Expression of Resistin, Chemerin, and Chemerin's Receptor in the Unstable Carotid Atherosclerotic Plaque.

Background and Purpose: Unstable carotid plaques are a common cause of ischemic strokes. Identifying markers that reflect/contribute to plaque instability has become a prominent focus in cardiovascular research. The adipokines, resistin and chemerin, and ChemR23 (chemerin receptor), may play a role in carotid atherosclerosis, making them potential candidates to assess plaque instability. However, the expression and interrelationship of resistin and chemerin (and ChemR23) protein and mRNA within the carotid atherosclerotic plaque remains elusive. Thus, we investigated herein, the association between plaque mRNA and protein expression of resistin and chemerin (and ChemR23) and carotid plaque instability in humans, and whether sex differences exist in the relationship between these adipokines and plaque instability. Methods: Human carotid plaques were processed for immunohistochemical/mRNA analysis of resistin, chemerin, and ChemR23. Plaque instability was assessed by gold-standard histological classifications. A semi-quantitative scoring system was used to determine the intensity of adipokine expression on macrophages/foam cells, as well as the percentage of inflammatory cells stained positive. Plaque adipokine protein expression was also digitally quantified and mRNA expression was assessed by qRT-PCR. Results: Resistin and chemerin mRNA expression was 80% and 32% lower, respectively, in unstable versus stable plaques (P<0.05), while no difference in ChemR23 mRNA expression was observed. In contrast, greater resistin staining intensity and percentage of cells stained positive were detected in unstable versus stable plaques (P<0.01). Similarly, chemerin and ChemR23 staining intensity and percentage of cells stained were positively associated with plaque instability (P<0.05). No strong sex-specific relationship was observed between adipokines and plaque instability. Conclusions: This study examined the relationship between resistin, chemerin, and ChemR23, and carotid plaque instability, with a specific analysis at the plaque level. We reported a positive association between plaque instability and protein levels of resistin, chemerin, and ChemR23 but a negative association with resistin and chemerin mRNA expression. This suggests these adipokines exert proinflammatory roles in the process of carotid atherosclerosis and may be regulated via a negative feedback regulatory mechanism.

Cytomegalovirus Genetic Diversity Following Primary Infection.

BACKGROUND: Infection with multiple cytomegalovirus (CMV) strains (mixed infection) was reported in a variety of hosts. As the virus genetic diversity in primary CMV infection and the changes over time remain incompletely defined, we examined CMV diversity and changes in diversity over time in healthy adolescent females who participated in a phase 2 CMV gB/MF59 vaccine trial. METHODS: CMV genetic diversity was determined by genotyping of 5 genes-gB (UL55), gH (UL75), gN (UL73), US28, and UL144-in urine, saliva, and plasma samples from 15 study subjects. RESULTS: At the time of primary infection, 5 of 12 (42%) urine samples had multiple virus strains, and 50% of vaccine recipients were infected with gB1 genotype (vaccine strain). Mixed infection was documented in all 15 subjects within 3 months after primary infection, and the majority had different CMV genotypes in different compartments. Changes in genotypes over time were observed in all subjects. CONCLUSIONS: Infection with multiple CMV genotypes was common during primary infection and further diversification occurred over time. Infection with gB1 genotype in vaccine recipients suggests a lack of strain-specific protection from the vaccine. As only 5 polymorphic genes were assessed, this study likely underestimated the true genetic diversity in primary CMV infection.

Elevated ACKR2 expression is a common feature of inflammatory arthropathies.

Objectives: Chemokines are essential contributors to leucocyte accumulation at sites of inflammatory pathology. Interfering with chemokine or chemokine receptor function therefore represents a plausible therapeutic option. However, our currently limited understanding of chemokine orchestration of inflammatory responses means that such therapies have not yet been fully developed. We have a particular interest in the family of atypical chemokine receptors that fine-tune, or resolve, chemokine-driven responses. In particular we are interested in atypical chemokine receptor 2 (ACKR2), which is a scavenging receptor for inflammatory CC-chemokines and that therefore helps to resolve in vivo inflammatory responses. The objective of the current study was to examine ACKR2 expression in common arthropathies. Methods: ACKR2 expression was measured by a combination of qPCR and immuno-histochemistry. In addition, circulating cytokine and chemokine levels in patient plasma were assessed using multiplexing approaches. Results: Expression of ACKR2 was elevated on peripheral blood cells as well as on leucocytes and stromal cells in synovial tissue. Expression on peripheral blood leucocytes correlated with, and could be regulated by, circulating cytokines with particularly strong associations being seen with IL-6 and hepatocyte growth factor. In addition, expression within the synovium was coincident with aggregates of lymphocytes, potentially atopic follicles and sites of high inflammatory chemokine expression. Similarly increased levels of ACKR2 have been reported in psoriasis and SSc. Conclusion: Our data clearly show increased ACKR2 in a variety of arthropathies and taking into account our, and others', previous data we now propose that elevated ACKR2 expression is a common feature of inflammatory pathologies.

Altered chemokine receptor expression in the peripheral blood lymphocytes in polymyositis and dermatomyositis.

OBJECTIVE: To examine the expression of chemokine receptors in different peripheral blood T-cell subsets in patients with polymyositis (PM) and dermatomyositis (DM). METHODS: We used flow cytometry to measure the frequencies of chemokinereceptors CXCR3 and CCR4 expression in the CD4+ or CD8+ lymphocytes. Enzyme linked immunosorbent assays were also used to measure the concentrations of C-X-C motif chemokine 10 (CXCL10), thymus and activation regulated chemokine (TARC) and macrophage derived chemokine (MDC). RESULTS: Comparing to 20 healthy controls, %CD4+CXCR3+ and %CD8+CXCR3+ T cells significantly decreased in 33DM patients, and %CD8+CXCR3+ cells decreased in 24PM patients, but %CD4+CCR4+ and %CD8+CCR4+ cells did not significantly change in both the PM and DM patients. Accordingly, the Th1/Th2 polarization, analyzed as the balance obtained after dividing %CD4+CXCR3+ cells by %CD4+CCR4+ cells, showed a significant reduction in DM. The serum concentration of CXCR3+ ligand, CXCL10, significantly increased and negatively correlated with circulating %CD4+CXCR3+ cells in DM patients. There was no significant change of TARC and MDC in PM and DM patients. Furthermore, %CD4+CXCR3+ cells decreased more severely in the patients with interstitial lung disease. CONCLUSIONS: The present results indicate that the distributions of circulating CXCR3+ T-cells differ among the PM and DM cases. Our findings suggest a pathogenic difference between PM and DM.

Stress responses to short-term intensified and reduced training in competitive weightlifters.

We sought to identify and evaluate the tolerance to, and consequences of, short-term variations in training load in competitive weightlifters. Seven international-level lifters performed 1 week of initial training followed by 2 weeks of intensified (INT: +100%, 36.5 ± 11.3 × 10(3) kg/week) and 1 week of subsequently reduced (RED: -25%) training within their annual program. After INT, but not RED, 90 min of weightlifting increased mRNA levels of chemokine (C-C motif) ligand 4 (CCL4), chemokine (C-X-C motif) receptor 4 (CXCR4) and cellular stress-associated DNA-damage-inducible transcript 4 (DDIT4) in peripheral blood mononuclear cells by 40-240%. Resting- and weightlifting-induced changes in plasma protein carbonyls, indicative of oxidative stress, but not pro-inflammatory CCL4 concentrations differed between INT and RED. Symptoms of stress (Daily Analysis of Life Demands of Athletes questionnaire) were reported as worse than normal more frequently during INT and RED than initial training. Global (negative) mood state increased during INT and declined during RED. Maximal snatch (-4.3 ± 3.7%) and vertical jump (-7.2 ± 6.5%), but not clean and jerk, were reduced after INT and restored after RED. Chemokine signaling may thus be part of the stress response to intense weightlifting and short-term reductions in training load support recovery from periodic INT training in weightlifters.

Inverse Relationship of the CMKLR1 Relative Expression and Chemerin Serum Levels in Obesity with Dysmetabolic Phenotype and Insulin Resistance.

BACKGROUND: In obesity there is a subclinical chronic low-grade inflammatory response where insulin resistance (IR) may develop. Chemerin is secreted in white adipose tissue and promotes low-grade inflammatory process, where it expressed CMKLR1 receptor. The role of chemerin and CMKLR1 in inflammatory process secondary to obesity is not defined yet. METHODS: Cross-sectional study with 134 individuals classified as with and without obesity by body mass index (BMI) and IR. Body fat storage measurements and metabolic and inflammatory markers were measured by routine methods. Soluble chemerin and basal levels of insulin by ELISA and relative expression of CMKLR1 were evaluated with qPCR and 2(-ΔΔCT) method. RESULTS: Differences (P < 0.05) were observed between obesity and lean individuals in body fat storage measurements and metabolic-inflammatory markers. Both CMKLR1 expression and chemerin levels were increased in obesity without IR. Soluble chemerin levels correlate with adiposity and metabolic markers (r = 8.8% to 38.5%), P < 0.05. CONCLUSION: The increment of CMKLR1 expression was associated with insulin production. Increased serum levels of chemerin in obesity were observed, favoring a dysmetabolic response. The results observed in this study suggest that both chemerin and CMKLR1 have opposite expression in the context of low-grade inflammatory response manifested in the development of IR.

Human cytomegalovirus UL55, UL144, and US28 genotype distribution in infants infected congenitally or postnatally.

Cytomegalovirus (CMV) is the most common cause of congenital infection. This pathogen exhibits extensive genetic variability in the genes that encode structural envelope glycoproteins, regulatory proteins, and proteins that contribute to immune evasion. However, the role of specific viral strains in the outcome of congenital CMV infection is unclear. Variation in the UL55 gene encoding glycoprotein B (gB), the UL144 gene encoding TNF α-like receptor, and the US28 gene encoding ß-chemokine receptor was determined in 60 newborn infants with congenital CMV infection and 90 infants with postnatal or undefined CMV infection. CMV polymorphisms were studied in relation to disease outcome and viral load. Genotyping was performed by a sequencing analysis of PCR-amplified fragments, and the viral load was measured by quantitative real-time PCR. The results demonstrated that (1) the UL55 and US28 genotype distributions were similar among the group of congenital and postnatal CMV infection; (2) the UL144 B1 genotype was more prevalent in congenital than in postnatal infection and was detected in 70% of newborns with asymptomatic congenital infection; and (3) none of the examined genotype was significantly linked with symptomatic CMV infection. No relationship was observed between genotype and viral load. The results revealed that UL55, UL144, and US28 polymorphisms are not associated with the outcome of CMV infection in infants, but the presence of UL144 B1 genotype might be virological marker of asymptomatic infection at birth.

Association of hydrogen sulfide with alterations of monocyte chemokine receptors, CCR2 and CX3CR1 in patients with coronary artery disease.

OBJECTIVES: Recent data in human and mice suggest that monocyte chemokine receptors CX3CR1 and CCR2 are involved in the pathogenesis of atherosclerosis. Our previous study showed that hydrogen sulfide, a novel gaseous mediator hampered the progression of atherosclerosis in fat-fed apoE(-/-) mice with downregulating CX3CR1 and CX3CL1 expressions. However, there is a paucity of information regarding the clinical association between endogenous H2S metabolism and alterations of monocyte chemokine receptors in patients with cardiovascular disease. Therefore, in this study, we investigated circulating monocyte heterogeneity with differential expressions of CCR2 and CX3CR1 and its relevance to plasma H2S level in patients with coronary artery disease (CAD). METHODS: Sixty-three CAD patients with acute coronary syndrome (ACS, n = 46) or stable angina pectoris (SAP, n = 17) undergoing either percutaneous coronary intervention or coronary angiography and eleven non-CAD patients were enrolled in the study. Plasma levels of H2S as well as chemokines (CCL2 and CX3CL1) and expressions of CCR2 and CX3CR1 on peripheral monocytes were measured. RESULTS: It was found that plasma H2S level was significantly reduced, whereas plasma CCL2 and CX3CL1 levels were substantially elevated in patients with ACS, as compared with patients with SAP or non-CAD patients. Furthermore, patients with ACS had significantly higher proportion of CD14(+)CCR2(+)CX3CR1(+) and CD14(+)CCR2(-)CX3CR1(+) monocytes but lower percentage of CD14(+)CCR2(+)CX3CR1(-) monocytes than SAP or non-CAD patients did. Lastly, plasma H2S level showed a significantly negative correlation with the proportion of CD14(+)CCR2(+)CX3CR1(+) monocytes, but not other monocyte subsets. CONCLUSIONS: These data indicate that decreased endogenous H2S production may predispose stable CAD patients to rupture of vulnerable plaque and thus to ACS, probably in relation to circulating monocyte phenotypic transformation with differential expressions of CCR2 and CX3CR1.

Expression of chemokine receptors on peripheral blood T cells in children with chronic kidney disease.

Chemokine receptors play a role in leukocyte recruitment, activation, and maintaining effector functions and regulate adaptive immune response and angiogenesis. The study aimed at flow cytometric analysis of T cell subsets with selected surface chemokine receptors (CCR4, CCR5, CCR7, CXCR3, and CXCR4) or receptor combination in peripheral blood of children with chronic kidney disease (CKD) on hemodialysis (HD). The percentage of T lymphocytes with CD8 and combined CD28,CCR7 expression was higher in HD children. The percentage of T lymphocytes expressing CCR7, CD28,CCR7, and CXCR4,CD8 was increased in children on conservative treatment. Total number (tn) of CXCR4+ cells was reduced in children on hemodialysis. The tn of T CXCR3+ cells was lower in children on conservative treatment. During HD the percentage of T CD4+ cells was higher and of T CXCR3+ lymphocytes was lower after HD session as compared to 15 min of session duration. During HD tn of T cells with expression of CCR4, CCR5, CCR7, CXCR3, and CXCR4 was constant. The alteration of chemokine receptors expression in children with CKD occurs early in the development. Diminished expression of CXCR3, CXCR4 on T cells in patients with CKD on HD might result in impaired inflammatory response. Increased CCR7+ T cell percentage could be responsible for the alteration of migration of cells into secondary lymphatic organs.

Chemokine Receptors CXCR3 and CCR6 and Their Ligands in the Liver and Blood of Patients with Chronic Hepatitis C.

We performed a comprehensive analysis of CCR6 and CXCR3 chemokine receptors and their ligands CCL20/MIP-3α, CXCL9/MIG, CXCL10/IP-10, and CXCL11/ITAC in the liver and blood of patients with chronic hepatitis C at different stages of the disease. TaqMan PCR was used to determine mRNA gene expression of chemokines and their receptors in liver specimens, xMAP multiplex analysis was performed to estimate the concentration of chemokines in blood plasma, and fl ow cytofluorometry was used to evaluate CCR6 and CXCR3 expression on peripheral blood lymphocyte populations. In the liver of patients with hepatitis C, mRNA expression of CXCL10, CCR6, and CXCR3 genes increases with fibrosis progression in the liver tissue. In the plasma, concentrations of all studied chemokines increased depending on the stage of liver fibrosis, CCR6 and CXCR3 expression was changed in various lymphocyte populations. Thus, chemokines are involved in the immunopathogenesis and fibrogenesis in chronic viral hepatitis C. The results suggest using these chemokines in the diagnosis and prognosis of the disease.

Elevated serum CXCL16 is an independent predictor of poor survival in ovarian cancer and may reflect pro-metastatic ADAM protease activity.

BACKGROUND: In certain cancers, expression of CXCL16 and its receptor CXCR6 associate with lymphocyte infiltration, possibly aiding anti-tumour immune response. In other cancers, CXCL16 and CXCR6 associate with pro-metastatic activity. In the current study, we aimed to characterise the role of CXCL16, sCXCL16, and CXCR6 in ovarian cancer (OC). METHODS: CXCL16/CXCR6 expression was analysed on tissue microarray containing 306 OC patient samples. Pre-treatment serum sCXCL16 was determined in 118 patients using ELISA. In vitro, (primary) OC cells were treated with an ADAM-10/ADAM-17 inhibitor (TAPI-2) and an ADAM-10-specific inhibitor (GI254023x), whereupon CXCL16 levels were evaluated on the cell membrane (immunofluorescent analysis, western blots) and in culture supernatants (ELISA). In addition, cell migration was assessed using scratch assays. RESULTS: sCXCL16 independently predicted for poor survival (hazard ratio=2.28, 95% confidence interval=1.29-4.02, P=0.005), whereas neither CXCL16 nor CXCR6 expression correlated with survival. Further, CXCL16/CXCR6 expression and serum sCXCL16 levels did not associate with lymphocyte infiltration. In vitro inhibition of both ADAM-17 and ADAM-10, but especially the latter, decreased CXCL16 membrane shedding and strongly reduced cell migration of A2780 and cultured primary OC-derived malignant cells. CONCLUSIONS: High serum sCXCL16 is a prognostic marker for poor survival of OC patients, possibly reflecting ADAM-10 and ADAM-17 pro-metastatic activity. Therefore, serum sCXCL16 levels may be a pseudomarker that identifies patients with highly metastatic tumours.

Elevated expression of CX3C chemokine receptor 1 mediates recruitment of T cells into bone marrow of patients with acquired aplastic anaemia.

OBJECTIVE: Acquired aplastic anaemia (AA) is a T-cell-mediated, organ-specific autoimmune disease characterized by haematopoietic stem cell destruction in the bone marrow. The exact molecular mechanism of T-cell trafficking into the bone marrow is unclear in AA. Very late activation antigen-4 (VLA-4) and CX3C chemokine receptor 1 (CX3CR1) play active roles in many autoimmune diseases. Therefore, we investigated whether VLA-4 and CX3CR1 also contribute to T-cell migration into the bone marrow in acquired AA. DESIGN, SETTING AND SUBJECTS: Expression levels of CX3CR1 and VLA-4 and their ligands [fractalkine (CX3CL1) and vascular cell adhesion molecule-1 (VCAM-1)] were examined in 63 patients with AA and 21 healthy control subjects. T-cell chemotaxis and adhesion were analysed in 17 patients with severe AA. We also prospectively evaluated the expression pattern of CX3CR1 during treatment with antithymocyte globulin plus cyclosporine in 11 patients with severe AA. RESULTS: The proportion of peripheral and bone marrow CD4(+) and CD8(+) T cells expressing CX3CR1 and the level of CX3CL1 was increased in patients with AA. However, there was no significant difference in VLA-4 expression or VCAM-1 levels. Functional studies demonstrated that chemotaxis towards autologous bone marrow plasma or soluble CX3CL1 was significantly higher in T cells from AA patients and could be blocked by CX3CR1 inhibitors. CX3CR1-mediated T-cell adhesion was also upregulated in these patients. The expression of CX3CR1 was associated with the efficacy of immunosuppressive therapy. CONCLUSION: The present findings demonstrate that CX3CR1 plays a pivotal role in recruitment of T cells into the bone marrow in acquired AA and is a potential therapeutic target for treatment of this disorder.

Decidual cell regulation of natural killer cell-recruiting chemokines: implications for the pathogenesis and prediction of preeclampsia.

First trimester human decidua is composed of decidual cells, CD56(bright)CD16(-) decidual natural killer (dNK) cells, and macrophages. Decidual cells incubated with NK cell-derived IFN-γ and either macrophage-derived TNF-α or IL-1ß synergistically enhanced mRNA and protein expression of IP-10 and I-TAC. Both chemokines recruit CXCR3-expressing NK cells. This synergy required IFN-γ receptor 1 and 2 mediation via JAK/STAT and NFκB signaling pathways. However, synergy was not observed on neutrophil, monocyte, and NK cell-recruiting chemokines. Immunostaining of first trimester decidua localized IP-10, I-TAC, IFN-γR1, and -R2 to vimentin-positive decidual cells versus cytokeratin-positive interstitial trophoblasts. Flow cytometry identified high CXCR3 levels on dNK cells and minority peripheral CD56(bright)CD16(-) pNK cells and intermediate CXCR3 levels on the majority of CD56(dim)CD16(+) pNK cells. Incubation of pNK cells with either IP-10 or I-TAC elicited concentration-dependent enhanced CXCR3 levels and migration of both pNK cell subsets that peaked at 10 ng/mL, whereas each chemokine at a concentration of 50 ng/mL inhibited CXCR3 expression and pNK cell migration. Deciduae from women with preeclampsia, a leading cause of maternal and fetal morbidity and mortality, displayed significantly lower dNK cell numbers and higher IP-10 and I-TAC levels versus gestational age-matched controls. Significantly elevated IP-10 levels in first trimester sera from women eventually developing preeclampsia compared with controls, identifying IP-10 as a novel, robust early predictor of preeclampsia.

Effect of lifestyle modification on serum chemerin concentration and its association with insulin sensitivity in overweight and obese adults with type 2 diabetes.

OBJECTIVE: Chemerin, a recently identified adipokine, has been linked to adiposity, insulin resistance, metabolic syndrome risk factors and inflammation. Here, we evaluated whether a 12-week lifestyle intervention in overweight and obese adults with type 2 diabetes could significantly affect the average blood glucose and serum chemerin levels over time. DESIGN: Thirty-five overweight or obese subjects with type 2 diabetes were randomized to receive intensive lifestyle modification including supervised exercise sessions or usual care for 12 weeks. Anthropometric and clinical data were collected before the intervention and after 12 weeks. RESULTS: Lifestyle intervention induced a significant decrease in HbA1c (-1·0 ± 0·5 vs 0·1 ± 0·6%, P < 0·001), BMI, total body fat content, serum lipocalin-2 and chemerin levels (-8·1 ± 21·6 vs + 8·2 ± 15·9 ng/ml, P = 0·021) and a significant increase in VO2 max after 12 weeks compared to the usual care group. Baseline chemerin levels were positively correlated with the homoeostasis model of assessment of insulin resistance (HOMA-IR), fasting insulin and the high-sensitivity C-reactive protein (hsCRP) and negatively correlated with insulin sensitivity index (ISI). Changes in the chemerin concentration during 12 weeks were independently negatively correlated with changes in ISI and positively correlated with changes in fasting plasma glucose, total cholesterol and lipocalin-2 levels. CONCLUSIONS: A 12-week intensive lifestyle intervention significantly decreased serum chemerin level compared to usual care. Decrease in serum chemerin level was associated with improved insulin sensitivity, and this may be involved in the beneficial effects of lifestyle intervention in overweight and obese type 2 diabetic patients.

Chemokine levels and chemokine receptor expression in the blood and the cerebrospinal fluid of HIV-infected patients with cryptococcal meningitis and cryptococcosis-associated immune reconstitution inflammatory syndrome.

BACKGROUND: Human immunodeficiency virus-infected patients with treated cryptococcal meningitis who start combination antiretroviral therapy (cART) are at risk of further neurological deterioration, in part caused by paradoxical cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS). We hypothesized that C-IRIS is associated with alterations of chemokine receptor expression on T cells and chemokine concentrations in cerebrospinal fluid (CSF) that enhance recruitment of T-helper 1 cells and/or myeloid cells to the central nervous system. METHODS: In a prospective study of 128 human immunodeficiency virus-infected patients with cryptococcal meningitis who received antifungal therapy followed by cART, we examined the proportions of CD4(+) and CD8(+) T cells expressing CCR5 and/or CXCR3, in CSF and whole blood and the concentrations of CXCL10, CCL2, and CCL3 in stored CSF and plasma. RESULTS: The proportion of CD4(+) and CD8(+) T cells expressing CXCR3(+)CCR5(+) and the concentrations of CXCL10, CCL2 and CCL3 were increased in CSF compared with blood at cART initiation (P < .0001). Patients with C-IRIS (n = 26), compared with those with no neurological deterioration (n = 63), had higher CSF ratios of CCL2/CXCL10 and CCL3/CXCL10 and higher proportions of CXCR3(+)CCR5(+)CD8(+)T cells in CSF compared with blood at cART initiation (P = .03, .0053, and .02, respectively). CONCLUSION: CD8(+) T-cell and myeloid cell trafficking to the central nervous system may predispose patients to C-IRIS.

Increased accumulation of CD16+ monocytes at local sites of inflammation in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) display a high prevalence of cardiovascular events and acute infections. Potential effector cells are the CD16(+) monocytes, known to be increased in the peripheral circulation in CKD. The aim of this study was to assess the expression of CD16 and CX3 CR1 on peripheral and in vivo extravasated monocytes in patients with CKD (GFR < 20 ml/min × 1.73 m²) using flow cytometry. In vivo extravasated monocytes were collected from a local inflammatory site, induced by a skin blistering technique. Soluble markers were assessed by Luminex. The number of CD16(+) monocytes was significantly higher in patients with CKD compared with healthy subjects, both in the peripheral circulation (P < 0.05) and at the site of induced inflammation (P < 0.001). Patients with CKD displayed significantly higher concentration of soluble CX3 CL1 both in the peripheral circulation (P < 0.01) and in the interstitial fluid (P < 0.001). In addition, patients with CKD had a significantly higher concentration of TNF-α in the peripheral circulation (P < 0.001). On the contrary, at the inflammatory site, concentrations of both TNF-α and IL-10 were significantly lower in patients with CKD compared with healthy controls (P < 0.05 for both). In conclusion, patients with CKD have an increased percentage of CD16(+) monocytes in both circulation and at the inflammatory site, and this finding is in concurrence with simultaneous changes in CX3 CR1. Together with distorted TNF-α and IL-10 levels, this may have potential impact on the altered inflammatory response in CKD.

Changes in chemokines and their receptors in blood during treatment with the TNF inhibitor infliximab in patients with rheumatoid arthritis.

OBJECTIVES: Chemokines are involved in leucocyte recruitment into inflammatory sites. The release of certain chemokines is augmented by tumour necrosis factor (TNF). Infliximab, a monoclonal antibody that blocks the effects of TNF, is used for treatment of rheumatoid arthritis (RA). The effect of TNF blockage on chemokines is not fully understood. The aim of this study was to analyse the effects on chemokines and their receptors on peripheral mononuclear cells of anti-TNF treatment in RA patients. METHOD: Twelve patients with established RA who started treatment with infliximab and nine patients with early RA treated with other anti-rheumatic drugs were followed clinically for 30 weeks and chemokine levels in blood samples were analysed along with chemokine receptor expression on the surface of T cells and monocytes. Nine healthy subjects were included as a control group. RESULTS: The chemokine CXCL10/IP-10 was significantly higher in RA patients than in healthy controls (p = 0.012). Two weeks after infliximab infusion, CXCL10/IP-10, CCL2/MCP-1, and CCL4/MIP-1ß had decreased significantly (p = 0.005, 0.037, and 0.028, respectively), and after 30 weeks of treatment, soluble CD26 was significantly increased (p = 0.050). Several chemokine receptors on T cells were elevated in RA patients at inclusion. The expression of CCR2 and CXCR1 on T cells decreased significantly after infliximab treatment. CONCLUSIONS: The chemokines CXCL10/IP-10, CCL2/MCP-1, and CCL4/MIP-1ß, mainly targeting the T-helper (Th)1 immune response, decreased after treatment with anti-TNF, suggesting a more pronounced effect on Th1 activity than on Th2-mediated response. Several chemokine receptors on blood T cells were elevated in RA patients, suggesting that they may be involved in the recruitment of T lymphocytes from the blood to affected tissues.

Regulation of chemerin chemoattractant and antibacterial activity by human cysteine cathepsins.

Chemerin, a ligand for the G-protein coupled receptor chemokine-like receptor 1, requires C-terminal proteolytic processing to unleash its chemoattractant activity. Proteolytically processed chemerin selectively attracts specific subsets of immunoregulatory APCs, including chemokine-like receptor 1-positive immature plasmacytoid dendritic cells (pDC). Chemerin is predicted to belong to the structural cathelicidin/cystatin family of proteins composed of antibacterial polypeptide cathelicidins and inhibitors of cysteine proteinases (cystatins). We therefore hypothesized that chemerin may interact directly with cysteine proteases, and that it might also function as an antibacterial agent. In this article, we show that chemerin does not inhibit human cysteine proteases, but rather is a new substrate for cathepsin (cat) K and L. cat K- and L-cleaved chemerin triggered robust migration of human blood-derived pDC ex vivo. Furthermore, cat K- and L-truncated chemerin also displayed antibacterial activity against Enterobacteriaceae. Cathepsins may therefore contribute to host defense by activating chemerin to directly inhibit bacterial growth and to recruit pDC to sites of infection.

A role for immature myeloid cells in immune senescence.

The reduced efficiency of the mammalian immune system with aging increases host susceptibility to infectious and autoimmune diseases. However, the mechanisms responsible for these pathologic changes are not well understood. In this study, we demonstrate that the bone marrow, blood, and secondary lymphoid organs of healthy aged mice possess increased numbers of immature myeloid cells that are phenotypically similar to myeloid-derived suppressor cells found in lymphoid organs of mice with progressive tumors and other pathologic conditions associated with chronic inflammation. These cells are characterized by the presence of Gr1 and CD11b markers on their surfaces. Gr1(+)CD11b(+) cells isolated from aged mice possess an ability to suppress T cell proliferation/activation and produce heightened levels of proinflammatory cytokines, both constitutively and upon activation, including IL-12, which promotes an excessive production of IFN-γ. IFN-γ priming is essential for excessive proinflammatory cytokine production and the suppressive activities by Gr1(+)CD11b(+) cells from aged mice. These cells suppress T cell proliferation through an NO-dependent mechanism, as depletion of splenic Gr1(+) cells reduces NO levels and restores T cell proliferation. Insights into mechanisms responsible for the proinflammatory and immune suppressive activities of Gr1(+)CD11b(+) cells from aged mice have uncovered a defective PI3K-Akt signaling pathway, leading to a reduced Akt-dependent inactivation of GSK3ß. Our data demonstrate that abnormal activities of the Gr1(+)CD11b(+) myeloid cell population from aged mice could play a significant role in the mechanisms responsible for immune senescence.

Expression of resistin, CXCR3, IP-10, CCR5 and MIP-1α in obese patients with different severity of asthma.

Asthma studies suggest that alteration in the inflammation pattern may be associated with the severity of asthma. The aim of this study was to compare in vitro the expression of chemokines, chemokine receptors and cytokine production from CD4+ T human lymphocytes of asthmatic, both obese and non-obese patients with different severity levels of asthma. Lymphocytes were labeled with monoclonal anti-human CXCR3/IP-10, MIP-1a/CCR5 antibodies and were analyzed by flow cytometry. Cell culture supernatants were used to measure production of interleukin IL-6 and resistin by ELISA. CXCR3/IP-10 expression increased in non-obese patients with mild persistent asthma (2.2%, p<0.05), moderate persistent asthma (3%, p<0.003) and severe persistent asthma (4%, p<0.004); this effect was stronger in obese patients with severe persistent asthma (35%, p<0.004). MIP-1 α / CCR5 increased in non-obese patients with intermittent asthma (0.65%, p<0.05) and severe asthma (1.4%, p<0.03); in obese patients, this expression was greater in intermittent asthma (8%, p<0.05) and severe persistent asthma (12%, p<0.04). Resistin production strongly increased in obese patients with intermittent (976 ng/ml) and severe persistent asthma (795 ng/ml). IL-6 increased in both lean and obese persons; however, the highest value was registered in the group of severe persistent obese asthmatics (992 pg/ml). Obesity per se increased the inflammatory profile of chemokines / cytokines secreted by cells of the blood, increasing the inflammatory status in asthmatic patients. Resistin showed characteristics of a pro-inflammatory cytokine mainly in severely obese asthmatics.