Markers Of Monocyte Activation Research Articles

556 Maternal Opioid Use Leads to Aberrant Maternal and Fetal Immunity

OBJECTIVES/GOALS: Maternal opioid use disorder (OUD) is linked to poor fetal outcomes. While it has been established that opioids can cross from maternal to fetal circulation, the mechanisms underlying these adverse outcomes remain poorly defined. This study aims to uncover OUD-associated immunological changes in maternal and fetal circulation. METHODS/STUDY POPULATION: To study the effect of maternal OUD on the maternal immune system at delivery, we collected maternal blood samples at delivery from healthy pregnant women (controls) and pregnant women with a diagnosis of severe OUD. To study the impact of maternal OUD on newborn immunity, we also collected umbilical cord blood (UCB) at delivery. Flow cytometry was used to determine the frequency and phenotype of circulating immune cell subsets and responses to stimulation. Isolated monocytes were stimulated with bacterial/viral agonist cocktails, while T and NK cells were stimulated with PMA/ionomycin. The impact of maternal OUD on circulating immune mediators was determined by Luminex and on monocyte activation markers sCD14 and CRP by ELISA. RESULTS/ANTICIPATED RESULTS: In maternal circulation, OUD was associated with a significant decrease in markers of inflammation, cell proliferation, and activation. Frequencies of immune cell subsets were impacted by OUD, shown by an expansion of CD8+ EMRA T cells, marginal-zone B cells, mDCs, non-classical monocytes, and CD16low NK cells. While no differences were seen in T and NK cell responses to stimulation, monocytes and pDCs had significantly lower responses to bacterial and viral agonist stimulation. Analysis of UCB revealed increased levels of pro-apoptotic/T cell exhaustion mediators and pro-inflammatory cytokines, albeit decreased levels of several chemokines and growth factors. The UCB immune landscape is altered with maternal OUD, as demonstrated by a shift from naive to memory CD8+ T cells and a decrease in pDC frequency. DISCUSSION/SIGNIFICANCE: OUD dampens maternal peripheral immunity, possibly contributing to poor placental function or premature/delayed labor. Monocytes and pDCs lack antimicrobial functionality, suggesting increased infection susceptibility with OUD. Finally, these implications extend to the fetal compartment, shown by heightened immune activation in UCB.

Association of Lipoprotein (a) with peri-coronary inflammation in persons with and without HIV infection

Persons with HIV (PWH) have an increased risk of developing cardiovascular disease (CVD) compared to persons without HIV (PWoH). Lipoprotein a (Lp(a)) is a known atherosclerotic risk factor in PWoH, but there are no studies investigating Lp(a) and peri-coronary inflammation. To investigate whether Lp(a) is associated with peri-coronary inflammation as assessed by the fat attenuation index (FAI) and activated monocytes and T lymphocytes in PWH and PWoH. We measured plasma levels of Lp(a) at study entry in 58 PWH and 21 PWoH without CVD and who had FAI measurements. Associations of Lp(a) with FAI values of the right coronary artery (RCA) and left anterior descending artery (LAD) were evaluated using multivariable regression models adjusted for potential confounders. Correlations between Lp(a) levels and systemic inflammatory markers and immune cell subsets were examined. Lp(a) was associated with greater peri-coronary inflammation among PWH compared to PWoH (β=1.73, P=0.019) in the RCA, in adjusted models. Significant correlations were observed with certain inflammatory markers (TNFR-I, b=0.295, P<0.001; TNFR-II, b=0.270, P=0.002; hs-CRP, b=0.195, P=0.028). Significant correlations were found between Lp(a) levels and several markers of monocyte activation: CD16 -CD163+ (b= -0.199, P=0.024), and CD16 -DR+ MFI (b= -0.179, P=0.042) and T cell subset CD38+CD4+ TEMRA (b= 0.177, P= 0.044). Lp(a) was associated with greater peri-coronary inflammation in the RCA in PWH compared to PWoH, as well as with select systemic inflammatory markers and specific subsets of immune cells in peripheral circulation.

Aberrant GPA expression and regulatory function of red blood cells in sickle cell disease

AbstractGlycophorin A (GPA), a red blood cell (RBC) surface glycoprotein, can maintain peripheral blood leukocyte quiescence through interaction with a sialic acid–binding Ig-like lectin (Siglec-9). Under inflammatory conditions such as sickle cell disease (SCD), the GPA of RBCs undergo structural changes that affect this interaction. Peripheral blood samples from patients with SCD before and after RBC transfusions were probed for neutrophil and monocyte activation markers and analyzed by fluorescence-activated cell sorting (FACS). RBCs were purified and tested by FACS for Siglec-9 binding and GPA expression, and incubated with cultured endothelial cells to evaluate their effect on barrier function. Activated leukocytes from healthy subjects (HS) were coincubated with healthy RBCs (RBCH), GPA-altered RBCs, or GPA-overexpressing (OE) cells and analyzed using FACS. Monocyte CD63 and neutrophil CD66b from patients with SCD at baseline were increased 47% and 27%, respectively, as compared with HS (P = .0017, P = .0162). After transfusion, these markers were suppressed by 22% and 17% (P = .0084, P = .0633). GPA expression in RBCSCD was 38% higher (P = .0291) with decreased Siglec-9 binding compared with RBCH (0.0266). Monocyte CD63 and neutrophil CD66b were suppressed after incubation with RBCH and GPA-OE cells, but not with GPA-altered RBCs. Endothelial barrier dysfunction after lipopolysaccharide challenge was restored fully with exposure to RBCH, but not with RBCSCD, from patients in pain crisis, or with RBCH with altered GPA. Pretransfusion RBCSCD do not effectively maintain the quiescence of leukocytes and endothelium, but quiescence is restored through RBC transfusion, likely by reestablished GPA-Siglec-9 interactions.

ACE2-independent SARS-CoV-2 virus entry through cell surface GRP78 on monocytes – evidence from a translational clinical and experimental approach

SARS-CoV-2 infects host cells via an ACE2/TMPRSS2 entry mechanism. Monocytes and macrophages, which play a key role during severe COVID-19 express only low or no ACE2, suggesting alternative entry mechanisms in these cells. In silico analyses predicted GRP78, which is constitutively expressed on monocytes and macrophages, to be a potential candidate receptor for SARS-CoV-2 virus entry. Hospitalized COVID-19 patients were characterized regarding their pro-inflammatory state and cell surface GRP78 (csGRP78) expression in comparison to healthy controls. RNA from CD14+ monocytes of patients and controls were subjected to transcriptome analysis that was specifically complemented by bioinformatic re-analyses of bronchoalveolar lavage fluid (BALF) datasets of COVID-19 patients with a focus on monocyte/macrophage subsets, SARS-CoV-2 infection state as well as GRP78 gene expression. Monocyte and macrophage immunohistocytochemistry on GRP78 was conducted in post-mortem lung tissues. SARS-CoV-2 spike and GRP78 protein interaction was analyzed by surface plasmon resonance, GST Pull-down and Co-Immunoprecipitation. SARS-CoV-2 pseudovirus or single spike protein uptake was quantified in csGRP78high THP-1cells. Cytokine patterns, monocyte activation markers and transcriptomic changes indicated typical COVID-19 associated inflammation accompanied by upregulated csGRP78 expression on peripheral blood and lung monocytes/macrophages. Subsequent cell culture experiments confirmed an association between elevated pro-inflammatory cytokine levels and upregulation of csGRP78. Interaction of csGRP78 and SARS-CoV-2 spike protein with a dissociation constant of KD=55.2nM was validated invitro. Infection rate analyses in ACE2low and GRP78high THP-1cells showed increased uptake of pseudovirus expressing SARS-CoV-2 spike protein. Our results demonstrate that csGRP78 acts as a receptor for SARS-CoV-2 spike protein to mediate ACE2-independent virus entry into monocytes. Funded by the Sino-German-Center for Science Promotion (C-0040) and the Germany Ministry BMWi/K [DLR-grant 50WB1931 and RP1920 to AC, DM, TW].

Low levels of peripheral blood activated and senescent T cells characterize people with HIV-1-associated neurocognitive disorders.

HIV infection induces a 75% increase in the risk of developing neurocognitive impairment (NCI), which has been linked to immune activation. We therefore looked for immune activation markers correlating with NCI. Sixty-five people aged 55-70 years living with controlled HIV-1 infection were enrolled in the study and their neurocognitive ability was assessed according to the Frascati criteria. Fifty-nine markers of T4 cell, T8 cell, NK cell, and monocyte activation, inflammation and endothelial activation were measured in their peripheral blood. White matter hyperintensities (WMH) were identified by magnetic resonance imaging. Double hierarchical clustering was performed for the activation markers and 240 patients including the 65 whose neurocognitive performance had been evaluated. Thirty-eight percent of volunteers presented NCI. Twenty-four percent of them were asymptomatic and fourteen percent had a mild disorder. Strikingly, activated (HLA-DR+) as well as senescent (CD57+CD28-CD27±) T4 cells and T8 cells were less prevalent in the peripheral blood of participants with NCI than in participants without the disorder. Accordingly, the percentage of HLA-DR+ T4 cells was lower in volunteers with periventricular and deep WMH. The double hierarchical clustering unveiled six different immune activation profiles. The neurocognitive performances of participants with two of these six profiles were poor. Here again, these two profiles were characterized by a low level of T4 and T8 cell activation and senescence. Our observation of low circulating levels of activated and senescent T cells in HIV-1 patients with NCI raises the interesting hypothesis that these lymphocytes may be recruited into the central nervous system.

Preliminary Study of sCD14 and sCD163 as Predictors of Disease Severity and ICU Admission in COVID-19: Relation to Hematological Parameters, Blood Morphological Changes and Inflammatory Biomarkers.

Research supports the role of monocyte/macrophage activation in COVID-19 immunopathology. This study aimed to evaluate sCD14 and sCD163 - the monocyte activation markers - and to investigate their relation to hematological parameters and blood morphology in COVID-19 infection. This is a case-control study that included 70 COVID-19 patients. Patients were subdivided into two groups: 23 severely diseased ICU-admitted patients and another group of 47 non-ICU-admitted patients. sCD163 and sCD14 levels were determined using ELISA. sCD163 and sCD14 showed significantly higher levels in sera of patients compared to the control group, with significantly higher levels of sCD163 in ICU-admitted patients than non-ICU admitted patients. Receiver operating characteristic curve analysis demonstrated the usefulness of sCD163 with a cut-off value of 734 ng/mL as a potential marker to discriminate between ICU and non-ICU admitted COVID-19 patients (sensitivity of 81.16%; specificity of 96.67% and positive predictive value of 98% with area under the curve of 0.930). sCD163 levels showed a positive correlation with total white blood cells, absolute neutrophilic count, Neutrophil/Lymphocyte ratio, and a negative correlation with platelet count. sCD14 levels positively correlated with D-dimer values associated with a shift to the left and neutrophilic toxic granulations in blood morphology. High sCD163 and sCD14 levels, hematological parameters, and blood morphology reflect monocyte activation in COVID-19 infection. sCD163 is a potential marker of disease severity. These findings support further study of therapeutics targeting macrophage activity in COVID-19 patients with high sCD163 levels.

Fungal plasma biomarkers in patients admitted for inpatient treatment of alcohol use disorder.

Fungal plasma biomarkers have not been studied in patients with unhealthy alcohol use and no apparent end-stage liver disease. We examined the prevalence of fungal plasma biomarkers, assessed by the presence of anti-Saccharomyces cerevisiae antibodies (ASCA; IgA and IgM), and its disease correlates in patients with alcohol use disorder (AUD). We performed logistic regression analyses to detect the association between clinical and laboratory characteristics and the presence of fungal plasma biomarkers. We included 395 patients (75.9% male, median age of 49 years, and median body mass index of 25.6) who drank a median of 150 g of alcohol daily and had a median duration of AUD of 20 years. ASCA IgA and IgG were present in 34.4% and 14.9%, respectively, and 9.9% had both ASCA IgA and ASCA IgG. The presence of ASCA IgA was associated with male sex (p < 0.01); values of serum aspartate transferase (AST) (p = 0.02), gamma-glutamyl transferase (GGT) (p < 0.01), alkaline phosphatase (ALP) (p < 0.01), and bilirubin in the highest quartile (p < 0.01); Fibrosis-4 Index (FIB-4) values suggestive of advanced liver fibrosis (p < 0.01); and values of the macrophage activation factors sCD163 (p < 0.01) and sCD14 (p < 0.01), the cytokine IL-6 (p = 0.01), and lipopolysaccharide-binding protein in the highest quartile (p < 0.01). The presence of ASCA IgG was associated with omeprazole use (p = 0.04); values of AST (p = 0.04) and GGT (p = 0.04) in the highest quartile; FIB-4 values suggestive of advanced liver fibrosis (p < 0.01); and values of sCD163 (p < 0.01) in the highest quartile. The variables associated with the presence of both ASCA IgA and IgG were male sex (p = 0.04) and values of GGT (p = 0.04) and sCD163 in the highest quartile (p < 0.01). In AUD patients, the presence of fungal biomarkers in plasma was common and associated with FIB-4 values suggestive of advanced liver fibrosis and with markers of liver damage, monocyte activation, and microbial translocation, male gender, and omeprazole use. These findings suggest that the presence of plasma anti-Saccharomyces cerevisiae antibodies could be used as a biomarker for an elevated risk of progressive liver disease in patients with AUD.

Plasma Derived Extracellular Vesicles Modulate Monocyte IL-18, IFN-α and IL-10 responses in Adults with HIV-related Cognitive Impairment

Abstract Background: HIV-associated neurocognitive dysfunction persists despite suppressive antiretroviral therapy (ART). Extracellular vesicles (EVs) are emerging modulators of immunological responses. We have previously shown that EVs expressing monocyte activation and neuronal markers associated with HIV associated cognitive impairment (CI). Whether these EV changes observed in people with HIV (PWH) influence innate cellular function among those with CI remains unclear. Method: Purified EV samples from 58 HIV-infected individuals on ART with either cognitive impairment (CI, n=48) or normal cognition (NC, n=10) and 8 uninfected controls were isolated using differential centrifugation and co-cultured with PBMCs from a single uninfected donor for 18 hrs. Eight intracellular cytokines and 13 surface chemokines and myeloid differentiation markers were assessed by spectral flow cytometry. Non-parametric statistical T tests were used. Result: Monocytes (mono) showed differential effects on multiple cytokine responses and cell surface receptors after exposure to EVs from HIV-infected individuals with or without CI. Levels of mono IL-18 were significantly lower after incubation with EVs derived from HIV-infected individuals compared to uninfected controls. Based on cognitive status, EVs from HIV-CI group significantly lower % of IL-18 mono responses and lower IFN-α and higher IL-10 responses on a per cell basis when compared to the NC group. Conclusion: These results suggest EVs can modulate mono function irrespective of HIV status. PWH with CI exhibited altered EV driven mono cytokine responses. Our data support interventions that target EVs to reverse or restore mono perturbations and limit neuropathology in PWH on ART. Supported by grants from NIH (R21NS106970 and R01NS117458)

TIMP-1 is a novel ligand of Amyloid Precursor Protein and triggers a proinflammatory phenotype in human monocytes.

The emerging cytokine tissue inhibitor of metalloproteinases-1 (TIMP-1) correlates with the progression of inflammatory diseases, including cancer. However, the effects of TIMP-1 on immune cell activation and underlying molecular mechanisms are largely unknown. Unbiased ligand-receptor-capture-screening revealed TIMP-1-interaction with Amyloid Precursor Protein (APP) family members, namely APP and Amyloid Precursor-like Protein-2 (APLP2), which was confirmed by pull-down assays and confocal microscopy. We found that TIMP-1 triggered glucose uptake and proinflammatory cytokine expression in human monocytes. In cancer patients, TIMP-1 expression positively correlated with proinflammatory cytokine expression and processes associated with monocyte activation. In pancreatic cancer, TIMP-1 plasma levels correlated with the monocyte activation marker sCD163, and the combined use of both clinically accessible plasma proteins served as a powerful prognostic indicator. Mechanistically, TIMP-1 triggered monocyte activation by its C-terminal domain and via APP as demonstrated by in vitro interference, in silico docking, and the employment of recombinant TIMP-1 variants. Identification of TIMP-1 as a trigger of monocyte activation opens new therapeutic perspectives for inflammatory diseases.

Circulating brain-derived extracellular vesicles expressing neuroinflammatory markers are associated with HIV-related neurocognitive impairment.

Neurocognitive impairment remains prevalent in people with HIV (PWH) despite long term virological suppression by antiretroviral therapy (ART) regimens. Systemic and neuro-inflammatory processes are suggested to contribute to the complex pathology leading to cognitive impairment in this population, yet the underlying mechanisms remain unresolved. Extracellular vesicles (EVs) play a central role in intracellular communication and have emerged as key modulators of immunological and inflammatory responses. In this report, we examined the impact of EVs in PWH experiencing cognitive deficits to determine their relevance in HIV associated neuropathology. EV phenotypes were measured in plasma samples from 108 PWH with either cognitive impairment (CI, n=92) or normal cognition (NC, n=16) by flow cytometry. Matched cerebrospinal fluid (CSF)-derived EVs were similarly profiled from a subgroup of 84 individuals who underwent a lumbar puncture. Peripheral blood mononuclear cells were assayed by flow cytometry to measure monocyte frequencies in a subset of 32 individuals. Plasma-EVs expressing CD14, CD16, CD192, C195, and GFAP were significantly higher in HIV-infected individuals with cognitive impairment compared to individuals with normal cognition. Increased CSF-EVs expressing GFAP and CD200 were found in the cognitive impairment group compared to the normal cognition group. Frequencies of patrolling monocytes correlated with plasma-EVs expressing CD14, CD66b, MCSF, MAP2, and GFAP. Frequencies of CD195 expression on monocytes correlated positively with plasma-EVs expressing CD41a, CD62P, and CD63. Expression of CD163 on monocytes correlated positively with CSF-EVs expressing GFAP and CD200. Finally, the expression of CD192 on total monocytes correlated with CSF-EVs expressing CD200, CD62P, and CD63. EVs expressing monocyte activation and neuronal markers associated with HIV associated cognitive impairment, suggesting that distinct EV subsets may serve as novel biomarkers of neuronal injury in HIV infection. Further circulating platelet EV levels were linked to monocyte activation indicating a potential novel interaction in the pathogenesis of HIV-related cognitive impairment.

Monocyte distribution width as a pragmatic screen for SARS-CoV-2 or influenza infection

Monocyte distribution width (MDW) is a novel marker of monocyte activation, which is known to occur in the immune response to viral pathogens. Our objective was to determine the performance of MDW and other leukocyte parameters as screening tests for SARS-CoV-2 and influenza infection. This was a prospective cohort analysis of adult patients who underwent complete blood count (CBC) and SARS-CoV-2 or influenza testing in an Emergency Department (ED) between January 2020 and July 2021. The primary outcome was SARS-CoV-2 or influenza infection. Secondary outcomes were measures of severity of illness including inpatient hospitalization, critical care admission, hospital lengths of stay and mortality. Descriptive statistics and test performance measures were evaluated for monocyte percentage, MDW, white blood cell (WBC) count, and neutrophil to lymphocyte ratio (NLR). 3,425 ED patient visits were included. SARS-CoV-2 testing was performed during 1,922 visits with a positivity rate of 5.4%; influenza testing was performed during 2,090 with a positivity rate of 2.3%. MDW was elevated in patients with SARS-Cov-2 (median 23.0U; IQR 20.5–25.1) or influenza (median 24.1U; IQR 22.0–26.9) infection, as compared to those without (18.9U; IQR 17.4–20.7 and 19.1U; 17.4–21, respectively, P < 0.001). Monocyte percentage, WBC and NLR values were within normal range in patients testing positive for either virus. MDW identified SARS-CoV-2 and influenza positive patients with an area under the curve (AUC) of 0.83 (95% CI 0.79–0.86) and 0.83 (95% CI 0.77–0.88), respectively. At the accepted cut-off value of 20U for MDW, sensitivities were 83.7% (95% CI 76.5–90.8%) for SARS-CoV-2 and 89.6% (95% CI 80.9–98.2%) for influenza, compared to sensitivities below 45% for monocyte percentage, WBC and NLR. MDW negative predictive values were 98.6% (95% CI 98.0–99.3%) and 99.6% (95% CI 99.3–100.0%) respectively for SARS-CoV-2 and influenza. Monocyte Distribution Width (MDW), available as part of a routine complete blood count (CBC) with differential, may be a useful indicator of SARS-CoV-2 or influenza infection.

Monocyte Distribution Width as a predictor of community acquired sepsis in patients prospectively enrolled at the Emergency Department

BackgroundMonocyte Distribution Width (MDW), a simple cellular marker of innate monocyte activation, can be used for the early recognition of sepsis. We performed an observational prospective monocentric study to assess the predictive role of MDW in detecting sepsis in a sample of consecutive patients presenting at the Emergency Department.MethodsProspective observational study using demographic and clinical characteristics, past medical history and other laboratory measurements to predict confirmed sepsis using multivariate logistic regression.ResultsA total of 2724 patients were included in the study, of which 272 (10%) had sepsis or septic shock. After adjusting for known and potential risk factors, logistic regression found the following independent predictors of sepsis: SIRS equal to 1 (OR: 2.32, 1.16–4.89) and 2 or more (OR: 27.8, 14.8–56.4), MDW > 22 (OR: 3.73, 2.46–5.70), smoking (OR: 3.0, 1.22–7.31), end stage renal function (OR: 2.3, 1.25–4.22), neurodegenerative disease (OR: 2.2, 1.31–3.68), Neutrophils ≥ 8.9 × 103/µL (OR: 2.73, 1.82–4.11), Lymphocytes < 1.3 × 103/µL (OR: 1.72, 1.17–2.53) and CRP ≥ 19.1 mg/L (OR: 2.57, 1.63–4.08). A risk score derived from predictive models achieved high accuracy by using an optimal threshold (AUC: 95%; 93–97%).ConclusionsThe study suggests that incorporating MDW in the clinical decision process may improve the early identification of sepsis, with minimal additional effort on the standard procedures adopted during emergency care.

Inflammation mediates approximately one quarter of excess relative all-cause mortality in persons with rheumatoid arthritis: the Trøndelag Health Study

Inflammation may contribute to excess mortality in rheumatoid arthritis (RA) patients. We investigated associations to all-cause mortality of the inflammation markers high-sensitivity C-reactive protein (CRP), lactoferrin (neutrophil activation marker), and neopterin (monocyte activation marker). From the population-based Trøndelag Health Study (3rd wave 2006–2008), 316 RA patients and 43,579 controls were included. Lactoferrin and neopterin were quantified in a nested cohort (n = 283 RA patients, n = 3698 controls). Follow-up was until death found by linkage to the Norwegian Cause of Death Registry or 31.12.2018. All-cause mortality was analyzed using Cox regression and Cox regression-based mediation analysis. Having RA (hazard ratio (HR): 1.25, 95%CI: 1.00, 1.56, p = 0.048), and CRP ≥ 3 mg/L (HR: 1.50, 95%CI: 1.41, 1.60, p < 0.001) were associated with all-cause mortality. The overall excess relative mortality risk of having RA was 38%. CRP ≥ 3 mg/L mediated approximately 1/4 of this risk (p < 0.001). In the nested cohort, CRP ≥ 3 mg/L (HR: 1.51, 95%CI: 1.26, 1.80, p < 0.001) and neopterin (HR: 1.17, 95%CI: 1.01, 1.36, p = 0.031) were associated with all-cause mortality. In conclusion, CRP levels ≥ 3 mg/L mediated approximately a quarter of the 38% excess relative all-cause mortality risk associated with RA. Using definitions of RA remission with emphasis both on joint status and the level of general inflammation may help guide the most efficient treatment regimens.

Glycocalyx Disruption Triggers Human Monocyte Activation in Acute Heart Failure Syndromes.

Acute heart failure (AHF) syndromes manifest increased inflammation and vascular dysfunction; however, mechanisms that integrate the two in AHF remain largely unknown. The glycocalyx (GAC) is a sugar-based shell that envelops all mammalian cells. Much GAC research has focused on its role in vascular responses, with comparatively little known about how the GAC regulates immune cell function. In this study, we sought to determine if GAC degradation products are elevated in AHF patients, how these degradation products relate to circulating inflammatory mediators, and whether the monocyte GAC (mGAC) itself modulates monocyte activation. Inflammatory markers and GAC degradation products were profiled using ELISAs. Flow cytometry was used to assess the mGAC and RNA-seq was employed to understand the role of the mGAC in regulating inflammatory activation programs. In a cohort of hospitalized AHF patients (n = 17), we found that (1) the GAC degradation product heparan sulfate (HS) was elevated compared with age-matched controls (4396 and 2903ng/mL; p = 0.01) and that (2) HS and soluble CD14 (a marker of monocyte activation) levels were closely related (Pearson's r = 0.65; p = 0.002). Mechanistically, Toll-like receptor (TLR) activation of human monocytes results in GAC remodeling and a decrease in the mGAC (71% compared with no treatment; p = 0.0007). Additionally, we found that ex vivo enzymatic removal of HS and disruption of the mGAC triggers human monocyte activation and amplifies monocyte inflammatory responses. Specifically, using RNA-seq, we found that enzymatic degradation of the mGAC increases transcription of inflammatory (IL6, CCL3) and vascular (tissue factor/F3) mediators. These studies indicate that the mGAC is dynamically remodeled during monocyte activation and that mGAC remodeling itself may contribute to the heightened inflammation associated with AHF.

Vascular Calcification and the Gut and Blood Microbiome in Chronic Kidney Disease Patients on Peritoneal Dialysis: A Pilot Study.

Vascular calcification (VC) is a frequent condition in chronic kidney disease (CKD) and a well-established risk factor for the development of cardiovascular disease (CVD). Gut dysbiosis may contribute to CVD and inflammation in CKD patients. Nonetheless, the role of gut and blood microbiomes in CKD-associated VC remains unknown. Therefore, this pilot study aimed to explore the link between gut and blood microbiomes and VC in CKD patients on peritoneal dialysis (CKD-PD). Our results showed relative changes in specific taxa between CKD-PD patients with and without VC, namely Coprobacter, Coprococcus 3, Lactobacillus, and Eubacterium eligens group in the gut, and Cutibacterium, Pajaroellobacter, Devosia, Hyphomicrobium, and Pelomonas in the blood. An association between VC and all-cause mortality risk in CKD-PD patients was also observed, and patients with higher mortality risk corroborate the changes of Eubacterium eligens in the gut and Devosia genus in the blood. Although we did not find differences in uremic toxins, intestinal translocation markers, and inflammatory parameters among CKD-PD patients with and without VC, soluble CD14 (sCD14), a nonspecific marker of monocyte activation, positively correlated with VC severity. Therefore, gut Eubacterium eligens group, blood Devosia, and circulating sCD14 should be further explored as biomarkers for VC, CVD, and mortality risk in CKD.

Estrogen May Enhance Toll-Like Receptor 4-Induced Inflammatory Pathways in People With HIV: Implications for Transgender Women on Hormone Therapy.

BackgroundTransgender women (TW) are at increased risk for both human immunodeficiency virus (HIV) and cardiovascular disease (CVD). Antiretroviral therapy-treated HIV has been associated with a two-fold increased risk of CVD, potentially due to dysregulated Toll-like receptor (TLR)-induced immune activation. Use of estrogens in feminizing hormone therapy (FHT) may enhance inflammatory responses and the risk of cardiovascular mortality in TW. Despite this, the immunomodulatory effects of estrogen use in TW with HIV have been inadequately explored.MethodsAs an in vitro model for FHT, cryopreserved PBMCs (cryoPBMCs) from HIV negative (HIV-), HIV+ ART-suppressed (HIV+SP), and HIV+ ART-unsuppressed (HIV+USP) cisgender men were cultured overnight in the presence of 17-β estradiol or 17-α ethinylestradiol with and without the TLR4 agonist LPS or the TLR8 agonist ssPolyU. Monocyte activation (CD69, HLA-DR, CD38) was assessed by flow cytometry. Cytokine levels (IL-6, TNF-α, IL-1β, and IL-10) were measured in cell culture supernatants by Legendplex. Levels of phosphorylated TLR signaling molecules (JNK, MAPK p38) were assessed by Phosflow. Plasma levels of immune activation biomarkers (LPS-binding protein, monocyte activation markers sCD14 and sCD163, and inflammatory molecules IL-6 and TNF-α receptor I) were measured by ELISA.ResultsPBMCs from people with HIV (PWH) produced greater levels of inflammatory cytokines following exposure to LPS or ssPolyU compared to levels from cells of HIV- individuals. While estrogen exposure alone induced mild changes in immune activation, LPS-induced TLR4 activation was elevated with estrogen in cisgender men (CM) with HIV, increasing monocyte activation and inflammatory cytokine production (IL-6, TNF-α). Interestingly, testosterone inhibited LPS-induced cytokine production in CM regardless of HIV status. Plasma markers of immune activation and microbial translocation (e.g., sCD14, sCD163, LPS-binding protein) were generally higher in PWH compared to HIV- CM, and these markers were positively associated with in vitro responsiveness to estrogen and LPS in CM with HIV.ConclusionsOur in vitro data suggest that estrogen exposure may enhance innate immune activation in PWH. Further examination is needed to fully understand the complex interactions of FHT, HIV, and CVD in TW, and determine optimal FHT regimens or supplementary treatments aimed at reducing excess immune activation.

Monocyte count and soluble markers of monocyte activation in people living with HIV and uninfected controls

BackgroundMonocytes play an important role in inflammation, and monocytosis and monocyte activation are features of chronic inflammation. We aimed to investigate if HIV status was associated with monocyte count and monocyte activation and to assess the relationship between monocyte count and monocyte activation markers and HIV-related factors.MethodsPersons living with HIV (PLWH) with measured monocyte count and sCD14 and sCD163 were included from the Copenhagen Comorbidity in HIV infection (COCOMO) study and matched 1:5 on sex and age with uninfected controls. In addition, 74 uninfected individuals from COCOMO with measured sCD14 and sCD163 were included. Identical protocols and equipment were used to determine monocyte counts and monocyte activation in PLWH and uninfected controls. Linear regression adjusted for age, sex, smoking and waist-to-hip-ratio was used to analyze the association between possible risk factors and monocyte outcomes.ResultsWe included 871 PLWH and 4355 uninfected controls. PLWH had − 0.021 [− 0.031 − 0.011] × 109/L) lower monocyte count than uninfected controls, and in adjusted analyses HIV status was independently associated with − 0.035 [− 0.045, − 0.025] × 109/L lower monocyte count. In contrast, PLWH had higher sCD163 and sCD14 concentrations than uninfected controls. After adjustment, HIV-status was associated with higher sCD14 and sCD163 concentrations (588 [325, 851] ng/ml, and 194 [57, 330] ng/ml, respectively).ConclusionPLWH had lower monocyte counts than controls, but the absolute difference was small, and any clinical impact is likely limited. In contrast, concentrations of monocyte activation markers, previously implicated as drivers of non-AIDS comorbidity, were higher in PLWH than in controls.

Impact of illicit opioid use on markers of monocyte activation and systemic inflammation in people living with HIV.

IntroductionWe hypothesize that illicit opioid use increases bacterial translocation from the gut, which intensifies systemic inflammation.ObjectiveTo investigate the association between opioid use and plasma soluble CD14 [sCD14], interleukin-6 [IL-6] and D-dimer in people living with HIV (PLWH).MethodsWe analyzed data from the Russia ARCH study–an observational cohort of 351 ART-naive PLWH in St. Petersburg, Russia. Plasma levels of sCD14 (primary outcome), IL-6 and D-dimer (secondary outcomes) were evaluated at baseline, 12, and 24 months. Participants were categorized into three groups based on illicit opioid use: current, prior, and never opioid use. Linear mixed effects models were used to evaluate associations.ResultsCompared to never opioid use, sCD14 levels were significantly higher for participants with current opioid use (AMD = 197.8 ng/ml [11.4, 384.2], p = 0.04). IL-6 levels were also higher for participants with current vs. never opioid use (ARM = 2.10 [1.56, 2.83], p <0.001). D-dimer levels were higher for current (ARM = 1.95 [1.43, 2.64], p <0.001) and prior (ARM = 1.57 [1.17, 2.09], p = 0.004) compared to never opioid use.ConclusionsAmong PLWH, current opioid use compared to never use is associated with increased monocyte activation and systemic inflammation.

Soluble CD14 is subtype-dependent in serum but not in cerebrospinal fluid in people with HIV

Monocytes and macrophages activation are crucial in human immunodeficiency virus (HIV) central nervous system (CNS) infection and HIV associated neurocognitive disorders (HAND) pathogenesis. The soluble form of CD14 (sCD14) is a marker of monocyte activation. We hypothesized that sCD14 levels would be lower in people with HIV-1 subtype C (HIV-1C) than in HIV-1B owing to a variant Tat cysteine dimotif (C30S31) with reduced chemotactic activity. A total of 68 paired cerebrospinal fluid (CSF) and blood samples from people with HIV (PWH); 27 samples of the HIV-1B subtype and 40 of the non-B HIV-1 subtypes (including 26,HIV-1C), and 18 HIV-negative controls were included. sCD14 levels were quantified using a high-sensitivity enzyme-linked immunosorbent assay. sCD14 increase in serum, but not in CSF, was higher in samples from HIV-1B than HIV-1C (p = 0.002; Cohen's d, 0.7). CSF or serum sCD14 values were not correlated with global deficit score or specific cognitive domains. The impact of HIV-1 on monocyte stimulation biomarkers evaluated by sCD14 in serum was subtype-dependent, higher in HIV-1B than HIV-1C, consistent with reduced chemotactic activity as hypothesized.

Ambient air pollution is associated with vascular disease in Ugandan HIV-positive adolescents.

In this study, we aim to investigate the relationship between particulate matter, a common proxy indicator for air pollution, and markers of inflammation, monocyte activation, and subclinical vascular disease. A cross-sectional study. Adolescents with perinatally acquired HIV (PHIV) and HIV-uninfected adolescents between 10 and 18years living near Kampala, Uganda were included. Daily ambient concentrations of particulate matter (PM2.5) were measured from the Eastern Arica GEOHealth Hub. Outcome variables measured were carotid intima-media thickness (IMT), as well as plasma markers of systemic inflammation, oxidized lipids, and gut integrity. Multivariable quantile regression models were used to explore the relationship between PM2.5 and IMT. One hundred and nineteen participants (69 PHIV, 50 HIV-uninfected) were included. The median (Q1, Q3) age was 12.7 (11.4,14.2) years, 55% were girls. Median daily PM2.5 exposure was 29.08 μg/m3 (23.40, 41.70). There was no significant difference in exposure of PM2.5 between groups (P = 0.073). PM2.5 significantly correlated with intestinal permeability (zonulin; r = 0.43, P < 0.001), monocyte activation (soluble CD163: r = 0.25, P = 0.053), and IMT (r = 0.35, P = 0.004) in PHIV but not in HIV-uninfected (P ≥ 0.05). In multivariable quantile regression, after adjusting for age, sex, poverty level, soluble CD163, and zonulin, daily PM2.5 concentrations remained associated with IMT [β = 0.005, 95% CI (0.0003-0.010), P = 0.037] in adolescents with PHIV. Adolescents in urban Uganda are exposed to high levels of air pollution. Both PM2.5 and HIV have independently been observed to contribute to atherosclerotic disease, and our findings suggest the combined effects of HIV and air pollution may amplify the development of cardiovascular disease.