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Immune dysfunction and chronic inflammation are characteristic of HIV infection and diabetes mellitus, with CD4 + T-cell metabolism implicated in the pathogenesis of each disease. However, there is limited information on CD4 + T-cell metabolism in HIV+ persons with diabetes mellitus. We examined CD4 + T-cell glucose metabolism in HIV+ women with and without diabetes mellitus.A case-control study was used to compare CD4 + T-cell glucose metabolism in women with HIV with or without diabetes mellitus.Nondiabetic (HIV+DM-, N = 20) or type 2 diabetic HIV+ women with (HIV+DM+, N = 16) or without (HIV+DMTx+, N = 18) antidiabetic treatment were identified from the WIHS and matched for age, race/ethnicity, smoking status and CD4 + cell count. CD4 + T-cell immunometabolism was examined by flow cytometry, microfluidic qRT-PCR of metabolic genes, and Seahorse extracellular flux analysis of stimulated CD4 + T cells.HIV+DM+ displayed a significantly elevated proportion of CD4 + T cells expressing the immunometabolic marker GLUT1 compared with HIV+DMTx+ and HIV+DM- ( P = 0.04 and P = 0.01, respectively). Relative expression of genes encoding key enzymes for glucose metabolism pathways were elevated in CD4 + T cells of HIV+DM+ compared with HIV+DMTx+ and HIV+DM-. T-cell receptor (TCR)-activated CD4 + T cells from HIV+DM+ showed elevated glycolysis and oxidative phosphorylation compared with HIV+DM-.CD4 + T cells from HIV+DM+ have elevated glucose metabolism. Treatment of diabetes mellitus among women with HIV may partially correct CD4 + T-cell metabolic dysfunction.

The Caribbean region is lacking an assessment of the antibody response and side effects experienced after AstraZeneca COVID-19 vaccination (AZD1222). We examined severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD) IgG levels and report the side effects noted in a Jamaican population after AZD1222 vaccination. Median RBD IgG levels for persons without evidence of previous SARS-CoV-2 infection were 43.1 binding international units (bIU)/mL 3 to 7 weeks after the first dose, increasing to 100.1 bIU/mL 3 to 7 weeks after the second dose, and decreasing to 46.9 bIU/mL 16 to 22 weeks after the second dose. The median RBD IgG level 2 to 8 weeks after symptom onset for unvaccinated SARS-CoV-2-infected persons of all disease severities was 411.6 bIU/mL. Common AZD1222 side effects after the first dose were injection site pain, headache, and chills. Most people reported no side effects after the second dose. AZD1222 is widely used across the English-speaking Caribbean, and our study provides evidence for its continued safe and effective use in vaccination programs.

PURPOSE OF REVIEW. An increasing body of evidence indicates that persons living with HIV (PLWH) display dysfunctional immunometabolism. Here we provide an updated review of this topic and its relationship to HIV-associated immune stimuli and age-related disease. RECENT FINDINGS. HIV infection alters immunometabolism by increasing reliance on aerobic glycolysis for energy and productive infection and repurposing oxidative phosphorylation machinery for immune cell proliferation and survival. Recent studies in PLWH with diabetes mellitus and cardiovascular disease have identified an association with elevated T cell and monocyte glucose metabolism, respectively. Immunometabolic dysfunction has also been observed in PLWH in frailty and additional studies suggest a role for immunometabolism in non-AIDS defining cancers and neurocognitive disease. There is a plethora of HIV-associated immune stimuli that could drive immunometabolic dysfunction and age-related disease in PLWH but studies directly examining their relationship are lacking. SUMMARY. Immunometabolic dysfunction is characteristic of HIV infection and is a potential link between HIV-associated stimuli and age-related comorbidities.

Background and ObjectivesMultisystem inflammatory syndrome of children (MISC) carries a high attributable morbidity. We describe children aged MethodsAll were tested for SARS-CoV-2, infectious disease consultations performed, modified CDC criteria for MISC applied, charts reviewed and data analyzed.ResultsAmong 79 consecutive children with SARS-CoV-2, 41(52%) were hospitalised; with median age 10.5 years; Afro-Caribbean ethnicity 40(98%); males 21(51%); SARS-CoV-2 RT-PCR positivity 26 (63%), IgG/IgM positivity 7(17%), community exposures 8 (20%). MISC-cases 18 (44%) vs. non-MISC 23(56%) had fever (94% vs. 30%; pConclusionMISC was treated successfully with intravenous gammaglobulin, steroids and/or aspirin in 94% before cardiopulmonary decompensation, or need for inotropes, vasopressors, or invasive ventilation.

The Caribbean region is lacking an assessment of the antibody response and side effects experienced after AstraZeneca COVID-19 vaccination (AZD1222). We examined SARS-CoV-2 spike receptor binding domain (RBD) IgG levels and reported side effects in a Jamaican population after AZD1222 vaccination. Median RBD IgG levels for persons without evidence of previous SARS-CoV-2 infection were 43.1 bIU/mL after 3-7 weeks post first dose, rising to 100.1 bIU/mL 3-7 weeks post second dose, and falling 46.9 bIU/mL 16-22 weeks post second dose. The median RBD IgG level 2-8 weeks after symptom onset for unvaccinated SARS-CoV-2 infected persons of all disease severities was 411.6 bIU/mL. Common AZD1222 side effects after first dose were injection site pain, headache and chills. Most persons reported no side effects after second dose. AZD1222 is widely used across the English-speaking Caribbean and the study provides evidence for its continued safe and effective use in vaccination programs.

Objectives To quantitatively determine the antimicrobial susceptibility of clinical Neisseria gonorrhoeae isolates from men with urethral discharge in Jamaica and to describe the syndromic treatment therapies administered. Methods Urethral eSwabs (Copan) were collected from 175 men presenting with urethral discharge to the Comprehensive Health Centre STI Clinic, Kingston, Jamaica. Clinical information was collected and MICs of eight antimicrobials were determined for N. gonorrhoeae isolates (n = 96) using Etest and interpreted using CLSI criteria. Results The median age of the subjects was 28 years (range: 18–73 years) with a median of 2 sexual partners (range: 1–25) per male in the previous 3 months. All examined N. gonorrhoeae isolates were susceptible to ceftriaxone (96/96), azithromycin (91/91), cefixime (91/91) and spectinomycin (91/91). For ciprofloxacin and gentamicin, respectively, 98.9% (91/92) and 91.3% (84/92) of the isolates were susceptible and 1.1% (1/92) and 8.7% (8/92) showed intermediate susceptibility/resistance. For tetracycline and benzylpenicillin, respectively, 38.0% (35/92) and 22.0% (20/91) of the isolates were susceptible, 52.2% (48/92) and 74.7% (68/91) showed intermediate susceptibility/resistance and 9.8% (9/92) and 3.3% (3/91) were resistant. Syndromic treatment was administered as follows: 93.1% received 250 mg of ceftriaxone intramuscularly plus 100 mg of doxycycline orally q12h for 1–2 weeks and 6.9% received 500 mg of ciprofloxacin orally plus 100 mg of doxycycline orally q12h for 1 week. Conclusions Ceftriaxone (250 mg) remains appropriate for gonorrhoea treatment in the examined population of men in Kingston, Jamaica. Surveillance of N. gonorrhoeae AMR should be expanded in Jamaica and other Caribbean countries to guide evidence-based treatment guidelines.

SARS-CoV-2 seroprevalence in an antenatal population in Kingston, Jamaica was assessed for September-November 2020 in a repeated cross-sectional study using the Abbott Architect SARS-CoV-2 IgG assay. After adjusting for test performance, seroprevalence was 6.9% for September, 16.9% for October, and 24.0% for November. Of the 37 pregnant women testing SARS-CoV-2 IgG positive, only 3 were symptomatic. One symptomatic woman testing SARS-CoV-2 IgG positive had multiple co-morbidities and succumbed to COVID-19 pneumonia. Up to January 31, 2021, 8 women identified as SARS-CoV-2 IgG positive delivered, all without complications. Comparison of test adjusted seroprevalence data with cumulative PCR-confirmed COVID-19 cases within the Kingston Metropolitan Area indicated that as many as 44.4 times more people were infected with SARS-CoV-2 than identified with PCR testing. These findings provide the first evidence for the extent of SARS-CoV-2 infections in Jamaica and will inform future SARS-CoV-2 testing strategies.

Background The performance of the Roche Elecsys® Anti-SARS-CoV-2, Abbott Architect SARS-CoV-2 IgM, Abbott Architect SARS-CoV-2 IgG, Euroimmun SARS-CoV-2 IgA, Euroimmun SARS-CoV-2 IgG ELISA, and Trillium IgG/IgM rapid assays was evaluated in Jamaica. Methods Diagnostic sensitivities of the assays were assessed by testing serum samples from SARS-CoV-2 PCR-confirmed persons and diagnostic specificity was assessed by testing serum samples collected during 2018–2019 from healthy persons and from persons with antibodies to a wide range of viral infections. Results Serum samples collected ≥14 days after onset of symptoms, or an initial SARS-CoV-2 RT-PCR positive test for asymptomatics, showed diagnostic sensitivities ranging from 67.9 to 75.0% when including all possible disease severities and increased to 90.0–95.0% when examining those with moderate to critical disease. Grouping moderate to critical disease showed a significant association with a SARS-CoV-2 antibody positive result for all assays. Diagnostic specificity ranged from 96.7 to 100.0%. For all assays examined, SARS-CoV-2 real-time PCR cycle threshold (Ct) values of the initial nasopharyngeal swab sample testing positive were significantly different for samples testing antibody positive versus negative. Conclusions These data from a predominantly African descent Caribbean population show comparable diagnostic sensitivities and specificities for all testing platforms assessed and limited utility of these tests for persons with asymptomatic and mild infections.

The performance of the Roche Elecsys® Anti-SARS-CoV-2, Abbott Architect SARS-CoV-2 IgG, Euroimmun SARS-CoV-2 IgA, Euroimmun SARS-CoV-2 IgG ELISA, and Trillium IgG/IgM rapid assays was evaluated in Jamaica, the largest country of the English-speaking Caribbean. Diagnostic sensitivities of the assays were assessed by testing serum samples from SARS-CoV-2 PCR-confirmed persons. Serum samples collected ≥14 days after onset of symptoms, or ≥14 days after an initial SARS-CoV-2 RT-PCR positive test for asymptomatics, showed diagnostic sensitivities ranging from 67.9-75.0% when including all possible disease severities and increased to 90.0-95.0% when examining those with moderate to critical disease. Grouping moderate to critical disease showed a significant association with a SARS-CoV-2 antibody positive result for all assays. Diagnostic specificity, assessed by testing serum samples collected during 2018-2019 from healthy persons and from persons with antibodies to a wide range of viral infections, ranged from 96.7-100.0%. For all assays examined, SARS-CoV-2 real-time PCR cycle threshold (Ct) values of the initial nasopharyngeal swab sample testing positive were significantly different for samples testing antibody positive versus negative. These data from a predominantly African descent Caribbean population shows comparable diagnostic sensitivities and specificities for all testing platforms assessed and limited utility of these tests for persons with asymptomatic and mild infections.

Introduction: Jamaica experienced its maiden Zika virus (ZIKV) epidemic in 2016, while dengue (serotypes 3 and 4) and chikungunya were also circulating. Aim: We describe initial trends in microcephaly and arthrogryposis observed by the clinicians from three urban birthing facilities during late 2016 to early 2017. Methods: Reporting of infant microcephaly was required from all birthing facilities in Jamaica. Staff were to be trained in measuring the occipito-frontal head circumference (OFC) using World Health Organization’s (WHO) standards. Affected newborns were to be referred for comprehensive paediatric evaluation. Results: Hospital A reported 15 full-term newborns with microcephaly, 10 were delivered between November 10, 2016 and January 6, 2017. All were full-term newborns with OFC ranging from 28.5 to 31.5 cm, severe microcephaly with OFC’s < -3 Z scores was seen in ten. Most (12, 80%) had the characteristic craniofacial phenotype of congenital syndrome associated with Zika (CSAZ). Ten had neonatal ultrasounds which revealed intracerebral calcifications (4), dilated and/or asymmetric lateral ventricles (4), grossly overlapping sutures and/or closed or small fontanelles (3), cerebral atrophy (one) and absent frontal lobe sulcation with increased periventricular white matter (one). Computerized tomography (CT) scans revealed calcifications and dilated ventricles with thinning of cortical mantle (two others). Four mothers reported rash. The rate of microcephaly was estimated as 0.8% (10/1212) live births. In hospital B, among 414/629 (65%) of primarily term vaginal live births reviewed during eight weeks of December to January 2017, 17 had OFCs < 32 cm; eight patients had OFC < -2 Z score, six patients had OFC < - 3 Z score and three patients had OFC at -2 Z score; 14 patients (3%) were therefore microcephalic. Seventeen had relative microcephaly. Among the 14 microcephaly cases, five term babies had low birthweight, three had seizures within 24 hours, 6/14 were adolescents aged 15–19 years and among 11/14 with uterine ultrasonography, one was abnormal with head-body discrepancy. Two had a cranial ultrasonogram showing intracerebral calcifications, dilated lateral ventricle and cerebral atrophy. One mother reported rash in pregnancy. Microcephaly rate was 1.63% (14/857 live births). Hospital C identified 2% (1/43) microcephaly rate (OFC < 31.4 cm < - 2 Z scores) amongst symptomatic mothers during May 1, 2016 through March 31, 2017. Four others had low OFCs (< 33 cm), but not in the range for microcephaly. Therefore, 84% (36/43) of babies born to symptomatic mothers had normal OFC. Microcephaly rate for all live births for the period was 2.2% (26/1180). The monthly rate varied from 0% to 5% (6/118) peaking in March. Of two babies referred with severe arthrogryposis and microcephaly, one had characteristic evidence on nuclear magnetic resonance imaging of corpus callosum dysgenesis, occipital lobe cyst, cerebellar hypoplasia and intracranial calcifications. In the other, CT scan of the brain revealed microcephaly with cortical atrophy, severe ventriculomegaly of the lateral and third ventricles, fine calcifications in the thalami and basal ganglia bilaterally and in the right frontal lobe, with a huge posterior fossa cyst communicating with the 4th ventricle. He died and autopsy confirmed these findings. Cross-reactivity of serological tests for dengue and Zika virus challenged laboratory diagnosis in mothers and newborns. Conclusion: Newborns with “characteristic CSAZ features” are being born in urban settings primarily to asymptomatic mothers in Jamaica. Diagnosis is challenged by serological crossreactivity between the circulating flaviviruses. Team management is multidisciplinary and will be a costly intervention for developing countries to implement to maximize the neurodevelopmental potential of this new and vulnerable population of children.

Immune cells cycle between a resting and an activated state. Their metabolism is tightly linked to their activation status and, consequently, functions. Ag recognition induces T lymphocyte activation and proliferation and acquisition of effector functions that require and depend on cellular metabolic reprogramming. Likewise, recognition of pathogen-associated molecular patterns by monocytes and macrophages induces changes in cellular metabolism. As obligate intracellular parasites, viruses manipulate the metabolism of infected cells to meet their structural and functional requirements. For example, HIV-induced changes in immune cell metabolism and redox state are associated with CD4+ T cell depletion, immune activation, and inflammation. In this review, we highlight how HIV modifies immunometabolism with potential implications for cure research and pathogenesis of comorbidities observed in HIV-infected patients, including those with virologic suppression. In addition, we highlight recently described key methods that can be applied to study the metabolic dysregulation of immune cells in disease states. Fil: Palmer, Clovis S.. Monash University; Australia. Burnet Institute; Australia Fil: Henstridge, Darren C.. Baker Heart and Diabetes Institute; Australia Fil: Yu, Di. Monash University; Australia Fil: Singh, Amit. Indian Institute of Science; India Fil: Balderson, Brad. Burnet Institute; Australia Fil: Duette, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentina Fil: Cherry, Catherine L.. Burnet Institute; Australia. Monash University; Australia. University of the Witwatersrand; Sudáfrica Fil: Anzinger, Joshua J.. University of the West Indies; Jamaica Fil: Ostrowski, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentina Fil: Crowe, Suzanne M.. Monash University; Australia. Burnet Institute; Australia

Monocyte activation during HIV-1 infection is associated with increased plasma levels of inflammatory markers and increased risk for premature development of age-related diseases. Because activated monocytes primarily use glucose to support cellular metabolism, we hypothesized that chronic monocyte activation during HIV-1 infection induces a hypermetabolic response with increased glucose uptake. To test this hypothesis, we evaluated glucose transporter 1 (Glut1) expression and glucose uptake by monocyte subpopulations in HIV-seropositive (HIV+) treatment-naive individuals (n = 17), HIV+ individuals on combination antiretroviral therapy with viral loads below detection (n = 11), and HIV-seronegative (HIV−) individuals (n = 16). Surface expression of Glut1 and cellular uptake of the fluorescent glucose analog 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2 deoxyglucose were analyzed by flow cytometry on monocyte subpopulations. Irrespective of treatment status, monocytes from HIV+ persons had significantly increased surface expression of Glut1 compared with those from HIV− controls. Nonclassical (CD14+CD16++) and intermediate (CD14++CD16+) monocyte subpopulations showed higher Glut1 expression than did classical (CD14++CD16−) monocytes. Intermediate monocytes from treatment-naive HIV+ individuals also showed increased uptake of 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2 deoxyglucose compared with those from HIV− controls. Our results show that HIV infection is associated with increased glucose metabolism in monocytes and that Glut1 expression by proinflammatory monocytes is a potential marker of inflammation in HIV-infected subjects. However, the possibility exists whereby other Gluts such as Glut3 and Glut4 may also support the influx of glucose into activated and inflammatory monocyte populations.

This report describes the presence of Aedes albopictus (Skuse) in Jamaica. The adults were found while conducting an ongoing survey of mosquitoes on the island. Specimens were collected using a combination of modified Center for Disease Control (CDC) miniature light traps and BG sentinel traps. A total of six adult female Ae. albopictus mosquitoes were collected at two different locations in October of 2018. This finding increases the number of Aedes mosquito species on the island bringing with it public health implications.

Although the recent Zika virus (ZIKV) epidemic in the Americas and its link to birth defects have attracted a great deal of attention1,2, much remains unknown about ZIKV disease epidemiology and ZIKV evolution, in part owing to a lack of genomic data. Here we address this gap in knowledge by using multiple sequencing approaches to generate 110 ZIKV genomes from clinical and mosquito samples from 10 countries and territories, greatly expanding the observed viral genetic diversity from this outbreak. We analysed the timing and patterns of introductions into distinct geographic regions; our phylogenetic evidence suggests rapid expansion of the outbreak in Brazil and multiple introductions of outbreak strains into Puerto Rico, Honduras, Colombia, other Caribbean islands, and the continental United States. We find that ZIKV circulated undetected in multiple regions for many months before the first locally transmitted cases were confirmed, highlighting the importance of surveillance of viral infections. We identify mutations with possible functional implications for ZIKV biology and pathogenesis, as well as those that might be relevant to the effectiveness of diagnostic tests., National Institutes of Health (U.S.) (Grant NIAID U19AI110818)

Objective: Fluid-phase pinocytosis is a receptor-independent mechanism of endocytosis that occurs in all mammalian cells and may be a mechanism for the uptake of LDL by macrophages. As there are currently no methods for the measurement of fluid-phase pinocytosis by individual aortic cells in vivo, we sought to identify a suitable method. Methods: ApoE-/- mice were retro-orbitally injected with AngioSPARK fluorescent nanoparticles specifically designed to not interact with cells. After 24 h, mice were sacrificed, and the aortas were isolated and then digested to analyze aortic cell uptake of AngioSPARK by flow cytometry. Results: CD11b-expressing aortic macrophages from mice injected with AngioSPARK showed high levels of fluid-phase pinocytosis compared to aortic cells not expressing CD11b (4,393.7 vs. 408.3 mean fluorescence intensity [MFI], respectively). Conclusion: This new technique allows for the measurement of fluid-phase pinocytosis by aortic cells in vivo, making it possible to examine the cell-signaling molecules and drugs that affect this process. Published by S. Karger AG, Basel

In human immunodeficiency virus (HIV) infection, persistent inflammation despite effective antiretroviral therapy (ART) is linked to increased risk of non-infectious chronic complications such as cardiovascular and thromboembolic disease. A better understanding of inflammatory and coagulation pathways in HIV infection is needed to optimize clinical care. Markers of monocyte activation and coagulation independently predict morbidity and mortality associated with non-AIDS events. In this study, we identified a specific subset of monocytes that express tissue factor (TF), persist after virological suppression and trigger the coagulation cascade by activating factor X. This subset of monocytes expressing TF had a distinct gene signature with upregulated innate immune markers as well as evidence of robust production of multiple proinflammatory cytokines including IL-1β, TNF-α, and IL-6 ex vivo and in vitro upon LPS stimulation. We validated our findings in a nonhuman primate model, showing that TF-expressing inflammatory monocytes were associated with SIV-related coagulopathy in the progressive (pigtail macaques) but not the non-pathogenic (African Green Monkeys) SIV infection model. Lastly, Ixolaris, an anti-coagulant that inhibits the TF pathway, was tested and potently blocked functional TF activity in vitro in HIV and SIV infection without affecting monocyte responses to toll-like receptor (TLR) stimulation. Strikingly, in vivo treatment of chronically infected PTMs with Ixolaris was associated with significant decreases in D-dimer and immune activation. These data suggest that TF expressing monocytes are at the epicenter of inflammation and coagulation in chronic HIV and SIV infection and may represent a potential therapeutic target.

The uptake of lipoproteins by macrophages is a critical step in the development of atherosclerotic lesions. Cultured monocyte-derived macrophages take up large amounts of native LDL by receptor-independent fluid-phase pinocytosis, either constitutively or in response to specific activating stimuli, depending on the macrophage phenotype. We therefore sought to determine whether fluid-phase pinocytosis occurs in vivo in macrophages in atherosclerotic lesions. We demonstrated that fluorescent pegylated nanoparticles similar in size to LDL (specifically nontargeted Qtracker quantum dot and AngioSPARK nanoparticles) can serve as models of LDL uptake by fluid-phase pinocytosis in cultured human monocyte-derived macrophages and mouse bone marrow-derived macrophages. Using fluorescence microscopy, we showed that atherosclerosis-prone Apoe-knockout mice injected with these nanoparticles displayed massive accumulation of the nanoparticles within CD68+ macrophages, including lipid-containing foam cells, in atherosclerotic lesions in the aortic arch. Similar results were obtained when atherosclerotic mouse aortas were cultured with nanoparticles in vitro. These results show that macrophages within atherosclerotic lesions can take up LDL-sized nanoparticles by fluid-phase pinocytosis and indicate that fluid-phase pinocytosis of LDL is a mechanism for macrophage foam cell formation in vivo.

Strategies that prevent initial HIV infection of cells are greatly needed. In this study, we determined the requirement of divalent cations for HIV infection of and attachment to peripheral blood mononuclear cells (PBMC), which contain several types of HIV-infectable cells—CD4+ T cells, monocytes and dendritic cells. EDTA, added only during PBMC exposure to HIV, reduced infection by an average of 92%. The reduction of infection by EDTA was accompanied by a reduction in HIV binding to PBMC; R5, X4 and dual-tropic HIV binding to PBMC were inhibited by >85%. EGTA similarly reduced HIV binding to PBMC, while addition of Ca2+ or Mn2+, but not Mg2+, fully restored binding. Virus attachment was inhibited in a dose-dependent manner by trypsin treatment of PBMC, indicating protein involvement in HIV binding. In contrast, mannan or soluble ICAM-1 did not inhibit HIV binding to PBMC. These data indicate that a Ca2+-dependent cell-surface protein(s) is responsible for the majority of HIV attachment to and infection of PBMC. Further studies of this are likely to reveal novel strategies to prevent infection of PBMC.

Previous studies have demonstrated that the ATP-binding cassette transporters (ABC)A1 and ABCG1 function in many aspects of cholesterol efflux from macrophages. In this current study, we continued our investigation of extracellular cholesterol microdomains that form during enrichment of macrophages with cholesterol. Human monocyte-derived macrophages and mouse bone marrow-derived macrophages, differentiated with macrophage colony-stimulating factor (M-CSF) or granulocyte macrophage colony-stimulation factor (GM-CSF), were incubated with acetylated LDL (AcLDL) to allow for cholesterol enrichment and processing. We utilized an anti-cholesterol microdomain monoclonal antibody to reveal pools of unesterified cholesterol, which were found both in the extracellular matrix and associated with the cell surface, that we show function in reverse cholesterol transport. Coincubation of AcLDL with 50 μg/ml apoA-I eliminated all extracellular and cell surface-associated cholesterol microdomains, while coincubation with the same concentration of HDL only removed extracellular matrix-associated cholesterol microdomains. Only at an HDL concentration of 200 µg/ml did HDL eliminate the cholesterol microdomains that were cell-surface associated. The deposition of cholesterol microdomains was inhibited by probucol, but it was increased by the liver X receptor (LXR) agonist TO901317, which upregulates ABCA1 and ABCG1. Extracellular cholesterol microdomains did not develop when ABCG1-deficient mouse bone marrow-derived macrophages were enriched with cholesterol. Our findings show that generation of extracellular cholesterol microdomains is mediated by ABCG1 and that reverse cholesterol transport occurs not only at the cell surface but also within the extracellular space.

Many HDL-microRNAs (miRNA) are well-characterized post-transcriptional regulators of inflammation, and are significantly increased on HDL with hypercholesterolemia and atherosclerosis in humans and mice. Therefore, we hypothesize that inflammatory cells uniquely control their own gene expression through cellular miRNA export to HDL and then regulate recipient cell gene expression through HDL-mediated miRNA delivery. To test this hypothesis, we used high-throughput proteomics, Open Arrays, small RNA sequencing, and gene expression microarrays. Human monocytes (plasma elutriation) were differentiated into dendritic cells and multiple macrophage phenotypes. Each cell-type was incubated with pure reconstituted HDL (rHDL), which was then purified from culture media by apolipoprotein A-I immunoprecipitation after 24 h, and both cellular and HDL-miRNAs were profiled using TaqMan Open Arrays. Macrophages were found to export high levels of miRNAs to HDL that inhibit monocyte/macrophage differentiation (miR-146a, miR-223); however, monocytes were also found to export many miRNAs associated with differentiation, including miR-92a, miR-222, miR-17, miR-20a, miR106a, and miR-21. Furthermore, many miRNAs were found to be transcribed in inflammatory cells, but completely exported to HDL and not retained in the cell. Most interestingly, HDL treatment was found to induce miR-223 transcription in monocytes, as determined by primary miR-223 transcript levels; however, intracellular levels of the mature form (miR-223) did not change. These results suggest that HDL induces the export of miRNAs it transports. PAR-CLIP with high-throughput small RNA sequencing was used to demonstrate that miRNAs are transferred from macrophages to endothelial cells and loaded onto cellular Argonaute 2-continaining RNA-induced silencing complexes. To demonstrate this in mice, human HDL, containing endogenous levels of miR-223, were injected into miR-223-null mice and inflammation-associated miRNA delivery was mapped in vivo. In summary, we found profound differences in the cellular response to HDL treatment and HDL-miRNA communication amongst inflammatory cell phenotypes that are physiologically relevant to cardiovascular disease.

Chikungunya virus (CHIKV) is a re-emerging global pathogen with pandemic potential, which causes fever, rash and debilitating arthralgia. Older adults over 65 years are particularly susceptible to severe and chronic CHIKV disease (CHIKVD), accounting for >90% of all CHIKV-related deaths. There are currently no approved vaccines or antiviral treatments available to limit chronic CHIKVD. Here we show that in old mice excessive, dysregulated TGFβ production during acute infection leads to a reduced immune response and subsequent chronic disease. Humans suffering from CHIKV infection also exhibited high TGFβ levels and a pronounced age-related defect in neutralizing anti-CHIKV antibody production. In vivo reduction of TGFβ levels minimized acute joint swelling, restored neutralizing antibody production and diminished chronic joint pathology in old mice. This study identifies increased and dysregulated TGFβ secretion as one key mechanism contributing to the age-related loss of protective anti-CHIKV-immunity leading to chronic CHIKVD., Author Summary Chikungunya virus (CHIKV) causes an acute febrile syndrome and severe acute and chronic joint disease that, for unknown reasons, especially affects older adults. CHIKV has recently reached the Americas and is threatening the Southeastern USA. At the present there is no approved vaccine or antiviral treatments against CHIKV and treatment is limited to non-steroidal anti-inflammatory drugs (NSAIDs). We have shown here in a mouse model that increased production of the immunosuppressive cytokine TGFβ contributes to the excess of CHIKV disease severity with aging. Blocking of this cytokine reduced early swelling and late joint/foot pathology, and increased production of neutralizing antibodies. Since our data demonstrate high levels of TGFβ in humans experiencing acute CHIKV infection and decreased anti-CHIKV neutralizing antibodies in older CHIKV-exposed humans, these results could pave the way to new treatments against CHIKV disease.

Accumulation of cholesterol by macrophage uptake of LDL is a key event in the formation of atherosclerotic plaques. Previous research has shown that granulocyte-macrophage colony-stimulating factor (GM-CSF) is present in atherosclerotic plaques and promotes aortic lipid accumulation. However, it has not been determined whether murine GM-CSF-differentiated macrophages take up LDL to become foam cells. GM-CSF-differentiated macrophages from LDL receptor-null mice were incubated with LDL, resulting in massive macrophage cholesterol accumulation. Incubation of LDL receptor-null or wild-type macrophages with increasing concentrations of 125I-LDL showed nonsaturable macrophage LDL uptake that was linearly related to the amount of LDL added, indicating that LDL uptake was mediated by fluid-phase pinocytosis. Previous studies suggest that phosphoinositide 3-kinases (PI3K) mediate macrophage fluid-phase pinocytosis, although the isoform mediating this process has not been determined. Because PI3Kγ is known to promote aortic lipid accumulation, we investigated its role in mediating macrophage fluid-phase pinocytosis of LDL. Wild-type macrophages incubated with LDL and the PI3Kγ inhibitor AS605240 or PI3Kγ-null macrophages incubated with LDL showed an ∼50% reduction in LDL uptake and cholesterol accumulation compared with wild-type macrophages incubated with LDL only. These results show that GM-CSF-differentiated murine macrophages become foam cells by fluid-phase pinocytosis of LDL and identify PI3Kγ as contributing to this process.

Background Monocyte-derived macrophages contribute to atherosclerotic plaque formation. Therefore, manipulating macrophage function could have significant therapeutic value. The objective of this study was to determine transduction efficiency of two HIV-based lentiviral vector configurations as delivery systems for the transduction of primary human blood monocyte-derived macrophages. Results Human blood monocytes were transduced using two VSV-G pseudotyped HIV-1 based lentiviral vectors containing EGFP expression driven by either native HIV-LTR (VRX494) or EF1α promoters (VRX1090). Lentiviral vectors were added to cultured macrophages at different times and multiplicities of infection (MOI). Transduction efficiency was assessed using fluorescence microscopy and flow cytometry. Macrophages transduced between 2 and 120 hours after culturing showed the highest transduction efficiency at 2-hours transduction time. Subsequently, cells were transduced 2 hours after culturing at various vector concentrations (MOIs of 5, 10, 25 and 50) to determine the amount of lentiviral vector particles required to maximally transduce human monocyte-derived macrophages. On day 7, all transduced cultures showed EGFP-positive cells by microscopy. Flow cytometric analysis showed with all MOIs a peak shift corresponding to the presence of EGFP-positive cells. For VRX494, transduction efficiency was maximal at an MOI of 25 to 50 and ranged between 58 and 67%. For VRX1090, transduction efficiency was maximal at an MOI of 10 and ranged between 80 and 90%. Thus, transductions performed with VRX1090 showed a higher number of EGFP-positive cells than VRX494. Conclusions This report shows that VSV-G pseudotyped HIV-based lentiviral vectors can efficiently transduce human blood monocyte-derived macrophages early during differentiation using low particle numbers that do not interfere with differentiation of monocytes into macrophages.

Previous studies have shown that cholesterol in atherosclerotic plaques is present in both intracellular and extracellular forms. In the current study, we investigated a mechanism for extracellular cholesterol accumulation and examined the capacity of this pool of cholesterol to be removed by cholesterol acceptors, a step in reverse cholesterol transport. Human monocyte-derived macrophages differentiated with macrophage-colony stimulating factor were incubated with acetylated LDL to allow cholesterol enrichment and processing. These macrophages were subsequently labeled with a monoclonal antibody that specifically detects ordered cholesterol arrays, revealing the presence of unesterified cholesterol-rich microdomains on the cell surfaces and in the extracellular matrix. Similar unesterified cholesterol-rich microdomains were present in human atherosclerotic plaques. Actin microfilaments functioned in microdomain deposition or maintenance, and Src family kinases regulated transfer of these microdomains from the cell surface onto the extracellular matrix. Mediators of reverse cholesterol transport, apolipoprotein A-I (apoA-I), and HDL were capable of removing these extracellular un-esterified cholesterol-rich microdomains. However, apoA-I removed the microdomains only when macrophages were present. ApoA-I removal of microdomains was blocked by glyburide and inhibitor of ATP-binding cassette transporter A1 (ABCA1) function. In summary, cultures of cholesterol-enriched human monocyte-derived macrophages generate extracellular unesterified cholesterol-rich microdomains, which can subsequently be removed by cholesterol acceptors and therefore potentially function in reverse cholesterol transport.

The actions of nucleotides and hormones at endothelial cell (EC) receptors are known to result in the release of ATP that acts as a local hormone to facilitate release of mediators such as NO and PGI2. Stimulation of ECs with the P2Y1 receptor agonist 2-MeSATP leads to the rapid release of Ca2+ from stores consistent with a role for inositol tris-phosphate (Ins-1,4,5-P3) in mediating the action of extracellular nucleotides. Guinea pig ECs were grown in primary culture. [3H]d-myo-inositol (30 Ci/mmol) labeling studies revealed maximal incorporation of radioactivity into [3H]Ins-1,4,5-P3 when glucose in the labeling buffer was lowered to 1 mM and non-radioactive inositol was added at 10 μM. Stimulation of EC for one sec led to the dose-dependent accumulation of [3H]Ins-1,4,5-P3 as well as [3H]IP4, [3H]IP5, and [3H]IP6. Unexpectedly, the metabolism of [3H]Ins-1,4,5-P3 to IP1 was disparate in stimulated versus un-stimulated cells. In [3H]d-Ins labeled stimulated EC or in homogenates derived from unlabeled, stimulated EC, dephosphorylation of [3H]Ins-1,4,5-P3 led to the exclusive formation of [3H]Ins-4-P1. Addition of non-nucleotide agonists such as bradykinin gave the same results suggesting that the dephosphorylation pathway for IP formation in EC is dependent on agonist stimulation and may be correlated with regulation of agonist responsiveness or heretofore unrecognized actions of IP isomers in stimulated versus un-stimulated cells.

Infections and inflammation in the genital tract can influence HIV expression or HIV susceptibility. The goal of this study was to determine if significant relationships exist between cytokines and HIV in genital tract secretions from 57 HIV-seropositive Rwandan women. Genital tract secretions were obtained by cervicovaginal lavage (CVL). Ten different cytokines in CVL were measured by multiplex cytometric bead arrays. HIV RNA in CVL and plasma were measured by quantitative PCR. In univariate analysis, genital tract HIV RNA was significantly associated with plasma HIV RNA and several of the cytokines, while in multivariate analysis, genital tract HIV RNA was significantly associated only with plasma HIV RNA and IL-6. This association of IL-6 with HIV RNA levels suggests that IL-6 is an indicator for conditions that induce HIV expression and that IL-6 may contribute to induction of HIV expression in the genital tract.

Resting neutrophils bind human immunodeficiency virus type 1 (HIV-1) and efficiently transfer infection to lymphocytes. The present study shows that a brief activation by inflammatory stimuli increases the neutrophil binding levels of both R5 and X4 isolates of HIV-1 at least twofold. The binding occurs independently of CD4, gp120, and incubation temperature and is observed with HIV-1 propagated either in lymphocytes or in HEK293 cells. Significantly, HIV-1 bound to the activated neutrophils accelerates the infection of activated lymphocytes compared to free HIV-1 or to HIV-1 bound to resting neutrophils. It is proposed that these events may contribute to the increased risk of HIV-1 transmission at sites of mucosal infection.

During atherosclerosis, low-density lipoprotein (LDL)-derived cholesterol accumulates in macrophages to form foam cells. Macrophage uptake of LDL promotes foam cell formation but the mechanism mediating this process is not clear. The present study investigates the mechanism of LDL uptake for macrophage colony-stimulating factor (M-CSF)-differentiated murine bone marrow-derived macrophages. LDL receptor-null (LDLR-/-) macrophages incubated with LDL showed non-saturable accumulation of cholesterol that did not down-regulate for the 24 h examined. Incubation of LDLR-/- macrophages with increasing concentrations of (125)I-LDL showed non-saturable macrophage LDL uptake. A 20-fold excess of unlabeled LDL had no effect on (125)I-LDL uptake by wild-type macrophages and genetic deletion of the macrophage scavenger receptors CD36 and SRA did not affect (125)I-LDL uptake, showing that LDL uptake occurred by fluid-phase pinocytosis independently of receptors. Cholesterol accumulation was inhibited approximately 50% in wild-type and LDLR-/- mice treated with LY294002 or wortmannin, inhibitors of all classes of phosphoinositide 3-kinases (PI3K). Time-lapse, phase-contrast microscopy showed that macropinocytosis, an important fluid-phase uptake pathway in macrophages, was blocked almost completely by PI3K inhibition with wortmannin. Pharmacological inhibition of the class I PI3K isoforms alpha, beta, gamma or delta did not affect macrophage LDL-derived cholesterol accumulation or macropinocytosis. Furthermore, macrophages from mice expressing kinase-dead class I PI3K beta, gamma or delta isoforms showed no decrease in cholesterol accumulation or macropinocytosis when compared with wild-type macrophages. Thus, non-class I PI3K isoforms mediated macropinocytosis in these macrophages. Further characterization of the components necessary for LDL uptake, cholesterol accumulation, and macropinocytosis identified dynamin, microtubules, actin, and vacuolar type H(+)-ATPase as contributing to uptake. However, Pak1, Rac1, and Src-family kinases, which mediate fluid-phase pinocytosis in certain other cell types, were unnecessary. In conclusion, our findings provide evidence that targeting those components mediating macrophage macropinocytosis with inhibitors may be an effective strategy to limit macrophage accumulation of LDL-derived cholesterol in arteries.

Background HIV infection of cells varies greatly between individuals, with multiple steps in the replication cycle potentially contributing to the variability. Although entry and post-entry variability of HIV infection levels in cells has been demonstrated, variability in HIV binding has not been examined. In this study, we examined variability of HIV binding to peripheral blood mononuclear cells (PBMC) from different donors. Results HIV binding to PBMC varied up to 3.9-fold between individuals and was independent of CD4. Replication of HIV in donor PBMC required CD4 and paralleled virus binding trends of donor PBMC. To assess the stability of virus binding phenotypes over time, HIV was bound to donors with low- and high-binding phenotypes. The binding phenotypes were maintained when tested weekly over a 4-week period for 3 of 4 donors, while one high-binding donor decreased to lower binding on the 4th week. The low- and high-binding phenotypes were also preserved across different HIV strains. Experiments performed to determine if there was an association between HIV binding levels and specific cell subset levels within PBMC showed no correlation, suggesting that HIV binds to multiple cell subsets. Conclusion These results show that differences exist in HIV binding to donor PBMC. Our data also show that HIV binding to donor PBMC is CD4-independent and can change over time, suggesting that virus binding variability is due to differences in the expression of changeable cell-surface host factors. Taken together, this study highlights the impact of cell-surface factors in HIV binding to, and infection of, PBMC which likely represents an important step in HIV infection in vivo.