Crystal Structure of the Labile Complex of IL-24 with the Extracellular Domains of IL-22R1 and IL-20R2

Crystal structure of the ternary complex of human IL-24 with two receptors, IL-22R1 and IL-20R2, has been determined at 2.15 Å resolution. A crystallizable complex was created by a novel approach involving fusing the ligand with a flexible linker to the presumed low-affinity receptor, and coexpression of this construct in Drosophila S2 cells together with the presumed high-affinity receptor. This approach, which may be generally applicable to other multiprotein complexes with low-affinity components, was necessitated by the instability of IL-24 expressed by itself in either bacteria or insect cells. Although IL-24 expressed in Escherichia coli was unstable and precipitated almost immediately upon its refolding and purification, a small fraction of IL-24 remaining in the folded state was shown to be active in a cell-based assay. In the crystal structure presented here, we found that two cysteine residues in IL-24 do not form a predicted disulfide bond. Lack of structural restraint by disulfides, present in other related cytokines, is most likely reason for the low stability of IL-24. Although the contact area between IL-24 and IL-22R1 is larger than between the cytokine and IL-20R2, calculations show the latter interaction to be slightly more stable, suggesting that the shared receptor (IL-20R2) might be the higher-affinity receptor.

Molecular characterization and expression analysis of IL-22 and its two receptors genes in yellow catfish (Pelteobagrus filvidraco) in response to Edwardsiella ictaluri challenge

Interleukin (IL)-22, as a member of the interleukin (IL)-10 family, is an important mediator between the immune cells and epithelial tissues during infection and inflammation. This study reported the characterization and mRNA expression patterns of Pf_IL-22 gene and its cell surface-associated receptors Pf_IL-22RA1 and soluble Pf_IL-22RA2 genes in yellow catfish (Pelteobagrus filvidraco). The open reading frames (ORFs) of the Pf_IL-22, Pf_IL-22RA1 and Pf_IL-22RA2 genes were 546 bp, 1740 bp and 690 bp in length, encoding 181, 579 and 229 amino acids, respectively. Alignments of the deduced amino acid sequences present that the Pf_IL-22 has a conserved IL-10 family signature motif, and the Pf_IL-22RA1 and Pf_IL-22RA2 have two conserved fibronectin type-III domains. Quantitative real-time PCR (qPCR) analyses showed that the Pf_IL-22 and Pf_IL-22RA1 mRNAs were highly expressed in mucosal tissues such as the fin, gill, intestine, skin mucus and stomach, and were weakly expressed in the kidney, liver and head kidney of adult yellow catfish, indicating that the Pf_IL-22 transcripts may be mainly produced by mucosal immune cells/tissues in healthy yellow catfish. The mRNA expression levels of the Pf_IL-22RA2 gene were high in the muscle and liver, and were relatively low in the spleen and kidney. The mRNA expression levels of the Pf_IL-22 and its two receptor genes were significantly up-regulated in both mucosal tissues (gill, hindgut, and skin mucus) and systemic immune tissues (spleen, head kidney and blood) after Edwardsiella ictaluri challenge. These results indicated that the Pf_IL-22 and its two receptors genes might play an important role in the innate immune defense against bacterial invasion.

Act1 is a negative regulator in T and B cells via direct inhibition of STAT3

Although Act1 (adaptor for IL-17 receptors) is necessary for IL-17-mediated inflammatory responses, Act1- (but not Il17ra-, Il17rc-, or Il17rb-) deficient mice develop spontaneous SLE- and Sjögren's-like diseases. Here, we show that Act1 functions as a negative regulator in T and B cells via direct inhibition of STAT3. Mass spectrometry analysis detected an Act1-STAT3 complex, deficiency of Act1 (but not Il17ra-, Il17rc-, or Il17rb) results in hyper IL-23- and IL-21-induced STAT3 activation in T and B cells, respectively. IL-23R deletion or blockade of IL-21 ameliorates SLE- and Sjögren's-like diseases in Act1-/- mice. Act1 deficiency results in hyperactivated follicular Th17 cells with elevated IL-21 expression, which promotes T-B cell interaction for B cell expansion and antibody production. Moreover, anti-IL-21 ameliorates the SLE- and Sjögren's-like diseases in Act1-deficient mice. Thus, IL-21 blocking antibody might be an effective therapy for treating SLE- and Sjögren's-like syndrome in patients containing Act1 mutation.

Identification of ANKDD1B variants in an ankylosing spondylitis pedigree and a sporadic patient

BACKGROUND

Ankylosing spondylitis (AS) is a debilitating autoimmune disease affecting tens of millions of people in the world. The genetics of AS is unclear. Analysis of rare AS pedigrees might facilitate our understanding of AS pathogenesis.

METHODS

We used genome-wide linkage analysis and whole-exome sequencing in combination with variant co-segregation verification and haplotype analysis to study an AS pedigree and a sporadic AS patient.

RESULTS

We identified a missense variant in the ankyrin repeat and death domain containing 1B gene ANKDD1B from a Han Chinese pedigree with dominantly inherited AS. This variant (p.L87V) co-segregates with all male patients of the pedigree. In females, the penetrance of the symptoms is incomplete with one identified patient out of 5 carriers, consistent with the reduced frequency of AS in females of the general population. We further identified a distinct missense variant affecting a conserved amino acid (p.R102L) of ANKDD1B in a male from 30 sporadic early onset AS patients. Both variants are absent in 500 normal controls. We determined the haplotypes of four major known AS risk loci, including HLA-B*27, 2p15, ERAP1 and IL23R, and found that only HLA-B*27 is strongly associated with patients in our cohort.

CONCLUSIONS

Together these results suggest that ANKDD1B variants might be associated with AS and genetic analyses of more AS patients are warranted to verify this association.

Inhibition of interleukin-12 and/or interleukin-23 for the treatment of psoriasis: What is the evidence for an effect on malignancy?

Immune cells and cytokines play an important role in the pathogenesis of psoriasis. Interleukin-12 (IL-12) and IL-23 promote cellular responses mediated by T cells, which contribute to an inflammatory loop responsible for the induction and maintenance of psoriatic plaques. Antibodies that inhibit IL-12/23 or IL-23 are key treatment options for patients with psoriasis. IL-12 and IL-23 also play a key role in immune responses to infections and tumors. A growing body of information from clinical trials, cohort studies, postmarketing reports, genetic studies and animal models provides insights into the potential biological relationships between IL-12/23 inhibition and malignancies. We summarize this information in tables and provide some context for the interpretation of these data with the goal of informing dermatologists who are using IL-12/23 or IL-23 inhibitors to treat patients with psoriasis.

Interleukin-22-deficiency and microbiota contribute to the exacerbation of Toxoplasma gondii-induced intestinal inflammation

Upon oral infection with Toxoplasma gondii cysts (76 K strain) tachyzoites are released into the intestinal lumen and cross the epithelial barrier causing damage and acute intestinal inflammation in C57BL/6 (B6) mice. Here we investigated the role of microbiota and IL-22 in T.gondii-induced small intestinal inflammation. Oral T.gondii infection in B6 mice causes inflammation with IFNγ and IL-22 production. In IL-22-deficient mice, T.gondii infection augments the Th1 driven inflammation. Deficiency in either IL-22bp, the soluble IL-22 receptor or Reg3γ, an IL-22-dependent antimicrobial lectin/peptide, did not reduce inflammation. Under germ-free conditions, T.gondii-induced inflammation was reduced in correlation with parasite load. But intestinal inflammation is still present in germ-free mice, at low level, in the lamina propria, independently of IL-22 expression. Exacerbated intestinal inflammation driven by absence of IL-22 appears to be independent of IL-22 deficiency associated-dysbiosis as similar inflammation was observed after fecal transplantation of IL-22-/- or WT microbiota to germ-free-WT mice. Our results suggest cooperation between parasite and intestinal microbiota in small intestine inflammation development and endogenous IL-22 seems to exert a protective role independently of its effect on the microbiota. In conclusion, IL-22 participates in T.gondii induced acute small intestinal inflammation independently of microbiota and Reg3γ.

Impact of IL-22 and IL-22 receptor alpha 1 polymorphisms on preeclampsia risk in Chinese Han women

Previous studies have indicated that an increased inflammatory response plays an important role in preeclampsia (PE), and rising levels of interleukin (IL)-22 can trigger inflammation and hyperproliferation, leading to increased production of several pro-inflammatory cytokines such as IL-1, IL-6, and IL-8. We aimed to investigate the association between polymorphisms of IL-22 and IL-22 receptor alpha 1 gene (IL-22RA1) and PE in Chinese Han population. Single nucleotide polymorphisms (SNPs) rs2227485 in IL-22 and rs3795299 in IL-22RA were genotyped by Taqman real-time PCR in 1071 PE patients and 1263 control subjects. Differences in genetic distribution were compared between two groups using the chi-square test. Significant differences were observed in genotypic and allelic frequencies of IL-22RA1 rs3795299 between healthy controls and PE patients (P < 0.001 by genotype; P = 0.001, odds ratio = 1.253, 95% confidence interval 1.103-1.424 by allele). There were also significant differences in genotypic and allelic frequencies of rs3795299 between late-onset/mild PE and control groups. In addition, we found obvious statistic difference for the allele of early-onset PE/the genotype of late-onset PE and control subgroups for IL-22 rs2227485. IL-22 rs2227485 and IL-22RA1 rs3795299 may be associated with the development of PE in Chinese Han population. However, further validation is required in other populations, as well as an evaluation of the association of other SNPs in IL-22 and IL-22RA1 with PE.

Targeting Inflammatory T Helper Cells via Retinoic Acid-Related Orphan Receptor Gamma t Is Ineffective to Prevent Allo-Response-Driven Colitis

Intestinal graft-versus-host disease (GvHD) is a life-threatening, inflammatory donor T cell-mediated complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the light of the reported efficacy of interleukin-23 (IL-23)-blockade to mitigate syngeneic intestinal inflammation in inflammatory bowel disease patients, targeting IL-23 and thereby interleukin-17a (IL-17a) producing T helper (Th17) cells as the T cell subset assumed to be mostly regulated by IL-23, has emerged as a putatively general concept to harness immune-mediated mucosal inflammation irrespective of the underlying trigger. However, the role of Th17 cells during allo-response driven colitis remains ambiguous due to a series of studies with inconclusive results. Interestingly, we recently identified granulocyte-macrophage colony-stimulating factor (GM-CSF+) T cells to be promoted by interleukin-7 (IL-7) signaling and controlled by the activating protein-1 transcription factor family member basic leucine zipper transcription factor ATF-like (BATF) as critical mediators of intestinal GvHD in mice. Given the dual role of BATF, the contribution of IL-23-mediated signaling within donor T cells and bona fide Th17 cells remains to be delineated from the regulation of GM-CSF+ T cells in the absence of BATF. Here, we found in a complete MHC class I-mismatched model that genetic inactivation of the IL-23 receptor (IL-23R) or the transcription factor retinoic acid-related orphan receptor gamma t (RORγt) within donor T cells similarly ablated Th17 cell formation in vivo but preserved the T cells' ability to induce intestinal GvHD in a compared to wild-type controls indistinguishable manner. Importantly, RORγt-independent manifestation of intestinal GvHD was completely dependent on BATF-regulated GM-CSF+ T cells as BATF/RORγt double-deficient T cells failed to induce colitis and the antibody-mediated blockage of IL-7/IL-7R interaction and GM-CSF significantly diminished signs of intestinal GvHD elicited by RORγt-deficient donor T cells. Finally, in analogy to our murine studies, colonic RORC expression levels inversely correlated with the presence of GvHD in allo-HSCT patients. Together, this study provides a crucial example of a BATF-dependent, however, IL-23R signaling- and RORγt-, i.e., Th17 fate-independent regulation of a colitogenic T cell population critically impacting the current understanding of intestinal GvHD.

Detection of gene expression in sentinel lymph node of primary breast cancer patients

Sentinel lymph node (SLN) micrometstasis detection improves outcome for breast cancer follow up procedure. The aim of the present study was to identify gene profiles that accurately predicted the outcome of breast cancer patients. Fifty tumor sample from breast cancer patients were analyzed for the expression of 3 genes using quantitative-PCR. Also clinical verification for recurrence to distant organs was performed. Three gene signature were confirmed based on tumor's stage, grade, ER status, using conditional logistic regression. Based on this findings, the negative reported lymph nodes for metastasis, had micro metastasis in significant values. There was a significant difference between normal and cancer samples in 3 gene expression marker and also there was meaningful relationship between three gene expression with tumor's grade, stage according to progression of tumor. A novel gene expression signature predictive of micro metastatic patients was evaluated. In this assessment, relationship between this gene with tumor's features   that finding clear role for these genes with tumor's outcome, needs to be established.

Role of IL-23 signaling in the progression of premalignant oral lesions to cancer

Mice bearing carcinogen-induced premalignant oral lesions were previously shown to have a pro-inflammatory phenotype, which is replaced with an immune inhibitory phenotype as lesions progress to cancer. Since Th17 cells are prominent at the premalignant lesion state and their levels are supported by IL-23, studies used mice that were IL-23 receptor deficient (IL-23R KO) to determine the requirement for IL-23 signaling in the immunological and clinical status of mice with premalignant oral lesions. The results showed a dependence on IL-23 signaling for the pro-inflammatory state of mice with oral lesions as levels of IL-2, IFN-γ, IL-6, IL-17 and TNF-α were elevated in wildtype mice with premalignant oral lesions, but not in IL-23R KO mice. In contrast, as lesions progressed to cancer, the pro-inflammatory phenotype subsided and was replaced with the inhibitory mediator IL-10 and with Treg cells in wildtype mice, although not in IL-23R KO mice. Clinically, early progression of premalignant oral lesions to cancer was enhanced in IL-23R KO mice compared to progression in wildtype mice. These results show the importance of IL-23 signaling in both the pro-inflammatory phenotype characteristic of premalignant oral lesions and the inhibitory phenotype as lesions progress to cancer.

Temporal expression of interleukin-22, interleukin-22 receptor 1 and interleukin-22-binding protein during experimental periodontitis in rats

BACKGROUND AND OBJECTIVE

Interleukin-22 (IL-22), mainly produced by CD4+ T-helper subtypes and innate lymphoid cells at barrier surfaces, is found to involve in several diseases, including diabetes, rheumatoid arthritis, peri-implantitis and chronic rhinosinusitis with nasal polyps. The purpose of this study was to investigate histological changes and the levels of interleukin-22, interleukin-22 receptor 1 (IL-22R1) and interleukin-22-binding protein (IL-22BP) in experimental periodontitis.

MATERIAL AND METHODS

Sixty male 8-week-old Sprague Dawley rats were randomly allocated to six groups of 10 rats each. In the periodontitis groups, experimental periodontitis was established and the rats were killed on days 3, 5, 7, 11 and 15 after ligation, while the rats without ligation were killed on day 0, representing the healthy control group (day 0 group). Histopathologic changes were detected by hematoxylin and eosin (H&E) staining, and alveolar bone loss was determined by micro-computed tomography (micro-CT). Tartrate-resistant acid phosphatase (TRAP) staining was used to investigate osteoclast formation. Real-time quantitative PCR (qPCR) and immunohistochemistry were used to investigate the expression and location of IL-22, IL-22R1 and IL-22BP in gingival tissues.

RESULTS

H&E staining showed increasingly severe destruction of the epithelial layer between day 3 and day 7, and the hyperplasia of pocket epithelium and the formation of periodontal pockets could be detected from day 11 to day 15. Micro-CT indicated an exponential increase in alveolar bone loss from day 3 to day 11 (P < .01). Bone resorption tended to be stationary after this period. TRAP staining showed that the number of multinucleate osteoclasts peaked at day 3 (P < .001, compared with day 0) and decreased at subsequent time points between day 5 and day 15. IL-22BP was expressed strongly under steady-state conditions in epithelial cells. IL-22-positive cells could be clearly observed both in the epithelial layer and around the lamina propria, whereas IL-22R1 was mainly localized in the epithelial layer of the damage period. Real-time qPCR revealed up-regulation of IL-22 and IL-22R1, as well as down-regulation of IL-22BP in gingival tissues during the destructive phase of periodontitis.

CONCLUSION

This study shows the expression and localization of IL-22, IL-22R1 and IL-22BP, as well as the relevant histopathological alterations during the development of experimental periodontitis.

Expression of IGF-1, IL-27 and IL-35 Receptors in Adjuvant Induced Rheumatoid Arthritis Model

BACKGROUND

IGF-1 and certain other cytokines have been shown to exert inflammatory/anti-inflammatory roles in chronic joint diseases.

OBJECTIVE

To assess the effect of IGF-1, IL-27 and IL-35, their interaction and their receptor expression in a rheumatoid arthritis model.

METHODS

Freund's adjuvant-induced chronic joint inflammation was operated on 160 male rats. Animals were divided into histopathology and receptor expression groups, each composed of 10 subgroups including; control, vehicle, IGF-1, IL-27, IL-35, their antagonists, IGF-1+IL-27 antagonist and IGF-1+IL-35 antagonist. After two weeks, vehicle or agonist/antagonists were injected into the joint space every other day until day 28 where joint histopathology was performed. The expression of IGF-1, IL-27 and IL-35 receptors were assessed by western blot analysis.

RESULTS

IGF-1 did not show pro- or anti- inflammatory functions; endogenous IL-27 and IL-35, on the other hand, exerted inflammatory effects. IL-27 and IL-35 antagonists exerted the highest anti-inflammatory effects. The total inflammation scores were 0.55 ± 0.06, 4.63 ± 0.40, 3.63 ± 0.60, 2.50 ± 0.38 and 1.63 ± 0.40 regarding control, vehicle, IGF-1 Ant., IL-27 Ant. and IL-35 Ant., respectively. IGF-1 receptor expression was reduced in chronic joint inflammation and all three antagonists augmented the IGF-1 receptor expression. IL-27 and IL-35 receptors were up-regulated by chronic joint inflammation.

CONCLUSION

Overall, the results demonstrated the pro-inflammatory role of endogenous IL-27 and IL-35 along with the over expression of their receptors in chronic joint inflammation. IL-27 and IL-35 antagonists exerted the most anti-inflammatory effects and increased IGF-1 receptor expression. These two antagonists may be potential agents for new treatment strategies in chronic joint inflammatory diseases.

A Protective Function of IL-22BP in Ischemia Reperfusion and Acetaminophen-Induced Liver Injury

Acute liver injury can be secondary to a variety of causes, including infections, intoxication, and ischemia. All of these insults induce hepatocyte death and subsequent inflammation, which can make acute liver injury a life-threatening event. IL-22 is a dual natured cytokine which has context-dependent protective and pathogenic properties during tissue damage. Accordingly, IL-22 was shown to promote liver regeneration upon acute liver damage. However, other studies suggest pathogenic properties of IL-22 during chronic liver injury. IL-22 binding protein (IL-22BP, IL-22Ra2) is a soluble inhibitor of IL-22 that regulates IL-22 activity. However, the significance of endogenous IL-22BP in acute liver injury is unknown. We hypothesized that IL-22BP may play a role in acute liver injury. To test this hypothesis, we used Il22bp-deficient mice and murine models of acute liver damage induced by ischemia reperfusion and N-acetyl-p-aminophenol (acetaminophen) administration. We found that Il22bp-deficient mice were more susceptible to acute liver damage in both models. We used Il22 × Il22bp double-deficient mice to show that this effect is indeed due to uncontrolled IL-22 activity. We could demonstrate mechanistically increased expression of Cxcl10 by hepatocytes, and consequently increased infiltration of inflammatory CD11b+Ly6C+ monocytes into the liver in Il22bp-deficient mice upon liver damage. Accordingly, neutralization of CXCL10 reversed the increased disease susceptibility of Il22bp-deficient mice. In conclusion, our data indicate that IL-22BP plays a protective role in acute liver damage, via controlling IL-22-induced Cxcl10 expression.

Genetic polymorphisms of IL-23R (rs7517847) and LEP (rs7799039) among Egyptian patients with hepatocellular carcinoma

BACKGROUND

Genetic polymorphisms of IL-23 R (rs7517847) and LEP (rs7799039) have been stated to be associated with various types of human cancers. The purpose of this work is to test the association of these genetic polymorphisms with hepatocellular carcinoma (HCC) among Egyptian patients.

SUBJECTS AND METHODS

This study involved 150 unrelated Egyptian HCC patients in addition to 100 healthy controls from the same locality. DNA was genotyped for these genetic polymorphisms using the PCR-RFLP technique.

RESULTS

The frequency of the IL-23 R (rs7517847) G and LEP (rs7799039) G alleles were significantly higher among HCC patients compared to controls (p = .004 and .02). However, HCC patients with the IL-23 R GG and LEP GG genotypes showed no significant difference compared to others regarding their clinical and laboratory markers.

CONCLUSIONS

IL-23 R (rs7517847) and LEP (rs7799039) polymorphisms were associated with an increased risk but not affecting the clinical presentation of HCC among Egyptian patients.

IL-23 drives differentiation of peripheral γδ17 T cells from adult bone marrow-derived precursors

Pro-inflammatory interleukin (IL)-17-producing γδ (γδ17) T cells are thought to develop exclusively in the thymus during fetal/perinatal life, as adult bone marrow precursors fail to generate γδ17 T cells under homeostatic conditions. Here, we employ a model of experimental autoimmune encephalomyelitis (EAE) in which hematopoiesis is reset by bone marrow transplantation and demonstrate unequivocally that Vγ4+ γδ17 T cells can develop de novo in draining lymph nodes in response to innate stimuli. In vitro, γδ T cells from IL-17 fate-mapping reporter mice that had never activated the Il17 locus acquire IL-17 expression upon stimulation with IL-1β and IL-23. Furthermore, IL-23R (but not IL-1R1) deficiency severely compromises the induction of γδ17 T cells in EAE, demonstrating the key role of IL-23 in the process. Finally, we show, in a composite model involving transfers of both adult bone marrow and neonatal thymocytes, that induced γδ17 T cells make up a substantial fraction of the total IL-17-producing Vγ4+ T-cell pool upon inflammation, which attests the relevance of this novel pathway of peripheral γδ17 T-cell differentiation.

Clinical and Histopathological Amelioration of Experimental Autoimmune Encephalomyelitis by AAV Vectors Expressing a Soluble Interleukin-23 Receptor

The role of the T helper (Th)17 pathway has been clearly demonstrated in the onset and progression of autoimmune diseases, where interleukin (IL)-23 is a key molecule in maintaining the response mediated by Th17 cells. As a consequence, recent strategies based on blocking the interaction between IL-23 and its receptor (IL-23R), for example the anti-p19 antibody tildrakizumab, have been developed to regulate the Th17 pathway from the initial stages of the disease. Here, a soluble (s)IL-23R cDNA was cloned in expression plasmids and viral vectors. The clinical efficacy of sIL-23R was evaluated in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis mice intravenously injected with a single dose of adeno-associated virus AAV8-sIL-23R vectors. Cytokine secretion was determined by multiplex assay, while histopathological analysis of the central nervous system was performed to study demyelination, inflammatory infiltration, and microglia and astroglia activation. We observed that administration of adeno-associated vector 8 encoding sIL-23R was associated with a significant disease improvement, including delay in the onset of the clinical signs; slower progress of the disease; interference with IL-23-mediated signal transducer and activator of transcription response by inhibiting of signal transducer and activator of transcription 3 phosphorylation; reduced demyelination and infiltration in the central nervous system; and lower astrocyte and microglia activation. Our results suggest that the use of vectors carrying sIL-23R to block the IL-23/IL-23R interaction may be a new therapeutic strategy for the treatment of multiple sclerosis.

[Single nucleotide polymorphism of IL-23 receptor gene is associated with susceptibility to recurrent oral ulceration]

Objective To explore whether single nucleotide polymorphism (SNP) in interleukin-23 receptor (IL-23R) gene is associated with the susceptibility to recurrent oral ulceration (ROU). Methods The genotype of SNP rs11465817 and rs1343152 was determined by MALDI-TOF-MS in 42 ROU patients and 86 age- and sex-matched healthy controls. The genotype and allele frequencies were analyzed by Chi-square test in both groups. Odds ratio (OR) and 95% confidence interval (95%CI) were calculated to analyze the associations between the susceptibility of ROU and the genotypes. Results The rs1343152 allele and genotype frequency distribution had no significantly difference between the case group and the control group. Compared with the control group, rs11465817 allele and genotype frequency distribution in the ROU group had significant difference (OR=2.715, 95%CI=1.543-4.777). The AA+AC genotype increased the risk of ROU occurrence by 2.44 times. Conclusion IL-23R rs11465817 contributes to the risk of ROU in Chinese.

Involvement of Leukotriene B4 Released from Keratinocytes in Itch-associated Response to Intradermal Interleukin-31 in Mice

A recent study suggests that interleukin-31 (IL-31) exerts its effect via indirect mechanisms rather than through direct stimulation of cutaneous nerves. However, the underlying peripheral mechanisms of IL-31-induced itch in the skin remain unclear. Therefore, the present study investigated the peripheral mechanisms underlying IL-31-induced itch in mice. IL-31-induced itch-related response was inhibited by anti-allergic drugs (tranilast and azelastine), but not by an H1 histamine receptor antagonist (terfenadine). Furthermore, a 5-lipoxygenase inhibitor (zileuton), but not a cyclooxygenase inhibitor (indomethacin), and a leuko-triene B4 (LTB4) receptor antagonist (CMHVA) attenuated the action of IL-31. IL-31 receptor-immunoreactivity was observed in the epidermis and primary sensory neurones. IL-31 receptor mRNA was expressed in mouse keratinocytes and dorsal root ganglia neurones. IL-31 increased the production of LTB4 in mouse keratinocytes. These results suggest that IL-31 elicits itch not only through direct action on primary sensory neurones, but also by inducing LTB4 production in keratinocytes.

IL-25-induced activation of nasal fibroblast and its association with the remodeling of chronic rhinosinusitis with nasal polyposis

Background and objective

Interleukin (IL)-25 has been shown to play an important role in the pathogenesis of chronic rhinosinusitis with nasal polyps. Nasal polyps are associated with chronic inflammation of the mucous membranes in the paranasal sinuses and are involved in extracellular matrix (ECM) accumulation. The aim of this study is to evaluate the effects of IL-25 on myofibroblast differentiation, ECM production and the expression of matrix metalloproteinases in nasal polyp derived fibroblasts (NPDFs) and to determine the molecular mechanism underlying these processes.

Materials and methods

A total of 40 patients were enrolled in this study for Immunofluorescence studies. Expression of IL17 receptor B was evaluated by real time reverse transcription polymerase chain reaction (PCR) in NPDFs. NPDFs were stimulated with IL-25 for 48 h in the presence or absence of mitogen-activated protein kinase (MAPK) and NF-κB inhibitors or small interfering RNAs (siRNA). The protein levels of fibrosis active mediators were examined using western blotting. Fibroblast migration was evaluated with a scratch assay. The total collagen amount was analyzed with the Sircol collagen assay.

Results

IL-25 induced α-SMA, fibronectin, and MMP-1 and -13, which were dependent on IL-17RB. IL-25 also induced activation of NF-κB and mitogen-activated protein kinase (MAPKs). By using the specific inhibitor of ERK, p38, JNK and NF-κB (U, SB, SP and Bay), we found that IL-25-induced expressions of α-SMA, fibronectin, and MMPs was regulated by the signaling pathways of MAPKs and NF-κB. IL-25 also induces α-SMA, fibronectin, and MMPs expression through IL-17RB-dependent pathways in NPDFs. The increased migration ability induced by IL-25 was suppressed by the specific inhibitors of MAPKs and NF-κB.

Conclusion

Our data indicate that IL-25 induced myofibroblast differentiation, fibronectin production, and MMP-1 and -13 expressions through the signaling pathways of MAPKs and NF-κB. in NPDFs and increased expression of IL-25 were also involved in the pathogenesis of nasal polyposis by affecting nasal fibroblasts in chronic rhinosinusitis with nasal polyps.

Association of UGT2B7, UGT1A9, ABCG2, and IL23R polymorphisms with rejection risk in kidney transplant patients

Despite advances in testing compatibility between donor and recipient, graft rejection remains a current concern. Single-nucleotide polymorphisms (SNPs) that codify altered enzymes of metabolism, drug transport, and the immune system may contribute to graft rejection in transplant patients. This study examined the association between SNPs present in genes of these processes and occurrence of graft rejection episodes in 246 kidney transplant patients, 35% of which were diagnosed with rejection. Genotype-gene expression associations were also assessed. Peripheral blood samples were used for genotyping of 24 SNPs on the following genes: CYP3A4, CYP3A5, CYP2E1, POR, UGT2B7, UGT1A9, ABCB1, ABCC2, ABCG2, SLCO1B1, TNF, IL2, IRF5, TGFB1, NFKBIA, IL10, IL23R, NFAT, and CCR5 by real-time PCR. The analysis of gene expression was performed by RT-qPCR. The association between graft rejection episodes and polymorphic variants was assessed using odds ratios. Polymorphisms rs7662029 (UGT2B7) and rs6714486 (UGT1A9) were associated with occurrence of graft rejection episodes, rs7662029 (UGT2B7) exhibited a protective effect (1.85-fold), and rs6714486 (UGT1A9) an increased 1.6-fold increased risk of graft rejection. Among drug transporter genes, only rs2231142 (ABCG2) demonstrated an association with a 1.92-fold decrease in the risk of graft rejection. The immunological SNP rs10889677 (IL23R) was associated with a 1.9-fold enhanced risk of graft rejection. Association between genotypes and gene expression was not detected. Therefore, SNPs of UGT2B7, UGT1A9, ABCG2, and IL23R genes may be useful as candidate markers for screening of risk graft rejection in renal transplant patients. These markers may improve medical decisions, avoiding adverse effects.

Limited Presence of IL-22 Binding Protein, a Natural IL-22 Inhibitor, Strengthens Psoriatic Skin Inflammation

Psoriasis is a chronic inflammatory disease resulting from dysregulated immune activation associated with a large local secretion of cytokines. Among them, IL-22 largely contributes to epithelial remodeling and inflammation through inhibiting the terminal differentiation of keratinocytes and inducing antimicrobial peptides and selected chemokines. The activity of IL-22 is regulated by IL-22 binding protein (IL-22BP); however, the expression and role of IL-22BP in psoriatic skin has remained unknown so far. Here we showed that nonaffected skin of psoriasis patients displayed lower expression of IL-22BP than skin of healthy controls. Furthermore, the strong IL-22 increase in lesional psoriatic skin was accompanied by a moderate induction of IL-22BP. To investigate the role of IL-22BP in controlling IL-22 during skin inflammation, we used imiquimod-induced skin disease in rodents and showed that rats with genetic IL-22BP deficiency (Il22ra2-/-) displayed exacerbated disease that associated with enhanced expression of IL-22-inducible antimicrobial peptides. We further recapitulated these findings in mice injected with an anti-IL-22BP neutralizing Ab. Hypothesizing that the IL-22/IL-22BP expression ratio reflects the level of bioactive IL-22 in psoriasis skin, we found positive correlations with the expression of IL-22-inducible molecules (IL-20, IL-24, IL-36γ, CXCL1, and BD2) in keratinocytes. Finally, we observed that serum IL-22/IL-22BP protein ratio strongly correlated with psoriasis severity. In conclusion, we propose that although IL-22BP can control deleterious actions of IL-22 in the skin, its limited production prevents a sufficient neutralization of IL-22 and contributes to the development and maintenance of epidermal alterations in psoriasis.

Interleukin-23 Receptor Gene Variants in Acute Lymphoblastic Leukemia and Their Relation to Prognostic Factors

BACKGROUND

Interleukin (IL)-23 has an important role in tumor immune regulation.

OBJECTIVE

To investigate the possible association of interleukin-23 receptor (IL23R) gene variants rs1884444, rs10889677 and rs11209026 with development of acute lymphoblastic leukemia (ALL).

METHODS

The IL23R variants were studied in 164 ALL patients and compared to 175 healthy controls by polymerase chain reaction-restriction fragment length polymorphism. The relationship between these variants and clinical and laboratory features of the patients and response to therapy were evaluated.

RESULTS

No significant differences in genotype and allele frequencies existed between patients and controls. The rs1884444TG genotype was significantly lower in patients who relapsed (24.2%) compared to those without relapse (55.9%, p=0.006). Fewer patients who relapsed had evidence of the G allele (p=0.034). The TG genotype was associated with a longer complete remission at 1804±116 days compared to other genotypes (<1217 days, p=0.028), however, this result was not significant in multivariate analysis. The rs10889677 AA genotype and A allele were associated with age (p<0.041) and platelet number (p=0.03) in precursor-B cell ALL (B-ALL) patients. Both occurred more frequently in patients aged 2-10 years (63.6% and 66%, respectively) and in those with platelets >100×10ˆ3 μL (68.4% and 52.4%, respectively).

CONCLUSION

Our findings showed a lack of association of the studied polymorphisms with the risk of ALL. The influence of the rs1884444 polymorphism on relapse rate and association of rs10889677 AA genotype with favorable prognostic factors suggest the effect of the studied polymorphisms on ALL response to therapy and prognosis.

IL-22R Ligands IL-20, IL-22, and IL-24 Promote Wound Healing in Diabetic db/db Mice

Diabetic foot ulcers (DFU) are one of the major complications in type II diabetes patients and can result in amputation and morbidity. Although multiple approaches are used clinically to help wound closure, many patients still lack adequate treatment. Here we show that IL-20 subfamily cytokines are upregulated during normal wound healing. While there is a redundant role for each individual cytokine in this subfamily in wound healing, mice deficient in IL-22R, the common receptor chain for IL-20, IL-22, and IL-24, display a significant delay in wound healing. Furthermore, IL-20, IL-22 and IL-24 are all able to promote wound healing in type II diabetic db/db mice. Mechanistically, when compared to other growth factors such as VEGF and PDGF that accelerate wound healing in this model, IL-22 uniquely induced genes involved in reepithelialization, tissue remodeling and innate host defense mechanisms from wounded skin. Interestingly, IL-22 treatment showed superior efficacy compared to PDGF or VEGF in an infectious diabetic wound model. Taken together, our data suggest that IL-20 subfamily cytokines, particularly IL-20, IL-22, and IL-24, might provide therapeutic benefit for patients with DFU.

A Gap Junction Protein, Inx2, Modulates Calcium Flux to Specify Border Cell Fate during Drosophila oogenesis

Intercellular communication mediated by gap junction (GJ) proteins is indispensable during embryogenesis, tissue regeneration and wound healing. Here we report functional analysis of a gap junction protein, Innexin 2 (Inx2), in cell type specification during Drosophila oogenesis. Our data reveal a novel involvement of Inx2 in the specification of Border Cells (BCs), a migratory cell type, whose identity is determined by the cell autonomous STAT activity. We show that Inx2 influences BC fate specification by modulating STAT activity via Domeless receptor endocytosis. Furthermore, detailed experimental analysis has uncovered that Inx2 also regulates a calcium flux that transmits across the follicle cells. We propose that Inx2 mediated calcium flux in the follicle cells stimulates endocytosis by altering Dynamin (Shibire) distribution which is in turn critical for careful calibration of STAT activation and, thus for BC specification. Together our data provide unprecedented molecular insights into how gap junction proteins can regulate cell-type specification.

Gap junction mediated intercellular communication modulates several processes during development, morphogenesis and normal tissue homeostasis. While gap junction proteins play an important role during intercellular communication, the underlying molecular mechanism(s) as to how they regulate diverse signaling cascades are unclear. By employing the Drosophila melanogaster oogenesis model we have characterized the role of gap junction protein, Innexin 2 (Inx2), in cell fate specification during Drosophila oogenesis. Our data demonstrate that loss of inx2 affects border cell specification. Border cells are a small group of 6–8 follicle cells that acquire migratory fate in response to the activation of JAK-STAT signaling. We show that perturbing Inx2 levels in the follicle cells inhibits JAK-STAT signaling thereby adversely influencing border cell fate specification. Using live cell imaging and molecular genetic analysis, we have elucidated the molecular mechanism underlying Inx2 function in this process. We show that Inx2 mediates inter-follicular calcium flux that is critical for border cell fate determination. Furthermore, our observations indicate that Inx2 regulates Domeless receptor internalization possibly via influencing distribution of Drosophila Dynamin, Shibire in the follicle cells. Taken together these results suggest a functional link between Inx2, calcium flux and receptor endocytosis during border cell fate specification in Drosophila oogenesis.

IL23R single nucleotide polymorphisms could be either beneficial or harmful in ulcerative colitis

AIM

To investigate the association of seven single nucleotide polymorphisms (SNPs) of the IL23R gene with the clinical picture of ulcerative colitis (UC).

METHODS

Genomic DNA samples of 131 patients (66 males, 65 females, mean age 55.4 ± 15.8 years) with Caucasian origin, diagnosed with UC were investigated. The diagnosis of UC was based on the established clinical, endoscopic, radiological, and histopathological guidelines. DNA was extracted from peripheral blood leukocytes by routine salting out method. Polymerase chain reaction and restriction fragment length polymorphism were used to identify the alleles of seven SNPs of IL23R gene (rs11209026, rs10889677, rs1004819, rs2201841, rs7517847, rs10489629, rs7530511).

RESULTS

Four out of seven analyzed SNPs had statistically significant influence on the clinical picture of UC. Two SNPs were associated with greater colonic extension (rs2201841 P = 0.0084; rs10489629 P = 0.0405). For two of the SNPs, there was more frequently need for operations (rs2201841 P = 0.0348, OR = 8.0; rs10889677 P = 0.0347, OR = 8.0). The rs2201841 showed to be a risk factor for the development of iron deficiency (P = 0.0388, OR = 6.1837). For patients with the rs10889677, a therapy with azathioprine was more frequently necessary (P = 0.0116, OR = 6.1707). Patients with rs10489629 SNP had a lower risk for weight loss (P = 0.0169, OR = 0.3394). Carriers of the heterozygous variant had a higher risk for an extended disease (P = 0.0284). The rs7517847 showed a protective character leading to mild bowel movements. Three SNPs demonstrated no statistically significant influence on any examined clinical features of UC.

CONCLUSION

We demonstrated susceptible or protective character of the investigated IL23R SNPs on the phenotype of UC, confirming the genetic association.