CXCR3-binding Chemokines: Novel Multifunctional Therapeutic Targets

Immune urinary biomarkers predict infant cardiac surgery-associated acute kidney injury

BACKGROUND

Acute kidney injury (AKI) occurs frequently after infant cardiac surgery and is associated with poor outcomes, including mortality and prolonged length of stay. AKI mechanisms are poorly understood, limiting therapeutic targets. Emerging data implicates dysregulated immune activation in post-cardiac surgery AKI development. We sought to identify immune-mediated AKI biomarkers after infant cardiopulmonary bypass (CPB)-assisted cardiac surgery.

METHODS

A single-center prospective study of 126 infants less than 1 year old undergoing CPB-assisted surgery enrolled between 10/2017 and 6/2019. Urine samples were collected before CPB and at 6, 24, 48, and 72 h after surgery. Immune-mediated biomarkers were measured using commercial ELISA and Luminex™ multiplex kits. Based on subject age, neonatal KDIGO (< 1 month) or KDIGO criteria defined AKI. The Kruskal-Wallis rank test determined the relationship between urinary biomarker measurements and AKI.

RESULTS

A total of 35 infants (27%) developed AKI. AKI subjects were younger, underwent more complex surgery, and had longer CPB time. Subjects with AKI vs. those without AKI had higher median urinary chemokine 10 (C-X-C motif) ligand levels at 24, 48, and 72 h, respectively: 14.3 pg/ml vs. 5.3 pg/ml, 3.4 pg/ml vs. 0.8 pg/ml, and 1.15 pg/ml vs. 0.22 pg/ml (p < 0.05) post-CPB. At 6 h post-CPB, median vascular cell adhesion protein 1 (VCAM) levels (pg/mL) were higher among AKI subjects (491 pg/ml vs. 0 pg/ml, p = 0.04).

CONCLUSIONS

Urinary CXCL10 and VCAM are promising pro-inflammatory biomarkers for early AKI detection and may indicate eventual AKI therapeutic targets. A higher resolution version of the Graphical abstract is available as Supplementary information.

Lipoxins A4 and B4 inhibit glial cell activation via CXCR3 signaling in acute retinal neuroinflammation

Lipoxins are small lipids that are potent endogenous mediators of systemic inflammation resolution in a variety of diseases. We previously reported that Lipoxins A4 and B4 (LXA4 and LXB4) have protective activities against neurodegenerative injury. Yet, lipoxin activities and downstream signaling in neuroinflammatory processes are not well understood. Here, we utilized a model of posterior uveitis induced by lipopolysaccharide endotoxin (LPS), which results in rapid retinal neuroinflammation primarily characterized by activation of resident macroglia (astrocytes and Müller glia), and microglia. Using this model, we observed that each lipoxin reduces acute inner retinal inflammation by affecting endogenous glial responses in a cascading sequence beginning with astrocytes and then microglia, depending on the timing of exposure; prophylactic or therapeutic. Subsequent analyses of retinal cytokines and chemokines revealed inhibition of both CXCL9 (MIG) and CXCL10 (IP10) by each lipoxin, compared to controls, following LPS injection. CXCL9 and CXCL10 are common ligands for the CXCR3 chemokine receptor, which is prominently expressed in inner retinal astrocytes and ganglion cells. We found that CXCR3 inhibition reduces LPS-induced neuroinflammation, while CXCR3 agonism alone induces astrocyte reactivity. Together, these data uncover a novel lipoxin-CXCR3 pathway to promote distinct anti-inflammatory and proresolution cascades in endogenous retinal glia.

Inflammatory and mental health sequelae of COVID-19

The COVID-19 pandemic has caused significant negative consequences to mental health. Increased inflammatory factors and neuropsychiatric symptoms, such as cognitive impairment ("brain fog"), depression, and anxiety are associated with long COVID [post-acute sequelae of SARS-CoV-2 infection (PASC), termed neuro-PASC]. The present study sought to examine the role of inflammatory factors as predictors of neuropsychiatric symptom severity in the context of COVID-19. Adults (n = 52) who tested negative or positive for COVID-19 were asked to complete self-report questionnaires and to provide blood samples for multiplex immunoassays. Participants who tested negative for COVID-19 were assessed at baseline and at a follow-up study visit (∼4 weeks later). Individuals without COVID-19 reported significantly lower PHQ-4 scores at the follow-up visit, as compared to baseline (p = 0.03; 95% CI-1.67 to -0.084). Individuals who tested positive for COVID-19 and experienced neuro-PASC had PHQ-4 scores in the moderate range. The majority of people with neuro-PASC reported experiencing brain fog (70% vs. 30%). Those with more severe COVID-19 had significantly higher PHQ-4 scores, as compared to those with mild disease (p = 0.008; 95% CI 1.32 to 7.97). Changes in neuropsychiatric symptom severity were accompanied by alterations in immune factors, particularly monokine induced by gamma interferon (IFN-γ) (MIG, a. k.a. CXCL9). These findings add to the growing evidence supporting the usefulness of circulating MIG levels as a biomarker reflecting IFN-γ production, which is important because individuals with neuro-PASC have elevated IFN-γ responses to internal SARS-CoV-2 proteins.

Microbiome Shapes the T Cell Receptor Repertoire among CD4+CD8+ Thymocytes

The microbiome shapes the mature T cell receptor (TCR) repertoire and thereby influences pathogen control. To investigate microbiome influences on T cells at an earlier, immature stage, we compared single-cell TCR transcript sequences between CD4+CD8+ (double-positive) thymocytes from gnotobiotic [E. coli mono-associated (Ec)] and germ-free (GF) mice. Identical TCRβ transcripts (termed repeat, REP) were more often shared between cells of individual Ec mice compared to GF mice (Fishers Exact test, p < 0.0001). Among Ec REPs, a cluster of Vβ genes (Vβ12-1, 12-2, 13-1, and 13-2, termed 12-13) was well represented, whereas 12-13 sequences were not detected among GF REPs (Fishers Exact test, p = 0.046). Vα genes located in the distal region of the TCRα locus were more frequently expressed in Ec mice compared to GF mice, both among REPs and total sequences (Fishers Exact test, p = 0.009). Results illustrate how gut bacteria shape the TCR repertoire, not simply among mature T cells, but among immature CD4+CD8+ thymocytes.

Changes of immune-related factors in the blood of schizophrenia and bipolar disorder patients receiving monotherapy

Schizophrenia (SCZ) and bipolar disorder (BPD) are associated with abnormal expression of immune-related factors (IRFs), which have been proposed as biomarkers of either disease diagnosis (trait markers) or treatment (state markers). However, the state markers have been found to be less reproducible than the trait markers in previous studies. In the current study, we focused on the changes of IRFs in blood of SCZ and BPD patients receiving monotherapy. SCZ (N = 49) and BPD (N = 49) Chinese patients were recruited at acute episode and followed for 9 to 51 days until remission. Blood samples were collected at two state-points, acute state before treatment and remission state after treatment. A total of 41 IRFs in plasma were quantified by the Luminex assay. After adjusting covariates, we found four cytokines or cytokine receptors were significantly increased at remission when compared to acute episode in all the patients, including CD30, BAFF, CCL20, and CXCL10 (Bonferroni corrected p < 0.05). CD30 and BAFF were consistently increased in both SCZ and BPD while the increase of CCL20 was only observed in BPD but not SCZ when analyzing the two disorders separately. CXCL10 change was not significant in either SCZ or BPD alone. The changes of these four factors were correlated with each other, but not with clinical features. CD30 concentration in the BPD acute state was correlated with sleep quality (Spearman's r_s = 0.365, Bonferroni corrected p < 0.05). Overall, we found that four factors (CD30, BAFF, CCL20, and CXCL10) might be associated with treatment of psychosis.

Biological Characteristics and Predictive Model of Biopsy-Proven Acute Rejection (BPAR) After Kidney Transplantation: Evidences of Multi-Omics Analysis

Objectives: Early diagnosis and detection of acute rejection following kidney transplantation are of great significance for guiding the treatment and improving the prognosis of renal transplant recipients. In this study, we are aimed to explore the biological characteristics of biopsy-proven acute rejection (BPAR) and establish a predictive model.

Methods: Gene expression matrix of the renal allograft samples in the GEO database were screened and included, using Limma R package to identify differentially expressed transcripts between BPAR and No-BPAR groups. Then a predictive model of BPAR was established based on logistic regression of which key transcripts involved in the predictive model were further explored using functional enrichment analyses including Gene Ontology analysis (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA).

Results: A total of four studies (GSE129166, GSE48581, GSE36059, and GSE98320) were included for extensive analysis of differential expression. 32 differential expressed transcripts were observed to be significant between two groups after the pooled analysis. Afterward, a predictive model containing the five most significant transcripts (IDO1, CXCL10, IFNG, GBP1, PMAIP1) showed good predictive efficacy for BPAR after kidney transplantation (AUC = 0.919, 95%CI = 0.902–0.939). Results of functional enrichment analysis showed that The functions of differential genes are mainly manifested in chemokine receptor binding, chemokine activity, G protein-coupled receptor binding, etc. while the immune infiltration analysis indicated that immune cells mainly related to acute rejection include Macrophages. M1, T cells gamma delta, T cells CD4 memory activated, eosinophils, etc.

Conclusion: We have identified a total of 32 differential expressed transcripts and based on that, a predictive model with five significant transcripts was established, which was suggested as a highly recommended tool for the prediction of BPAR after kidney transplantation. However, an extensive study should be performed for the evaluation of the predictive model and mechanism involved.

Increased serum CXCL10 levels are associated with clinical severity and radiographic progression in patients with lumbar disc degeneration

BACKGROUND

Lumbar intervertebral degenerative disc disease (IDD) is a multifaceted progressive condition that commonly occurs in conjunction with lumbar disc herniation (LDH). CXCL10 mRNA appears to be increased in both IDD and LHD.

OBJECTIVE

This study was performed to identify the relationship between serum CXCL10 levels and disease severity in patients with IDD.

METHODS

136 IDD patients with low back pain, 127 asymptomatic volunteers and 120 healthy controls were enrolled. Serum CXCL10 protein concentrations were detected using commercial human CXCL10 ELISA Kits. Serum CXCL10 mRNA were examined using qRT-PCR. Clinical severity was assessed using the visual analog scale (VAS) and Oswestry Disability Index(ODI) scores. Radiographic severity was defined using the MRI-based Pfirrmann classification of disc degeneration. Receiver operating characteristic (ROC) curve analysis was used in estimating the correlation between CXCL10 and Pfirrmann grade. The cross-sectional area (CSA) of the lumbar multifidus muscle (LMM) and psoas major (PM) were calculated, and fat infiltration was evaluated by Ropponen-Kjaer criteria.

RESULTS

Serum CXCL10 concentrations were markedly raised in IDD patients with low back pain in contrast to asymptomatic individuals and healthy controls. Serum CXCL10 levels were positively associated with Pfirrmann grade. ROC curve analysis indicated that serum CXCL10 correlated well with Pfirrmann grade. In addition, serum CXCL10 concentrations were significantly higher in IDD patients with LMM and PM degeneration compared with IDD patients without degeneration. Increased CXCL10 levels positively correlated with VAS and ODI scores, as well as decreased CSA and fat filtration of the LMM and PM.

CONCLUSION

Increased serum CXCL10 levels correspond to clinical severity and radiographic progression in IDD patients.

Expression level of long non-coding RNA colon adenocarcinoma hypermethylated serves as a novel prognostic biomarker in patients with thyroid carcinoma

The present study attempts to identify the prognostic value and potential mechanism of action of colorectal adenocarcinoma hypermethylated (CAHM) in thyroid carcinoma (THCA) by using the RNA sequencing (RNA-seq) dataset from The Cancer Genome Atlas (TCGA). The functional mechanism of CAHM was explored by using RNA-seq dataset and multiple functional enrichment analysis approaches. Connectivity map (CMap) online analysis tool was also used to predict CAHM targeted drugs. Survival analysis suggests that THCA patients with high CAHM expression have lower risk of death than the low CAHM expression (log-rank P=0.022, adjusted P=0.011, HR = 0.187, 95% confidence interval (CI) = 0.051–0.685). Functional enrichment of CAHM co-expression genes suggests that CAHM may play a role in the following biological processes: DNA repair, cell adhesion, DNA replication, vascular endothelial growth factor receptor, Erb-B2 receptor tyrosine kinase 2, ErbB and thyroid hormone signaling pathways. Functional enrichment of differentially expressed genes (DEGs) between low- and high-CAHM phenotype suggests that different CAHM expression levels may have the following differences in biological processes in THCA: cell adhesion, cell proliferation, extracellular signal-regulated kinase (ERK) 1 (ERK1) and ERK2 cascade, G-protein coupled receptor, chemokine and phosphatidylinositol-3-kinase-Akt signaling pathways. Connectivity map have identified five drugs (levobunolol, NU-1025, quipazine, anisomycin and sulfathiazole) for CAHM targeted therapy in THCA. Gene set enrichment analysis (GSEA) suggest that low CAHM phenotype were notably enriched in p53, nuclear factor κB, Janus kinase-signal transducer and activators of transcription, tumor necrosis factor, epidermal growth factor receptor and other signaling pathways. In the present study, we have identified that CAHM may serve as novel prognostic biomarkers for predicting overall survival (OS) in patients with THCA.

Neurological and Neuropsychological Changes Associated with SARS-CoV-2 Infection: New Observations, New Mechanisms

SARS-CoV-2 infects cells through angiotensin-converting enzyme 2 (ACE2), a ubiquitous receptor that interacts with the virus' surface S glycoprotein. Recent reports show that the virus affects the central nervous system (CNS) with symptoms and complications that include dizziness, altered consciousness, encephalitis, and even stroke. These can immerge as indirect immune effects due to increased cytokine production or via direct viral entry into brain tissue. The latter is possible through neuronal access via the olfactory bulb, hematogenous access through immune cells or directly across the blood-brain barrier (BBB), and through the brain's circumventricular organs characterized by their extensive and highly permeable capillaries. Last, the COVID-19 pandemic increases stress, depression, and anxiety within infected individuals, those in isolation, and high-risk populations like children, the elderly, and health workers. This review surveys the recent updates of CNS manifestations post SARS-CoV-2 infection along with possible mechanisms that lead to them.

Acute Kidney Injury in Children after Hematopoietic Cell Transplantation Is Associated with Elevated Urine CXCL10 and CXCL9

Acute kidney injury (AKI) is nearly universally associated with worse outcomes, especially among children after hematopoietic stem cell transplant (HCT). Our objective was to examine urinary immune biomarkers of AKI after HCT to provide insights into novel mechanisms of kidney injury in this population. Studying patients undergoing allogeneic HCT provides a unique opportunity to examine immune markers of AKI because the risk of AKI is high and the immune system newly develops after transplant. Children (>2 years old) and young adults undergoing their first allogeneic HCT and enrolled in a prospective, observational cohort study at 2 large children's hospitals had urine collected pre-HCT and monthly for the first 4 months after HCT. Urine samples at each monthly time point were assayed for 8 immune-related biomarkers. AKI was defined as a 1.5-fold increase in the monthly serum creatinine value, which was recorded ±1 day from when the research urine sample was obtained, as compared with the pre-HCT baseline. Generalized estimating equation regression analysis evaluated the association between the monthly repeated measures (urinary biomarkers and AKI). A total of 176 patients were included from 2 pediatric centers. Thirty-six patients from 1 center were analyzed as a discovery cohort and the remaining 140 patients from the second center were analyzed as a validation cohort. AKI rates were 18% to 35% depending on the monthly time point after HCT. Urine CXCL10 and CXCL9 concentrations were significantly higher among children who developed AKI compared with children who did not (P < .01) in both cohorts. In order to gain a better understanding of the cellular source for these biomarkers in the urine, we also analyzed in vitro expression of CXCL10 and CXCL9 in kidney cell lines after stimulation with interferon-γ and interferon-α. HEK293-epithelial kidney cells demonstrated interferon-induced expression of CXCL10 and CXCL9, suggesting a potential mechanism driving the key finding. CXCL10 and CXCL9 are associated with AKI after HCT and are therefore promising biomarkers to guide improved diagnostic and treatment strategies for AKI in this high-risk population.

Switching renal transplant recipients to belatacept therapy: results of a real-life gradual conversion protocol

Conversion to belatacept immunosuppression is a therapeutic option for renal-transplant recipients with calcineurin inhibitors (CNI) toxicity, but it associates with high risk of acute rejection. Gradual conversion and serial immune monitoring with urinary chemokine CXCL9 may allow increasing safety of this maneuver. We converted kidney transplant recipients with signs of toxicity to CNI or other immunosuppressive drugs to belatacept over a 2-month period. We monitored renal function, metabolic profile, and circulating lymphocyte subsets. We also quantified urinary CXCL9 over a 12-month follow-up period. Between September 2016 and March 2017, 35 patients were successfully switched to belatacept immunosuppression at 3.3 (1.3-7.2) years after transplant. Two patients had a reversible rise in serum creatinine, associated with acute rejection in one case. Urinary CXCL9 increased before serum creatinine. After conversion, blood pressure and HbA1c significantly declined while eGFR and proteinuria remained stable. The percentage of circulating effector T cells and memory B cells significantly declined. Conversion from CNI to belatacept, in this setting, was feasible and safe, provided it was performed over a 2-month time-period. Monitoring urinary CXCL9 may further increase safety through earlier identification of patients at risk for acute rejection. The procedure associates with improved blood pressure, metabolic profile, and reduced circulating effector T and B cells.

Analysis of Biomarkers Within the Initial 2 Years Posttransplant and 5-Year Kidney Transplant Outcomes: Results From Clinical Trials in Organ Transplantation-17

BACKGROUND

An early posttransplant biomarker/surrogate marker for kidney allograft loss has the potential to guide targeted interventions. Previously published findings, including results from the Clinical Trials in Organ Transplantation (CTOT)-01 study, showed that elevated urinary chemokine CXCL9 levels and elevated frequencies of donor-reactive interferon gamma (IFNγ)-producing T cells by enzyme-linked immunosorbent spot (ELISPOT) assay associated with acute cellular rejection within the first year and with lower 1-year posttransplant estimated glomerular filtration rate (eGFR). How well these biomarkers correlate with late outcomes, including graft loss, is unclear.

METHODS

In CTOT-17, we obtained 5-year outcomes in the CTOT-01 cohort and correlated them with (a) biomarker results and (b) changes in eGFR (Chronic Kidney Disease Epidemiology Collaboration formula) over the initial 2 years posttransplant using univariable analysis and multivariable logistic regression.

RESULTS

Graft loss occurred in 14 (7.6%) of 184 subjects 2 to 5 years posttransplant. Neither IFNγ ELISPOTs nor urinary CXCL9 were informative. In contrast, a 40% or greater decline in eGFR from 6 months to 2 years posttransplant independently correlated with 13-fold odds of 5-year graft loss (adjusted odds ratio, 13.1; 95% confidence interval, 3.0-56.6), a result that was validated in the independent Genomics of Chronic Allograft Rejection cohort (n = 165; adjusted odds ratio, 11.2).

CONCLUSIONS

We conclude that although pretransplant and early posttransplant ELISPOT and chemokine measurements associate with outcomes within 2 years posttransplant, changes in eGFR between 3 or 6 months and 24 months are better surrogates for 5-year outcomes, including graft loss.

Certainties and uncertainties concerning the contribution of pericytes to the pathogenesis of systemic sclerosis

The role of pericytes in systemic sclerosis (SSc) is unclear because of the difficulty in phenotyping them. They are mainly distributed in the pre-capillary, capillary and post-capillary abluminal side of non-muscular micro-vessels, express platelet-derived growth factor receptors (PDGFRs), and preside over vascular integrity and regeneration. By establishing close contact with many endothelial cells, a single pericyte can regulate ion influx, mechanical stress, leukocyte diapedesis, and platelet activation. Moreover, under pathological conditions such as SSc, pericytes may acquire a contractile phenotype and respond to various stimuli, including endothelin, angiotensin II and reactive oxygen species. The pericytes of SSc patients share some molecular patterns with myofibroblasts or fibroblasts, including A disintegrin and metalloproteinase domain 12 (ADAM-12), α-smooth muscle actin (α-SMA), the extra domain A (ED-A) variant of fibronectin, and Thy-1. Following stimulation with PDGF-β or transforming growth factor-β (TGF-β), pericytes may acquire a myofibroblast phenotype, and produce extracellular matrix or indirectly promote fibroblast activation. They may also contribute to fibrosis by means of epigenetic regulation. The pericyte plasmalemma is particularly rich in caveolae containing caveolin-1, a deficit of which has been associated with defective vessel tone control and lung fibrosis in mice. Consequently, dysfunctional pericytes may underlie the microangiopathy and fibrosis observed in SSc patients. However, given its variability in biological behaviour and the lack of a pan-pericyte marker, the exact role of these cells in SSc warrants further investigation.

Rapid Biolayer Interferometry Measurements of Urinary CXCL9 to Detect Cellular Infiltrates Noninvasively After Kidney Transplantation

Introduction

Measuring the chemokine CXCL9 in urine by enzyme-linked immunosorbent assay (ELISA) can diagnose acute cellular rejection (ACR) noninvasively after kidney transplantation, but the required 12- to 24-hour turnaround time is not ideal for rapid, clinical decision-making.

Methods

We developed a biolayer interferometry (BLI)-based assay to rapidly measure urinary CXCL9 in <1 hour. We validated this new assay versus standard ELISA in 86 urine samples from kidney transplantation recipients with various diagnoses. We then used BLI to analyze samples from 56 kidney transplantation recipients, including 46 subjects who experienced an acute rise in serum creatinine associated with biopsy-proven ACR (n = 22), subclinical rejection (n = 15), or no infiltrates (n = 9), and 10 stable kidney transplantation recipients with surveillance biopsies. To assess its usefulness in detecting adequacy of therapy we serially measured serum creatinine and urinary CXCL9 in 6 subjects after treatment for ACR, and correlated the results with histological diagnoses on follow-up biopsies.

Results

BLI accurately and reproducibly detected urinary CXCL9 in <1 hour. BLI-based results showed that urinary CXCL9 was >200 pg/ml in subjects with ACR and ≤100 pg/ml in subjects with stable kidney function without cellular infiltrates. In samples obtained after treatment for ACR, BLI CXCL9 measurements detected biopsy-proven intragraft infiltrates despite treatment-induced reduction in serum creatinine.

Discussion

Together, our proof-of-principle results demonstrate that BLI-based urinary CXCL9 detection has potential as a point-of-care noninvasive biomarker to diagnose and guide therapy for ACR in kidney transplantation recipients.

CXCL10 and IL-6: Markers of two different forms of intra-amniotic inflammation in preterm labor

Problem

To determine whether amniotic fluid (AF) CXCL10 concentration is associated with histologic chronic chorioamnionitis in patients with preterm labor (PTL) and preterm prelabor rupture of the membranes (PROM).

Method of Study

This study included 168 women who had an episode of PTL or preterm PROM. AF interleukin (IL)‐6 and CXCL10 concentrations were determined by immunoassay.

Results

(i) Increased AF CXCL10 concentration was associated with chronic (OR: 4.8; 95% CI: 1.7‐14), but not acute chorioamnionitis; (ii) increased AF IL‐6 concentration was associated with acute (OR: 4.2; 95% CI: 1.3‐13.7) but not chronic chorioamnionitis; and (iii) an increase in AF CXCL10 concentration was associated with placental lesions consistent with maternal anti‐fetal rejection (OR: 3.7; 95% CI: 1.3‐10.4). (iv) All patients with elevated AF CXCL10 and IL‐6 delivered preterm.

Conclusion

Increased AF CXCL10 concentration is associated with chronic chorioamnionitis or maternal anti‐fetal rejection, whereas increased AF IL‐6 concentration is associated with acute histologic chorioamnionitis.

Immune Responses in the Central Nervous System Are Anatomically Segregated in a Non-Human Primate Model of Human Immunodeficiency Virus Infection

The human immunodeficiency virus (HIV) accesses the central nervous system (CNS) early during infection, leading to HIV-associated cognitive impairment and establishment of a viral reservoir. Here, we describe a dichotomy in inflammatory responses in different CNS regions in simian immunodeficiency virus (SIV)-infected macaques, a model for HIV infection. We found increased expression of inflammatory genes and perivascular leukocyte infiltration in the midbrain of SIV-infected macaques. Conversely, the frontal lobe showed downregulation of inflammatory genes associated with interferon-γ and interleukin-6 pathways, and absence of perivascular cuffing. These immunologic alterations were not accompanied by differences in SIV transcriptional activity within the tissue. Altered expression of genes associated with neurotoxicity was observed in both midbrain and frontal lobe. The segregation of inflammatory responses to specific regions of the CNS may both account for HIV-associated neurological symptoms and constitute a critical hurdle for HIV eradication by shielding the CNS viral reservoir from antiviral immunity.

Pro-tumoural CXCL10/CXCR3-A autocrine loop in invasive mucinous lung adenocarcinoma

Invasive mucinous adenocarcinoma (IMA) is a mucinous variant of lepidic predominant lung adenocarcinoma (LPA) and associated with a worse prognosis. We postulated that cytokine expression would enable us to differentiate IMA from LPA in terms of prognosis and acquisition of pro-tumoural capacities.

A 30-cytokine panel was assessed in bronchoalveolar lavage fluids (BALF) from IMA (n=38), LPA (n=25) and control samples (n=7). We investigated the expression of differentially expressed cytokines and splice variants of their receptors in surgical samples. The presence of EGFR and KRAS mutations were determined. We also examined the expression of cytokines and splice variants of their receptors in different cell lines, exploring their functional impact on signalling pathways, proliferation and migration.

Only C-X-C motif chemokine 10 (CXCL10) was differentially expressed, namely overexpressed in IMA BALF compared with LPA. CXCL10 overexpression in BALF was linked to a worse prognosis. In surgical samples, CXCL10 and its receptor C-X-C motif chemokine receptor 3 (CXCR3) were overexpressed in IMA compared to LPA. A pro-tumoural CXCR3-A splice variant was overexpressed in IMA, suggesting a CXCL10/CXCR3-A autocrine loop in IMA. CXCL10 and CXCR3 expression were not correlated with EGFR or KRAS status. CXCL10 up-regulated CXCR3-A expression, Erk1/2 phosphorylation and enhanced migration in the mucinous H2228 cell line.

CXCL10/CXCR3-A may play a pro-tumoural role in IMA via an autocrine mechanism.

Invasive mucinous lung adenocarcinoma derived pro-tumoural advantages by means of a CXCL10/CXCR3-A autocrine loophttp://ow.ly/2Gjj308QxwK

VEGF Neutralization Plus CTLA-4 Blockade Alters Soluble and Cellular Factors Associated with Enhancing Lymphocyte Infiltration and Humoral Recognition in Melanoma

Immune recognition of tumor targets by specific cytotoxic lymphocytes is essential for the effective rejection of tumors. A phase I clinical trial of ipilimumab (an antibody that blocks CTLA-4 function) in combination with bevacizumab (an antibody that inhibits angiogenesis) in patients with metastatic melanoma found favorable clinical outcomes were associated with increased tumor endothelial activation and lymphocyte infiltration. To better understand the underlying mechanisms, we sought features and factors that changed as a function of treatment in patients. Ipilimumab plus bevacizumab (Ipi-Bev) increased tumor vascular expression of ICAM1 and VCAM1. Treatment also altered concentrations of many circulating cytokines and chemokines, including increases of CXCL10, IL1α, TNFα, CXCL1, IFNα2, and IL8, with decreases in VEGF-A in most patients. IL1α and TNFα induced expression of E-selectin, CXCL1, and VCAM1 on melanoma tumor-associated endothelial cells (TEC) in vitro and promoted adhesion of activated T cells onto TEC. VEGFA inhibited TNFα-induced expression of ICAM1 and VCAM1 and T-cell adhesion, which was blocked by bevacizumab. CXCL10 promoted T-cell migration across TEC in vitro, was frequently expressed by melanoma cells, and was upregulated in a subset of tumors in treated patients. Robust upregulation of CXCL10 in tumors was accompanied by increased T-cell infiltration. Ipi-Bev also augmented humoral immune responses recognizing targets in melanoma, tumor endothelial, and tumor mesenchymal stem cells. Our findings suggest that Ipi-Bev therapy augments immune recognition in the tumor microenvironment through enhancing lymphocyte infiltration and antibody responses. IL1α, TNFα, and CXCL10, together with VEGF neutralization, contribute to Ipi-Bev-induced melanoma immune recognition. Cancer Immunol Res; 4(10); 858-68. ©2016 AACR.

PRMT5-Mediated Methylation of NF-κB p65 at Arg174 Is Required for Endothelial CXCL11 Gene Induction in Response to TNF-α and IFN-γ Costimulation

Inflammatory agonists differentially activate gene expression of the chemokine family of proteins in endothelial cells (EC). TNF is a weak inducer of the chemokine CXCL11, while TNF and IFN-γ costimulation results in potent CXCL11 induction. The molecular mechanisms underlying TNF plus IFN-γ-mediated CXCL11 induction are not fully understood. We have previously reported that the protein arginine methyltransferase PRMT5 catalyzes symmetrical dimethylation of the NF-κB subunit p65 in EC at multiple arginine residues. Methylation of Arg30 and Arg35 on p65 is critical for TNF induction of CXCL10 in EC. Here we show that PRMT5-mediated methylation of p65 at Arg174 is required for induction of CXCL11 when EC are costimulated with TNF and IFN-γ. Knockdown of PRMT5 by RNAi reduced CXCL11 mRNA and protein levels in costimulated cells. Reconstitution of p65 Arg174Ala or Arg174Lys mutants into EC that were depleted of endogenous p65 blunted TNF plus IFN-γ-mediated CXCL11 induction. Mass spectrometric analyses showed that p65 Arg174 arginine methylation is enhanced by TNF plus IFN-γ costimulation, and is catalyzed by PRMT5. Chromatin immunoprecipitation assays (ChIP) demonstrated that PRMT5 is necessary for p65 association with the CXCL11 promoter in response to TNF plus IFN-γ. Further, reconstitution of p65 Arg174Lys mutant in EC abrogated this p65 association with the CXCL11 promoter. Finally, ChIP and Re-ChIP assays revealed that symmetrical dimethylarginine-containing proteins complexed with the CXCL11 promoter were diminished in p65 Arg174Lys-reconstituted EC stimulated with TNF and IFN-γ. In total, these results indicate that PRMT5-mediated p65 methylation at Arg174 is essential for TNF plus IFN-γ-mediated CXCL11 gene induction. We therefore suggest that the use of recently developed small molecule inhibitors of PRMT5 may present a therapeutic approach to moderating chronic inflammatory pathologies.

Chronic inflammation of the placenta: definition, classification, pathogenesis, and clinical significance

Chronic inflammatory lesions of the placenta are characterized by the infiltration of the organ by lymphocytes, plasma cells, and/or macrophages and may result from infections (viral, bacterial, parasitic) or be of immune origin (maternal anti-fetal rejection). The 3 major lesions are villitis (when the inflammatory process affects the villous tree), chronic chorioamnionitis (which affects the chorioamniotic membranes), and chronic deciduitis (which involves the decidua basalis). Maternal cellular infiltration is a common feature of the lesions. Villitis of unknown etiology (VUE) is a destructive villous inflammatory lesion that is characterized by the infiltration of maternal T cells (CD8+ cytotoxic T cells) into chorionic villi. Migration of maternal T cells into the villi is driven by the production of T-cell chemokines in the affected villi. Activation of macrophages in the villi has been implicated in the destruction of the villous architecture. VUE has been reported in association with preterm and term fetal growth restriction, preeclampsia, fetal death, and preterm labor. Infants whose placentas have VUE are at risk for death and abnormal neurodevelopmental outcome at the age of 2 years. Chronic chorioamnionitis is the most common lesion in late spontaneous preterm birth and is characterized by the infiltration of maternal CD8+ T cells into the chorioamniotic membranes. These cytotoxic T cells can induce trophoblast apoptosis and damage the fetal membranes. The lesion frequently is accompanied by VUE. Chronic deciduitis consists of the presence of lymphocytes or plasma cells in the basal plate of the placenta. This lesion is more common in pregnancies that result from egg donation and has been reported in a subset of patients with premature labor. Chronic placental inflammatory lesions can be due to maternal anti-fetal rejection, a process associated with the development of a novel form of fetal systemic inflammatory response. The syndrome is characterized by an elevation of the fetal plasma T-cell chemokine. The evidence that maternal anti-fetal rejection underlies the pathogenesis of many chronic inflammatory lesions of the placenta is reviewed. This article includes figures and histologic examples of all chronic inflammatory lesions of the placenta.

CXCR3 Polymorphism and Expression Associate with Spontaneous Preterm Birth

Spontaneous preterm birth (SPTB) is a major factor associating with deaths and with lowered quality of life in humans. Environmental and genetic factors influence the susceptibility. Previously, by analyzing families with recurrent SPTB in linkage analysis, we identified a linkage peak close to the gene encoding CXCR3. Present objectives were to investigate the association of CXCR3 with SPTB in Finnish mothers (n = 443) and infants (n = 747), to analyze CXCR3 expression levels in human placenta and levels of its ligands in umbilical cord blood, and to verify the influence of Cxcr3 on SPTB-associating cytokines in mice. We detected an association between an intronic CXCR3 polymorphism, rs2280964, and SPTB in infants from families with recurrent preterm births (p = 0.009 versus term controls, odds ratio 0.52, 95% confidence interval 0.32-0.86). The minor allele was protective and undertransmitted to SPTB infants (p = 0.007). In the placenta and fetal membranes, the rs2280964 major allele homozygotes had higher expression levels than minor allele homozygotes; decidual trophoblasts showed strong CXCR3 immunoreactivity. Expression was higher in SPTB placentas compared with those from elective deliveries. Concentration of a CXCR3 ligand, CXCL9, was increased in cord blood from SPTB, and the protective rs2280964 allele was associated with low CXCL9. In CXCR3-deficient mice (Mus musculus), SPTB-associating cytokines were not acutely increased in amniotic fluid after preterm birth-inducing dose of maternal LPS. Our results indicate that CXCR3 contributes to SPTB. Activation of CXCR3 signaling may disturb the maternal-fetal tolerance, and this may promote labor.

Elevated urinary CXCL10-to-creatinine ratio is associated with subclinical and clinical rejection in pediatric renal transplantation

BACKGROUND

Subclinical and clinical T cell-mediated rejection (TCMR) has significant prognostic implications in pediatric renal transplantation. The goal of this study was to independently validate urinary CXCL10 as a noninvasive biomarker for detecting acute rejection in children and to extend these findings to subclinical rejection.

METHODS

Urines (n = 140) from 51 patients with surveillance or indication biopsies were assayed for urinary CXCL10 using enzyme-linked immunosorbent assay and corrected with urinary creatinine.

RESULTS

Median urinary CXCL10-to-creatinine (Cr) ratio (ng/mmol) was significantly elevated in subclinical TCMR (4.4 [2.6, 25.4], P < 0.001, n = 17); clinical TCMR (24.3 [11.2, 44.8], P < 0.001, n = 9); and antibody-mediated rejection (6.0 [3.3, 13.7], P = 0.002, n = 9) compared to noninflamed histology (1.4 [0.4, 4.2], normal and interstitial fibrosis and tubular atrophy, n = 52), and borderline tubulitis (3.3, [1.3, 4.9], n = 36). Elevated urinary CXCL10:Cr was independently associated with t scores (P < 0.001) and g scores (P = 0.006) on multivariate analysis. The area under receiver operating curve for subclinical and clinical TCMR was 0.81 (P = 0.045) and 0.88 (P = 0.019), respectively. This corresponded to a sensitivity-specificity of 0.59-0.67 and 0.77-0.60 for subclinical and clinical TCMR at cutoffs of 4.82 and 4.72 ng/mmol, respectively.

CONCLUSION

This study demonstrates that urinary CXCL10:Cr corresponds with microvascular inflammation and is a sensitive and specific biomarker for subclinical and clinical TCMR in children. This may provide a noninvasive monitoring tool for posttransplant immune surveillance for pediatric renal transplant recipients.

'Neuroinflammation' differs categorically from inflammation: transcriptomes of Alzheimer's disease, Parkinson's disease, schizophrenia and inflammatory diseases compared

'Neuroinflammation' has become a widely applied term in the basic and clinical neurosciences but there is no generally accepted neuropathological tissue correlate. Inflammation, which is characterized by the presence of perivascular infiltrates of cells of the adaptive immune system, is indeed seen in the central nervous system (CNS) under certain conditions. Authors who refer to microglial activation as neuroinflammation confuse this issue because autoimmune neuroinflammation serves as a synonym for multiple sclerosis, the prototypical inflammatory disease of the CNS. We have asked the question whether a data-driven, unbiased in silico approach may help to clarify the nomenclatorial confusion. Specifically, we have examined whether unsupervised analysis of microarray data obtained from human cerebral cortex of Alzheimer's, Parkinson's and schizophrenia patients would reveal a degree of relatedness between these diseases and recognized inflammatory conditions including multiple sclerosis. Our results using two different data analysis methods provide strong evidence against this hypothesis demonstrating that very different sets of genes are involved. Consequently, the designations inflammation and neuroinflammation are not interchangeable. They represent different categories not only at the histophenotypic but also at the transcriptomic level. Therefore, non-autoimmune neuroinflammation remains a term in need of definition.

Small RNA as a regulator of hematopoietic development, immune response in infection and tumorigenesis

Posttranscriptional gene regulation by small RNAs (15-40-nucleotide noncoding RNAs) is now established as an important branch of the gene regulatory system. It has recently been revealed that noncoding RNAs can be categorized into different types and that they work through novel mechanisms. In addition, it has been shown that noncoding RNAs mediate intercellular communication and, importantly, that cross talk between coding and noncoding RNAs occurs. In this review, we discuss the recent findings concerning small RNAs. It was originally proposed that microRNAs (miRNAs) work to "fine tune" the determination of cell fate. However, critical functions beyond fine tuning have been revealed. In addition to miRNAs, next-generation sequencing has revealed the existence of various species of non-canonical small RNAs: mirtrons, piRNAs, 21U-RNA, endo-siRNAs, snoRNAs, usRNAs, and Y-RNA-derived small RNAs. Some of these species are involved in response to viral infection. Finally, we highlight the intracellular functions of small RNAs, which involve the exosomes.

The involvement of CXCL11 in bone marrow-derived mesenchymal stem cell migration through human brain microvascular endothelial cells

Bone marrow-derived mesenchymal stem cells (MSCs) transplant into the brain, where they play a potential therapeutic role in neurological diseases. However, the blood-brain barrier (BBB) is a native obstacle for MSCs entry into the brain. Little is known about the mechanism behind MSCs migration across the BBB. In the present study, we modeled the interactions between human MSCs (hMSCs) and human brain microvascular endothelial cells (HBMECs) to mimic the BBB microenvironment. Real-time PCR analysis indicated that the chemokine CXCL11 is produced by hMSCs and the chemokine receptor CXCR3 is expressed on HBMECs. Further results indicate that CXCL11 secreted by hMSCs may interact with CXCR3 on HBMECs to induce the disassembly of tight junctions through the activation of ERK1/2 signaling in the endothelium, which promotes MSCs transendothelial migration. These findings are relevant for understanding the biological responses of MSCs in BBB environments and helpful for the application of MSCs in neurological diseases.

Expression of CXCR3 and its ligands CXCL9, -10 and -11 in paediatric opsoclonus-myoclonus syndrome

Opsoclonus-myoclonus syndrome (OMS) is a neuroinflammatory disorder associated with remote cancer. To understand more clearly the role of inflammatory mediators, the concentration of CXCR3 ligands CXCL10, CXCL9 and CXCL11 was measured in 245 children with OMS and 81 paediatric controls using enzyme-linked immunosorbent assay (ELISA), and CXCR3 expression on CD4(+) T cells was measured by flow cytometry. Mean cerebrospinal fluid (CSF) CXCL10 was 2·7-fold higher in untreated OMS than controls. Intrathecal production was demonstrated by significantly different CXCL10 CSF : serum ratios. The dichotomized 'high' CSF CXCL10 group had higher CSF leucocyte count (P = 0·0007) and B cell activating factor (BAFF) and CXCL13 concentrations (P < 0·0001). CSF CXCL10 did not correlate with clinical severity or relapse using grouped data, although it did in some patients. Among seven types of immunotherapy, including rituximab or chemotherapy, only adrenocorticotrophic hormone (ACTH) monotherapy showed reduced CSF CXCL10, but prospective longitudinal studies of ACTH combination therapies indicated no reduction in CXCL10 despite clinical improvement (P < 0·0001). CXCL10 concentrations were 11-fold higher in CSF and twofold higher in serum by multiplexed fluorescent bead-based immunoassay than enzyme-linked immunosorbent assay, but the two correlated (r = 0·7 and 0·83). In serum, no group differences for CXCL9 or CXCL11 were found. CXCR3 expression on CD4(+) T cells was fivefold higher in those from CSF than blood, but was not increased in OMS or altered by conventional immunotherapy. These data suggest alternative roles for CXCL10 in OMS. Over-expression of CXCL10 was not reduced by clinical immunotherapies as a whole, indicating the need for better therapeutic approaches.

Characterization of cytomegalovirus disease in solid organ transplant recipients by markers of inflammation in plasma

Background

While several studies have examined the general inflammatory responses in relation to cytomegalovirus infection, the identification of the various inflammatory mediators as well as their relative importance is far from clear.

Patients and Methods

Solid organ recipients enrolled in an international multicenter trial of cytomegalovirus disease treatment (the VICTOR study) were analyzed (n = 289) (ClinicalTrials.gov NCT00431353). Plasma markers of inflammation and endothelial cell activation were assessed at baseline by enzyme immunoassays.

Results

The major findings were: (i) Plasma levels of the CXC-chemokine interferon-inducible protein-10 (P<0.001) and C-reactive protein (P = 0.046) were independently associated with the presence of cytomegalovirus DNAemia above lower level of quantification. (ii) High levels of CC-chemokine ligand 21 (P = 0.027) and pentraxin 3 (P = 0.033) were independently associated with tissue invasive cytomegalovirus disease as opposed to cytomegalovirus syndrome.

Conclusion

Our findings illustrate the complex interaction between cytomegalovirus and the immune system, involving a wide range of inflammatory mediators that could be associated to disease manifestations in cytomegalovirus related disease.

Association of IP-10 gene polymorphism with susceptibility to Enterovirus 71 infection

Enterovirus 71 (EV71) often causes large outbreaks of diseases among children worldwide and its pathogenesis remains unclear. The aim of the present study was to investigate the association between interferon-inducible protein 10 (IP-10) polymorphism in children with EV71 infection. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were performed to analyze the gene polymorphisms of IP-10 (-1596C/T) in 58 EV71-infected and 48 control patients. The results showed that in EV71-infected patients the frequency of carrying CT + TT genotype and T allele is 10.3 and 6.0%, respectively, which is significantly lower than that of the controls (29.2 and 15.6%, respectively). Individuals with T allele had a lower risk of EV71 infection [odds ratio (OR) = 0.35, 95% confidence interval (CI), 0.13-0.89]. The results of this study indicated that -1596T allele for the IP-10 gene may be a beneficial factor for EV71 infection.

Interference of IP-10 expression inhibits vascular smooth muscle cell proliferation and intimal hyperplasia in carotid artery: a new insight in the prevention of restenosis

After vascular angioplasty, vascular smooth muscle cell (VSMC) proliferation causes atherosclerosis and intimal hyperplasia leading to restenosis. Interferon-γ-inducible protein (IP)-10 plays a role in atherogenesis, but the mechanism remains unclear. We evaluated the role of IP-10 in intimal hyperplasia and restenosis. IP-10 expression was determined in arterial specimens from 20 arteriosclerotic obliteration patients and 6 healthy individuals. VSMCs were stimulated in vitro with IFN-γ and transfected with IP-10 siRNA. Silencing was verified with RT-PCR/Western blot; cell proliferation rate was detected by methyl-thiazol-tetrazolium. The carotid artery model of atherosclerosis injury was established with IP-10 siRNA. IP-10 expression was detected at 1 and 4 weeks using RT-PCR and immunohistochemistry. Artery morphology was assessed with hematoxylin-and-eosin staining, and intimal hyperplasia was evaluated by electron microscopy. IP-10 was overexpressed in arteriosclerotic obliteration group compared with control group (P < 0.05). IP-10 expression in transfected group was significantly lower than in untransfected group. The intima-to-media ratio of transfected group at 4 weeks was lower than that of untransfected group (P < 0.01). The transfected group exhibited more regular intimal structure and less hyperplasia under electron microscopy. We, therefore, concluded that IP-10 played an important role in intimal hyperplasia as siRNA-mediated IP-10 silencing inhibited aberrant VSMCs hyperplasia and reduced restenosis.

Treating tumors with a vaccinia virus expressing IFNβ illustrates the complex relationships between oncolytic ability and immunogenicity

Since previous work using a nonreplicating adenovirus-expressing mouse interferon-β (Ad.mIFNβ) showed promising preclinical activity, we postulated that a vector-expressing IFNβ at high levels that could also replicate would be even more beneficial. Accordingly a replication competent, recombinant vaccinia viral vector-expressing mIFNβ (VV.mIFNβ) was tested. VV.mIFNβ-induced antitumor responses in two syngeneic mouse flank models of lung cancer. Although VV.mIFNβ had equivalent in vivo efficacy in both murine tumor models, the mechanisms of tumor killing were completely different. In LKRM2 tumors, viral replication was minimal and the tumor killing mechanism was due to activation of immune responses through induction of a local inflammatory response and production of antitumor CD8 T-cells. In contrast, in TC-1 tumors, the vector replicated well, induced an innate immune response, but antitumor activity was primarily due to a direct oncolytic effect. However, the VV.mIFNβ vector was able to augment the efficacy of an antitumor vaccine in the TC-1 tumor model in association with increased numbers of infiltrating CD8 T-cells. These data show the complex relationships between oncolytic viruses and the immune system which, if understood and harnessed correctly, could potentially be used to enhance the efficacy of immunotherapy.

PF-4var/CXCL4L1 predicts outcome in stable coronary artery disease patients with preserved left ventricular function

Background

Platelet-derived chemokines are implicated in several aspects of vascular biology. However, for the chemokine platelet factor 4 variant (PF-4var/CXCL4L1), released by platelets during thrombosis and with different properties as compared to PF-4/CXCL4, its role in heart disease is not yet studied. We evaluated the determinants and prognostic value of the platelet-derived chemokines PF-4var, PF-4 and RANTES/CCL5 in patients with stable coronary artery disease (CAD).

Methodology/Principal Findings

From 205 consecutive patients with stable CAD and preserved left ventricular (LV) function, blood samples were taken at inclusion and were analyzed for PF-4var, RANTES, platelet factor-4 and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Patients were followed (median follow-up 2.5 years) for the combined endpoint of cardiac death, non-fatal acute myocardial infarction, stroke or hospitalization for heart failure. Independent determinants of PF-4var levels (median 10 ng/ml; interquartile range 8–16 ng/ml) were age, gender and circulating platelet number. Patients who experienced cardiac events (n = 20) during follow-up showed lower levels of PF-4var (8.5 [5.3–10] ng/ml versus 12 [8–16] ng/ml, p = 0.033). ROC analysis for events showed an area under the curve (AUC) of 0.82 (95% CI 0.73–0.90, p<0.001) for higher NT-proBNP levels and an AUC of 0.32 (95% CI 0.19–0.45, p = 0.009) for lower PF-4var levels. Cox proportional hazard analysis showed that PF-4var has an independent prognostic value on top of NT-proBNP.

Conclusions

We conclude that low PF-4var/CXCL4L1 levels are associated with a poor outcome in patients with stable CAD and preserved LV function. This prognostic value is independent of NT-proBNP levels, suggesting that both neurohormonal and platelet-related factors determine outcome in these patients.

CXCL10: a candidate biomarker in transplantation

Interferon (IFN) γ-induced protein 10 kDa (IP-10) or C-X-C motif chemokine 10 (CXCL10) is a small cytokine belonging to the CXC chemokine family. This family of signaling molecules is known to control several biological functions and to also play pivotal roles in disease initiation and progression. By binding to its specific cognate receptor CXCR3, CXCL10 critically regulates chemotaxis during several immune-inflammatory processes. In particular, this chemokine controls chemotaxis during the inflammatory response resulting from allograft rejection after transplantation. Interestingly, a strong association has been described between CXCL10 production, immune response and the fate of the graft following allotransplantation. Enhanced CXCL10 production has been observed in recipients of transplants of different organs. This enhanced production likely comes from either the graft or the immune cells and is correlated with an increase in the concentration of circulating CXCL10. Because CXCL10 can be easily measured in the serum and plasma from a patient, the detection and quantitation of circulating CXCL10 could be used to reveal a transplant recipient's immune status. The purpose of this review is to examine the critical role of CXCL10 in the pathogenesis of allograft rejection following organ transplantation. This important role highlights the potential utilization of CXCL10 not only as a therapeutic target but also as a biomarker to predict the severity of rejection, to monitor the inflammatory status of organ recipients and, hopefully, to fine-tune patient therapy in transplantation.

Inflammatory response in human skeletal muscle cells: CXCL10 as a potential therapeutic target

Inflammatory myopathies (IMs) are systemic diseases characterized by a T helper (Th) 1 type inflammatory response and cell infiltrates within skeletal muscles. The mainstay of treatment is drugs aimed at suppressing the immune system - corticosteroids and immunosuppressants. About 25% of patients are non-responders. Skeletal muscle cells seem actively involved in the immune-inflammatory response and not only a target; understanding the molecular bases of IMs might help drug development strategies. Within muscles the interaction between the chemokine interferon (IFN)γ inducible 10 kDa protein, CXCL10 or IP-10, and its specific receptor CXCR3, present on Th1 type infiltrating cells, likely plays a pivotal role, potentially offering the opportunity for therapeutic intervention. We aimed to clarify the involvement of human skeletal muscle cells in inflammatory processes in terms of CXCL10 secretion, to elucidate the engaged molecular mechanism(s) and, finally, to evaluate muscular cell responses, if any, to some immunosuppressants routinely used in IM treatment, such as methylprednisolone, methotrexate, cyclosporin A and Infliximab. We first isolated and characterized human fetal skeletal muscle cells (Hfsmc), which expressed the specific lineage markers and showed the competence to react in the context of an in vitro alloresponse. CXCL10 protein secretion by Hfsmc was similarly induced by the inflammatory cytokines interferon (IFN)γ and tumor necrosis factor (TNF)α, above undetectable control levels, through the activation of Stat1 and NF-kB pathways, respectively; CXCL10 secretion was significantly magnified by cytokine combination, and this synergy was associated to a significant up-regulation of TNFαRII; cytokine-induced CXCL10 secretion was considerably affected only by Infliximab. Our data suggested that human skeletal muscle cells might actively self-promote muscular inflammation by eliciting CXCL10 secretion, which is known to amplify Th1 cell tissue infiltration in vivo. In conclusion, we sustain that pharmacological targeting of CXCL10 within muscular cells might contribute to keep in control pro-Th1 polarization of the immune/inflammatory response.

MAOS and medicinal chemistry: some important examples from the last years

This review aims to highlight microwave-assisted organic synthesis as applied to medicinal chemistry in the last years, showing some reactions performed under microwave irradiation for the synthesis of distinct structurally molecules of biological interest, divided into the following groups: antineoplastics, anti-inflammatory, antimicrobial agents, antivirals, agents for the treatment of neglected diseases and central nervous system-acting prototypes.

Identification of anti-inflammatory targets for Huntington's disease using a brain slice-based screening assay

Huntington's disease (HD) is a late-onset, neurodegenerative disease for which there are currently no cures nor disease-modifying treatments. Here we report the identification of several potential anti-inflammatory targets for HD using an ex vivo model of HD that involves the acute transfection of human mutant huntingtin-based constructs into rat brain slices. This model recapitulates key components of the human disease, including the formation of intracellular huntingtin protein (HTT)-containing inclusions and the progressive neurodegeneration of striatal neurons-both occurring within the native tissue context of these neurons. Using this "high-throughput biology" screening platform, we conducted a hypothesis-neutral screen of a collection of drug-like compounds which identified several anti-inflammatory targets that provided neuroprotection against HTT fragment-induced neurodegeneration. The nature of these targets provide further support for non-cell autonomous mechanisms mediating significant aspects of neuropathogenesis induced by mutant HTT fragment proteins.

STAT3 inhibitors attenuate interferon-γ-induced neurotoxicity and inflammatory molecule production by human astrocytes

Activation of signal transducer and activator of transcription (STAT) 3 is observable in reactive astrocytes under certain neuropathological conditions. Interferon (IFN)-γ is shown to activate STAT3 in cultured rodent astrocytes. Here we investigated the effects of inhibiting STAT3 signaling on IFNγ-activated human astrocytes since we have recently demonstrated that human astrocytes become neurotoxic when stimulated by IFNγ. We found that 5'-deoxy-5'-(methylthio)adenosine (MTA) (300 μM), S3I-201 (10 μM), STAT3 inhibitor VII (3 μM) and JAK-inhibitor I (0.3 μM) had anti-neurotoxic effects on IFN-γ (50 U/ml)-activated astrocytes and U373-MG astrocytoma cells. Another inhibitor, AG490 (30 μM) had no significant effect. The active inhibitors also attenuated IFN-γ-induced phosphorylation of Tyr(705)-STAT3 and astrocytic expression of intercellular adhesion molecule-1 (ICAM-1). They also decreased astrocytic production of IFN-γ-inducible T cell α chemoattractant (I-TAC). AG490, which did not affect the Tyr(705)-STAT3 phosphorylation or ICAM-1 expression, nevertheless reduced the I-TAC secretion. Because these results indicate that pharmacological inhibition of STAT3 signaling correlates with reduced astrocytic neurotoxicity and ICAM-1 expression, but not that of I-TAC secretion, we consider that STAT3 activation mediates, at least in part, the IFN-γ-induced neurotoxicity and ICAM-1 expression by human astrocytes.

Elevated expression of CXC chemokines in pediatric osteosarcoma patients

BACKGROUND

Osteosarcoma is the most common malignant bone tumor in children. Despite the advent of chemotherapy, the survival of osteosarcoma patients has not been significantly improved recently. Chemokines are a group of signaling molecules that have been implicated in tumorigenesis and metastasis.

METHODS

The authors used an antibody microarray to identify chemokines that were elevated in the plasma samples of osteosarcoma patients. The results were validated using enzyme-linked immunosorbent assays on an independent set of samples. The tumor expressions of 3 chemokines were examined in 2 sets of osteosarcoma tissue arrays. The authors also evaluated the proliferative effect of the chemokines in 4 osteosarcoma cell lines.

RESULTS

The authors found that the plasma levels of CXCL4, CXCL6, and CXCL12 in the osteosarcoma patients were significantly higher than those in the controls, and the results were validated by an independent osteosarcoma cohort (P < .05). However, CXCL4 (100%) and CXCL6 (91%) were frequently expressed in osteosarcoma, whereas CXCL12 was only expressed in 4%. Survival analysis further showed that higher circulating levels of CXCL4 and CXCL6, but not CXCL12, were associated with a poorer outcome of osteosarcoma patients. Addition of exogenous chemokines significantly promoted the growth of different osteosarcoma cells (P < .05).

CONCLUSIONS

The results demonstrate that CXCL4 and CXCL6 are frequently expressed in osteosarcoma, and that the plasma levels of these 2 chemokines are associated with patient outcomes. Further study of these circulating chemokines may provide a promising approach for prognostication of osteosarcoma. Targeting these chemokines or their receptors may also lead to a novel therapeutic invention.

IFN-gamma triggers CCR2-independent monocyte entry into the brain during systemic infection by virulent Listeria monocytogenes

Listeria monocytogenes (Lm) is a bacterial pathogen that infects the brain via parasitized monocytes. CCR2 is important for monocyte migration into the brain after it is infected, but the degree of CCR2 involvement in monocyte migration to the CNS during systemic infection is less clear. Our recent data demonstrate that systemic infection with non-neuroinvasive DeltaactA Lm mutants triggers IFN-gamma-dependent brain influxes of Ly-6C(high) monocytes. Studies presented here tested the extent to which CCR2 and IFN-gamma are essential for monocyte migration to the brain during systemic infection with virulent Lm. For this, we assessed expression of monocyte-attracting chemokines in brains of normal and IFN-gamma mice during infection and tested the degree to which brain influxes of Ly-6C(high) monocytes were inhibited in chemokine- and chemokine receptor-deficient mice. In normal mice, systemic infection induced up-regulation of CCR2-binding (CCL2, CCL7, CCL8, CCL12) and CXCR3-binding chemokines (CXCL9, CXCL10). IFN-gamma mice had negligible mRNA and protein expression of CXCR3-binding chemokines, whereas expression of CCR2-binding chemokines was reduced, but remained significant. In addition, infection-triggered monocyte influxes were significantly reduced in IFN-gamma mice. Remarkably, brain monocyte influxes were normal during infection of CXCR3-, CCL2-, CCR1-, CCR5-, and CX3CR1-deficient mice. Influxes were transiently reduced in CCR2(-/-) mice, corresponding with retention of monocytes in the bone marrow but this was eventually overcome during infection. These data show that IFN-gamma is critical for triggering brain influxes of Ly-6C(high) monocytes during systemic infection with virulent Lm. This initial burst of monocyte migration is largely independent of individual chemokine receptors.

Poly-ICLC promotes the infiltration of effector T cells into intracranial gliomas via induction of CXCL10 in IFN-alpha and IFN-gamma dependent manners

Stimulation of double-stranded (ds)RNA receptors can increase the effectiveness of cancer vaccines, but the underlying mechanisms are not completely elucidated. In this study, we sought to determine critical roles of host IFN-alpha and IFN-gamma pathways in the enhanced therapeutic efficacy mediated by peptide vaccines and polyinosinic-polycytidylic acid [poly(I:C)] stabilized by lysine and carboxymethylcellulose (poly-ICLC) in the murine central nervous system (CNS) GL261 glioma. C57BL/6-background wild type (WT), IFN-alpha receptor-1 (IFN-alphaR1)(-/-) or IFN-gamma(-/-) mice bearing syngeneic CNS GL261 glioma received subcutaneous (s.c.) vaccinations with synthetic peptides encoding CTL epitopes with or without intramuscular (i.m.) injections of poly-ICLC. The combinational treatment induced a robust transcription of CXCL10 in the glioma site. Blockade of CXCL10 with a specific monoclonal antibody (mAb) abrogated the efficient CNS homing of antigen-specific type-1 CTL (Tc1). Both IFN-alphaR(-/-) and IFN-gamma(-/-) hosts failed to up-regulate the CXCL10 mRNA and recruit Tc1 cells to the tumor site, indicating non-redundant roles of type-1 and type-2 IFNs in the effects of poly-ICLC-assisted vaccines. The efficient trafficking of Tc1 also required Tc1-derived IFN-gamma. Our data point to critical roles of the host-IFN-alpha and IFN-gamma pathways in the modulation of CNS glioma microenvironment, and the therapeutic effectiveness of poly-ICLC-assisted glioma vaccines.

Innate inflammatory responses of human decidual cells to periodontopathic bacteria

OBJECTIVE

The purpose of this study was to test the hypothesis that periodontopathic bacteria exert potent proinflammatory effects in human decidua.

STUDY DESIGN

The immunostimulatory effects of Gram-positive and negative periodontopathic bacteria and their lipopolysaccharides were tested in human decidual cell cultures in comparison with Escherichia coli. Cytokine production was measured by enzyme-linked immunosorbent assay; inflammatory gene expression was measured by oligonucleotide arrays and quantitative real time-polymerase chain reaction.

RESULTS

All bacteria that were tested elicited an inflammatory response, although concentration-dependence and efficacy varied considerably with organism and culture. Lipopolysaccharides were more potent stimuli than intact bacterial cells, although bacteria exerted greater effects at high concentrations. Of 112 genes on the arrays, 18 genes were stimulated significantly by one or more lipopolysaccharide preparation.

CONCLUSION

The ability of periodontopathic bacteria to stimulate a decidual inflammatory response is highly variable and partly dependent on the presence and structure of constituent lipopolysaccharides. This adds to our understanding of the causal association between periodontal disease and preterm birth.

Dipyrithione inhibits IFN-gamma-induced JAK/STAT1 signaling pathway activation and IP-10/CXCL10 expression in RAW264.7 cells

Objective

This study investigates the effects of dipyrithione (PTS2) on the expression of IP-10/CXCL10, which has been observed in a wide variety of chronic inflammatory disorders and autoimmune conditions.

Methods

RAW264.7 cells (a murine macrophage-like cell line) were cultured in the absence or in the presence of PTS2 (3–10 μM) together with or without IFN-γ (10 ng/ml). IP-10/CXCL10 expression was measured by specific enzyme-amplified immunoassays and reverse transcriptase-PCR (RT-PCR). Phosphorylation of JAK1, JAK2 and STAT1 were detected by Western blot analysis.

Results

We found that PTS2 inhibited IFN-γ-induced up-regulation of IP-10/CXCL10 protein level in a dose- and time-dependent manner in RAW264.7 cells. RT-PCR experiments showed that PTS2 suppressed IFN-γ-induced IP-10/CXCL10 expression at mRNA levels. Mechanistically, PTS2 prevented phosphorylation of JAK1, JAK2 and STAT1, but did not interfere with the p38 pathway. Furthermore, the inhibitory effect of PTS2 on IP-10/CXCL10 up-regulation was slightly stronger than JAK2 inhibitor AG490.

Conclusion

PTS2 inhibits IFN-γ-induced IP-10/CXCL10 expression in RAW264.7 cells by targeting the JAK/STAT1 signaling pathway, suggesting that PTS2 could exert anti-inflammatory effects through attenuating the formation of chemokine IP-10/CXCL10.

The role of chemokines in B cell chronic lymphocytic leukaemia: pathophysiological aspects and clinical impact

Chemokines are centrally involved in leukocyte migration, homing and haematopoiesis. Besides these physiological aspects, their role in pathological processes especially with respect to solid tumour and haematological neoplasias is well established. In this context, the focus was set here on disclosing their contribution in B cell chronic lymphocytic leukaemia (B-CLL), which is regarded as the most characteristic low-grade lymphoma. Up to now, it has been demonstrated that several chemokines are involved in migration of B-CLL cells to lymph nodes, secondary lymphoid organs and bone marrow. Moreover, some chemokines are known to have an anti-apoptotic effect and thus contribute to the survival of B-CLL cells. By interfering with both of these aspects, new therapeutic targets for this yet incurable disease may be developed. Furthermore, a correlation can be drawn between the concentration of some chemokines in patients' serum, the expression of their respective receptors on B-CLL cells and well-established predictive clinical parameters. Consequently, further systematic investigation of the chemokine network may lead to the identification of new diagnostic and prognostic markers. This review focuses on the impact of chemokines and their receptors on B-CLL pathophysiology and points out potential implications for both treatment and diagnosis.

CXCL10 expression and prognostic significance in stage II and III colorectal cancer

CXC Chemokine Ligand 10 (CXCL10), an interferon-inducible protein, has been demonstrated to inhibit the proliferation and metastasis in many tumors. In this study, we focus on the expression of CXCL10 in stage II and III colorectal cancer (CRC) and its correlation with metastasis. Real-time reverse-transcription polymerase chain reaction (real-time RT-PCR) and RT-PCR were performed in 36 snap-frozen CRC tissues with recurrence and 28 CRC tissues without recurrence to examine CXCL10 expression. For further examination in mRNA level, three CRC-metastasis-derived cell lines (SW620, Lovo, Colo205) and three primary-CRC-derived ones (SW480, Caco-2, HCT116) were also subjected to real-time RT-PCR. Analysis showed that CXCL10 down-regulated in CRC with recurrence both in tissues and cells (P < 005). Immunohistochemistry was also performed in 118 paraffin-embedded specimens. CRC were scored as strong and low CXCL10 expressers (-/+ and ++/+++, respectively). The correlation between clinicopathological or molecular variables and survival was analyzed. Lowly expressed CXCL10 mRNA were detected in snap-frozen tissues with recurrence (P < 0.05) and in cell lines derived from CRC metastases (SW620, Lovo, Colo205). No significant correlation was found between CXCL10 level detected by immunostaining and tumor location, size, histological type, lymphvascular invasion, perineural invasion or TNM stage. However, patients with lower levels of CXCL10 expression showed the poorer prognosis [low expression 70% (57/81) versus strong expression 27% (10/37); P < 0.05]. Kaplan-Meier curves comparing different CXCL10 expression levels with survival showed highly significant separation (P < 0.05, log-rank test). The Cox proportional hazards regression model also showed that low CXCL10 expression was an independent adverse prognosticator in stage II and III CRC (P < 0.05). We concluded that detection of CXCL10, as a prognostic marker for stage II and III CRC patients, may contribute to predicting clinical outcome.

Airway smooth muscle chemokine receptor expression and function in asthma

BACKGROUND

Chemokine receptors play an important role in cell migration and wound repair. In asthma, CCR3 and 7 are expressed by airway smooth muscle (ASM) and CCR7 has been implicated in the development of ASM hyperplasia. The expression profile of other chemokine receptors by ASM and their function needs to be further explored.

OBJECTIVE

We sought to investigate ASM chemokine receptor expression and function in asthma.

METHODS

ASM cells were derived from 17 subjects with asthma and 36 non-asthmatic controls. ASM chemokine receptor expression was assessed by flow cytometry and immunofluorescence. The function of chemokine receptors expressed by more than 10% of ASM cells was investigated by intracellular calcium measurements, chemotaxis, wound healing, proliferation and survival assays.

RESULTS

In addition to CCR3 and 7, CXCR1, 3 and 4 were highly expressed by ASM. These CXC chemokine receptors were functional with an increase in intracellular calcium following ligand activation and promotion of wound healing [CXCL10 (100 ng/mL) 34 +/- 2 cells/high-powered field (hpf) vs. control 29 +/- 1; P=0.03; n=8]. Spontaneous wound healing was inhibited by CXCR3 neutralizing antibody (mean difference 7 +/- 3 cells/hpf; P=0.03; n=3). CXC chemokine receptor activation did not modulate ASM chemotaxis, proliferation or survival. No differences in chemokine receptor expression or function were observed between ASM cells derived from asthmatic or non-asthmatic donors.

CONCLUSIONS

Our findings suggest that the chemokine receptors CXCR1, 3 and 4 modulate some aspects of ASM function but their importance in asthma is uncertain.

IP-10 induces dissociation of newly formed blood vessels

The signals that prune the exuberant vascular growth of tissue repair are still ill defined. We demonstrate that activation of CXC chemokine receptor 3 (CXCR3) mediates the regression of newly formed blood vessels. We present evidence that CXCR3 is expressed on newly formed vessels in vivo and in vitro. CXCR3 is expressed on vessels at days 7-21 post-wounding, and is undetectable in unwounded or healed skin. Treatment of endothelial cords with CXCL10 (IP-10), a CXCR3 ligand present during the resolving phase of wounds, either in vitro or in vivo caused dissociation even in the presence of angiogenic factors. Consistent with this, mice lacking CXCR3 express a greater number of vessels in wound tissue compared to wild-type mice. We then hypothesized that signaling from CXCR3 not only limits angiogenesis, but also compromises vessel integrity to induce regression. We found that activation of CXCR3 triggers micro-calpain activity, causing cleavage of the cytoplasmic tail of beta3 integrins at the calpain cleavage sites c'754 and c'747. IP-10 stimulation also activated caspase 3, blockage of which prevented cell death but not cord dissociation. This is the first direct evidence for an extracellular signaling mechanism through CXCR3 that causes the dissociation of newly formed blood vessels followed by cell death.