Aberrant expression of CC and CXC chemokines and their receptors in patients with asthma

Cytokine antibody array-based analysis of IL-37 treatment effects in asthma

Asthma is driven by group 2 innate lymphoid cells, antigen-specific CD4+ T helper type 2 cells and their cytokines such as interleukin (IL)-4, IL-5, IL-13. IL-37 is decreased in asthma and negatively related to Th2 cytokines and other pro-inflammatory cytokines. Our study showed that IL-37 level in asthmatic peripheral blood mononuclear cells was lower than in healthy. Further, IL-37 was negatively correlated with exhaled nitric oxide, asthma control test score, atopy and rhinitis history in asthmatics. Then an OVA-induced asthma mice model treated with rhIL-37 was established. An antibody array was employed to uncover altered cytokines induced by IL-37 in mice lung tissue. 20 proteins differentially expressed after rhIL-37 treatment and five of them were validated in asthmatic peripheral blood mononuclear cells. Consistent with cytokine antibody array, CCL3, CCL4, CCL5 decreased after IL-37 administration. While CXCL9 and CXCL13 were no change. We concluded that IL-37 reduce asthmatic symptoms by inhibit pro-inflammatory cytokine such as CCL3, CCL4, CCL5.

Decrease of IL-5 Production by Naive T Cells Cocultured with IL-18-Producing BCG-Pulsed Dendritic Cells from Patients Allergic to House Dust Mite

The only currently available anti-tuberculosis vaccine, Bacillus Calmette–Guérin (BCG), has been reported to also protect against unrelated diseases, including inflammatory diseases such as allergic asthma. Recombinant BCG strains that produce IL-18 have been shown to enhance Th1 responses over non-recombinant BCG and to reduce IL-5 production and bronchoalveolar eosinophilia in mice. However, their ability to decrease the immune polarization of human Th2 cells is not known. Here, we show that BCG and recombinant BCG producing human IL-18 (rBCG-hIL-18) induced the maturation of Der p 1-stimulated monocyte-derived dendritic cells (MD-DCs) from healthy controls and from patients allergic to house dust mites. After incubation with mycobacteria and Der p 1, MD-DCs produced significantly more IL-23 and IP-10 but had no effect on IL-12p70 or IL-10 production compared to Der p 1-pulsed MD-DCs in the absence of mycobacteria. In the presence of Der p 1, BCG- and rBCG-hIL-18-pulsed MD-DCs cocultured with naive, but not with memory T cells from allergic patients, resulted in a decrease in IL-5 production compared to non-pulsed MD-DCs cultured in the presence of Der p 1. BCG, and especially rBCG-hIL-18, may thus be potential therapeutic tools to reduce exacerbated Th2 responses in patients with allergic asthma.

Relationship between chemokines and T lymphocytes in the context of respiratory allergies (Review)

Allergic diseases have been classified in the last decades using various theories. The main classes of the newest classification in allergic respiratory diseases focus on the characterization of the endotype (which takes into account biomarkers related to determinant pathophysiological mechanisms) and of the phenotype (based on the description of the disease). Th2, Th1 and Th17 lymphocytes and the type of inflammatory response mediated by them represent the basis for Th2 and non-Th2 endotype classification. In addition, new lymphocytes were also used to characterize allergic diseases: Th9 lymphocytes, Th22 lymphocytes, T follicular helper cells (T_FH) lymphocytes and invariant natural killer T (iNKT) lymphocytes. In the last decade, a growing body of evidence focused on chemokines, chemoattractant cytokines, which seems to have an important contribution to the pathogenesis of this pathology. This review presents the interactions between chemokines and Th lymphocytes in the context of Th2/non-Th2 endotype classification of respiratory allergies.

Evaluation of C-C Chemokine Ligand 5 (CCL5) Chemokine, Interleukin 5 (IL-5) Cytokine, and Eosinophil Counts as Potential Biomarkers in Saudi Patients with Chronic Asthma During Sandstorms

Background and objectives

Asthma is a common chronic inflammatory disorder of the lung that can be exacerbated by environmental triggers during sandstorms. This study aimed to evaluate the usefulness of C-C chemokine ligand 5 (CCL5) chemokine and interleukin 5 (IL-5) cytokine and determine the total eosinophil count in blood and sputum for use as biomarkers in Saudi patients with chronic asthma who visited emergency departments during sandstorms.

Methods

The study included 42 Saudi patients with chronic asthma and 20 healthy controls. Plasma levels of CCL5, IL-5, and total immunoglobulin E (IgE) were measured using a specific enzyme-linked immunosorbent assay (ELISA). Total eosinophils in peripheral blood were counted using a hematology analyzer (CELL-DYN Ruby System; Abbott Diagnostics, Chicago, Illinois); in sputum, eosinophils stained with Giemsa were examined under a microscope, counted, and expressed as a percentage of the total cells.

Results

Total IgE levels were significantly higher in patients with asthma (mean 433 IU/ml, P = 0.0001) as compared to normal controls (139 IU/ml). There was no significant difference in the levels of CCL5 in patients with asthma (625 pg/ml) as compared to normal controls (663 pg/ml, P = 0. 57). No correlation was found between total IgE and CCL5 levels. IL-5 was not detected in patients with asthma or in controls. Moreover, the total counts of eosinophils in the blood did not increase in patients with asthma as compared to controls while eosinophils in sputum samples were increased in the former (mean =3.128%).

Conclusion

Plasma levels of CCL5 and IL-5 or eosinophil counts in the peripheral blood may not be useful diagnostic biomarkers to evaluate airway inflammation and monitor asthma severity. Conversely, the sputum eosinophil count may represent a useful diagnostic marker for assessing the magnitude of asthma exacerbation during sandstorms.

Gene Expression Analysis in Sinonasal Polyposis before and after Oral Corticosteroids: A Preliminary Investigation

OBJECTIVE: To characterize gene expression in sinonasal polyps and to gain insight into change in expression after oral corticosteroid treatment.

STUDY DESIGN AND METHODS: Nasal polyps were obtained before and after oral corticosteroid treatment and gene expression was analyzed with a focused gene array technique.

RESULTS: Pretreated sinonasal polyps demonstrated high gene expression for chemokine and leukotriene receptor genes (CCR2, CCR5, CX3CL1, and LTB4R) in all patients. After treatment, the global effects of corticosteroids were evident on gene expression.

CONCLUSIONS: Gene array techniques hold promise as a research method in sinonasal polyposis. The potential benefits, as well as the potential challenges, in using these research methods will be discussed.

Selected CC and CXC chemokines in children with atopic asthma

INTRODUCTION

There are only limited data on CC and CXC chemokines regulation in children with asthma.

AIM

We compared the serum profile of selected CC and CXC chemokines in patients with atopic asthma and healthy children.

MATERIAL AND METHODS

Serum concentration of CC chemokines RANTES, MCP-1, and CXC chemokines IP-10, MIG, IL-8, RANTES was measured using cytometric bead array in 44 children with atopic asthma and 17 healthy subjects.

RESULTS

The concentration of RANTES was significantly higher and the MIG level was lower in all children with asthma as compared to their control counterparts. We observed increased RANTES and decreased MIG levels also in patients with stable asthma when compared with children in the control group. The IP-10 concentration was similar between the whole asthma group and healthy controls, while significantly increased levels of this chemokine in acute asthma have been observed when compared to stable asthma. For MCP-1 and IL-8, the serum concentration was similar in all compared groups. The MIG concentration correlated positively with IP-10, IL-8, and CRP levels and negatively with the eosinophil count. A negative correlation between the IP-10 and eosinophil count and a negative correlation between FEV1 and IP-10 were found.

CONCLUSIONS

An increased serum RANTES level in children with asthma may result in enhancement of Th2 lymphocyte recruitment into the airway. A decreased expression of Th1 chemokine MIG in children with stable asthma may contribute to a diminished antagonizing effect on Th2 cytokine production and hence intensify Th2 predominance. An increased IP-10 level in children during an asthma attack suggest that this chemokine is a serological marker of disease exacerbation.

Aberrant expression of regulatory cytokine IL-35 and pattern recognition receptor NOD2 in patients with allergic asthma

We investigated the plasma concentration of the novel regulatory cytokine IL-35 and intracytosolic pattern recognition receptors nucleotide-binding oligomerization domain (NOD)-like receptors in granulocytes and explored their potential implication in disease severity monitoring of allergic asthma. The expression of circulating IL-35 and other pro-inflammatory mediators in asthmatic patients or control subjects were evaluated using enzyme-linked immunosorbent assay (ELISA). The intracellular expressions of NOD1 and NOD2 in CCR3+ granulocytes were assessed using flow cytometry. Plasma concentrations of IL-35, IL-17A, basophil activation marker basogranulin, and eosinophilic airway inflammation biomarker periostin were significantly elevated in allergic asthmatic patients compared to non-atopic control subjects (all probability (p) <0.05). Both granulocyte markers exhibited significant and positive correlation with plasma IL-35 concentration in asthmatic patients (all p < 0.05). Significant positive correlation was also identified between plasma concentrations of IL-35 and periostin with disease severity score in asthmatic patients (both p < 0.05). The basophil activation allergenicity test was positive in allergic asthmatic patients but not in control subjects. Despite significantly elevated eosinophil count in allergic asthmatic patients, downregulation of NOD2 in CCR3+ granulocytes was observed in these patients (both p < 0.05). A negative correlation between plasma concentrations of tumor necrosis factor family member LIGHT and soluble herpesvirus entry mediator was observed in patients with elevated plasma concentration of IL-35 (p < 0.05). Aberrant expression of NOD2 in granulocytes may be contributed to the impaired innate immunity predisposing allergic asthma. IL-35 may serve as a potential surrogate biomarker for disease severity of allergic asthma.

Expression of Th1, Th2, lymphocyte trafficking and activation markers on CD4+ T-cells of Hymenoptera allergic subjects and after venom immunotherapy

Systemic reactions to Hymenoptera stings can be fatal and represent a reduction in the quality of life. The immune mechanisms involved in venom allergic subjects are barely known. Nevertheless, a shift towards a Th1-type response with an increase in IFNγ levels has been observed after venom immunotherapy (VIT). There is currently no information available about the expression of markers on CD4+ T-cells or their involvement in venom allergy, nor following VIT. For this, we have studied the expression of Th1 and Th2-cell markers, homing receptors and activation markers on CD4+ T-cells of subjects who presented systemic allergic reactions, mainly to Polistes dominulus, and after receiving a 4-month conventional VIT protocol. The markers studied were: CD26 (Th1), CD30 (Th2), CXCR4, CXCR3 (Th1), CCR4 (Th2), CD154 (CD40L), CD152 (CTLA-A), and ICOS. We also determined the IL-4 (Th2) and IFNγ (Th1) intracellular cytokine levels in T-cells and carried out a basophil activation test (BAT). Comparing venom allergic subjects with non-allergic healthy controls, we have found up-regulation of CD26, CXCR4, CXCR3, CD154 and ICOS. Conversely, a down-regulation of CD30, CD154 and CD152 occurred upon immune intervention, whereas the remaining markers were not affected. Equally, VIT has been shown to be effective, as evidenced by the decrease of basophil degranulation and increase of IFNγ levels in T-cells after the fourth month of treatment. These new findings highlight the possible application of these surface molecules as markers to distinguish between symptomatic and asymptomatic subjects sensitized to Hymenoptera venom, as well as revealing information about the immune changes associated with VIT.

Serum chemokines RANTES and monocyte chemoattractant protein-1 in Egyptian patients with atopic asthma: relationship to disease severity

BACKGROUND AND AIMS

Asthma is a highly prevalent, complex inflammatory disease of the airways often associated with bronchial hyperreactivity and atopy. The chemokine RANTES (regulated upon activation, normal T -cell expressed and secreted) is an important element for the chemotaxis at the site of allergic inflammation. This study aimed to assess the serum levels of the chemokines RANTES and monocyte chemoattractant protein-1 (MCP-1) in Egyptian patients with atopic asthma and to evaluate their possible relation t the severity of airway obstruction.

METHODS

The study included 60 Egyptian patients with atopic asthma and 20 healthy volunteers. Serum levels of the chemokines RANTES and MCP-1 were measured. Total serum IgE level and absolute eosinophil counts were determined. The severity of airway obstruction was assessed using spirometric measurement (FEV(1)).

RESULTS

The serum levels of RANTES were significantly higher in all asthmatic patients than the controls (p <0.001). Moreover, RANTES levels were significantly increased in patients with moderate and severe asthma as compared to those with mild asthma (p <0.001). Serum RANTES correlated positively with absolute eosinophil counts and total serum IgE and negatively with FEV(1), whereas there was no significant correlation with serum MCP-1 in all asthmatic patients.

CONCLUSIONS

Serum RANTES may be used as a useful noninvasive marker of airway obstruction and a potential diagnostic tool for monitoring asthma severity. In this regard, identification and blocking of this chemokine and/or its receptor may be a promising therapeutic approach to asthmatic patients.

Decreased interleukin-18 response in asthmatic children with severe Mycoplasma pneumoniae pneumonia

Purpose

Mycoplasma pneumoniae (M. pneumoniae) is a common causative agent of pneumonia in children. The aim of this study is to determine whether there is any difference in selected cytokine or chemokines response in asthmatic children compared to non-asthmatic children during acute M. pneumoniae pneumonia.

Methods

Seventy-five children, 6–12 years of age, admitted with M. pneumoniae pneumonia were enrolled. Two patient groups were defined: the children with known asthma (N = 40) and non-asthmatic children (N = 35). Interleukin (IL)-18 and selected chemokines, IL-8, CXCL9, CXCL10, and regulation upon activation normal T-cell expressed and secreted (RANTES) were measured by means of ELISA in the plasma samples of the patients collected on admission. We investigated the values of these mediators in relation to the asthma status and symptom severity of the patients. Twenty age-matched, non-infected controls were also studied.

Results

Plasma levels of IL-18 and the chemokines increased significantly in the patients with M. pneumoniae pneumonia compared to non-infected, age-matched controls (P < 0.01). However, the asthmatic patients showed significantly reduced IL-18 and CXCL10 responses (P < 0.01, <0.05, respectively) and had more severe pneumonia symptoms (P < 0.01) compared to non-asthmatic patients. IL-18 was significantly lower in severe pneumonia group than in non-severe group (P < 0.05).

Conclusions

Our study suggests that IL-18 and the chemokines are importantly involved in the pathogenesis of M. pneumoniae pneumonia. It also indicates that some asthmatic children have deficient IL-18 response when affected by M. pneumoniae pneumonia, which might be associated with more severe pneumonia observed in this group of patients.

Early production of IL-22 but not IL-17 by peripheral blood mononuclear cells exposed to live Borrelia burgdorferi: the role of monocytes and interleukin-1

If insufficiently treated, Lyme borreliosis can evolve into an inflammatory disorder affecting skin, joints, and the CNS. Early innate immunity may determine host responses targeting infection. Thus, we sought to characterize the immediate cytokine storm associated with exposure of PBMC to moderate levels of live Borrelia burgdorferi. Since Th17 cytokines are connected to host defense against extracellular bacteria, we focused on interleukin (IL)-17 and IL-22. Here, we report that, despite induction of inflammatory cytokines including IL-23, IL-17 remained barely detectable in response to B. burgdorferi. In contrast, T cell-dependent expression of IL-22 became evident within 10 h of exposure to the spirochetes. This dichotomy was unrelated to interferon-γ but to a large part dependent on caspase-1 and IL-1 bioactivity derived from monocytes. In fact, IL-1β as a single stimulus induced IL-22 but not IL-17. Neutrophils display antibacterial activity against B. burgdorferi, particularly when opsonized by antibodies. Since neutrophilic inflammation, indicative of IL-17 bioactivity, is scarcely observed in Erythema migrans, a manifestation of skin inflammation after infection, protective and antibacterial properties of IL-22 may close this gap and serve essential functions in the initial phase of spirochete infection.

Spatial and temporal expression of CCR3 and the common beta chain of the IL-3, IL-5 and GM-CSF receptor in the nasal epithelium and lymphoid tissues in a rat model of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) and asthma are closely related conditions that often co-exist, and are characterized by a Th2 inflammatory response where eosinophils occupy a predominant role. Strategies aimed at blocking signaling through the CC chemokine receptor 3 (CCR3) and/or the common beta chain of the IL-3, IL-5 and GM-CSF receptor (βc) efficiently reduced eosinophilic inflammation in both animal models and in asthmatic patients. This study was therefore aimed at characterizing the spatio-temporal expression pattern of βc and CCR3 using a rat model of AR.

METHODS

Sensitized rats were challenged with ovalbumin and sacrificed at 2h, 8h, 16h or 24h post-challenge. Nasal tissues were microdissected and used for mRNA quantification by QPCR, while histological evaluation determined the presence of eosinophils and mucosubstances.

RESULTS

Allergen-induced recruitment of eosinophils in the distal septum and turbinates was maximal at 8h post-challenge, and was correlated with 2-4-fold increase in CCR3 and βc mRNA. Recruitment of eosinophils was also accompanied by upregulated IL-5, IL-4Rα, TNF-α and IFN-γ mRNA at early time-points. In contrast, IL-13 and MUC5AC mRNA, as well as production of mucosubstances were maximal at 24h.

CONCLUSIONS

βc and CCR3 could play important roles in the modulation of the allergic response, and their inhibition may represent a promising therapeutic approach for AR.

Activation of peripheral Th17 lymphocytes in patients with asthma

A recently identified interleukin (IL)-17-producing T-helper (Th) lymphocyte subset, which comprises Th17 cells producing hallmark cytokines IL-17A, IL-17F and IL-22, is involved in chronic inflammatory diseases. Elevated gene and protein expressions of IL-17 are manifested in allergic asthma. We further characterized the activation of Th17 cells in asthmatic patients. Peripheral blood mononuclear cells (PBMC) were purified from 31 asthmatic patients and 20 sex- and age-matched control subjects. The number of IL-17A secreting cells in peripheral blood was enumerated by enzyme-linked immunosorbent spot assay. Cell surface expression of Th17-related chemokine receptor CCR6, and plasma level of IL-17A, IL-17F and IL-22, and ex vivo production of IL-17A and IL-22 were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. The number of peripheral Th17 lymphocytes, expression of CCR6 on Th cells, and ex vivo IL-23, anti-CD3 and anti-CD28 induced production of IL-22 by PBMC were significantly elevated in asthmatic patients compared with control subjects (all p < 0.01). This clinical study further confirmed increased number of peripheral Th17 lymphocytes and cell surface expression of CCR6 receptors on Th cells in asthmatic patients. Pro-inflammatory cytokine IL-23 can exacerbate disease severity by activating pathogenic Th17 lymphocytes to release downstream inflammatory cytokine IL-22 in asthma.

A common intronic variant of CXCR3 is functionally associated with gene expression levels and the polymorphic immune cell responses to stimuli

BACKGROUND

CXCR3 is a chemokine receptor that plays important roles in mediating chemotactic signals and modulating the activation of lymphocytes. We have previously conducted a case-control study by using a candidate gene approach to investigate the association of CXCR3 polymorphisms with the risk of asthma. Results from the epidemiologic study showed that a common nucleotide variant in the CXCR3 intron (rs2280964G>A) was associated with disease susceptibility (1006 cases and 384 control subjects; odds ratio, 0.81; 95% CI, 0.69-0.94; P = .007).

OBJECTIVE

The aim of our study was to evaluate the epidemiologic study and provide functional evidence for the association of rs2280964G>A with asthma by investigating the effects of intronic variant on chemokine-mediated phenotypes of human-derived T cells.

METHODS

We used cell line-based in vitro and human primary T cell-based ex vivo studies to examine the functional consequences of the intronic polymorphism, focusing on the regulation of gene expression, splicing, and immune responsiveness toward activating signals.

RESULTS

We present functional evidence indicating that the rs2280964A allele significantly correlates with decreased CXCR3 gene expression, which would lead to variation in immune cell responses to chemokine-cytokine signals in vitro and ex vivo that includes a decrease in chemotactic activity.

CONCLUSION

These findings, in conjunction with those of our previous epidemiologic studies, might implicate a functional link between a common nucleotide variant of a chemokine receptor gene, CXCR3, and a cause for a complex-trait disease, asthma.

Circulating levels of both Th1 and Th2 chemokines are elevated in patients with sarcoidosis

BACKGROUND

In sarcoidosis, the T helper type 1 (Th1) response tends to predominate at affected disease sites; however, whether Th1/Th2 polarization occurs in the peripheral circulation is unknown.

METHODS

Fifty-two patients with sarcoidosis and 21 healthy volunteers were investigated. The concentrations of interferon-inducible protein 10 (IP-10)/CXCL10 and thymus- and activation-regulated chemokine (TARC)/CCL17 in the serum, bronchoalveolar lavage fluid (BALF) and culture supernatant were measured by an enzyme-linked immunosorbent assay. The circulating CXCR3+ CD4+ T cells and CCR4+ CD4+ T cells were assessed by flow cytometry.

RESULTS

The CXCR3- or CCR4-positive ratios among CD4+ T cells were both higher in sarcoidosis than in healthy volunteers. The serum levels of both IP-10 and TARC of the patients with sarcoidosis were significantly higher than those of the healthy volunteers. In patients with sarcoidosis, a larger amount of IP-10 was generated by the BALF cells, whereas IP-10 production by peripheral blood mononuclear cells did not increase in comparison to the control subjects. The TARC levels produced by peripheral blood mononuclear cells of sarcoidosis patients were significantly higher than those of the controls, while no difference existed between the 2 groups regarding TARC production by BALF cells.

CONCLUSION

IP-10 is mainly produced at the lung and TARC in the peripheral circulation in sarcoidosis patients. Both IP-10 and TARC cooperatively play a role in the pathogenesis of sarcoidosis.

Intracellular JNK, p38 MAPK and NF-kappaB regulate IL-25 induced release of cytokines and chemokines from costimulated T helper lymphocytes

Novel Th2 cytokine IL-25 has been shown to be elevated in allergic inflammation. We investigated the intracellular mechanisms regulating IL-25-induced Th2 cytokines and chemokines from human Th lymphocytes upon costimulation by anti-CD3 and anti-CD28 antibodies. Cytokines, chemokines, and phosphorylated p38 mitogen activated protein kinases (MAPK), c-Jun amino-terminal kinase (JNK) and extracellular signal-regulated protein kinase were analyzed by bead-based array using flow cytometry. Nuclear factor (NF)-kappaB and total MAPK were assessed by electrophoretic mobility shift assay and Western blot, respectively. IL-25 could synergistically induce the release of Th2 cytokines IL-4, IL-5 and IL-10, inflammatory cytokine IL-6, Th1 related chemokines CXCL9 and CXCL10, and chemokine CCL5 from anti-CD3 and anti-CD28 antibodies costimulated Th cells, especially memory Th cells. Costimulation could also upregulate the cell surface expression of IL-25 receptor on Th cells. Costimulation with or without IL-25 treatment could activate JNK, p38 MAPK and NF-kappaB. The upregulation of costimulation-induced IL-25 receptors and release of cytokines and chemokines from IL-25 treated costimulated Th cells were differentially regulated by intracellular JNK, p38 MAPK and NF-kappaB activity. Therefore, the optimal activation of Th cells by IL-25 for the release of Th2 cytokines and chemokines requires the CD3 and CD28 mediated costimulation of Th cells via the upregulation of IL-25 receptors and the activation of intracellular signaling pathways. This mechanistic study shows that IL-25 and CD28 costimulation can play pathophysiological roles by inducing inflammation and hyperresponsiveness through the production of both Th2 cytokines and chemokines from memory Th cells.

Increased expression of plasma and CD4+ T lymphocyte costimulatory molecule CD26 in adult patients with allergic asthma

CD26, which is a costimulatory molecule and peptidase, is responsible for the degradation of interferon (IFN)-gamma-induced chemokines. To elucidate the immunopathological role of CD26 in allergic asthma, we investigated plasma soluble CD26 (sCD26) concentration and its cell surface expression on lymphocytes, monocytes, CD4+ T helper, CD8+ T suppressor plus cytotoxic T, invariant natural killer T (iNKT), and CD19+ B lymphocytes in allergic asthmatic patients. Plasma sCD26 was significantly elevated in asthmatic patients regardless of inhaled corticosteroid treatment (all P < 0.05). Cell surface expression of CD26 was significantly up-regulated on lymphocytes, especially on CD4+ and iNKT lymphocytes (all P < 0.05), but not on other cell types. Significant positive correlations were found between sCD26 and the percentage of eosinophils, Th2-related chemokines CCL5 and CCL22, and costimulatory molecule sCTLA-4 (all P < 0.05). In conclusion, the aberrant expression of CD26 may contribute to the inflammatory process and Th2 predominance in the immunopathogenesis of allergic asthma.

Decreased T-bet expression and changes in chemokine levels in adults with asthma

T-bet is a novel transcription factor regulating lineage commitment of T helper (Th) lymphocytes to a predominant Th1 phenotype. Previous studies on T-bet and asthma focused mainly on bronchial biopsy specimens. This study assessed the relationship between T-bet expression and levels of selected chemokines in the peripheral blood of asthmatics. Blood was collected from 24 steroid-naive asthmatics, 39 asthmatics on inhaled corticosteroid and 32 age- and sex-matched controls for assay of T-bet expression, specific IgE and chemokines (interferon-gamma inducible protein-10 (IP-10/CXCL10), monokines induced by interferon-gamma (MIG/CXCL9), monocyte chemotactic protein-1 (MCP-1/CCL2), regulated upon activation normal T cell expressed and secreted (RANTES/CCL5) and interleukin-8 (IL-8/CXCL8) levels. T-bet mRNA expression was assessed by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Chemokine levels were assessed by immunofluorescence flow cytometry. The mean (s.d.) age and forced expiratory volume in 1 s (FEV(1))% predicted of the asthmatics were 43 x 6 (14 x 6) years and 85 x 9 (20.0)%, respectively. The median (IQR) T-bet expression after normalization with beta-actin was suppressed in asthmatics versus controls [asthmatics 0 x 71 (0 x 59) versus controls 1 x 07 (1 x 14), P=0 x 03].The median (IQR) of plasma RANTES was elevated, whereas IP-10 was suppressed in asthmatics versus controls (RANTES: 13658 x 0 (13673 x 3) versus 6299 x 5 (19407 x 8) pg/ml, P=0 x 03; IP-10: 1047 x 6 (589 x 8) versus 1306 x 4 (759 x 9) pg/ml, P=0 x 001). There was a weak and negative correlation between T-bet expression and RANTES level in the asthmatics (r=-0 x 29, P=0 x 032). T-bet could be measured in peripheral blood and its expression was suppressed in asthmatics. This is in keeping with asthma being a predominantly Th2 disease and T-bet probably plays a role in the pathogenesis of asthma. Further studies are needed to explore the potential application of peripheral blood monitoring of T-bet.

Interleukin (IL)-4 and IL-13 up-regulate monocyte chemoattractant protein-1 expression in human bronchial epithelial cells: involvement of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase 1/2 and Janus kinase-2 but not c-Jun NH2-terminal kinase 1/2 signalling pathways

The Th2 cytokines interleukin (IL)-4 and IL-13 and chemokine monocyte chemoattractant protein-1 (MCP-1) are significantly involved in bronchial hyperreactivity (BHR) and remodelling in allergic asthma. Although IL-4 and IL-13 can regulate a number of chemokines from bronchial epithelium, their regulatory effect on the expression of MCP-1 is as yet unproved. We aim to investigate the intracellular signalling mechanisms of IL-4 and IL-13 regulating the expression and secretion of MCP-1 from human bronchial epithelial cells. BEAS-2B cells, derived from a human bronchial epithelial cell line, were activated with or without IL-4 and/or IL-13 for different time intervals. MCP-1 gene expression and protein secretion were measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Activation of signalling molecules p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK) and Janus kinase-2 (JAK-2) was accessed by Western blotting. IL-4 and IL-13 were found to up-regulate gene expression and significantly increase the release of MCP-1 from BEAS-2B cells. Both cytokines could activate p38 MAPK, ERK and JAK-2, but not JNK activity. Inhibition of p38 MAPK, ERK and JAK-2 activities by pretreating the cells with their corresponding inhibitors SB203580, PD98059 and AG490, respectively, significantly suppressed IL-4- and IL-13-induced MCP-1 production in BEAS-2B cells. Together, the above results illustrate that the activation of p38 MAPK, ERK and JAK-2 but not JNK is crucial for IL-4- and IL-13-induced MCP-1 release in human bronchial epithelial cells. Our findings may provide insight into the future development of more effective therapeutic agents for treating allergic asthma.