IgE sensitization to food allergens and airborne allergens in relation to biomarkers of type 2 inflammation in asthma.

BACKGROUND: We have recently reported that sensitization to food allergens and sensitization to airborne allergens had independent associations with increased fraction of exhaled nitric oxide (FeNO) and blood eosinophils in middle-aged adults and in young subjects with asthma. OBJECTIVE: To investigate the relation between IgE sensitization and several type 2 inflammation biomarkers in adult asthmatics. METHODS: FeNO, urinary eosinophil-derived neurotoxin (U-EDN), serum eosinophil cationic protein (S-ECP) and periostin were measured in 396 asthmatics, aged 17-76 years, from the Swedish GA2LEN study. Sensitization to airborne allergens was examined with skin prick tests (≥3 mm wheal) and sensitization to food allergens with measurement of specific IgE (≥0.35 kU/L). RESULTS: Asthmatics sensitized to food allergens had higher FeNO, 22.3 ppb (18.6, 26.7) vs 16.1 ppb (14.2, 18.2) (P = .005), S-ECP, 17.7 mg/L (14.8, 21.1) vs 12.8 mg/L (10.9, 14.9) (P = .01), and periostin, 73.7 (67.5, 80.3) ng/mL vs 59.9 (55.8, 64.2) ng/mL (P = .003), than non-sensitized subjects. Periostin levels in this group were also significantly higher than in the group sensitized only to airborne allergens (P = .01). Sensitization to food allergens related independently to FeNO (P = .02), S-ECP (P = .006) and periostin (P = .004), whereas sensitization only to airborne allergens related only to FeNO (P = .02) after adjustments for age, sex, height, weight and smoking history. FeNO correlated weakly with S-ECP (r = .17, P < .001), periostin (r = .19, P < .001) and U-EDN (0.16, P < .001). S-ECP also correlated weakly with U-EDN (r = .12, P = .02). None of the correlations between the remaining pairs of markers of type 2 inflammation were significant. CONCLUSIONS & CLINICAL RELEVANCE: Sensitization to food allergens related to several local and systemic type 2 inflammation markers, such as FeNO, S-ECP and periostin. Assessing the profile of allergic sensitization, including to food allergens, might improve the understanding and interpretation of inflammatory markers and potentially improve asthma management.

Prospective predictors of exacerbation status in severe asthma over a 3-year follow-up.

BACKGROUND: A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor. OBJECTIVE: This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma. METHODS: We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status." RESULTS: Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05). CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."

The IL-13/periostin/IL-24 pathway causes epidermal barrier dysfunction in allergic skin inflammation.

BACKGROUND: Barrier dysfunction is an important feature of atopic dermatitis (AD) in which IL-4 and IL-13, signature type 2 cytokines, are involved. Periostin, a matricellular protein induced by IL-4 or IL-13, plays a crucial role in the onset of allergic skin inflammation, including barrier dysfunction. However, it remains elusive how periostin causes barrier dysfunction downstream of the IL-13 signal. METHODS: We systematically identified periostin-dependent expression profile using DNA microarrays. We then investigated whether IL-24 downregulates filaggrin expression downstream of the IL-13 signals and whether IL-13-induced IL-24 expression and IL-24-induced downregulation of filaggrin expression are dependent on the JAK/STAT pathway. To build on the significance of in vitro findings, we investigated expression of IL-24 and activation of STAT3 in mite-treated mice and in AD patients. RESULTS: We identified IL-24 as an IL-13-induced molecule in a periostin-dependent manner. Keratinocytes are the main IL-24-producing tissue-resident cells stimulated by IL-13 in a periostin-dependent manner via STAT6. IL-24 significantly downregulated filaggrin expression via STAT3, contributing to barrier dysfunction downstream of the IL-13/periostin pathway. Wild-type mite-treated mice showed significantly enhanced expression of IL-24 and activation of STAT3 in the epidermis, which disappeared in both STAT6-deficient and periostin-deficient mice, suggesting that these events are downstream of both STAT6 and periostin. Moreover, IL-24 expression was enhanced in the epidermis of skin tissues taken from AD patients. CONCLUSIONS: The IL-13/periostin pathway induces IL-24 production in keratinocytes, playing an important role in barrier dysfunction in AD.

IL4Rα and ADAM33 as genetic markers in asthma exacerbations and type-2 inflammatory endotype.

BACKGROUND: Genetic markers of susceptibility to asthma exacerbations in adults remain unclear. OBJECTIVE: To identify genetic markers of asthma exacerbations, particularly in patients with type-2 inflammatory endotype. METHODS: In this observational study of patients enrolled in the Kinki Hokuriku Airway disease Conference multicenter study, frequency of exacerbations requiring systemic corticosteroids during 2 years after enrolment and associated risk factors was determined. For genetic marker analysis, interleukin-4 receptor α (IL4RA) rs8832 and a disintegrin and metalloprotease 33 (ADAM33) S_2 (rs528557), T_1 (rs2280091), T_2 (rs2280090), and V_4 (rs2787094) variants were included. Elevated serum periostin levels at enrolment (≥95 ng/mL, defined as type-2 inflammatory endotype) were considered in the analysis. RESULTS: Among 217 patients who were successfully followed up for 2 years after enrolment, 60 patients showed at least one asthma exacerbation during the 2 years. Airflow limitation (%FEV1 <80%) and recent exacerbations but not genetic variants were identified as risk markers of exacerbations. A total of 27 patients showed type-2 inflammatory endotype (serum periostin ≥95 ng/mL at enrolment) and subsequent exacerbations; risk factors in these patients were airflow limitation (odds ratio, 6.51; 95% confidence interval (CI): 2.37-18.6; P=.0003), GG genotype of IL4RA rs8832 (odds ratio, 4.01; 95% CI: 1.47-11.0; P=.007), and A allele of ADAM33 T_2 (odds ratio, 2.81; 95% CI: 1.05-7.67; P=.04) by multivariate analysis. In addition, GG genotype of IL4RA rs8832 was associated with type-2 endotype, whereas A allele of ADAM33 T_2 was associated with mixed type of eosinophilic/type-2 and neutrophilic inflammations. CONCLUSIONS AND CLINICAL RELEVANCE: IL4RA and ADAM33 variants may be risk markers of asthma exacerbations in type-2 inflammatory endotype. Precise endotyping may facilitate the identification of genetic risk markers of asthma exacerbations.

Serum periostin relates to type-2 inflammation and lung function in asthma: Data from the large population-based cohort Swedish GA(2)LEN.

BACKGROUND: Periostin has been suggested as a novel, phenotype-specific biomarker for asthma driven by type 2 inflammation. However, large studies examining relationships between circulating periostin and patient characteristics are lacking and the suitability of periostin as a biomarker in asthma remains unclear. AIM: To examine circulating periostin in healthy controls and subjects with asthma from the general population with different severity and treatment profiles, both with and without chronic rhinosinusitis (CRS), in relation to other biomarkers and clinical characteristics. METHODS: Serum periostin was examined by ELISA in 1100 subjects aged 17-76 from the Swedish Global Allergy and Asthma European Network (GA(2)LEN) study, which included 463 asthmatics with/without chronic rhinosinusitis (CRS), 98 individuals with CRS only, and 206 healthy controls. Clinical tests included measurement of lung function, Fraction of exhaled NO (FeNO), IgE, urinary eosinophil-derived neurotoxin (U-EDN), and serum eosinophil cationic protein (S-ECP), as well as completion of questionnaires regarding respiratory symptoms, medication, and quality of life. RESULTS: Although median periostin values showed no differences when comparing disease groups with healthy controls, multiple regression analyses revealed that periostin was positively associated with higher FeNO, U-EDN, and total IgE. In patients with asthma, an inverse relationship with lung function was also observed. Current smoking was associated with decreased periostin levels, whereas increased age and lower body mass index (BMI) related to higher periostin levels in subjects both with and without asthma. CONCLUSION: We confirm associations between periostin and markers of type 2 inflammation, as well as lung function, and identify novel constitutional factors of importance to the use of periostin as a phenotype-specific biomarker in asthma.

Allergen immunotherapy for allergic asthma: A systematic review and meta-analysis.

BACKGROUND: To inform the development of the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines on Allergen Immunotherapy (AIT) for allergic asthma, we assessed the evidence on the effectiveness, cost-effectiveness and safety of AIT. METHODS: We performed a systematic review, which involved searching nine databases. Studies were screened against predefined eligibility criteria and critically appraised using established instruments. Data were synthesized using random-effects meta-analyses. RESULTS: 98 studies satisfied the inclusion criteria. Short-term symptom scores were reduced with a standardized mean difference (SMD) of -1.11 (95% CI -1.66, -0.56). This was robust to a prespecified sensitivity analyses, but there was evidence suggestive of publication bias. Short-term medication scores were reduced SMD -1.21 (95% CI -1.87, -0.54), again with evidence of potential publication bias. There was no reduction in short-term combined medication and symptom scores SMD 0.17 (95% CI -0.23, 0.58), but one study showed a beneficial long-term effect. For secondary outcomes, subcutaneous immunotherapy (SCIT) improved quality of life and decreased allergen-specific airway hyperreactivity (AHR), but this was not the case for sublingual immunotherapy (SLIT). There were no consistent effects on asthma control, exacerbations, lung function, and nonspecific AHR. AIT resulted in a modest increased risk of adverse events (AEs). Although relatively uncommon, systemic AEs were more frequent with SCIT; however no fatalities were reported. The limited evidence on cost-effectiveness was mainly available for sublingual immunotherapy (SLIT) and this suggested that SLIT is likely to be cost-effective. CONCLUSIONS: AIT can achieve substantial reductions in short-term symptom and medication scores in allergic asthma. It was however associated with a modest increased risk of systemic and local AEs. More data are needed in relation to secondary outcomes, longer-term effectiveness and cost-effectiveness.

Utility of serum periostin and free IgE levels in evaluating responsiveness to omalizumab in patients with severe asthma.

BACKGROUND: Omalizumab, a humanized anti-IgE monoclonal antibody, has demonstrated efficacy in patients with severe allergic asthma. However, treatment responses vary widely among individuals. Despite a lack of data, free serum IgE levels following omalizumab treatment have been proposed as a marker of treatment responsiveness. METHODS: In this prospective, observational study, we assessed the utility of biomarkers of type 2 inflammation in predicting omalizumab treatment responses, as determined by the absence of asthma exacerbation during the first year of treatment. Free serum IgE levels were monitored for 2 years to examine their association with baseline biomarker levels and the number of exacerbations. RESULTS: We enrolled thirty patients who had been treated with omalizumab for at least 1 year, of whom 27 were treated for 2 years. Baseline serum periostin levels and blood eosinophil counts were significantly higher in patients without exacerbations during the first year of treatment than in patients with exacerbations. Baseline serum periostin levels, but not eosinophil counts, were negatively associated with free serum IgE levels after 16 or 32 weeks of treatment. Reduced free serum IgE levels during treatment from those at baseline were associated with reduced exacerbation numbers at 2 years. In 14 patients who continued to have exacerbations during the first year of treatment, exacerbation numbers gradually and significantly decreased over the 2-year study period, with concurrent significant reductions in free serum IgE levels. CONCLUSION: Baseline serum periostin levels and serum free IgE levels during treatment follow-up may be useful in evaluating responses to omalizumab treatment.

Elevation of serum squamous cell carcinoma antigen 2 in patients with psoriasis: associations with disease severity and response to the treatment.

BACKGROUND: Squamous cell carcinoma antigen (SCCA) belongs to the ovalbumin-serpin family and is a known tumour marker. Expression of SCCA is upregulated in the serum and skin of patients with psoriasis. OBJECTIVES: The aim of this study was to determine SCCA2 levels in association with disease severity and treatment efficacy in patients with psoriasis. MATERIALS AND METHODS: Patients with psoriasis (n = 123) and healthy controls (n = 25) were enrolled in this prospective cross-sectional study. Enzyme-linked immunosorbent assay (ELISA) analysis was performed to determine serum SCCA2 levels. SCCA2 expression in skin was evaluated using immunohistochemical analysis. Serum SCCA2 levels were compared with Psoriasis Area Severity Index (PASI) scores. The effect of treatment on serum SCCA2 levels was assessed using serial examinations. Induction of SCCA2 by several psoriatic cytokines in human keratinocytes was evaluated. RESULTS: The serum levels of SCCA2 were significantly higher in patients with psoriasis than healthy controls and correlated well with disease severity. Increased SCCA2 staining was observed in lesional skin but not in nonlesional skin of patients with psoriasis. In addition, SCCA2 expression levels in skin correlated with serum concentrations of SCCA2. SCCA2 significantly decreased according to improvement of PASI scores. Interleukin (IL)-17 and IL-22 synergistically increased the production of SCCA2 at both mRNA and protein levels in human keratinocytes. CONCLUSIONS: Significant elevation of SCCA2 is associated with disease severity and reflects treatment efficacy. SCCA2 may be a useful biomarker in psoriasis, reflecting T-helper 17-type inflammation - the main determinant of the severity of psoriasis.

Serum periostin levels correlate with airway hyper-responsiveness to methacholine and mannitol in children with asthma.

BACKGROUND: Periostin is a matricellular protein, and its synthesis in airway epithelial cells and lung fibroblasts is induced by interleukin (IL)-4 and IL-13. The significance of periostin as a biomarker of TH 2-induced airway inflammation, and (importantly) as a measure of the response to TH 2-targeted therapy, has recently been emphasized. We explored the relationship between periostin and airway hyperresponsiveness (AHR) in asthmatic children. METHODS: The study included 83 children aged 6-15 years in an asthmatic group (n = 54) and healthy controls (n = 29). We measured the periostin levels in serum and performed methacholine and mannitol provocation challenges. The responses to mannitol were expressed as the provocative dose causing a 15% fall in the FEV1 (the PD15 dose). RESULTS: Of the 54 subjects with asthma, all had positive methacholine bronchial provocation test (BPT) results and 38 had positive mannitol BPT results. Children with asthma had significantly higher periostin levels than controls [76.0 (65.0-91.8) vs 71.0 (57.5-80.0) ng/mL; P = 0.017]. Periostin levels were significantly correlated with both the methacholine PC20 and mannitol PD15 values. CONCLUSION: Serum levels of periostin, a new biomarker induced by IL-13, were higher in asthmatic children, and were associated with AHR to methacholine and mannitol.

GLCCI1 variant accelerates pulmonary function decline in patients with asthma receiving inhaled corticosteroids.

BACKGROUND: In steroid-naive patients with asthma, several gene variants are associated with a short-term response to inhaled corticosteroid (ICS) treatment; this has mostly been observed in Caucasians. However, not many studies have been conducted for other ethnicities. Here, we aimed to determine the relationship between the annual decline in forced expiratory flow volume in one second (FEV1 ) and the variant of the glucocorticoid-induced transcript 1 gene (GLCCI1) in Japanese patients with asthma receiving long-term ICS treatment, taking into account the effect of high serum periostin levels, a known association factor of pulmonary function decline and a marker of refractory eosinophilic/Th2 inflammation. METHODS: In this study, 224 patients with asthma receiving ICS treatment for at least 4 years were enrolled. The effects of single-nucleotide polymorphisms (SNPs) in GLCCI1, stress-induced phosphoprotein 1 (STIP1), and T gene on the decline in FEV1 of 30 ml/year or greater were determined. RESULTS: Besides the known contributing factors, that is, the most intensive treatment step, ex-smoking, and high serum periostin levels (≥95 ng/ml), the GG genotype of GLCCI1 rs37973, and not other SNPs, was independently associated with a decline in FEV1 of 30 ml/year or greater. When patients were stratified according to their serum periostin levels, the GG genotype of rs37973 was significantly associated with blood eosinophilia (≥250/µl) in the high serum periostin group. CONCLUSIONS: A GLCCI1 variant is a risk factor of pulmonary function decline in Japanese patients with asthma receiving long-term ICS treatment. Thus, GLCCI1 may be associated with response to ICS across ethnicities.

Periostin levels correlate with disease severity and chronicity in patients with atopic dermatitis.

BACKGROUND: Recent findings indicate that periostin, an extracellular matrix protein induced by T helper 2 cytokines, plays a critical role in the pathogenesis of atopic dermatitis (AD). OBJECTIVES: To determine whether serum periostin level is associated with clinical phenotype in adult patients with AD. METHODS: An enzyme-linked immunosorbent assay was performed to determine serum periostin levels in 257 adult patients with AD, 66 patients with psoriasis vulgaris (PV) as a disease control and 25 healthy controls. Serum periostin levels were analysed together with clinical characteristics and laboratory parameters, including thymus and activation-regulated chemokine (TARC), lactate dehydrogenase (LDH), blood eosinophil count and total IgE. Immunohistochemical analysis evaluated the expression of periostin in association with various clinical phenotypes of AD. The effect of treatment on serum periostin level was also assessed. RESULTS: Serum periostin was significantly higher in patients with AD than in patients with PV and healthy controls. Periostin level was found to be positively correlated with disease severity, TARC level, LDH level and eosinophil count, but not with IgE level. Higher serum periostin level was observed in patients with extrinsic AD compared with patients with intrinsic AD; the positive correlation of disease severity disappeared in patients with intrinsic AD. Robust expression of periostin was detected in the dermis of patients with AD with erythroderma, lichenification and, to a lesser extent, scaly erythema. Serial measurement of serum periostin revealed decreased levels of periostin after treatment for AD. CONCLUSIONS: Periostin may play a critical role in disease severity and chronicity in the pathogenesis of AD.

Serum periostin levels are correlated with progressive skin sclerosis in patients with systemic sclerosis.

BACKGROUND: Periostin, a matricellular protein, serves as a regulator of wound healing and fibrosis. The role of periostin in the pathogenesis of systemic sclerosis (SSc) is unknown. OBJECTIVE: To determine periostin levels in association with severity of skin fibrosis in patients with SSc. METHODS: Expression of periostin was immunohistochemically examined in skin obtained from patients with SSc and healthy controls. Enzyme-linked immunosorbent assay was performed to evaluate serum periostin levels in association with clinical characteristics in 56 patients with SSc [diffuse cutaneous SSc (dSSc), n=16; and limited cutaneous SSc (lSSc), n=40] and 66 healthy controls. RESULTS: Periostin was strongly expressed in the affected dermis from patients with SSc. Periostin was colocalized in α-smooth muscle actin-positive myofibroblasts and platelet endothelial cell adhesion molecule-1-positive endothelial cells in SSc dermis. Serum levels of periostin in patients with dSSc were markedly elevated compared with those in patients with lSSc and control subjects. Patients with lSSc had increased periostin levels compared with healthy controls. In addition, significantly higher levels of periostin were observed in patients with dSSc with disease duration ≤5 years compared with those with disease duration >5 years. Furthermore, the modified Rodnan total skin thickness score (MRSS) was positively correlated with periostin levels in patients with SSc. Serial analysis revealed a correlation between periostin and MRSS; namely, MRSS decreased in line with decreased periostin levels in some patients with dSSc as the disease progressed. CONCLUSION: An elevated periostin level in patients with SSc is associated with severity of skin sclerosis. Periostin may be a potential biomarker for progressive skin fibrosis in SSc.

Periostin, a matrix protein, is a novel biomarker for idiopathic interstitial pneumonias.

Idiopathic interstitial pneumonias (IIPs) are histopathologically classified into several types, including usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP) and cryptogenic organising pneumonia (COP). We investigated whether periostin, a matrix protein, could be used as a biomarker to assess histopathological types of IIPs. We performed immunohistochemical analyses in each histopathological type of IIP, examined serum levels of periostin in IIP patients and analysed the relationship between serum levels of periostin and the pulmonary functions in patients with idiopathic pulmonary fibrosis (IPF). Periostin was strongly expressed in lungs of UIP and fibrotic NSIP patients, whereas expression of periostin was weak in the lungs of cellular NSIP and COP patients, as well as in normal lungs. Serum levels of periostin in IPF were significantly higher than those of healthy subjects and COP patients. Furthermore, periostin levels in IPF patients were inversely correlated with their pulmonary functions. Thus, we have found that periostin is a novel component of fibrosis in IIP. Periostin may be a potential biomarker to distinguish IIP with fibrosis.

A notable case report of May-Hegglin anomaly with immune complex-related nephropathy: a genetic and histological analysis.

May-Hegglin anomaly (MHA) is a rare autosomal dominant disease characterized by macrothrombocytopenia and leukocyte inclusions with microfilaments in the ribosomes. Mutations in the MYH9 gene, encoding non-muscle myosin heavy chain IIA (NMMHC-IIA) have been identified in patients with MHA and other MYH9-related diseases. Two young males (an older and younger brother) presented with macrothrombocytopenia and leukocyte inclusion bodies. Electron microscopy (EM) revealed parallel filaments in leukocyte inclusion bodies characteristic of MHA. Immunofluorescence microscopy (IF) showed NMMHC-IIA antibodies in 1 - 2 leukocyte inclusion bodies. These findings were consistent with MHA and they were identified to express the MYH9 mutation, D1424H. The older brother underwent a renal biopsy because of persistent proteinuria. Histology revealed mesangial proliferative glomerulonephritis with granular deposits of IgG and C1q. EM showed that the dense deposits were located in subendothelial cells, mesangial cells and Bowman's capsule. Immunocytochemistry revealed that NMMHC-IIA antibodies were localized in podocyte and endothelial cells in the glomerulus. Moreover, the expression of nephrin and podocin, slit diagram protein, was normal. An inflammatory mechanism may occur separately from MYH9-related disease. This report presents a case of MHA with immune complex-related nephropathy.

IL-13: a promising therapeutic target for bronchial asthma.

The incidence of allergic diseases has dramatically increased in recent decades, especially in urban and industrialized areas. It is important socially as well as medically to establish more useful strategies to overcome allergic disorders. Bronchial asthma is a complex disease characterized by airway inflammation involving a Th2-cytokine, interleukin (IL)-13. A substantial body of evidence has accumulated pointing to the pivotal role of IL-13 in the pathogenesis of bronchial asthma, based on mainly analyses of mouse models. In addition to such analyses, the high expression of IL-13 in lesions and genetic association of several genes coding IL-13 signaling molecules with bronchial asthma have raised the possibility that IL-13 plays a pivotal role in the onset or exacerbation of human bronchial asthma. Therefore, IL-13 and its signal pathway are thought to be promising targets to develop a therapeutic agent for bronchial asthma. In this article, we describe how IL-13 is involved in the pathogenesis of bronchial asthma and then how therapeutic agents to block IL-13 signals are developed for bronchial asthma.

Lipopolysaccharide increases cyclo-oxygenase-2 expression in a colon carcinoma cell line through nuclear factor-kappa B activation.

Both nonneoplastic colon epithelium and colon carcinoma cells in situ are continuously exposed to lipopolysaccharide (LPS). Few reports have addressed possible direct effects of LPS in promotion of colon carcinoma and underlying mechanisms. We found evidence that LPS directly stimulated growth of the human colon carcinoma cell line CE-1 through an increase in the production of prostaglandin E2 (PGE2) as a result of cyclo-oxygenase-2 (COX-2) expression. LPS induced significant increases in PGE2 production in CE-1 cells, which were found to express a high-affinity LPS receptor, CD14. Positive correlations were found between PGE2 production and activation of nuclear factor (NF)-kappa B as well as expression of both COX-2 mRNA and protein in LPS-stimulated CE-1 cells. When CE-1 cells were exposed to exogenous PGE2, DNA synthesis increased. These results indicate that LPS may stimulate DNA synthesis in certain colon carcinoma cells as a result of PGE2 production involving increased COX-2 expression that might result in turn from activation of NF-kappa B by LPS. Further investigation of the pathways mediating LPS-induced stimulation of colon carcinoma cells may provide insights into LPS effects in in vivo tumor biology.

Association of the interleukin-4 receptor alpha chain with p47phox, an activator of the phagocyte NADPH oxidase in B cells.

Interleukin (IL)-4 plays an important role in IgE synthesis in B cells and in Th2 differentiation in T cells. IL-4 conducts its biological activities through binding to the IL-4 receptor (IL-4R) on the surface of target cells. IL-4R are thought to be composed of the IL-4R alpha chain (IL-4R alpha) and either the IL-2R gamma chain or the IL-13R alpha chain. We have previously shown that the membrane-proximal portion in the cytoplasmic domain of the human IL-4R alpha (hIL-4R alpha) is critical for proliferation, generation of germline epsilon transcript, and activation of STAT6, based on analyses of truncated hIL-4R alphas. In this study, we found that p47phox, an activator of the phagocyte NADPH oxidase, binds to this portion by the two-hybrid system. Furthermore, we observed the association of p47phox with the hIL-4R alpha in B cells derived from a normal donor. These results suggest that p47phox is involved in the signal transduction of IL-4 in B cells. However, activation of STAT6, CD23 expression, and IgE synthesis induced by IL-4 were not affected in p47phox-deficient patients, which raises the possibility that p47phox may be important in other signaling activities as well in B cells.

Selective DNA-binding activity of interleukin-10-stimulated STAT molecules in human monocytes.

It has been demonstrated that interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) have various reverse effects on macrophages; however, the molecular mechanism of this difference has not been fully understood. In this study, we analyzed the binding activity of IL-10- and IFN-gamma-activated STAT molecules to two kinds of GAS-motif sequences. IL-10-activated STAT1 could bind to the GAS-motif sequence in the promoter region of the Fcgamma receptor, but not to that in the promoter region of the COX-2 gene, whereas IFN-gamma-activated STAT1 and STAT5 could bind to both sequences. IL-10 inhibited IFN-gamma-induced STAT activation without newly synthesized protein. We further demonstrated that aspirin, but not dexamethasone, suppressed IFN-gamma-induced STAT activation. Taken together, these results suggest that IL-10-activated STAT1 has a specificity in binding to the GAS-motif sequences, whereas IFN-gamma-activated STAT1 and STAT5 have a broader spectrum in binding to the GAS-motif sequences. This may explain the difference between IL-10 and IFN-gamma in biological activity, and the inhibitory effect of IL-10 on IFN-gamma activities.

Hakata antigen, a new member of the ficolin/opsonin p35 family, is a novel human lectin secreted into bronchus/alveolus and bile.

Hakata antigen was first reported as a serum protein that reacted with an autoantibody from patients with systemic lupus erythematosus. Recently, it has been found that Hakata antigen is a new member of the ficolin/opsonin p35 family, which is a distinct lectin family, on the basis of homology of structures and the common characteristic of possessing lectin activity. In this study we analyzed the tissue distribution of Hakata antigen. Hakata antigen mRNA and protein were generated in the lung and liver. In the lung, Hakata antigen was produced by both ciliated bronchial epithelial cells and Type II alveolar epithelial cells and was secreted into the bronchus and alveolus. In the liver, Hakata antigen was produced by bile duct epithelial cells and hepatocytes and was also secreted into the bile duct. These results demonstrate that Hakata antigen is a unique lectin protein that exists not only in serum but also in bronchus/alveolus and bile, and indicate that Hakata antigen plays a role in bronchus/alveolus and bile under physiological conditions.