The extended IL-10 superfamily: IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, IL-28, and IL-29

IL-22 mRNA expression in blood samples as a useful biomarker for assessing the adverse health effects of PCBs on allergic children

To facilitate the assessment of adverse effects of very low concentrations of air pollutants on general populations, we planned to establish a reliable biomarker that is also useful in identifying vulnerable populations. For this purpose we monitored several inflammation markers in blood samples from 2 year old Japanese children (N = 30), and found that those children living close to major highways (<50 m) show higher levels of mRNA expression IL-22 in their blood samples than those living further away (+50 m). This tendency was more pronounced among subjects showing positive IgE against egg and milk. We further examined association between IL-22 mRNA expression and PCB residues and found a number of significant positive correlations between each individual PCB congener and IL-22 expression. To identify the most vulnerable population among those children we selected asthma as a typical allergy-related disease, and could show that there are significant differences in the levels of IL-22 mRNA expression between IgE negative non-asthmatic subject and asthmatic children showing positive IgE reaction toward egg or milk, again. These observations support our main conclusion that IL-22 expression is a sensitive biomarker which is useful in identifying sub-populations of children who are especially vulnerable to air pollution.

Clinical outcome in IL-10- and IL-10 receptor-deficient patients with or without hematopoietic stem cell transplantation

BACKGROUND

Inherited deficiencies of IL-10 or IL-10 receptor (IL-10R) lead to immune dysregulation with life-threatening early-onset enterocolitis.

OBJECTIVES

We sought to gather clinical data of IL-10/IL-10R-deficient patients and devise guidelines for diagnosis and management, including hematopoietic stem cell transplantation (HSCT).

METHODS

We enrolled 40 patients with early-onset enterocolitis and screened for mutations in IL10/IL10R using genetic studies, functional studies, or both of the IL-10 signaling pathway. Medical records of IL-10/IL-10R-deficient patients were reviewed and compiled.

RESULTS

Of 40 patients, we identified 7 with novel mutations, predominantly in consanguineous families with more than 1 affected member. IL-10/IL-10R-deficient patients had intractable enterocolitis, perianal disease, and fistula formation. HSCT was carried out in 2 patients with IL-10 deficiency and 1 patient with IL-10R α chain deficiency and proved to be an effective therapy, leading to rapid improvement of clinical symptoms and quality of life.

CONCLUSION

Because the defect in patients with IL-10/IL-10R deficiency resides in hematopoietic lineage cells and their colitis is resistant to standard immunosuppressive therapy, HSCT should be considered early as a potentially curative therapeutic option.

Changes of the cytokine profile in inflammatory bowel diseases

Cytokines are indispensable signals of the mucosa-associated immune system for maintaining normal gut homeostasis. An imbalance of their profile in favour of inflammation initiation may lead to disease states, such as that is observed in inflammatory bowel diseases (IBD). Although Crohn's disease (CD) is often described as a prototype of T-helper 1-type diseases, and ulcerative colitis (UC) is traditionally viewed as a T-helper 2-mediated condition, the classic paradigm, which categorises cytokines into pro- and anti-inflammatory groups, has recently been changed. The inflammation regulatory pathways may not be mutually exclusive as individual cytokines can have diverse and even opposing functions in various clinical and immunological settings. None the less there are many common immunological responses in IBD that are mediated by cytokines. Although they regulate and influence the development, course and recurrence of the inflammatory process, the concrete pathogenic role of these small signaling molecules is sometimes not unambiguous in the subtypes of the disease. Our aim is to review the current information about pro- and anti-inflammatory effects of traditionally studied and recently discovered cytokines in the pathogenesis of UC and CD. The better understanding of their production and functional activity may lead to the development of new therapeutic modalities.

Interleukin-29 modulates proinflammatory cytokine production in synovial inflammation of rheumatoid arthritis

INTRODUCTION

The immunoregulatory function of interleukin (IL)-29 has recently been recognized. However, little is known about the involvement of IL-29 in the pathogenesis of rheumatoid arthritis (RA). This study aimed to examine the expression profiles of IL-29 in blood, synovial fluid (SF) and synovium in RA patients and investigate the effect of IL-29 on cytokines production in RA synovial fibroblasts.

METHODS

The transcript levels of IL-29 and its specific receptor IL-28Rα in peripheral blood mononuclear cells (PBMC) and synovium were determined by real-time reverse transcription-polymerase chain reaction (real-time PCR). The concentrations of IL-29 in serum and synovial fluid (SF) were quantified by enzyme-linked immunoassay (ELISA), and the correlation of serum IL-29 levels with disease activity in RA patients was investigated. Furthermore, the expression of IL-29 in RA synovium was examined by immunohistochemistry and double immunofluorescence analysis. Finally, the expression of IL-6, IL-8, IL-10, IL-17 and matrix metalloproteinase-3 (MMP-3) in synovial fibroblasts upon IL-29 stimulation was determined by real-time PCR.

RESULTS

IL-29 and IL-28Rα mRNA expression in PBMC was significantly increased in patients with RA compared with healthy controls (HC). The serum levels of circulating IL-29 were higher in RA than those in HC. Increased IL-29 levels were detected in RA SF when compared with osteoarthritis (OA) SF. However, serum IL-29 levels showed no significant correlation with RA disease activity. IL-29 was mostly expressed in the lining region of RA synovium. Moreover, IL-29 was expressed predominately in synovial macrophages and fibroblasts. RA synovial fibroblasts exposed to IL-29 specifically upregulated IL-6, -8 and MMP-3 but downregulated IL-10.

CONCLUSIONS

The findings in the present study indicate, for the first time, that IL-29 is dysregulated in patients with RA, which may contribute to the RA pathogenesis via inducing the production of proinflammatory cytokines, chemokines or matrix metalloproteinases in synovial fibroblasts.

From IL-2 to IL-37: the expanding spectrum of anti-inflammatory cytokines

Feedback regulatory circuits provided by regulatory T cells (T(reg) cells) and suppressive cytokines are an intrinsic part of the immune system, along with effector functions. Here we discuss some of the regulatory cytokines that have evolved to permit tolerance to components of self as well as the eradication of pathogens with minimal collateral damage to the host. Interleukin 2 (IL-2), IL-10 and transforming growth factor-β (TGF-β) are well characterized, whereas IL-27, IL-35 and IL-37 represent newcomers to the spectrum of anti-inflammatory cytokines. We also emphasize how information accumulated through in vitro as well as in vivo studies of genetically engineered mice can help in the understanding and treatment of human diseases.

Interleukin-10 and interleukin-10-receptor defects in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease characterized by abdominal pain, bloody diarrhoea, and malabsorption leading to weight loss. It is considered the result of inadequate control of an excessive reaction of the immune system to the resident flora of the gut. Like other primary immunodeficiencies, IL-10 and IL-10 receptor (IL10R) deficiency present with IBD and demonstrate the sensitivity of the intestine to any changes of the immune system. Both IL-10 and IL10R deficiency cause severe early-onset enterocolitis and can be successfully treated by hematopoietic stem cell transplantation (HSCT).

IL-19 and IL-20 genes polymorphisms and haplotype analysis in a vesicoureteral reflux population

Vesicoureteral reflux (VUR) is a common childhood problem, causing renal wounds and escalating the risk of renal deficiency and hypertension. A vast literature exists suggesting that genetic variations play a significant role in the pathogenesis of VUR. The aim of the present study was to estimate whether genetic polymorphisms of IL-19 (GC rs2243158, AT rs2243158) and IL-20 (AG rs2981573, TG rs2981572) genes are involved in the development of VUR.

MATERIALS AND METHODS

The tetra amplification mutation refractory system-polymerase chain reaction (Tetra-ARMS PCR) was applied for analyzing four polymorphic sites of IL-19 (GC rs2243158, AT rs2243158) and IL-20 (AG rs2981573, TG rs2981572) genes in 110 healthy controls and 124 VUR children.

RESULTS

A significant association was found between the combined genotypes of IL19GC+CC and IL20TG+GG and increased risk of VUR (OR = 1.90, 95% CL, 1.06-3.41; OR=1.87, 95% CL, 1.06-3.29, respectively). The frequency of allele G in both sites of IL-20 (IL20AG rs2981573 and IL20TG, rs2981572) showed a statistically significant difference (p = 0.01) between cases and controls in comparison with the wild type. The combined haplotype analysis of IL-19 and IL-20 polymorphic sites revealed that HT2, HT3 and HT5 haplotypes marginally increased the risk of VUR, but not statistically significantly. Gene-gene interaction data of IL-19 (GC rs2243158, AT rs2243158) and IL-20 (AG rs2981573, TG rs2981572) in various genotype patterns highlighted the fact that most of the genotype combinations increased the risk of disease insignificantly.

CONCLUSION

This is the first evidence regarding IL-19 and IL-20 cytokine genes polymorphism and risk of VUR, suggesting the need for further study with large sample size and in different populations to confirm the presented data.

Lineage-specific adjacent IFNG and IL26 genes share a common distal enhancer element

Certain groups of physically linked genes remain linked over long periods of evolutionary time. The general view is that such evolutionary conservation confers 'fitness' to the species. Why gene order confers 'fitness' to the species is incompletely understood. For example, linkage of IL26 and IFNG is preserved over evolutionary time yet Th17 lineages express IL26 and Th1 lineages express IFNG. We considered the hypothesis that distal enhancer elements may be shared between adjacent genes, which would require linkage be maintained in evolution. We test this hypothesis using a bacterial artificial chromosome transgenic model with deletions of specific conserved non-coding sequences. We identify one enhancer element uniquely required for IL26 expression but not for IFNG expression. We identify a second enhancer element positioned between IL26 and IFNG required for both IL26 and IFNG expression. One function of this enhancer is to facilitate recruitment of RNA polymerase II to promoters of both genes. Thus, sharing of distal enhancers between adjacent genes may contribute to evolutionary preservation of gene order.

IFN-λ and IgE-mediated allergic disease: a potential future role?

Reduced early microbial exposure has become a leading candidate to explain the rise in allergic disease, and research has focused on studying the interaction between the developing immune system and the microbial environment. However, despite intense interest, the pathways that lead to dysregulation of the immune system in allergic disease are still poorly understood. The newly described type III IFN-λ molecules were initially shown to exhibit antiviral activity, but these molecules are also likely to have an important role to play in the immune-epithelial interface, given their immunomodulatory functions and restricted receptor expression to immune and epithelial cells. Previous studies on the role of IFN-λ in allergic disease have been limited to allergic asthma. More recently, a genetic variation flanking IL28B encoding IFN-λ3 has been associated with allergic disease. Here, we examine this family and suggest how IFN-λ may be an important player in allergic disease.

IFN-λ inhibits HIV-1 integration and post-transcriptional events in vitro, but there is only limited in vivo repression of viral production

The lambda interferons (IL-28a, 28b, and IL-29) inhibit the replication of many viruses, but their role in the inhibition of HIV-1 infection remains unclear. During this study, we monitored IL-29 production in HIV-1 infected individuals and analyzed the in vitro and in vivo inhibition of HIV-1 production. Prior treatment with IL-28a or IL-29 induced an antiviral state in cultured primary T-cells, which suppressed HIV-1 integration and post-transcriptional events. The antiviral factors MxA, OAS, and PKR were up-regulated. In HIV-1 infected patients, IL-29 level was increased along with the depletion of CD4⁺ T-cells in peripheral blood, while the elevated IL-29 did not show a significantly negative correlation with viral load. Further analysis of HIV-1 infected individuals showed that IL-29 was positively correlated with IFN-β and anti-inflammatory cytokine IL-10, and was negatively correlated with IFN-γ, which might suggest that IFN-λ participates in modulating antiviral immune responses during HIV-1 infection in vivo. Together, although IFN-λ impeded HIV-1 infection of T-cells in vitro, IFN-λ showed only limited in vivo repression of viral production. The modulation of IFN-λ on inflammatory factors might be worthy for further concentrating on for better understanding the host immune response during HIV-1 infection.

IL-22 is expressed by the invasive trophoblast of the equine (Equus caballus) chorionic girdle

The invasive trophoblast cells of the equine placenta migrate into the endometrium to form endometrial cups, dense accumulations of trophoblast cells that produce equine chorionic gonadotropin between days 40 and 120 of normal pregnancy. The mechanisms by which the trophoblast cells invade the endometrium while evading maternal immune destruction are poorly defined. A gene expression microarray analysis performed on placental tissues obtained at day 34 of gestation revealed a >900-fold upregulation of mRNA encoding the cytokine IL-22 in chorionic girdle relative to noninvasive chorion. Quantitative RT-PCR assays were used to verify high expression of IL-22 in chorionic girdle. Additional quantitative RT-PCR analysis showed a striking increase in IL-22 mRNA expression in chorionic girdle from days 32 to 35 and an absence of IL-22 expression in other conceptus tissues. Bioinformatic analysis and cDNA sequencing confirmed the predicted length of horse IL-22, which carries a 3' extension absent in IL-22 genes of humans and mice, but present in the cow and pig. Our discovery of IL-22 in the chorionic girdle is a novel finding, as this cytokine has been previously reported in immune cells only. IL-22 has immunoregulatory functions, with primary action on epithelial cells. mRNA of IL-22R1 was detected in pregnant endometrium at levels similar to other equine epithelia. Based upon these findings, we hypothesize that IL-22 cytokine produced by the chorionic girdle binds IL-22R1 on endometrium, serving as a mechanism of fetal-maternal communication by modulating endometrial responses to trophoblast invasion.

TH-1 and TH-2 cytokines in stable chronic alcoholics

In alcoholics, the activation of Kupffer cells by gram negative bacteriae leads to an inflammatory response and cytokine secretion, which in turn activate T-lymphocytes. Possibly, Th-1 lymphocytes are activated first, followed by a Th-2 response. Th-2 cytokines, especially interleukin (IL)-13 (scarcely studied in alcoholics), may be involved in the progression to chronic stages.

AIMS

The aim of the study was to analyze the relationship of Th-1 and Th-2 cytokines with liver function, alcohol consumption, nutritional status and survival.

METHODS

Serum Th-1 [interferon-γ (IFN-γ)] and Th-2 cytokines (IL-4, IL-13), IL-10, IL-6 and tumor necrosis factor (TNF-α), were determined for 18 controls and 47 stable alcoholics with variable liver function impairment, who were followed-up during a median time of 90 months, a period during which 14 patients died.

RESULTS

IL-4 was lower among patients; no differences were observed regarding IL-6, but the remaining ILs were higher among alcoholics. IL-10 and IL-13 were even higher in cirrhotics (Z = 2.88, P = 0.004, and Z = 2.09, P = 0.037, respectively). A significant, direct, correlation was observed between IL-13 and IL-10 (ρ = 0.49, P = 0.001), and non-significant, inverse ones were observed between IFN-γ and IL-13 (ρ = -0.23), IL-4 (ρ = -0.14) and IL-10 (ρ = -0.09). IL-13 and IL-10 were inversely related with liver function and, directly with immunoglobulin A levels, but not with survival.

CONCLUSION

Serum IFN-γ values were increased in alcoholics, who also showed raised IL-13 and IL-10, but lower IL-4 levels. Given the immunomodulatory roles of IL-10 and IL-13, this increase may be interpreted as a compensatory rise of anti-inflammatory cytokines. We failed to find any relation with mortality.

Is interleukin-10 gene polymorphism a predictive marker in HCV infection?

The clinical outcome of hepatitis C virus (HCV) infection varies between individuals - from spontaneous viral clearance and persistence without complication, to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Also patterns of response to interferon-based anti-HCV therapy are different from person to person. This diversity may be affected by host genetic factors, including alterations in genes encoding cytokines. Interleukin-10, as an anti-inflammatory cytokine and immune response modulator, may influence on HCV infection susceptibility as well as spontaneous and treatment-induced HCV eradication. Moreover, it is stated that IL-10 has antifibrotic properties and play a role in progression of liver disease. This review summarized studies on interleukin-10 gene polymorphisms (mainly promoter SNPs at positions -1082(G/A), -819(C/T) and -592(C/A)), which may determine IL-10 production, regarding susceptibility to HCV infection, course of HCV-related liver disease (fibrosis, cirrhosis, hepatocellular carcinoma, ALT abnormalities), spontaneous viral elimination as well as hepatitis C treatment outcomes. Analysis of hereby summarized studies shows that it is difficult to unambiguously determine the importance of IL-10 polymorphism as a predictor of clinical outcome of hepatitis C and response to anti-HCV therapy before its beginning. Thus, future larger studies need to address these issues. Continuation of studies on interleukin-10 polymorphisms as well as identification of other candidate predictive markers in HCV infection has important practical implications and there is a chance that may contribute to reduce the scale of hepatitis C problem.

Inflammation and genetics: an insight in the centenarian model

The number of centenarians is growing worldwide. This specific cohort has aroused the attention of scientists worldwide and is considered one of the most valuable models to study the mechanisms involved in the aging process. In fact, they have reached the extreme limits of human life span and, most important of all, they show relatively good health being able to perform their routine daily life. Because they have escaped the common lethal diseases, the role of their genetic background has been brought into focus. In fact, sequence variations, in a variety of pro- or anti-inflammatory cytokine genes, have been found to influence successful ageing and longevity. The key role played by cytokines has been also confirmed in centenarians as we know that inflammation has been related to several pathological burdens (e.g., obesity, atherosclerosis, and diabetes). Successful ageing seems to be related to an optimal functioning of the immune system, pointing out that polymorphisms for the immune system genes, which are involved in the regulation of immune-inflammatory responses, may play a key role in the genetics of ageing. This review provides an update in the field of ageing related to inflammation and genetics.

Multifaceted Antiviral Actions of Interferon-stimulated Gene Products

Interferons (IFNs) are extremely powerful cytokines for the host defence against viral infections. Binding of IFNs to their receptors activates the JAK/STAT signalling pathway with the Janus kinases JAK1, 2 and TYK2 and the signal transducer and activators of transcription (STAT) 1 and STAT2. Depending on the cellular setting, additional STATs (STAT3-6) and additional signalling pathways are activated. The actions of IFNs on infected cells and the surrounding tissue are mediated by the induction of several hundred IFN-stimulated genes (ISGs). Since the cloning of the first ISGs, considerable progress has been made in describing antiviral effector proteins and their many modes of action. Effector proteins individually target distinct steps in the viral life cycle, including blocking virus entry, inhibition of viral transcription and translation, modification of viral nucleic acids and proteins and, interference with virus assembly and budding. Novel pathways of viral inhibition are constantly being elucidated and, additionally, unanticipated functions of known antiviral effector proteins are discovered. Herein, we outline IFN-induced antiviral pathways and review recent developments in this fascinating area of research.

Inflamed gut mucosa: downstream of interleukin-10

BACKGROUND

Interleukin-10 is a pleiotropic cytokine, whose main function is limitation and ultimately termination of immune responses. This is especially true for environmental interfaces such as the gastrointestinal tract. IL-10 acts as a key mediator for maintaining gut homeostasis. IL-10 knockout mice are well established as a genetic model for inflammatory bowel disease (IBD), and sequence variants in the IL-10 locus contribute to ulcerative colitis (UC).

DESIGN

This review covers the significance of IL-10 signalling in the intestinal immune response both in health and disease. It explains the biological role of IL-10, its deregulation in IBD and its contribution to intestinal inflammation via endoplasmic reticulum stress response.

RESULTS

Many IBD susceptibility genes have been discovered in the past years, linking fundamental biological systems, like innate and adaptive immunity, stress responses, autophagy and mucosal barrier to the pathogenesis of Crohn's disease (CD) and UC. IL-10 has long been known for its substantial role in regulating gut immunity, but its contribution to IBD was somewhat elusive. A recent study identified mutations in either IL-10 receptor subunits that are associated with early-onset enterocolitis, a severe phenotype of IBD. Other than genetic variants of IL-10 receptors, IL-10 and STAT3 genes are also associated with IBD, emphasizing the involvement of the IL-10 signalling cascade in the pathogenesis of CD and UC.

CONCLUSIONS

  The discovery of inherited deregulations in the IL-10 signalling cascade is not only considered the missing link between IL-10 and intestinal homeostasis, but also demonstrates how findings made in animal models help explaining human disease.

Inflammatory bowel disease: is it a primary immunodeficiency?

Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease are chronic and relapsing conditions, characterized by abdominal pain, diarrhea, bleeding and malabsorption. IBD has been considered a hyperinflammatory state due to disturbed interactions between the immune system and the commensal bacterial flora of the gut. However, there is evidence that Crohn's disease might be the consequence of a reduced release of pro-inflammatory cytokines and an impaired acute inflammatory response, thereby suggesting that IBD might be an immunodeficiency rather than an excessive inflammatory reaction. This theory has been supported by observations in patients with primary immunodeficiencies such as the Wiskott-Aldrich syndrome and IPEX (immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome). In contrary, defects in the anti-inflammatory down-regulation of the immune response as they are seen in patients with Mendelian defects in the IL10 signaling pathway support the hyper-inflammatory theory. In this review, we describe and discuss primary immunodeficiencies associated with IBD and show that the bowel is a highly sensitive indicator of dysregulations, making IBD a model disease to study and identify key regulators required to balance the human mucosal immune system.

Upregulated IL-19 in breast cancer promotes tumor progression and affects clinical outcome

PURPOSE

Interleukin (IL)-19 was expressed in invasive ductal carcinoma (IDC) of the breast tissue but not in healthy breast tissue. We explored the effects of IL-19 on the pathogenesis of breast cancer and its clinical outcome.

EXPERIMENTAL DESIGN

Tumor expression of IL-19 was assessed by immunohistochemistry and/or real-time quantitative PCR between two groups of patients with breast IDC (n = 60 and 143, respectively) with available clinical and survival data. We examined the effects of IL-19 on cytokine and chemokine production as well as proliferation and migration in breast cancer cells. Mice were injected with IL-19-overexpressing or vector control 67NR cells and the tumor growth and lung metastatic micronodules were measured.

RESULTS

Of the IDC specimens, high IL-19 expression was associated with advanced tumor stage, high tumor metastasis, and worse survival. In vitro, IL-19 induced transcripts of IL-1β, IL-6, TGF-β, matrix metalloproteinase (MMP)2, MMP9, and CXCR4 in 4T1 breast cancer cells; induced fibronectin expression and assembly; and promoted cancer cell proliferation and migration, which were inhibited by anti-IL-19 monoclonal antibody (mAb). Endogenous fibronectin expression and cancer cell migration were lower in IL-19 knockdown 4T1 cells. In 4T1 cells, hypoxia induced IL-19 and CXCR4 expression, which was inhibited by anti-IL-19 mAb. IL-19 overexpression in noninvasive 67NR cancer cells increased cell proliferation and migration. In vivo, mice injected with IL-19-overexpressing 67NR cell clones showed larger tumors and more metastatic micronodules in the lung.

CONCLUSIONS

High IL-19 expression in breast cancer tissue is associated with a poor clinical outcome. IL-19 is pivotal in the pathogenesis of breast cancer.

IL-10 and IL-10 receptor defects in humans

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is chronic in nature and is characterized by abdominal pain, diarrhea, bleeding, and malabsorption. It is considered a complex multigenic and multifactorial disorder that results from disturbed interactions between the immune system and commensal bacteria of the gut. Recent work has demonstrated that IBD with an early-onset within the first months of life can be monogenic: mutations in IL-10 or its receptor lead to a loss of IL-10 function and cause severe intractable enterocolitis in infants and small children. Both IL-10 and IL-10 receptor deficiency can be successfully treated by hematopoietic stem cell transplantation.

Interleukin-19 downregulates interleukin-4-induced eotaxin production in human nasal fibroblasts

BACKGROUND

Interleukin-19 (IL-19), a member of the IL-10 family, is characterized as the cytokine suppressing the release and function of several proinflammatory cytokines. For regulation of local reaction in allergic rhinitis (AR), IL-19 might play an especially important role.

METHODS

We examined effects of IL-19 on IL-4-induced eotaxin production by human nasal fibroblasts. Early receptor-mediated events (expression of the suppressors of cytokine signaling (SOCS) and phosphorylation of signal transducer and activator of transcription 6 [STAT6]) by IL-19 was examined. Knockdown methods by RNAi were administered to investigate the involvement of those signal transductions.

RESULTS

Pretreatment with IL-19 downregulates IL-4-induced eotaxin production, but not interferon-γ(IFN-γ)-induced RANTES. Pretreatment with IL-19 suppressed the IL-4-induced STAT6 phosphorylation. The IL-19 induced SOCS-1, but not SOCS-3 or SOCS-5. The SOCS-1 knockdown by RNAi diminished pretreatment with IL-19-induced down-regulation of eotaxin production.

CONCLUSIONS

These results suggest that IL-19 down-regulates IL-4-induced eotaxin production via SOCS-1 in human nasal fibroblasts. In non-hematopoietic cells in AR, IL-19 might be an immunosuppressive factor.

Induced interleukin-19 contributes to cell-mediated immunosuppression in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass

BACKGROUND

Coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) promotes immunosuppression, which predisposes patients to infectious complications. We investigated the role of interleukin (IL)-19 in the functions of CD4+ T cells in patients undergoing CABG with CPB.

METHODS

Blood samples were withdrawn from 42 patients undergoing elective CABG with CPB. Serum levels of IL-19 were analyzed by enzyme-linked immunosorbent assay (ELISA). The CD4+/CD25+ T-cell population was determined with flow cytometry. Isolated CD4+ T cells were cultured and assayed for proliferation and cytokine production under phorbol myristate acetate/ionomycin stimulation. Cytokine production and Foxp3 mRNA expression in CD4+ T cells from healthy volunteers with or without IL-19 treatment were determined with ELISA and real-time polymerase chain reaction, respectively.

RESULTS

Proliferation percentages were 162%, 48%, 34%, and 39%, and interferon (IFN)-γ production was 1.22 ng/mL, 0.56 ng/mL, 0.33 ng/mL, and 0.35 ng/mL in the CD4+ T cells of patients before CPB and at 24 hours, 48 hours, and 96 hours, respectively, after CPB. Serum levels of IL-19 were higher but negatively correlated with CD4+ T-cell proliferation and IFN-γ production. The populations of CD4+/CD25+ T cells and expression of Foxp3 mRNA in T cells were higher and were positively correlated with IL-19 levels after CPB. Treatment with IL-19 reduced T-cell proliferation and IFN-γ production, increased Foxp3 mRNA expression, and induced the regulatory activity of CD4+ T cells.

CONCLUSIONS

Interleukin-19 reduces T-cell responses and promotes the regulatory activity of CD4+ T cells. Induced IL-19 in patients undergoing CABG with CPB contributes to cell-mediated immunosuppression.

High expression of IL-22 suppresses antigen-induced immune responses and eosinophilic airway inflammation via an IL-10-associated mechanism

Allergic inflammation in the airway is generally considered a Th2-type immune response. However, Th17-type immune responses also play important roles in this process, especially in the pathogenesis of severe asthma. IL-22 is a Th17-type cytokine and thus might play roles in the development of allergic airway inflammation. There is increasing evidence that IL-22 can act as a proinflammatory or anti-inflammatory cytokine depending on the inflammatory context. However, its role in Ag-induced immune responses is not well understood. This study examined whether IL-22 could suppress allergic airway inflammation and its mechanism of action. BALB/c mice were sensitized and challenged with OVA-Ag to induce airway inflammation. An IL-22-producing plasmid vector was delivered before the systemic sensitization or immediately before the airway challenge. Delivery of the IL-22 gene before sensitization, but not immediately before challenge, suppressed eosinophilic airway inflammation. IL-22 gene delivery suppressed Ag-induced proliferation and overall cytokine production in CD4(+) T cells, indicating that it could suppress Ag-induced T cell priming. Antagonism of IL-22 by IL-22-binding protein abolished IL-22-induced immune suppression, suggesting that IL-22 protein itself played an essential role. IL-22 gene delivery neither increased regulatory T cells nor suppressed dendritic cell functions. The suppression by IL-22 was abolished by deletion of the IL-10 gene or neutralization of the IL-10 protein. Finally, IL-22 gene delivery increased IL-10 production in draining lymph nodes. These findings suggested that IL-22 could have an immunosuppressive effect during the early stage of an immune response. Furthermore, IL-10 plays an important role in the immune suppression by IL-22.

Transcription of T cell-related genes in teleost fish, and the European sea bass (Dicentrarchus labrax) as a model

In recent years the cloning of genes coding for immuno-regulatory peptides, as well as the sequencing of genomes, provided fish immunologists with a growing amount of information on nucleotide sequences. Research is now also addressed in investigating the functional immunology counterpart of nucleotide sequence transcripts in various fish species. In this respect, studies on functional immunology of T cell activities are still at their beginning, and much work is needed to investigate T cell responses in teleost fish species. In this review we summarise the current knowledge on the group of genes coding for main T cell-related peptides in fish, and the expression levels of these genes in organs and tissues. Particular attention is paid to European sea bass (Dicentrarchus labrax), a marine species in which some information on functional immunology has been obtained, and we reassume here the expression of some T cell-related genes in basal conditions. In addition, we provide original data showing that T cells purified from the intestinal mucosa of sea bass with a specific mAb, express transcripts for TRβ, TRγ, CD8α, and RAG-1, thus showing similarities with intra-epithelial leucocytes of mammals.

Comparative analysis of the human hepatic and adipose tissue transcriptomes during LPS-induced inflammation leads to the identification of differential biological pathways and candidate biomarkers

BACKGROUND

Insulin resistance (IR) is accompanied by chronic low grade systemic inflammation, obesity, and deregulation of total body energy homeostasis. We induced inflammation in adipose and liver tissues in vitro in order to mimic inflammation in vivo with the aim to identify tissue-specific processes implicated in IR and to find biomarkers indicative for tissue-specific IR.

METHODS

Human adipose and liver tissues were cultured in the absence or presence of LPS and DNA Microarray Technology was applied for their transcriptome analysis. Gene Ontology (GO), gene functional analysis, and prediction of genes encoding for secretome were performed using publicly available bioinformatics tools (DAVID, STRING, SecretomeP). The transcriptome data were validated by proteomics analysis of the inflamed adipose tissue secretome.

RESULTS

LPS treatment significantly affected 667 and 483 genes in adipose and liver tissues respectively. The GO analysis revealed that during inflammation adipose tissue, compared to liver tissue, had more significantly upregulated genes, GO terms, and functional clusters related to inflammation and angiogenesis. The secretome prediction led to identification of 399 and 236 genes in adipose and liver tissue respectively. The secretomes of both tissues shared 66 genes and the remaining genes were the differential candidate biomarkers indicative for inflamed adipose or liver tissue. The transcriptome data of the inflamed adipose tissue secretome showed excellent correlation with the proteomics data.

CONCLUSIONS

The higher number of altered proinflammatory genes, GO processes, and genes encoding for secretome during inflammation in adipose tissue compared to liver tissue, suggests that adipose tissue is the major organ contributing to the development of systemic inflammation observed in IR. The identified tissue-specific functional clusters and biomarkers might be used in a strategy for the development of tissue-targeted treatment of insulin resistance in patients.

Pathophysiology of allergic inflammation

Allergic inflammation is due to a complex interplay between several inflammatory cells, including mast cells, basophils, lymphocytes, dendritic cells, eosinophils, and sometimes neutrophils. These cells produce multiple inflammatory mediators, including lipids, purines, cytokines, chemokines, and reactive oxygen species. Allergic inflammation affects target cells, such as epithelial cells, fibroblasts, vascular cells, and airway smooth muscle cells, which become an important source of inflammatory mediators. Sensory nerves are sensitized and activated during allergic inflammation and produce symptoms. Allergic inflammatory responses are orchestrated by several transcription factors, particularly NF-κB and GATA3. Inflammatory genes are also regulated by epigenetic mechanisms, including DNA methylation and histone modifications. There are several endogenous anti-inflammatory mechanisms, including anti-inflammatory lipids and cytokines, which may be defective in allergic disease, thus amplifying and perpetuating the inflammation. Better understanding of the pathophysiology of allergic inflammation has identified new therapeutic targets but developing effective novel therapies has been challenging. Corticosteroids are highly effective with a broad spectrum of anti-inflammatory effects, including epigenetic modulation of the inflammatory response and suppression of GATA3.

Immunology of allergy

Knowledge of the immune system is advancing rapidly. This review provides an update on the allergy players-the cells and major mediators-and the form and function of each; discusses how these cells and mediators weave together in the elegant but destructive dance of allergy; and details how specific immunotherapy can cure allergy.

Autocrine regulation of pulmonary inflammation by effector T-cell derived IL-10 during infection with respiratory syncytial virus

Respiratory syncytial virus (RSV) infection is the leading viral cause of severe lower respiratory tract illness in young infants. Clinical studies have documented that certain polymorphisms in the gene encoding the regulatory cytokine IL-10 are associated with the development of severe bronchiolitis in RSV infected infants. Here, we examined the role of IL-10 in a murine model of primary RSV infection and found that high levels of IL-10 are produced in the respiratory tract by anti-viral effector T cells at the onset of the adaptive immune response. We demonstrated that the function of the effector T cell -derived IL-10 in vivo is to limit the excess pulmonary inflammation and thereby to maintain critical lung function. We further identify a novel mechanism by which effector T cell-derived IL-10 controls excess inflammation by feedback inhibition through engagement of the IL-10 receptor on the antiviral effector T cells. Our findings suggest a potentially critical role of effector T cell-derived IL-10 in controlling disease severity in clinical RSV infection.

IL-10 is a major anti-inflammatory protein that plays an essential role in regulating the balance between pathogen clearance by the immune response and immune mediated injury resulting from the immune response to pathogen infection. In this report, we demonstrate that anti-viral effector T cells, a critical cell type responsible for respiratory syncytial virus clearance, are able to produce a large quantity of IL-10. The function of IL-10 is to control the immune response in order to avoid the development of excessive pulmonary inflammation associated with the clearance of infectious virus. We further identified a likely mechanism that T cell-derived IL-10 operates to control inflammation and describe a novel potential target of IL-10 action in the RSV infected lungs. Our data thus may lay the ground for the future studies exploring the application of IL-10 in therapeutic approaches to modulate pulmonary inflammation and injury in young infants suffering severe respiratory syncytial virus induced diseases.

Interferon-α abrogates tolerance induction by human tolerogenic dendritic cells

Background

Administration of interferon-α (IFN-α) represents an approved adjuvant therapy as reported for malignancies like melanoma and several viral infections. In malignant diseases, tolerance processes are critically involved in tumor progression. In this study, the effect of IFN-α on tolerance induction by human tolerogenic dendritic cells (DC) was analyzed. We focussed on tolerogenic IL-10-modulated DC (IL-10 DC) that are known to induce anergic regulatory T cells (iTregs).

Methodology/Principal Findings

IFN-α promoted an enhanced maturation of IL-10 DC as demonstrated by upregulation of the differentiation marker CD83 as well as costimulatory molecules. IFN-α treatment resulted in an increased capacity of DC to stimulate T cell activation compared to control tolerogenic DC. We observed a strengthened T cell proliferation and increased IFN-γ production of CD4⁺ and CD8⁺ T cells stimulated by IFN-α-DC, demonstrating a restoration of the immunogenic capacity of tolerogenic DC in the presence of IFN-α. Notably, restimulation experiments revealed that IFN-α treatment of tolerogenic DC abolished the induction of T cell anergy and suppressor function of iTregs. In contrast, IFN-α neither affected the priming of iTregs nor converted iTregs into effector T cells.

Conclusions/Significance

IFN-α inhibits the induction of T cell tolerance by reversing the tolerogenic function of human DC.

Interleukin-19 blockade attenuates collagen-induced arthritis in rats

OBJECTIVES

RA is the most common form of inflammatory arthritis. IL-19 acts as a pro-inflammatory cytokine involved in the pathogenesis of RA. We investigated whether anti-IL-19 antibody treatment would modulate the severity of the disease in a CIA rat model.

METHODS

We generated a CIA model by immunizing rats with bovine type II collagen. CIA rats were s.c. treated with anti-IL-19 antibody 1BB1. The effects of 1BB1 on CIA rats were determined by hind-paw thickness, severity score, bone destruction, BMD and cytokine production, which were evaluated using radiological scans, micro-CT, real-time quantitative PCR and ELISA. To analyse gene regulation by IL-19, rat synovial fibroblasts (SFs) were isolated and analysed for the expression of TNF-α, IL-1β and RANK ligand (RANKL).

RESULTS

In vivo, IL-19 was highly expressed in the synovial tissue and SFs isolated from CIA rats. 1BB1 significantly ameliorated the severity of arthritis by decreasing hind-paw thickness and swelling; prevented bone destruction and bone loss; inhibited the expression of TNF-α, IL-1β, IL-6 and RANKL in synovial tissue; and decreased the production of IL-6 in serum. In vitro, IL-19-induced TNF-α, IL-1β, IL-6 and RANKL expression in CIA SFs.

CONCLUSIONS

Specifically blocking IL-19 inhibited pro-inflammatory cytokine production and prevented bone destruction in CIA rats. These findings provide evidence that IL-19 is a novel target, and that anti-IL-19 antibody may be a potential target to ameliorate the severity of RA.

Myeloid cells migrate in response to IL-24

IL-24 (melanoma differentiation associated gene 7 product) is a member of the IL-10 cytokine family that has been reported to possess anti-tumor activity. IL-24 is produced by immune tissues and its expression can be induced in human peripheral blood mononuclear cells by pathogen-associated molecules. While immune cells are known to produce IL-24, the response of immune cells to IL-24 is unclear. Using recombinant human IL-24, we demonstrated that IL-24 induces human monocyte and neutrophil migration, in vitro. An in vivo chemotaxis model showed that IL-24 attracted CD11b positive myeloid cells. To further characterize the chemotactic IL-24 response and type(s) of receptor(s) utilized by IL-24, we treated monocytes with signaling pathway inhibitors. IL-24-induced migration was reduced by pertussis toxin treatment, thus implicating G-protein coupled receptors in this process. Additionally, MEK and JAK inhibitors markedly decreased monocyte migration toward IL-24. These results suggest that IL-24 activates several signaling cascades in immune cells eliciting migration of myeloid cells, which may contribute to the known anti-cancer effects of IL-24.

Cell-free antigens from Paracoccidioides brasiliensis drive IL-4 production and increase the severity of paracoccidioidomycosis

The thermally dimorphic fungus Paracoccidioides brasiliensis (Pb) is the causative agent of paracoccidioidomycosis (PCM), one of the most frequent systemic mycosis that affects the rural population in Latin America. PCM is characterized by a chronic inflammatory granulomatous reaction, which is consequence of a Th1-mediated adaptive immune response. In the present study we investigated the mechanisms involved in the immunoregulation triggered after a prior contact with cell-free antigens (CFA) during a murine model of PCM. The results showed that the inoculation of CFA prior to the infection resulted in disorganized granulomatous lesions and increased fungal replication in the lungs, liver and spleen, that paralleled with the higher levels of IL-4 when compared with the control group. The role of IL-4 in facilitating the fungal growth was demonstrated in IL-4-deficient- and neutralizing anti-IL-4 mAb-treated mice. The injection of CFA did not affect the fungal growth in these mice, which, in fact, exhibited a significant diminished amount of fungus in the tissues and smaller granulomas. Considering that in vivo anti-IL-4-application started one week after the CFA-inoculum, it implicates that IL-4-CFA-induced is responsible by the mediation of the observed unresponsiveness. Further, the characterization of CFA indicated that a proteic fraction is required for triggering the immunosuppressive mechanisms, while glycosylation or glycosphingolipids moieties are not. Taken together, our data suggest that the prior contact with soluble Pb antigens leads to severe PCM in an IL-4 dependent manner.

Interferon-lambda1 induces peripheral blood mononuclear cell-derived chemokines secretion in patients with systemic lupus erythematosus: its correlation with disease activity

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple organ systems. Previous studies have suggested that interferon-lambda 1 (IFN-λ1), a type III interferon, plays an immunomodulatory role. In this study we investigated its role in SLE, including its correlation with disease activity, organ disorder and production of chemokines.

METHODS

We determined levels of IFN-λ1 mRNA in peripheral blood mononuclear cells (PBMC) and serum protein levels in patients with SLE using real-time polymerase chain reaction (real-time PCR) and enzyme-linked immunoassay (ELISA). Further, we detected the concentration of IFN-inducible protein-10 (IP-10), monokine induced by IFN-γ (MIG) and interleukin-8 (IL-8) secreted by PBMC under the stimulation of IFN-λ1 using ELISA.

RESULTS

IFN-λ1 mRNA and serum protein levels were higher in patients with SLE compared with healthy controls. Patients with active disease showed higher IFN-λ1 mRNA and serum protein levels compared with those with inactive disease as well. Serum IFN-λ1 levels were positively correlated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), anti-dsDNA antibody, C-reactive protein (CRP) and negatively correlated with complement 3. Serum IFN-λ1 levels were higher in SLE patients with renal involvement and arthritis compared with patients without the above-mentioned manifestations. IFN-λ1 with different concentrations displayed different effects on the secretion of the chemokines IP-10, MIG and IL-8.

CONCLUSIONS

These findings indicate that IFN-λ1 is probably involved in the renal disorder and arthritis progression of SLE and associated with disease activity. Moreover, it probably plays an important role in the pathogenesis of SLE by stimulating secretion of the chemokines IP-10, MIG and IL-8. Thus, IFN-λ1 may provide a novel research target for the pathogenesis and therapy of SLE.

An intracytoplasmic IL-10 receptor variant permits rapid reduction in STAT3 activation

Within the interleukin-10 receptor 1 (IL10R1) gene, two common variants are associated with certain diseases: single-nucleotide polymorphism 3 (SNP3), a serine-138 to glycine mutation is in linkage disequilibrium with SNP4, a glycine-330 to arginine mutation, both of which are considered loss-of-function alleles. However, the molecular consequence of G330R is unknown. We investigated possible roles of G330R on the dynamics of IL10R1 surface expression and signal transducer and activator of transduction (STAT) phosphorylation. HeLa cells expressing the respective IL10R1 haplotype were stimulated with IL-10. Significant reduction of IL10R1 surface expression was observed after ligand binding. Receptor expression remained low on continuous incubation with IL-10. In contrast, when treated with an IL-10 pulse, IL10R1 surface expression returned to its resting state within 3-9 h irrespective of the haplotype. STAT3 was rapidly phosphorylated both in cells with wild-type (WT) or variant IL10R1, and maintained phosphorylated when cells were cultured with IL-10. On IL-10 pulse, however, STAT3 phosphorylation declined rapidly in cells expressing IL10R1-G330R but not IL10R1-WT or S138G. Similar dynamics were observed with STAT1 phosphorylation at Tyr701. No differences in janus kinase 1 (JAK1) activation were observed in cells with WT or variant IL10R1. Our results indicate that IL10R1-G330R does not alter surface expression but duration of STAT phosphorylation, indicating that the position of G330 is important in stabilizing the STAT signal.

Haplotype-dependent differential activation of the human IL-10 gene promoter in macrophages and trophoblasts: implications for placental IL-10 deficiency and pregnancy complications

PROBLEM

polymorphic changes in the IL-10 gene promoter have been identified that lead to altered IL-10 production. We hypothesized that because of these genotypic changes, the IL-10 promoter might be expressed in a cell type-specific manner and may respond differentially to inflammatory triggers.

METHOD OF STUDY

we created reporter gene promoter constructs containing GCC, ACC, and ATA haplotypes using DNA from patients harboring polymorphic changes at -1082 (G→A), -819 (C→T), and -592 (C→A) sites in the IL-10 promoter. These individual luciferase reporter constructs were transiently transfected into either primary term trophoblasts or THP1 monocytic cells. DNA-binding studies were performed to implicate the role of the Sp1 transcription factor in response to differential promoter activity.

RESULTS

our results suggest that the GCC promoter construct was activated in trophoblast cells in response to lipopolysaccharide (LPS), as demonstrated by reporter gene expression, but not in monocytic cells. The ACC construct showed weaker activation in both cell types. Importantly, while the ATA promoter was constitutively activated in both cell types, its expression was selectively repressed in response to LPS, but only in trophoblasts. DNA-nuclear protein binding assays with nuclear extracts from LPS treated or untreated cells suggested a functional relevance for Sp1 binding differences at the -592 position.

CONCLUSIONS

these results demonstrate cell type-specific effects of the genotypic changes in the IL-10 gene promoter. These responses may be further modulated by bacterial infections or other inflammatory conditions to suppress IL-10 production in human trophoblasts.

Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases

Advancing our understanding of mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections could lead to effective and targeted therapies. Subsets of immune and inflammatory cells interact via ILs and IFNs; reciprocal regulation and counter balance among T(h) and regulatory T cells, as well as subsets of B cells, offer opportunities for immune interventions. Here, we review current knowledge about ILs 1 to 37 and IFN-γ. Our understanding of the effects of ILs has greatly increased since the discoveries of monocyte IL (called IL-1) and lymphocyte IL (called IL-2); more than 40 cytokines are now designated as ILs. Studies of transgenic or knockout mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided important information about IL and IFN functions. We discuss their signaling pathways, cellular sources, targets, roles in immune regulation and cellular networks, roles in allergy and asthma, and roles in defense against infections.

Evolutionary divergence and functions of the human interleukin (IL) gene family

Cytokines play a very important role in nearly all aspects of inflammation and immunity. The term 'interleukin' (IL) has been used to describe a group of cytokines with complex immunomodulatory functions -- including cell proliferation, maturation, migration and adhesion. These cytokines also play an important role in immune cell differentiation and activation. Determining the exact function of a particular cytokine is complicated by the influence of the producing cell type, the responding cell type and the phase of the immune response. ILs can also have pro- and anti-inflammatory effects, further complicating their characterisation. These molecules are under constant pressure to evolve due to continual competition between the host's immune system and infecting organisms; as such, ILs have undergone significant evolution. This has resulted in little amino acid conservation between orthologous proteins, which further complicates the gene family organisation. Within the literature there are a number of overlapping nomenclature and classification systems derived from biological function, receptor-binding properties and originating cell type. Determining evolutionary relationships between ILs therefore can be confusing. More recently, crystallographic data and the identification of common structural motifs have led to a more accurate classification system. To date, the known ILs can be divided into four major groups based on distinguishing structural features. These groups include the genes encoding the IL1-like cytokines, the class I helical cytokines (IL4-like, γ-chain and IL6/12-like), the class II helical cytokines (IL10-like and IL28-like) and the IL17-like cytokines. In addition, there are a number of ILs that do not fit into any of the above groups, due either to their unique structural features or lack of structural information. This suggests that the gene family organisation may be subject to further change in the near future.

Interleukin 22 signaling promotes cell growth in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a specific type of aggressive B-cell non-Hodgkin lymphoma. We recently found that IL-22RA1, one of the two subunits of the interleukin 22 (IL-22) receptor, is expressed in MCL cell lines but not benign lymphocytes. In view of normal functions of IL-22 signaling, we hypothesized that the aberrant expression of IL-22RA1 may contribute to the deregulation of various cell signaling pathways, thereby promoting cell growth in MCL. In this study, we first demonstrated the expression of IL-22RA1 in all three MCL cell lines and eight frozen tumors examined using reverse transcription-polymerase chain reaction and Western blot analysis. In support of the concept that IL-22 signaling is biologically important in MCL, we found that MCL cells treated with recombinant IL-22 had a significant increase in cell growth that was associated with STAT3 activation. To investigate the mechanism underlying the aberrant expression of IL-22RA1, we analyzed the gene promoter of IL-22RA1, and we found multiple binding sites for NF-κB, a transcriptional factor strongly implicated in the pathogenesis of MCL. Pharmacologic inhibition of NF-κB resulted in a substantial reduction in the level of IL-22RA1 protein expression in MCL cells. To conclude, IL-22RA is aberrantly expressed in MCL, and we have provided evidence that IL-22 signaling contributes to the pathogenesis of MCL.

In patients with idiopathic venous thrombosis, interleukin-10 is decreased and related to endothelial dysfunction

The aim of this study was to evaluate the levels of anti-inflammatory interleukin-10 and pro-inflammatory cytokines and their relationship to endothelial function in patients with idiopathic venous thrombosis. Forty-nine eligible patients of both sexes with idiopathic venous thrombosis and 48 matched control subjects were studied. Levels of inflammatory markers were determined. Endothelial function was evaluated by ultrasound measurement of the flow mediated dilatation (FMD) of the brachial artery. Compared to the control group, patients with idiopathic venous thrombosis had significantly lower levels of interleukin-10 1.81 pg/ml (1.53-2.21) versus 2.71 pg/ml (1.84-3.65), p < 0.001. Patients also had increased levels of pro-inflammatory cytokines: interleukin-6 2.37 pg/ml (1.59-4.09) versus 2.03 pg/ml (1.49-2.59), p = 0.025, interleukin-8 3.53 pg/ml (2.94-5.30) versus 2.25 pg/ml (1.77-2.90), p < 0.001. Furthermore, decreased FMD was observed in patients: 5.0% (3.9-6.9) versus 12.7% (10.8-15.6), p < 0.001. FMD was related to levels of interleukin-10 (r = 0.33, p = 0.001) and was inversely related to pro-inflammatory cytokines interleukin-6 (r = -0.34, p = 0.001) and interleukin-8 (r = -0.43, p < 0.001). Patients with idiopathic venous thrombosis have decreased levels of IL-10 and increased levels of pro-inflammatory cytokines. This imbalance indicates that in the stable phase of the disease, patients have an increased systemic inflammatory response. This inflammatory response could be the consequence of the disease, but most probably is involved in the pathogenesis of venous thrombosis.

Th2 Cytokine Levels Distort the Association of IL-10 and IFN-γ with Allergic Phenotypes

The expression of allergic phenotypes involves complex inter-relationships among several Th2 and Th1 cytokines as well as the regulator cytokine interleukin (IL)-10. These direct or indirect interrelationships may distort the true associations of cytokine responses with these phenotypes. In this study, we aimed to clarify the effects of the regulatory cytokine IL-10 and Th1 cytokine interferon-gamma (IFN-γ) on allergic phenotypes after adjusting for the correlations with Th2 cytokines. After adjusting for Th2 cytokines, IL-10 and IFN-γ were protective against atopy. Adjusted levels of IL-10 and IFN-γ stimulated with house-dust mite (HDM) were significantly lower in atopics than non-atopics, for IL-10 adjusting for IL-5 (P = 0.002), IL-13 (P = 0.012), IL-9 (P = 0.016), and IL-4 (P = 0.043), and for IFN-γ adjusting for IL-5 (P = 0.005), IL-13 (P = 0.005), and IL-9 (P = 0.037). IL-10 and IFN-γ levels stimulated with phytohaemagglutinin (PHA) and staphylococcal enterotoxin B (SEB) exhibited a similar pattern. The adjusted levels of IL-10 and IFN-γ stimulated with HDM, PHA or SEB were all significantly negatively correlated with total serum IgE, except for IFN-γ stimulated with SEB. Levels of Th2 cytokines distort the associations of IL-10 and IFN-γ with allergic phenotypes. Removing the covariance with Th2 cytokines, both IL-10 and IFN-γ were protective against atopy.

Functional gene polymorphisms of interleukin-10 are associated with liver disease progression in Japanese patients with hepatitis C virus infection

OBJECTIVE

The inter-individual difference in response to liver injury appears to be important in the progression of liver fibrosis. Interleukin 10 (IL-10) is an anti-inflammatory cytokine, and several functional gene polymorphisms have been found. The aim of this study was to examine the possible association of IL-10 polymorphisms with the progression of liver fibrosis in hepatitis C virus (HCV)-related chronic liver disease patients.

METHODS

We examined the IL-10 -1087 A/G and -824 T/C gene polymorphisms in 184 Japanese patients with HCV-related chronic liver disease: 94 chronic hepatitis (CH) and 90 with liver cirrhosis (LC).

RESULTS

There were no significant differences in the genotype distributions or allele frequencies of IL-10 -824 T/C and -1087 A/G between the CH and LC groups. However, among the cirrhotic patients, the lower transcriptional allele, -824 T homozygotes had significantly lower serum albumin and platelet counts, and a higher Child-Pugh score than the -824 C carriers, and the lower transcriptional allele, -1087 A homozygotes had a higher ICG-R 15 compared with -1087 G carriers. Haplotype analysis of IL-10 -1087/-824 showed no significant difference between the CH and LC groups, but the combinations of AT and AC haplotypes (AT/AT, AT/AC and AC/AC) had a significantly higher ICG-R 15 than the GC carriers.

CONCLUSION

IL-10 lower transcriptional -824 T allele, -1087 A allele, and -1087/-824 haplotypes AT and AC are risk factors for the progression of liver fibrosis in HCV-related chronic liver disease.

Effects of medroxyprogesterone acetate on gene expression in myometrial explants from pregnant women

CONTEXT

Progesterone is important physiologically and therapeutically to maintain uterine quiescence during pregnancy, in part through controlling myometrial gene expression.

OBJECTIVE

The objective of the study was to use expression microarray and quantitative reverse transcriptase-PCR (qRT-PCR) validation to determine the changes in gene expression induced by prolonged exposure of human myometrium to a synthetic progestogen.

DESIGN

Myometrial explants, obtained at elective cesarean section (n=9), were maintained in culture, under 0.6 g tension, for 65 h in the presence of medroxyprogesterone acetate (100 nm) or vehicle. Expression array was performed using Illumina beadchip arrays. Approximately 30% of differentially expressed transcripts were validated in biological replicates (n=10) by qRT-PCR.

RESULTS

The 114 significantly regulated transcripts were significantly enriched in inflammatory response (P=0.00001), growth factor activity (P=0.0004), and cytokine activity genes (P=0.008). Thirty-four transcripts were validated using qRT-PCR in explants obtained from 10 further women. There was very close agreement in the fold changes obtained by array and qRT-PCR (r2=0.9, P<0.0001). We confirmed significant down-regulation of a number of genes that have been well characterized as progesterone sensitive (IL-1B, IL-6, PTGS2, and GJA1). However, the top and sixth most down-regulated transcripts encoded two cytokines, IL-11 and IL-24, respectively, not previously implicated in mediating the effects of progesterone in myometrium. Both were validated by qRT-PCR (4.3- and 2.2-fold down-regulated, both P<0.001).

CONCLUSIONS

Medroxyprogesterone acetate controls expression of multiple genes in myometrium, including many that have not previously been characterized as progestogen regulated in this tissue, including IL-11 and IL-24. It is plausible that proteins encoded by some of these genes may have important but as yet uncharacterized effects in controlling human parturition.

Interleukin-20 antibody is a potential therapeutic agent for experimental arthritis

OBJECTIVE

Interleukin-20 (IL-20) is a proinflammatory cytokine involved in the pathogenesis of rheumatoid arthritis (RA). We investigated whether anti-IL-20 antibody treatment would modulate the severity of the disease in a collagen-induced arthritis (CIA) rat model.

METHODS

We generated a CIA model by immunizing rats with bovine type II collagen. Rats with CIA were treated subcutaneously with anti-IL-20 antibody 7E, with the tumor necrosis factor (TNF) blocker etanercept, or with 7E in combination with etanercept. Arthritis severity was determined according to the hind paw thickness, arthritis severity score, degree of cartilage damage, bone mineral density, and cytokine production, which were evaluated using radiologic scans, microfocal computed tomography, and enzyme-linked immunosorbent assay. To analyze gene regulation by IL-20, rat synovial fibroblasts (SFs) were isolated and analyzed for the expression of RANKL, IL-17, and TNFα. We also used real-time quantitative polymerase chain reaction analysis and flow cytometry to determine IL-20-regulated RANKL in mouse osteoblastic MC3T3-E1 cells and Th17 cells.

RESULTS

In vivo, treatment with 7E alone or in combination with etanercept significantly reduced the severity of arthritis by decreasing the hind paw thickness and swelling, preventing cartilage damage and bone loss, and reducing the expression of IL-20, IL-1β, IL-6, RANKL, and matrix metalloproteinases (MMPs) in synovial tissue. In vitro, IL-20 induced TNFα expression in SFs from rats with CIA. IL-20 markedly induced RANKL production in SFs, osteoblasts, and Th17 cells.

CONCLUSION

Selectively blocking IL-20 inhibited inflammation and bone loss in rats with CIA. Treatment with 7E combined with etanercept protected rats from CIA better than treatment with etanercept alone. Our findings provide evidence that IL-20 is a novel target and that 7E may be a potential therapeutic agent for RA.