Efflux Capacity in Newly Diagnosed HIV and Effects of Antiretroviral Therapy.

J Clin Endocrinol Metab 2017 11;102(11):4250-4259

Lipid Metabolism Unit/Center for Computational and Integrative Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114.

Context: In the general population, high-density lipoprotein (HDL) cholesterol efflux capacity (HCEC) relates inversely to incident cardiovascular events. Previous studies have suggested that HCEC is decreased in HIV and that antiretroviral therapy (ART) initiation might improve HCEC.

Objective: To evaluate HCEC in the context of ART initiation and immune activation in HIV.

Design And Outcome Measures: Baseline HCEC from 10 ART-naive HIV-infected males and 12 prospectively matched non-HIV-infected males were analyzed. In the HIV cohort, HCEC 6 months after elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (E/C/F/TDF) therapy was evaluated. HCEC served as the primary outcome and was measured by the ability of J774 mouse macrophages to efflux cholesterol. Our ex vivo assay used two cholesterol acceptors [apolipoprotein B (apoB)-depleted sera or purified HDL] and modulation of cellular efflux pathways using a liver X receptor (LXR) agonist.

Results: The median age was 34 years [interquartile range (IQR), 27 to 51], and baseline HDL was 46 mg/dL (IQR, 38 to 61). HCEC was significantly greater in the non-HIV-infected subjects than in the HIV-infected subjects at baseline. HCEC, assessed using apoB-depleted sera, significantly increased after ART (no LXR agonist, baseline: median, 8.1%; IQR, 7.0% to 11.9%; after ART: median, 12.9%; IQR, 10.4% to 21.1%; P = 0.006; LXR agonist, baseline, 1.3% ± 1.3%; after ART, 2.5% ± 1.0%; P = 0.02), although not to the levels in the non-HIV-infected subjects (no LXR agonist: median, 14.9%; IQR, 11.5% to 19.1%; LXR agonist: 5.8% ± 1.3%). HCEC, assessed using purified HDL, did not significantly increase after ART. The change in HCEC with ART related inversely to the change in the percentage of CD14-CD16+ (nonclassical) monocytes (ρ = -0.74, P = 0.04) and directly to the change in the percentage of CD14+CD16- (classical) monocytes (ρ = 0.72, P = 0.045).

Conclusions: Our data suggest improvement of HCEC with E/C/F/TDF and a relationship between the ART-induced decrease in immune activation and ART-induced improvement in HCEC.
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http://dx.doi.org/10.1210/jc.2017-01334DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5673269PMC
November 2017

Insights into the Impact of CD8 Immune Modulation on Human Immunodeficiency Virus Evolutionary Dynamics in Distinct Anatomical Compartments by Using Simian Immunodeficiency Virus-Infected Macaque Models of AIDS Progression.

J Virol 2017 12 14;91(23). Epub 2017 Nov 14.

Emerging Pathogens Institute and Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, USA

A thorough understanding of the role of human immunodeficiency virus (HIV) intrahost evolution in AIDS pathogenesis has been limited by the need for longitudinally sampled viral sequences from the vast target space within the host, which are often difficult to obtain from human subjects. CD8 lymphocyte-depleted macaques infected with simian immunodeficiency virus (SIV) provide an increasingly utilized model of pathogenesis due to clinical manifestations similar to those for HIV-1 infection and AIDS progression, as well as a characteristic rapid disease onset. Comparison of this model with SIV-infected non-CD8 lymphocyte-depleted macaques also provides a unique opportunity to investigate the role of CD8 cells in viral evolution and population dynamics throughout the duration of infection. Using several different phylogenetic methods, we analyzed viral sequences obtained from extensive longitudinal sampling of multiple tissues and enriched leukocyte populations from SIVmac251-infected macaques with or without CD8 lymphocyte depletion. SIV evolutionary and selection patterns in non-CD8 lymphocyte-depleted animals were characterized by sequential population turnover and continual viral adaptation, a scenario readily comparable to intrahost evolutionary patterns during human HIV infection in the absence of antiretroviral therapy. Alternatively, animals that were depleted of CD8 lymphocytes exhibited greater variation in population dynamics among tissues and cell populations over the course of infection. Our findings highlight the major role for CD8 lymphocytes in prolonging disease progression through continual control of SIV subpopulations from various anatomical compartments and the potential for greater independent viral evolutionary behavior among these compartments in response to immune modulation. Although developments in combined antiretroviral therapy (cART) strategies have successfully prolonged the time to AIDS onset in HIV-1-infected individuals, a functional cure has yet to be found. Improvement of drug interventions for a virus that is able to infect a wide range of tissues and cell types requires a thorough understanding of viral adaptation and infection dynamics within this target milieu. Although it is difficult to accomplish in the human host, longitudinal sampling of multiple anatomical locations is readily accessible in the SIV-infected macaque models of neuro-AIDS. The significance of our research is in identifying the impact of immune modulation, through differing immune selective pressures, on viral evolutionary behavior in a multitude of anatomical compartments. The results provide evidence encouraging the development of a more sophisticated model that considers a network of individual viral subpopulations within the host, with differing infection and transmission dynamics, which is necessary for more effective treatment strategies.
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http://dx.doi.org/10.1128/JVI.01162-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5686727PMC
December 2017

An oral form of methylglyoxal-bis-guanylhydrazone reduces monocyte activation and traffic to the dorsal root ganglia in a primate model of HIV-peripheral neuropathy.

J Neurovirol 2017 08 1;23(4):568-576. Epub 2017 May 1.

Department of Neuroscience, Temple University School of Medicine, 3500 North Broad Street, MERB 755, Philadelphia, PA, 19140, USA.

Peripheral neuropathy (PN) is a major comorbidity of HIV infection that is caused in part by chronic immune activation. HIV-PN is associated with infiltration of monocytes/macrophages to the dorsal root ganglia (DRG) causing neuronal loss and formation of Nageotte nodules. Here, we used an oral form of methylglyoxal-bis-guanylhydrazone (MGBG), a polyamine biosynthesis inhibitor, to specifically reduce activation of myeloid cells. MGBG is selectively taken up by monocyte/macrophages in vitro and inhibits HIV p24 expression and DNA viral integration in macrophages. Here, MGBG was administered to nine SIV-infected, CD8-depleted rhesus macaques at 21 days post-infection (dpi). An additional nine SIV-infected, CD8-depleted rhesus macaques were used as untreated controls. Cell traffic to tissues was measured by in vivo BrdU pulse labeling. MGBG treatment significantly diminished DRG histopathology and reduced the number of CD68+ and CD163+ macrophages in DRG tissue. The number of recently trafficked BrdU+ cells in the DRG was significantly reduced with MGBG treatment. Despite diminished DRG pathology, intraepidermal nerve fiber density (IENFD) did not recover after treatment with MGBG. These data suggest that MGBG alleviated DRG pathology and inflammation.
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http://dx.doi.org/10.1007/s13365-017-0529-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5623097PMC
August 2017

Immunologic Pathways That Predict Mortality in HIV-Infected Ugandans Initiating Antiretroviral Therapy.

J Infect Dis 2017 04;215(8):1270-1274

University of California, San Francisco, USA

The plasma kynurenine/tryptophan (KT) ratio, a marker of adaptive immune defects, strongly predicts mortality during treated human immunodeficiency virus (HIV) disease in Ugandans as compared to US-based populations. Here, the KT ratio and T-cell and plasma biomarkers of immune activation were measured among 535 HIV-infected Ugandans prior to ART initiation and at month 6 of viral suppression. The month 6 KT ratio (adjusted hazard ratio [aHR], 2.74), soluble CD14 level (aHR, 2.32), interleukin 6 level (aHR, 2.34), and D-dimer level (aHR, 1.95) were associated with mortality occurring ≥6 months after ART initiation. The KT ratio remained significantly predictive of mortality even after adjustment for the additional biomarkers, suggesting an independent contribution to clinical outcomes in resource-limited settings.
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http://dx.doi.org/10.1093/infdis/jix113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5853335PMC
April 2017

Effects of pitavastatin and pravastatin on markers of immune activation and arterial inflammation in HIV.

AIDS 2017 03;31(6):797-806

aMassachusetts General Hospital, Program in Nutrition and Metabolism and Harvard Medical School, Boston bDepartment of Biology, Boston College, Chestnut Hill, Massachusetts cDepartment of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania dMount Sinai Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, New York eKOWA Pharmaceuticals America Inc., Montgomery, Alabama, USA.

Objective: Persistent immune activation is thought to contribute to increased cardiovascular disease risk in HIV and statins may help modulate systemic immune activation. We aimed to compare the effects of two key statins on markers of systemic immune activation and arterial inflammation in the HIV population.

Design: Double-blind, active-controlled, parallel-group comparative trial performed in 45 sites.

Methods: Two hundred and fifty-two antiretroviral therapy-treated HIV-infected participants with dyslipidemia were randomized (1 : 1) to pitavastatin 4 mg daily vs. pravastatin 40 mg daily in the HIV-infected patieNts and TREatment with PItavastatin vs. pravastatin for Dyslipidemia (INTREPID) trial. In this analysis of the INTREPID trial, we assessed markers of immune activation and arterial inflammation using a modified intent-to-treat population. This trial is registered with ClinicalTrials.gov (NCT01301066).

Results: One hundred and twenty-six participants were randomized to receive pitavastatin and 126 to pravastatin. Ninety-nine participants in the pitavastatin group and 91 participants in the pravastatin group completed the study. Median age was 50 (45, 56) years [median (interquartile range)]. Baseline, low-density lipoprotein-cholestrol (LDL-C) was 153 (135, 171) mg/dl, log HIV-1 viral load was 1.1 ± 0.2 copies/ml, and CD4 cell count was 580 (439, 794) cells/μl. At week 52, the pitavastatin group had a significantly greater reduction (% change) compared with pravastatin in soluble CD14 (sCD14), (-10.0 vs. 0.6%, P = 0.02), oxidized LDL (oxLDL) (-26.9 vs. -17.5%, P = 0.02), and lipoprotein-associated phospholipase 2 (Lp-PLA2) (-26.6 vs. -15.5%, P = 0.005) (pitavastatin vs. pravastatin).

Conclusion: Fifty-two weeks of pitavastatin 4 mg daily (vs. pravastatin 40 mg daily) led to a greater reduction in select markers of immune activation and arterial inflammation (sCD14, oxLDL, and LpPLA2) among HIV-infected participants. Further work is needed to assess whether immune-modulatory effects of pitavastatin reduce cardiovascular disease risk in HIV.
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http://dx.doi.org/10.1097/QAD.0000000000001427DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5382495PMC
March 2017

Application of a Novel CD206+ Macrophage-Specific Arterial Imaging Strategy in HIV-Infected Individuals.

J Infect Dis 2017 04;215(8):1264-1269

Program in Nutritional Metabolism and.

Background: The ability to noninvasively assess arterial CD206+ macrophages may lead to improved understanding of human immunodeficiency virus (HIV)-associated cardiovascular disease.

Methods: We trialed a novel macrophage-specific arterial imaging technique.

Results: We demonstrated colocalization between technetium Tc 99m tilmanocept (99mTc-tilmanocept) and CD206+ macrophages ex vivo. In vivo application of 99mTc-tilmanocept single-photon emission computed tomography/computed tomography revealed high-level 99mTc-tilmanocept uptake across 20.4% of the aortic surface volume among HIV-infected subjects, compared with 4.3% among non-HIV-infected subjects (P = .009). Among all subjects, aortic high-level 99mTc-tilmanocept uptake was related to noncalcified aortic plaque volume (r = 0.87; P = .003) on computed tomographic angiography, and this relationship held when we controlled for HIV status.

Conclusion: These first-in-human data introduce a novel macrophage-specific arterial imaging technique in HIV.

Clinical Trials Registration: NCT02542371.
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http://dx.doi.org/10.1093/infdis/jix095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5853590PMC
April 2017

Direct Targeting of Macrophages With Methylglyoxal-Bis-Guanylhydrazone Decreases SIV-Associated Cardiovascular Inflammation and Pathology.

J Acquir Immune Defic Syndr 2017 04;74(5):583-592

*Department of Biology, Boston College, Chestnut Hill, MA; †Cornell University College of Veterinary Medicine, Ithaca, NY; and ‡Department of Pathology and Laboratory Medicine, UCSF, San Francisco, CA.

Background: Despite effective combination antiretroviral therapy, HIV-infected individuals develop comorbidities, including cardiovascular disease, where activated macrophages play a key role. To date, few therapies target activated monocytes and macrophages.

Methods: We evaluated a novel oral form of the polyamine biosynthesis inhibitor methylglyoxal-bis-guanylhydrazone (MGBG) on cardiovascular inflammation, carotid artery intima-media thickness (cIMT), and fibrosis in a simian immunodeficiency virus infection model of AIDS. Eleven simian immunodeficiency virus-infected animals received MGBG (30 mg/kg) once daily and 8 received a placebo control both beginning at 21 days postinfection (dpi). Animals were time sacrificed at 49 days post infection (dpi), when their matched placebo controls developed AIDS (63, 70, 77, 80), or at the study end-point (84 dpi). Aorta, carotid artery, and cardiac tissues were analyzed. Quantitative analyses of macrophage populations and T lymphocytes were done and correlated with cIMT and fibrosis.

Results: MGBG treatment resulted in 2.19-fold (CD163), 1.86-fold (CD68), 2.31-fold (CD206), and 2.12-fold (MAC387) decreases in macrophages in carotid arteries and significant 2.07-fold (CD163), 1.61-fold (CD68), 1.95-fold (MAC387), and 1.62-fold (CD206) decreases in macrophages in cardiac tissues. cIMT (1.49-fold) and fibrosis (2.05-fold) also were significantly decreased with MGBG treatment. Numbers of macrophage and the degree of fibrosis in treated animals were similar to uninfected animals. A positive correlation between decreased macrophage in the carotid artery and cIMT, and cardiac macrophages and fibrosis was found.

Conclusions: These data demonstrate that directly targeting macrophages with MGBG can reduce cardiovascular inflammation, cIMT, and fibrosis. They suggest that therapies targeting macrophages with HIV could be used in conjunction with combination antiretroviral therapy.
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http://dx.doi.org/10.1097/QAI.0000000000001297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5370195PMC
April 2017

A method for obtaining simian immunodeficiency virus RNA sequences from laser capture microdissected and immune captured CD68+ and CD163+ macrophages from frozen tissue sections of bone marrow and brain.

J Immunol Methods 2017 03 14;442:59-63. Epub 2017 Jan 14.

Department of Biology, Boston College, Chestnut Hill, MA, USA. Electronic address:

Laser capture microdissection (LCM) is used to extract cells or tissue regions for analysis of RNA, DNA or protein. Several methods of LCM are established for different applications, but a protocol for consistently obtaining lentiviral RNA from LCM captured immune cell populations is not described. Obtaining optimal viral RNA for analysis of viral genes from immune-captured cells using immunohistochemistry (IHC) and LCM is challenging. IHC protocols have long antibody incubation times that increase risk of RNA degradation. But, immune capture of specific cell populations like macrophages without staining for virus cannot result in obtaining only a fraction of cells which are productively lentivirally infected. In this study we sought to obtain simian immunodeficiency virus (SIV) RNA from SIV gp120+ and CD68+ monocyte/macrophages in bone marrow (BM) and CD163+ perivascular macrophages in brain of SIV-infected rhesus macaques. Here, we report an IHC protocol with RNase inhibitors that consistently results in optimal quantity and yield of lentiviral RNA from LCM-captured immune cells.
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http://dx.doi.org/10.1016/j.jim.2017.01.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5338743PMC
March 2017

Effects of Sodium Restriction on Activation of the Renin-Angiotensin-Aldosterone System and Immune Indices During HIV Infection.

J Infect Dis 2016 Nov 22;214(9):1336-1340. Epub 2016 Aug 22.

Program in Nutritional Metabolism, Massachusetts General Hospital and Harvard Medical School.

Background:  Human immunodeficiency virus (HIV)-infected patients demonstrate increased activation of the renin-angiotensin-aldosterone system (RAAS). We evaluated changes in immune markers with physiological RAAS activation.

Methods:  Immune activation markers were assessed serially in 18 HIV-infected and 7 non-HIV-infected subjects consuming an ad libitum diet followed by a standardized low-sodium diet.

Results:  Levels of CCL-2 (P = .0004) and soluble CD163 (P = .0001) significantly increased with sodium restriction and RAAS activation, compared with levels in individuals with ad libitum sodium intake, among chronically treated HIV-infected subjects (mean duration of ART [±SEM], 11 ± 1 years), but not among non-HIV-infected subjects of similar age and sex.

Conclusions:  Dietary sodium restriction, which activates RAAS, uniquely stimulates critical indices of immune activation during HIV infection.

Clinical Trials Registration:  NCT01407237.
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http://dx.doi.org/10.1093/infdis/jiw392DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5079375PMC
November 2016

Effects of Antiretroviral Therapy on Immune Function and Arterial Inflammation in Treatment-Naive Patients With Human Immunodeficiency Virus Infection.

JAMA Cardiol 2016 07;1(4):474-80

Program in Nutritional Metabolism, Massachusetts General Hospital and Harvard Medical School, Boston.

Importance: Individuals with human immunodeficiency virus (HIV) infection receiving combined antiretroviral therapy (ART) have an increased risk of myocardial infarction. Effects of ART on arterial inflammation among treatment-naive individuals with HIV are unknown.

Objective: To determine the effects of newly initiated ART on arterial inflammation and other immune/inflammatory indices in ART-naive patients with HIV infection.

Design, Setting, Participants: Twelve treatment-naive HIV-infected individuals underwent fludeoxyglucose F 18 ([18F]-FDG) positron emission tomographic scanning for assessment of arterial inflammation, coronary computed tomographic angiography for assessment of subclinical atherosclerosis, and systemic immune and metabolic phenotyping before and 6 months after the initiation of therapy with elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (combined ART). Systemic immune and metabolic factors were also assessed in 12 prospectively recruited individuals without HIV serving as controls. The study began July 24, 2012, and was completed May 7, 2015.

Interventions: Combined ART in the HIV-infected cohort.

Main Outcomes And Measures: The primary outcome was change in aortic target-background ratio (TBR) on [18F]-FDG-PET with combined ART in the HIV-infected group.

Results: For the 12 participants with HIV infection (mean (SD) age, 35 [11] years), combined ART suppressed viral load (mean [SD] log viral load, from 4.3 [0.6] to 1.3 [0] copies/mL; P < .001), increased the CD4+ T-cell count (median [IQR], from 461 [332-663] to 687 [533-882] cells/mm3; P < .001), and markedly reduced percentages of circulating activated CD4+ T cells (human leukocyte antigen-D related [HLA-DR]+CD38+CD4+) (from 3.7 [1.8-5.0] to 1.3 [0.3-2.0]; P = .008) and CD8+ T cells (HLA-DR+CD38+CD8+) (from 18.3 [8.1-27.0] to 4.0 [1.5-7.8]; P = .008), increased the percentage of circulating classical CD14+CD16- monocytes (from 85.8 [83.7-90.8] to 91.8 [87.5-93.2]; P = .04), and reduced levels of CXCL10 (mean [SD] log CXCL10, from 2.4 [0.4] to 2.2 [0.4] pg/mL; P = .03). With combined ART, uptake of [18F]-FDG in the axillary lymph nodes, as measured by TBR, decreased from a median (IQR) of 3.7 (1.3-7.0) at baseline to 1.4 (0.9-1.9; P = .01) at study end. In contrast, no significant decrease was seen in aortic TBR in response to combined ART (mean [SD], 1.9 [0.2]; median [IQR], 2.0 [1.8-2.1] at baseline to 2.2 [0.4]; 2.1 [1.9-2.6], respectively, at study end; P = .04 by 2-way test, P = .98 for test of decrease by 1-way test). Changes in aortic TBR during combined ART were significantly associated with changes in lipoprotein-associated phospholipase A2 (n = 10; r = 0.67; P = .03). Coronary plaque increased among 3 participants with HIV infection with baseline plaque and developed de novo in 1 participant during combined ART.

Conclusions And Relevance: Newly initiated combined ART in treatment-naive individuals with HIV infection had discordant effects to restore immune function without reducing arterial inflammation. Complementary strategies to reduce arterial inflammation among ART-treated HIV-infected individuals may be needed.
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http://dx.doi.org/10.1001/jamacardio.2016.0846DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944348PMC
July 2016

α4-Integrin Antibody Treatment Blocks Monocyte/Macrophage Traffic to, Vascular Cell Adhesion Molecule-1 Expression in, and Pathology of the Dorsal Root Ganglia in an SIV Macaque Model of HIV-Peripheral Neuropathy.

Am J Pathol 2016 07 6;186(7):1754-1761. Epub 2016 May 6.

Department of Biology, Boston College, Chestnut Hill, Massachusetts. Electronic address:

Traffic of activated monocytes into the dorsal root ganglia (DRG) is critical for pathology in HIV peripheral neuropathy. We have shown that accumulation of recently recruited (bromodeoxyuridine(+) MAC387(+)) monocytes is associated with severe DRG pathology and loss of intraepidermal nerve fibers in SIV-infected macaques. Herein, we blocked leukocyte traffic by treating animals with natalizumab, which binds to α4-integrins. SIV-infected CD8-depleted macaques treated with natalizumab either early (the day of infection) or late (28 days after infection) were compared with untreated SIV-infected animals sacrificed at similar times. Histopathology showed diminished DRG pathology with natalizumab treatment, including decreased inflammation, neuronophagia, and Nageotte nodules. Natalizumab treatment resulted in a decrease in the number of bromodeoxyuridine(+) (early), MAC387(+) (late), CD68(+) (early and late), and SIVp28(+) (late) macrophages in DRG tissues. The number of CD3(+) T lymphocytes in DRGs was not affected by natalizumab treatment. Vascular cell adhesion molecule 1, an adhesion molecule that mediates leukocyte traffic, was diminished in DRGs of all natalizumab-treated animals. These data show that blocking monocyte, but not T lymphocyte, traffic to the DRG results in decreased inflammation and pathology, supporting a role for monocyte traffic and activation in HIV peripheral neuropathy.
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http://dx.doi.org/10.1016/j.ajpath.2016.03.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4929389PMC
July 2016

Evolution of Neuroadaptation in the Periphery and Purifying Selection in the Brain Contribute to Compartmentalization of Simian Immunodeficiency Virus (SIV) in the Brains of Rhesus Macaques with SIV-Associated Encephalitis.

J Virol 2016 07 10;90(13):6112-6126. Epub 2016 Jun 10.

Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, USA

Unlabelled: The emergence of a distinct subpopulation of human or simian immunodeficiency virus (HIV/SIV) sequences within the brain (compartmentalization) during infection is hypothesized to be linked to AIDS-related central nervous system (CNS) neuropathology. However, the exact evolutionary mechanism responsible for HIV/SIV brain compartmentalization has not been thoroughly investigated. Using extensive viral sampling from several different peripheral tissues and cell types and from three distinct regions within the brain from two well-characterized rhesus macaque models of the neurological complications of HIV infection (neuroAIDS), we have been able to perform in-depth evolutionary analyses that have been unattainable in HIV-infected subjects. The results indicate that, despite multiple introductions of virus into the brain over the course of infection, brain sequence compartmentalization in macaques with SIV-associated CNS neuropathology likely results from late viral entry of virus that has acquired through evolution in the periphery sufficient adaptation for the distinct microenvironment of the CNS.

Importance: HIV-associated neurocognitive disorders remain prevalent among HIV type 1-infected individuals, whereas our understanding of the critical components of disease pathogenesis, such as virus evolution and adaptation, remains limited. Building upon earlier findings of specific viral subpopulations in the brain, we present novel yet fundamental results concerning the evolutionary patterns driving this phenomenon in two well-characterized animal models of neuroAIDS and provide insight into the timing of entry of virus into the brain and selective pressure associated with viral adaptation to this particular microenvironment. Such knowledge is invaluable for therapeutic strategies designed to slow or even prevent neurocognitive impairment associated with AIDS.
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http://dx.doi.org/10.1128/JVI.00137-16DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4907235PMC
July 2016

Associations between Cognition, Gender and Monocyte Activation among HIV Infected Individuals in Nigeria.

PLoS One 2016 1;11(2):e0147182. Epub 2016 Feb 1.

Institute for Human Virology, University of Maryland, School of Medicine, Baltimore, Maryland, United States of America.

The potential role of gender in the occurrence of HIV-related neurocognitive impairment (NCI) and associations with markers of HIV-related immune activity has not been previously examined. In this study 149 antiretroviral-naïve seropositive subjects in Nigeria (SP, 92 women and 57 men) and 58 seronegative (SN, 38 women and 20 men) were administered neuropsychological testing that assessed 7 ability domains. From the neuropsychological test scores was calculated a global deficit score (GDS), a measure of overall NCI. Percentages of circulating monocytes and plasma HIV RNA, soluble CD163 and soluble CD14 levels were also assessed. HIV SP women were found to be younger, more educated and had higher CD4+ T cell counts and borderline higher viral load measures than SP men. On the neuropsychological testing, SP women were more impaired in speed of information processing and verbal fluency and had a higher mean GDS than SN women. Compared to SP men, SP women were also more impaired in speed of information processing and verbal fluency as well as on tests of learning and memory. Numbers of circulating monocytes and plasma sCD14 and sCD163 levels were significantly higher for all SP versus all SN individuals and were also higher for SP women and for SP men versus their SN counterparts. Among SP women, soluble CD14 levels were slightly higher than for SP men, and SP women had higher viral load measurements and were more likely to have detectable virus than SP men. Higher sCD14 levels among SP women correlated with more severe global impairment, and higher viral load measurements correlated with higher monocyte numbers and sCD14 and sCD14 levels, associations that were not observed for SP men. These studies suggest that the risk of developing NCI differ for HIV infected women and men in Nigeria and, for women, may be linked to effects from higher plasma levels of HIV driving activation of circulating monocytes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0147182PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734765PMC
July 2016

Macrophage Polarization in AIDS: Dynamic Interface between Anti-Viral and Anti-Inflammatory Macrophages during Acute and Chronic Infection.

J Clin Cell Immunol 2015 Jun 24;6(3). Epub 2015 Jun 24.

Department of Biology, Boston College, Chestnut Hill, MA, 02467, USA.

Monocyte and macrophage inflammation in parenchymal tissues during acute and chronic HIV and SIV infection plays a role in early anti-viral immune responses and later in restorative responses. Macrophage polarization is observed in such responses in the central nervous system (CNS) and the heart and cardiac vessels that suggest early responses are M1 type antiviral responses, and later responses favor M2 restorative responses. Macrophage polarization is unique to different tissues and is likely dictated as much by the local microenvironment as well as other inflammatory cells involved in the viral responses. Such polarization is found in HIV infected humans, and the SIV infected animal model of AIDS, and occurs even with effective anti-retroviral therapy. Therapies that directly target macrophage polarization in HIV infection have recently been implemented, as have therapies to directly block traffic and accumulation of macrophages in tissues.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612489PMC
June 2015

Editorial: Identification of in vivo markers for human polarized macrophages: a need that's finally met.

J Leukoc Biol 2015 Oct;98(4):449-50

*Department of Biology, Boston College, Chestnut Hill, Massachusetts, USA; and Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, USA

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http://dx.doi.org/10.1189/jlb.1CE0615-233RRDOI Listing
October 2015

Anti-α4 Integrin Antibody Blocks Monocyte/Macrophage Traffic to the Heart and Decreases Cardiac Pathology in a SIV Infection Model of AIDS.

J Am Heart Assoc 2015 Jul 16;4(7). Epub 2015 Jul 16.

Department of Biology, Boston College, Chestnut Hill, MA (J.A.W., G.A.B., J.H.C., T.H.B., K.C.W.).

Background: Cardiovascular disease (CVD), myocarditis and fibrosis are comorbidities of HIV(+) individuals on durable antiretroviral therapy (ART). Although mechanisms for these vary, monocytes/macrophages are increasingly demonstrated to be key players.

Methods And Results: We directly blocked monocyte/macrophage traffic to the heart in an SIV model of AIDS using an anti-alpha-4 integrin antibody (natalizumab). Nineteen Rhesus macaques were SIVmac251 infected and CD8-lymphocyte depleted for the development of rapid AIDS. Ten animals received natalizumab once a week, for 3 weeks, and were sacrificed 1 week later. Six animals began treatment at the time of infection (early) and the remaining 4 began treatment 28 days post-infection (late), a time point we have previously established when significant cardiac inflammation occurs. Nine animals were untreated controls; of these, 3 were sacrificed early and 6 were sacrificed late. At necropsy, we found decreased SIV-associated cardiac pathology in late natalizumab-treated animals, compared to untreated controls. Early and late treatment resulted in significant reductions in numbers of CD163(+) and CD68(+) macrophages in cardiac tissues, compared to untreated controls, and a trend in decreasing numbers of newly recruited MAC387(+) and BrdU(+) (recruited) monocytes/macrophages. In late treated animals, decreased macrophage numbers in cardiac tissues correlated with decreased fibrosis. Early and late treatment resulted in decreased cardiomyocyte damage.

Conclusions: These data demonstrate a role for macrophages in the development of cardiac inflammation and fibrosis, and suggest that blocking monocyte/macrophage traffic to the heart can alleviate HIV- and SIV-associated myocarditis and fibrosis. They underscore the importance of targeting macrophage activation and traffic as an adjunctive therapy in HIV infection.
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http://dx.doi.org/10.1161/JAHA.115.001932DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608078PMC
July 2015

High expression levels of BLyS/BAFF by blood dendritic cells and granulocytes are associated with B-cell dysregulation in SIV-infected rhesus macaques.

PLoS One 2015 24;10(6):e0131513. Epub 2015 Jun 24.

Laboratoire d'immunogénétique, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Canada; Département de Microbiologie, Infectiologie et Immunologie de l'Université de Montréal, Montréal, Canada.

Dendritic cells (DCs) modulate B-cell survival and differentiation, mainly through production of growth factors such as B lymphocyte stimulator (BLyS/BAFF). In recent longitudinal studies involving HIV-1-infected individuals with different rates of disease progression, we have shown that DCs were altered in number and phenotype in the context of HIV-1 disease progression and B-cell dysregulations were associated with increased BLyS/BAFF expression in plasma and by blood myeloid DCs (mDCs) in rapid and classic progressors but not in HIV-1-elite controllers (EC). Suggesting that the extent to which HIV-1 disease progression is controlled may be linked to BLyS/BAFF expression status and the capacity to orchestrate B-cell responses. Herein, longitudinal analyses of simian immunodeficiency virus (SIV)-infected rhesus macaques also revealed increased expression of BLyS/BAFF by blood mDCs as soon as day 8 and throughout infection. Strikingly, granulocytes presented the highest BLyS/BAFF expression profile in the blood of SIV-infected macaques. BLyS/BAFF levels were also increased in plasma and correlated with viral loads. Consequently, these SIV-infected animals had plasma hyperglobulinemia and reduced blood B-cell numbers with altered population frequencies. These data underscore that BLyS/BAFF is associated with immune dysregulation in SIV-infected rhesus macaques and suggest that BLyS/BAFF is a key regulator of immune activation that is highly conserved among primates. These findings emphasize the potential importance of this SIV-infected primate model to test whether blocking excess BLyS/BAFF has an effect on the overall inflammatory burden and immune restoration.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0131513PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4479440PMC
April 2016

Tracking the Emergence of Host-Specific Simian Immunodeficiency Virus env and nef Populations Reveals nef Early Adaptation and Convergent Evolution in Brain of Naturally Progressing Rhesus Macaques.

J Virol 2015 Aug 3;89(16):8484-96. Epub 2015 Jun 3.

Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, USA Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA

Unlabelled: While a clear understanding of the events leading to successful establishment of host-specific viral populations and productive infection in the central nervous system (CNS) has not yet been reached, the simian immunodeficiency virus (SIV)-infected rhesus macaque provides a powerful model for the study of human immunodeficiency virus (HIV) intrahost evolution and neuropathogenesis. The evolution of the gp120 and nef genes, which encode two key proteins required for the establishment and maintenance of infection, was assessed in macaques that were intravenously inoculated with the same viral swarm and allowed to naturally progress to simian AIDS and potential SIV-associated encephalitis (SIVE). Longitudinal plasma samples and immune markers were monitored until terminal illness. Single-genome sequencing was employed to amplify full-length env through nef transcripts from plasma over time and from brain tissues at necropsy. nef sequences diverged from the founder virus faster than gp120 diverged. Host-specific sequence populations were detected in nef (~92 days) before they were detected in gp120 (~182 days). At necropsy, similar brain nef sequences were found in different macaques, indicating convergent evolution, while gp120 brain sequences remained largely host specific. Molecular clock and selection analyses showed weaker clock-like behavior and stronger selection pressure in nef than in gp120, with the strongest nef selection in the macaque with SIVE. Rapid nef diversification, occurring prior to gp120 diversification, indicates that early adaptation of nef in the new host is essential for successful infection. Moreover, the convergent evolution of nef sequences in the CNS suggests a significant role for nef in establishing neurotropic strains.

Importance: The SIV-infected rhesus macaque model closely resembles HIV-1 immunopathogenesis, neuropathogenesis, and disease progression in humans. Macaques were intravenously infected with identical viral swarms to investigate evolutionary patterns in the gp120 and nef genes leading to the emergence of host-specific viral populations and potentially linked to disease progression. Although each macaque exhibited unique immune profiles, macaque-specific nef sequences evolving under selection were consistently detected in plasma samples at 3 months postinfection, significantly earlier than in gp120 macaque-specific sequences. On the other hand, nef sequences in brain tissues, collected at necropsy of two animals with detectable infection in the central nervous system (CNS), revealed convergent evolution. The results not only indicate that early adaptation of nef in the new host may be essential for successful infection, but also suggest that specific nef variants may be required for SIV to efficiently invade CNS macrophages and/or enhance macrophage migration, resulting in HIV neuropathology.
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http://dx.doi.org/10.1128/JVI.01010-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4524235PMC
August 2015

SIV encephalitis lesions are composed of CD163(+) macrophages present in the central nervous system during early SIV infection and SIV-positive macrophages recruited terminally with AIDS.

Am J Pathol 2015 Jun 8;185(6):1649-65. Epub 2015 May 8.

Biology Department, Boston College, Chestnut Hill, Massachusetts. Electronic address:

Macrophage recruitment to the central nervous system (CNS) during AIDS pathogenesis is poorly understood. We measured the accumulation of brain perivascular (CD163(+)) and inflammatory (MAC387(+)) macrophages in SIV-infected monkeys. Monocyte progenitors were 5-bromo-2'-deoxyuridine (BrdU) labeled in bone marrow, and CNS macrophages were labeled serially with fluorescent dextrans injected into the cisterna magna. MAC387(+) macrophages accumulated in the meninges and choroid plexus in early inflammation and in the perivascular space and SIV encephalitis (SIVE) lesions late. CD163(+) macrophages accumulated in the perivascular space and SIVE lesions with late inflammation. Most of the BrdU(+) cells were MAC387(+); however, CD163(+)BrdU(+) macrophages were present in the meninges and choroid plexus with AIDS. Most (81.6% ± 1.8%) of macrophages in SIVE lesions were present in the CNS before SIVE lesion formation. There was a 2.9-fold increase in SIVp28(+) macrophages entering the CNS late compared with those entering early (P < 0.05). The rate of CD163(+) macrophage recruitment to the CNS inversely correlated with time to death (P < 0.03) and increased with SIVE. In SIVE animals, soluble CD163 correlated with CD163(+) macrophage recruitment (P = 0.02). Most perivascular macrophages that comprise SIVE lesions and multinucleated giant cells are present in the CNS early, before SIVE lesions are formed. Most SIV-infected macrophages traffic to the CNS terminally with AIDS.
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http://dx.doi.org/10.1016/j.ajpath.2015.01.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4450314PMC
June 2015

Distinct phenotype, longitudinal changes of numbers and cell-associated virus in blood dendritic cells in SIV-infected CD8-lymphocyte depleted macaques.

PLoS One 2015 27;10(4):e0119764. Epub 2015 Apr 27.

Department of Biology, Boston College, Chestnut Hill, Massachusetts, United States of America.

Loss of circulating CD123+ plasmacytoid dendritic cells (pDCs) during HIV infection is well established. However, changes of myeloid DCs (mDCs) are ambiguous since they are studied as a homogeneous CD11c+ population despite phenotypic and functional heterogeneity. Heterogeneity of CD11c+ mDCs in primates is poorly described in HIV and SIV infection. Using multiparametric flow cytometry, we monitored longitudinally cell number and cell-associated virus of CD123+ pDCs and non-overlapping subsets of CD1c+ and CD16+ mDCs in SIV-infected CD8-depleted rhesus macaques. The numbers of all three DC subsets were significantly decreased by 8 days post-infection. Whereas CD123+ pDCs were persistently depleted, numbers of CD1c+ and CD16+ mDCs rebounded. Numbers of CD1c+ mDCs significantly increased by 3 weeks post-infection while numbers of CD16+ mDCs remained closer to pre-infection levels. We found similar changes in the numbers of all three DC subsets in CD8 depleted animals as we found in animals that were SIV infected animals that were not CD8 lymphocyte depleted. CD16+ mDCs and CD123+ pDCs but not CD1c+ mDCs were significantly decreased terminally with AIDS. All DC subsets harbored SIV RNA as early as 8 days and then throughout infection. However, SIV DNA was only detected in CD123+ pDCs and only at 40 days post-infection consistent with SIV RNA, at least in mDCs, being surface-bound. Altogether our data demonstrate that SIV infection differently affects CD1c+ and CD16+ mDCs where CD16+ but not CD1c+ mDCs are depleted and might be differentially regulated in terminal AIDS. Finally, our data underline the importance of studying CD1c+ and CD16+ mDCs as discrete populations, and not as total CD11c+ mDCs.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0119764PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4410956PMC
April 2016

High-density lipoprotein-mediated cholesterol efflux capacity is improved by treatment with antiretroviral therapy in acute human immunodeficiency virus infection.

Open Forum Infect Dis 2014 Dec 16;1(3):ofu108. Epub 2014 Dec 16.

Program in Nutritional Metabolism.

Background: Individuals infected with human immunodeficiency virus (HIV) have decreased high-density lipoprotein (HDL)-cholesterol and increased cardiovascular disease (CVD). Reverse cholesterol transport from macrophages may be inhibited by HIV and contribute to increased CVD. Human studies have not investigated longitudinal effects of HIV and antiretroviral therapy (ART) on cholesterol efflux.

Methods: Subjects with acute HIV infection were randomized to ART or not. Cholesterol efflux capacity was determined ex vivo after exposure of murine macrophages to apolipoprotein B-depleted patient sera obtained at baseline and after 12 weeks.

Results: After 12 weeks, HIV RNA decreased most in subjects randomized to ART. Available data on cholesterol demonstrated that efflux capacity from Abca1(+/+) macrophages was increased most by sera obtained from ART-treated subjects (20.5% ± 5.0% to 24.3 % ± 6.9%, baseline to 12 weeks, P = .007; ART group [n = 6] vs 18.0 % ± 3.9% to 19.1 % ± 2.9%, baseline to 12 weeks, P = .30; untreated group [n = 6] [P = .04 ART vs untreated group]). Change in HIV RNA was negatively associated with change in Abca1(+/+) macrophage cholesterol efflux (r = - 0.62, P = .03), and this finding remained significant (P = .03) after controlling for changes in HDL-cholesterol, CD4(+) cells, and markers of monocyte or macrophage activation.

Conclusions: In subjects acutely infected with HIV, ATP-binding cassette transporter A1-mediated cholesterol efflux was stimulated to a greater degree over time by apolipoprotein B-depleted serum from subjects randomized to ART. The improvement in cholesterol efflux capacity is independently related to reduction in viral load.
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http://dx.doi.org/10.1093/ofid/ofu108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4324225PMC
December 2014