Targeting Neutrophils in Severe Asthma via Siglec-9.

Severe asthma comprises only 5% of patients with asthma, but the burden it brings to the social health system accounts for more than half of all asthmatics. Clinical evidence shows that severe asthma is often linked to the recruitment and activation of neutrophils in the airways. However, the underlying molecular and immunological mechanisms of neutrophilia in severe asthma are not clear and currently available drugs exert only limited effects on neutrophilic inflammation. Great efforts are underway to address the mystery of neutrophilic inflammation in chronic respiratory disorders. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are members of the immunoglobulin gene family. Of note, Siglec-9 is uniquely expressed by human neutrophils and monocytes, as well as a minor population of natural killer cells. Engaging this structure with antibodies or glycan ligands results in programmed cell death in human neutrophils. Intriguingly, the administration of Siglec-E antibody abolished the recruitment of neutrophils in mouse models of neutrophilic pulmonary inflammation in vivo. Given that neutrophils are probably a major culprit in the generation and perpetuation of inflammation, targeting Siglec-9 could be beneficial for the treatment of severe asthma, chronic obstructive pulmonary disease, and related pulmonary disorders characteristic of neutrophilia.

Effect of Golgi phosphoprotein 2 (GOLPH2/GP73) on autophagy in human hepatocellular carcinoma HepG2 cells.

This study aims to investigate the effect of Golgi Protein 73 (GP73) on autophagy in human hepatoma line cells HepG2. We investigated the functional effects of GP73 on autophagy in hepatoma cell line HepG2 using immunofluoscence staining, Western blotting and real-time PCR. Our data showed that specific small interference RNA (siRNA) notably induced formation of autophagic vacuoles. In addition, upregulation of GP73 significantly inhibited formation of starvation-induced LC3-positive structures. We provide the first experimental evidence to show that GP73 may play an important role in the inhibitory regulation of autophagy. Therefore, our data suggest a new molecular mechanism for GP73-related hepatoma progression.

Disease spectrum and prognostic factors in patients treated for tuberculous meningitis in Shaanxi province, China.

Background: Tuberculous meningitis (TBM) is the most severe form of tuberculosis (TB) and can be difficult to diagnose and treat. We aimed to describe the clinical presentation, diagnosis, disease spectrum, outcome, and prognostic factors of patients treated for TBM in China. Methods: A multicenter retrospective study was conducted from 2009 to 2019 enrolling all presumptive TBM patients referred to Xijing tertiary Hospital from 27 referral centers in and around Shaanxi province, China. Patients with clinical features suggestive of TBM (abnormal CSF parameters) were included in the study if they had adequate baseline information to be classified as "confirmed," "probable," or "possible" TBM according to international consensus TBM criteria and remained in follow-up. Patients with a confirmed alternative diagnosis or severe immune compromise were excluded. Clinical presentation, central nervous system imaging, cerebrospinal fluid (CSF) results, TBM score, and outcome-assessed using the modified Barthel disability index-were recorded and compared. Findings: A total of 341 presumptive TBM patients met selection criteria; 63 confirmed TBM (25 culture positive, 42 Xpert-MTB/RIF positive), 66 probable TBM, 163 possible TBM, and 49 "not TBM." Death was associated with BMRC grade III (OR = 5.172; 95%CI: 2.298-11.641), TBM score ≥ 15 (OR = 3.843; 95%CI: 1.372-10.761), age > 60 years (OR = 3.566; 95%CI: 1.022-12.442), and CSF neutrophil ratio ≥ 25% (OR = 2.298; 95%CI: 1.027-5.139). Among those with confirmed TBM, nearly one-third (17/63, 27.0%) had a TBM score < 12; these patients exhibited less classic meningitis symptoms and signs and had better outcomes compared with those with a TBM score ≥ 12. In this group, signs of disseminated/miliary TB (OR = 12.427; 95%CI: 1.138-135.758) and a higher TBM score (≥15, OR = 8.437; 95%CI: 1.328-53.585) were most strongly associated with death. Conclusion: TBM patients who are older (>60 years) have higher TBM scores or CSF neutrophil ratios, have signs of disseminated/miliary TB, and are at greatest risk of death. In general, more effort needs to be done to improve early diagnosis and treatment outcome in TBM patients.

[Flexible bronchoscopic intervention for endobronchial hamartoma].

OBJECTIVE: To evaluate the effectiveness and safety of interventional treatment in the removal of endobronchial hamartoma by flexible bronchoscopy. METHODS: A retrospective analysis was conducted in 8 inpatients with histologically confirmed endobronchial hamartoma , diagnosed between May 2009 to January 2012 in the First Affiliated Hospital of Nanjing Medical University. The clinical, radiological and bronchoscopic features of hamartoma, and the clinical outcomes after bronchoscopic intervention were described. The endoscopic interventional treatments included resection by electrosurgical snare, electrocautery, argon plasma coagulation (APC) and cryotherapy. Thoracic computed tomography(CT)and bronchoscopy were used to evaluate the airway stenosis during follow-up. RESULTS: The 8 patients, 7 males and 1 female, aged (62 ± 8) years, underwent 13 times of interventional treatment for endobronchial hamartoma. Four patients were cured after receiving a single endoscopic treatment, while 3 patients had recurrence after initial interventional treatment but were cured after the second treatment. Three times of interventional treatment was carried out in 1 patient who had two relapses but later became stable with a 40% stenosis of the airway lumen. The rates of cure and effectiveness were 87.5% and 100%, respectively. Following interventional treatment, pneumothorax occurred in 1 patient who was cured after oxygen therapy. There were no serious complications such as massive haemorrhage, airway perforation, airway ignition and suffocation. CONCLUSION: Interventional treatments through flexible bronchoscopy appear to be safe and effective for removing endobronchial hamartoma.

Interferon-λ mediates oral tolerance and inhibits antigen-specific, T-helper 2 cell-mediated inflammation in mouse intestine.

BACKGROUND & AIMS: Oral tolerance is an important component of gastrointestinal homeostasis, but mechanisms of its development are not fully understood. Loss of oral tolerance occurs during food allergen-related inflammation in the gastrointestinal tract. Interferon (IFN)-λ regulates immunity, but its role in oral tolerance is not clear. We investigated the role and the mechanism of IFN-λ in the development of oral tolerance and its effect on antigen-induced, T-helper (Th)-2 cell-mediated inflammation in the intestine. METHODS: Expression of IFN-λ and its receptor were analyzed by immunohistochemical, flow cytometric, or immunoblot analyses. Tolerogenic dendritic cells (DCs) and regulatory T cells were examined in vitro and in vivo. A mouse model of antigen-induced, Th2 cell-mediated intestinal inflammation was used to examine the role of IFN-λ and T cells in oral tolerance in the intestine. RESULTS: CD3+ cells expressed the IFN-λ receptor, which was up-regulated following antigen-specific or nonspecific activation. Interaction between IFN-λ and its receptor induced apoptosis of T cells and their subsequent phagocytosis by DCs. This led to the generation of tolerogenic DCs and T regulatory cells in vitro and in vivo. Passive transfer of IFN-λ-primed CD3+ cells inhibited Th2 cell-mediated inflammation in the intestine. CONCLUSIONS: IFN-λ is involved in development and maintenance of oral tolerance in the intestines of mice; it might be used to suppress antigen-specific Th2 cell-mediated inflammation in patients.

Eosinophil-derived interferon-lambda contributes to initiation of allergen-related inflammation in the intestine.

BACKGROUND AND AIMS: Epithelial barrier dysfunction plays a critical role in the initiation of a number of immune diseases; the causative factors are not fully understood. The present study aimed to elucidate the mechanism by which the eosinophil-derived interferon (IFN)-lambda induced the gut epithelial barrier dysfunction. METHODS: The duodenal biopsies were obtained from patients with or without food allergies. The eosinophils and IFNλ expression were observed by immune staining. Intestinal epithelial cell line, T84 cells, and a mouse model were employed to observe the effect of IFNλ on the epithelial barrier function and the initiation of skewed T helper (Th)2 polarization in the mouse intestine. RESULTS: IFNλ expression was observed in over 80% human eosinophils of the subjects with or without food allergies. Exposure to microbial products, lipopolysaccharide or peptidoglycan, could induce eosinophils to release IFNλ. Exposure to IFNλ could induce intestinal epithelial barrier dysfunction via inducing the epithelial cell apoptosis. Concurrent exposure to microbial products and food antigens could induce aberrant antigen specific Th2 polarization and Th2 pattern inflammation in the intestine. CONCLUSIONS: Eosinophils express IFNλ that can induce intestinal epithelial barrier dysfunction and promotes the initiation of the aberrant Th2 polarization in the intestine.

[Advances on Golgi glycoprotein 73 and its association with diseases].

Golgi glycoprotein 73(GP73) is a transmembrane glycoprotein residing in the cis-Golgi complex, which is strongly expressed in hepatocellular carcinoma (HCC) and secreted into the blood. It has been regarded as a promising serum tumor marker for the detection of HCC with higher sensitivity and specificity than AFP. GP73 is also significantly elevated in kidney cancer, prostate cancer, lung adenocarcinoma, esophageal cancer and seminomas; therefore, it would be helpful for the diagnosis of these diseases. However, the function of GP73 and the regulatory mechanism for its expression are unclear. In this article, the physical-chemical properties, the regulation of its expression, the relation with various cancers and the clinical applications of GP73 are reviewed.

[Induction of monocyte-derived dendritic cell differentiation by asthmatic serum in a transendothelial trafficking model].

OBJECTIVE: To explore the effect of asthmatic and healthy serum on differentiation and function of monocyte-derived dendritic cells (MDDC) in a transendothelial trafficking model. METHODS: The sera and peripheral blood mononuclear cells (PBMC) were separated from 12 asthmatic patients and 12 healthy volunteers, and monocytes were selected from PBMC using magnetic beads. The trypsin-digested human umbilical vein endothelial cells (HUVEC) at passage 2 from 5 healthy lying-in women were used to construct the transendothelial trafficking model under asthmatic or healthy serum, wherein MDDC were identified by silver nitrate staining and scanning electron microscopy. Nuclear factor κB (NF-κB) activity was determined by electrophoretic mobility shift assay. Flow cytometry, ELISA and mixed leukocyte reaction were relevantly utilized to detect the phenotype, cytokine and T cell proliferation. RESULTS: (1) Monocytes traversed through HUVEC monolayer after 2 h, and reverse-transmigrated to develop into DC 48 h later. (2) The healthy serum stimulated monocytes into immature MDDC with lower CD(14) [(20 ± 5)%] (F = 49.01, P < 0.05), and higher HLA-DR, CD(80), CD(86) and CD(83) [(43 ± 4)%, (17.9 ± 3.5)%, (43 ± 11)% and (6.7 ± 1.8)%, respectively] (F = 10.35 - 40.17, all P < 0.05) than monocytes did before transmigration at 0 h [CD(14) (81 ± 6)%, HLA-DR (24 ± 5)%, CD(80) (2.8 ± 2.0)%, CD(86) (14 ± 4)% and CD(83) (0.9 ± 0.8)%, respectively]. (3) The asthmatic serum stimulated monocytes into mature MDDC, characteristic of dendrites, with similar HLA-DR and CD(86) [(55 ± 6)% and (59 ± 12)%] (F = 15.29 and 35.97, all P > 0.05), higher CD(80) and CD(83) [(49.7 ± 10.2)% and (30.2 ± 6.8)%] (F = 4.01 and 20.68, all P < 0.05), accompanied by increased levels of NF-κB activity, IL-12 p70 and T cell proliferation [(100 ± 11)%, (568 ± 43) ng/L and (2033 ± 198) cpm, respectively] (F = 49.23 - 350.84, all P < 0.05) relative to the healthy serum-stimulated immature MDDC [(12 ± 3)%, (220 ± 35) ng/L and (952 ± 64) cpm, respectively]. CONCLUSION: The asthmatic serum induces mature MDDC in association with NF-κB overactivation in the transendothelial trafficking model, which provides a promising experimental platform for both investigation of immunological mechanisms in asthma and screening of novel anti-asthma drugs in vitro.

Characteristics of Helicobacter pylori Heteroresistance in Gastric Biopsies and Its Clinical Relevance.

BACKGROUND: Antimicrobial susceptibility testing (AST) plays a vital role in anti-Helicobacter pylori treatment, but the traditional AST method has difficulty detecting heteroresistance, which may cause an increased prevalence of resistant strains and eradication failure. AIMS: To investigate the characteristics of heteroresistance in H. pylori in gastric biopsies and investigate its clinical relevance. METHOD: A total of 704 gastric biopsies were selected for 23S rRNA and gyrA gene sequencing, 470 H. pylori isolates from these biopsies were selected for AST, and the clinical characteristics of the patients were reviewed. RESULT: For the 699 biopsies that were positive for 23S rRNA gene, 98 (14.0%) showed a heteroresistance genotype, and a wild type (WT) combined with A2143G (86.7%) genotype was found in most samples. For the 694 biopsies that were positive for gyrA gene, 99 (14.3%) showed a heteroresistance genotype, and a WT combined with 87K (26.3%) or WT combined with 91N (23.2%) genotype was predominant. According to the E-test results, the resistance rates of heteroresistance genotype samples for clarithromycin and levofloxacin were 36.2% and 68.1%, respectively. When dividing the heteroresistance samples into different groups according to the sequencing profile peaks of the mutation position, the resistance rates were higher along with mutation peaks at the mutation position. In addition, patients infected with mutated or heteroresistant strains showed lower peptic ulcer detection rates than those infected with the WT strain (p < 0.05). CONCLUSION: Heteroresistance genotypes for clarithromycin and levofloxacin were not rare in H. pylori. Most cases with a heteroresistance genotype showed a susceptible phenotype for clarithromycin and a resistance phenotype for levofloxacin. Patients infected with heteroresistance genotype strains showed a lower peptic ulcer detection rate than those infected with the WT strain.

Genes related to the very early stage of ConA-induced fulminant hepatitis: a gene-chip-based study in a mouse model.

BACKGROUND: Due to the high morbidity and mortality of fulminant hepatitis, early diagnosis followed by early effective treatment is the key for prognosis improvement. So far, little is known about the gene expression changes in the early stage of this serious illness. Identification of the genes related to the very early stage of fulminant hepatitis development may provide precise clues for early diagnosis. RESULTS: Balb/C mice were used for ConA injection to induce fulminant hepatitis that was confirmed by pathological and biochemical examination. After a gene chip-based screening, the data of gene expression in the liver, was further dissected by ANOVA analysis, gene expression profiles, gene network construction and real-time RT-PCR. At the very early stage of ConA-triggered fulminant hepatitis, totally 1,473 genes with different expression variations were identified. Among these, 26 genes were finally selected for further investigation. The data from gene network analysis demonstrate that two genes, MPDZ and Acsl1, localized in the core of the network. CONCLUSIONS: At the early stages of fulminant hepatitis, expression of twenty-six genes involved in protein transport, transcription regulation and cell metabolism altered significantly. These genes form a network and have shown strong correlation with fulminant hepatitis development. Our study provides several potential targets for the early diagnosis of fulminant hepatitis.

Unusual life-threatening Rosai-Dorfman disease of the trachea: role of NF-κB.

Rosai-Dorfman disease (RDD) is a rare non-neoplastic histioproliferative disorder characterised by painless lymphadenopathy, low fever, high erythrocyte sedimentation rate, leucocytosis and hypergammaglobulinaemia. Overactivity of nuclear factor κB (NF-κB) is linked with inflammatory, cancerous and autoimmune diseases. The first case is described of an unusual life-threatening RDD of the trachea with no lymphadenopathy at risk of suffocation in a 39-year-old Chinese woman. A diagnosis of RDD was made following CT scans, thoracotomy and histological examination. Gel shift assay revealed an essential role for NF-κB overactivity in RDD. The patient remains well with no evidence of progression without treatment. Histological confirmation should be sought in all cases as the clinical manifestation of RDD is similar to asthma or lung carcinoma.

[Inhibitory effects of apigenin on the expression of GATA-3 and Th2 cytokines in asthmatic mice].

OBJECTIVE: To investigate the inhibitory effects and mechanism of apigenin (APG) on dominant response of Th2 cells in asthma model of mice. METHODS: Thirty-two 6-week-old healthy BALB/c mice, SPF grade, were randomly divided into four groups equally, the normal control group (A), the asthma model group (B), and the two APG groups (C and D) consisted of asthma model mice treated respectively with high-dose (20 mg/kg per day) and low-dose (2 mg/kg per day) APG given by dissolving in 1% dimethyl sulphoxide via intraperitoneal injection. The murine asthma model was established by ovalbumin (OVA) sensitization and provocation. Twenty-four hours after the last airway provocation, acetylcholine (Ach) was administered via caudalis vein for measuring airway resistance by pulmonary function detector; levels of IL- 4 and IL-13 in bronchoalveolar lavage fluid (BALF) and total IgE in serum were determined by enzyme-linked immunosorbent assay (ELISA); total and differential cell counts in BALF were measured by light microscopy; the airway inflammatory infiltration was detected by haematoxylin and eosin (HE) staining; and the signal transducer and activator of transcription 3 (GATA-3) in the lung tissue was determined by Western blot analysis. RESULTS: As compared with Group A, the airway hyper-reactivity, airway inflammation, cell count and eosinophil percentage in BALF, levels of total serum IgE and BALF IL-4 and IL-13, and GATA-3 protein expression in the lung tissue were significantly increased in Group B (P < 0.05). As compared with Group B, all the above-mentioned indices in Group C and D were lower, showing respective significant difference (P < 0.05), and significant difference was also shown between the two APG treated groups (P < 0.05). CONCLUSION: APG could reduce the airway inflammation and hyper-reactivity by down-regulating the expressions of pulmonary GATA-3 and Th, cytokines, which is a potential drug for asthma therapy.

Reduction of Human DNA Contamination in Clinical Cerebrospinal Fluid Specimens Improves the Sensitivity of Metagenomic Next-Generation Sequencing.

Metagenomics next-generation sequencing (mNGS) is increasingly available for the detection of obscure infectious diseases of the central nervous system. However, human DNA contamination from elevated white cells, one of the characteristic cerebrospinal fluid (CSF) features in meningitis patients, greatly reduces the sensitivity of mNGS in the pathogen detection. Currently, effective approaches to selectively reduce host DNA contamination from clinical CSF samples are still lacking. In this study, a total of 20 meningitis patients were enrolled, including 10 definitively diagnosed tuberculous meningitis (TBM) and 10 definite cryptococcal meningitis (CM) cases. To evaluate the effect of reduced human DNA in the sensitivity of mNGS detection, three specimen-processing protocols were performed: (i) To remove human DNA, saponin, a nonionic surfactant, was used to selectively lyse white cells in CSF followed by DNase treatment prior to the extraction of DNA; (ii) to reduce host DNA, CSF was centrifuged to remove human cells, and the supernatant was collected for DNA extraction; and (iii) DNA extraction from the unprocessed specimens was set as the control. We found that saponin processing significantly elevated the NGS unique reads for Cryptococcus (P < 0.01) compared with the control but had no effects for Mycobacterium tuberculosis (P > 0.05). However, detection of centrifuged supernatants improved the NGS unique reads for both TBM and CM compared with controls (P < 0.01). Our results demonstrate that the use of mNGS of centrifuged supernatants from clinical CSF samples in patients with TBM and CM is a simple and effective method to improve the sensitivity of pathogen detection.

Targeted NF-kappaB inhibition of asthmatic serum-mediated human monocyte-derived dendritic cell differentiation in a transendothelial trafficking model.

Transendothelial trafficking model mimics in vivo differentiation of monocytes into dendritic cells (DC). The serum from patients with systemic lupus erythematosus promotes the differentiation of monocytes into mature DC. We have shown that selective inhibition of NF-kappaB by adenoviral gene transfer of a novel mutated IkappaBalpha (AdIkappaBalphaM) in DC contributes to T cell tolerance. Here we demonstrated for the first time that asthmatic serum facilitated human monocyte-derived DC (MDDC) maturation associated with increased NF-kappaB activation in this model. Furthermore, selective blockade of NF-kappaB by AdIkappaBalphaM in MDDC led to increased apoptosis, and decreased levels of CD80, CD83, CD86, and IL-12 p70 but not IL-10 in asthmatic serum-stimulated MDDC, accompanied by reduced proliferation of T cells. These results suggest that AdIkappaBalphaM-transferred MDDC are at a more immature stage which is beneficial to augment the immune tolerance in asthma.

Imiquimod, a toll-like receptor 7 ligand, inhibits airway remodelling in a murine model of chronic asthma.

1. Imiquimod, a synthetic Toll-like receptor (TLR) 7 ligand, has been shown to attenuate airway inflammation and airway hyperresponsiveness (AHR) in acute murine models of allergic asthma. In the present study, we investigated the effect of imiquimod on allergen-induced airway remodelling in chronic experimental asthma. 2. Ovalbumin (OVA)-sensitized mice were chronically challenged with aerosolized OVA for 8 weeks. Some mice were exposed to an aerosol of 0.15% imiquimod daily during the period of OVA challenge. Twenty-four hours after the last OVA challenge, mice were evaluated for the development of airway inflammation, AHR and airway remodelling. The levels of total serum IgE and Th2 cytokines (interleukin (IL)-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF) and the expression of transforming growth factor (TGF)-beta1 protein in lungs were measured by ELISA and immunohistochemistry, respectively. 3. The results demonstrated that imiquimod significantly inhibited chronic inflammation, persistent AHR and airway remodelling in chronic experimental asthma. In addition, imiquimod reduced levels of total serum IgE and BALF Th2 cytokines and diminished expression of TGF-beta1 in remodelled airways. 4. In summary, the results of the present study indicate that imiquimod may attenuate the progression of airway inflammation and remodelling, providing potential in the treatment of asthma.

High-sensitivity C-reactive protein: a predicative marker in severe asthma.

BACKGROUND AND OBJECTIVE: Serum levels of high-sensitivity CRP (hs-CRP) are associated with asthma but the relationship between higher levels of hs-CRP and the degree of asthma severity remains unclear. This study investigated whether hs-CRP is associated with asthma severity as well as with other clinical indices of asthma activity (pulmonary function, total serum IgE, and peripheral blood eosinophil counts). METHODS: Levels of hs-CRP and clinical indices of asthma were determined among 177 control subjects and 281 asthmatic patients (84 intermittent, 30 mild, 63 moderate and 104 severe). RESULTS: The level of hs-CRP was examined as both a continuous variable and by quartiles (<0.23, 0.23-0.51, 0.51-1.42 and >or=1.42 mg/L) in the five groups. Compared with the first quartile of hs-CRP, patients with higher levels were at increased risk of severe asthma independently of other clinical indices (adjusted OR 3.49, 95% CI: 1.51-8.12 for the third quartile; adjusted OR 6.46, 95% CI: 2.85-16.62 for fourth quartile, respectively). CONCLUSIONS: These findings suggest that hs-CRP might be a sensitive marker for severe asthma.

Increased RhoGDI2 and peroxiredoxin 5 levels in asthmatic murine model of beta2-adrenoceptor desensitization: a proteomics approach.

BACKGROUND: Beta(2)-adrenoceptor (beta(2)AR) desensitization is a common problem in clinical practice. beta(2)AR desensitization proceeds by at least such three mechanisms as heterologous desensitization, homologous desensitization and a kind of agonist-induced rapid phosphorylation by a variety of serine/threonine kinases. It is not clear whether there are other mechanisms. This study aimed to investigate potential mechanisms of beta(2)AR desensitization. METHODS: Twenty-four BALB/c (6-8 weeks old) mice were divided into three groups, which is, group A, phosphate buffered saline (PBS)-treated; group B, ovalbumin (OVA)-induced; and group C, salbutamol-treated. Inflammatory cell counts, cytokine concentrations of bronchoalveolar lavage fluid (BALF), pathological sections, total serum IgE, airway responsiveness, membrane receptor numbers and total amount of beta(2)AR were observed. Asthmatic mouse model and beta(2)AR desensitization asthmatic mouse model were established. Groups B and C were selected for two-dimensional gel electrophoresis (2DE) analysis so as to find key protein spots related to beta(2)AR desensitization. RESULTS: Asthmatic mouse model and beta(2)AR desensitization asthmatic mouse model were verified by inflammatory cell count, cytokine concentration of BALF, serum IgE level, airway hyperreactivity measurement, radioligand receptor binding assay, Western blot analysis, and pathologic examination. Then the two groups (groups B and C) were subjected to 2DE. Two key protein spots associated with beta(2)AR desensitization, Rho GDP-dissociation inhibitor 2 (RhoGDI(2)) and peroxiredoxin 5, were found by comparative proteomics (2DE and mass spectrum analysis). CONCLUSION: Oxidative stress and small G protein regulators may play an important role in the process of beta(2)AR desensitization.

Expression of surface markers on peripheral CD4+CD25high T cells in patients with atopic asthma: role of inhaled corticosteroid.

BACKGROUND: CD4(+)CD25(+) regulatory T cells (Tregs) mediate immune suppression through cell-cell contact with surface molecules, particularly cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR), and transforming growth factor beta (TGF-beta), but little is known about the exact role of Tregs in the pathogenesis of asthma. This study sought to characterize the expression of surface markers on peripheral blood mononuclear cells-derived Tregs in patients with atopic asthma and healthy subjects, and to investigate the effect of inhaled corticosteroid on them. METHODS: The expression of surface molecules on CD4(+)CD25(high) Tregs was detected by flow cytometry. The effect of inhaled corticosteroid on expression of the surface molecules on Tregs was determined in vivo and in vitro. Total serum immunoglobulin E (IgE) and high-sensitivity C-reactive protein were measured by enzyme linked immunosorbent assay and latex enhanced immunoturbidimetric assay, respectively. RESULTS: Equivalent numbers of peripheral Tregs were found in patients with atopic asthma (stable and acute) and healthy subjects. Tregs preferentially expressed CTLA-4, GITR, toll-like receptor 4 (TLR4), latency-associated peptide (LAP/TGF-beta1), and forkhead box P3 (FOXP3). Patients with acute asthma had decreased numbers of CD4(+)CD25(high)LAP(+) T cells compared to healthy subjects and stable asthmatics. Inhaled corticosteroid enhanced the percentage of Tregs expressing LAP in vivo and in vitro dose-dependently. Furthermore, the percentages of Tregs expressing LAP were negatively correlated with total serum IgE levels and severity of asthma, but positively correlated with forced expiratory volume in one second percentage of the predicted value in patients with asthma. CONCLUSIONS: The results suggest that membrane-bound TGF-beta1 is a potential candidate for predicting the severity of asthma, and may contribute to the sustained remission of asthma. Strategies targeting Tregs on their surface markers, especially TGF-beta1, are promising for future therapy of asthma.