Interleukin-33 and Behçet disease: Another cytokine among others

A single nucleotide polymorphism in the IL1RL1 gene is associated with Behcet's disease in a Chinese Han population

AIM

To explore the association of single nucleotide polymorphisms (SNPs) in the IL33/IL1RL1 gene region with the susceptibility to Behcet's disease (BD) in a Chinese Han population.

METHODS

A total of eight SNPs in the candidate gene region (rs11792633, rs7025417, rs10975519 and rs1048274 in IL33; rs2310220, rs12712142, rs13424006 and rs3821204 in IL1RL1) were genotyped in783 BD patients and 701 healthy controls by the Sequenom Mass Array iPLEX platform.

RESULTS

A statistically significant association was observed between IL1RL1 rs12712142 and BD patients. The frequency of IL1RL1 rs12712142 variant allele A was significantly lower in BD patients than that in controls (OR=0.8, 95%CI: 0.69-0.94, Pc=0.039); the genotype distribution (Pc=0.043) and additive and dominant genetic model analyses (OR=0.8, 95%CI: 0.69-0.94, Pc=0.040 and OR=0.72, 95%CI: 0.58-0.88, Pc=0.011) also indicated a strong association between rs12712142 and BD patients.

CONCLUSION

This is the first study to reveal the association between IL1RL1 rs12712142 variant allele A and the decreased risk of BD in the Chinese Han population, indicating a protective role of IL1RL1 in the pathogenesis of BD.

The Role of the IL-33/ST2 Immune Pathway in Autoimmunity: New Insights and Perspectives

Interleukin (IL)-33, a member of IL-1 cytokine family, is produced by various immune cells and acts as an alarm to alert the immune system after epithelial or endothelial cell damage during cell necrosis, infection, stress, and trauma. The biological functions of IL-33 largely depend on its ligation to the corresponding receptor, suppression of tumorigenicity 2 (ST2). The pathogenic roles of this cytokine have been implicated in several disorders, including allergic disease, cardiovascular disease, autoimmune disease, infectious disease, and cancers. However, alerted levels of IL-33 may result in either disease amelioration or progression. Genetic variations of IL33 gene may confer protective or susceptibility risk in the onset of autoimmune diseases. The purpose of this review is to discuss the involvement of IL-33 and ST2 in the pathogenesis of a variety of autoimmune disorders, such as autoimmune rheumatic, neurodegenerative, and endocrine diseases.

Serum IL-4, IL-12, IL-13, IL-27, and IL-33 levels in active and inactive ocular Behcet's disease

PURPOSE

To investigate serum levels of interleukin (IL)-12 (Th1 cytokine), IL-27 (an immunomodulatory cytokine), IL-4 (suppressor of Th1-cell growth), IL-13 (a stimulatory signal for Th2 cytokines), and IL-33 (an epithelial cell-derived cytokine) and their relations with the disease activity in Behcet's Disease (BD).

METHODS

Four groups, each composed of 20 participants were enrolled in the study; active ocular BD (Group-A), ocular BD in remission (Group-B), nonocular BD in remission (Group-C) and healthy controls (Group-D). IL levels were compared between the study groups and their correlation with the disease activity parameters were analyzed.

RESULTS

IL-13 and IL-33 were higher in Group-A. IL-27 was lower in all BD groups. Additionally, IL-13 and IL-33 levels were positively correlated with disease activity parameters.

CONCLUSION

These findings show Th2 dominance in the active phase of BD. Besides, decreased levels of IL-27, and presumably, its protective anti-inflammatory effect in all study groups may exert a new pathologic finding in BD.

Haplotype Analysis of Candidate Genes Involved in Inflammation and Oxidative Stress and the Susceptibility to Preeclampsia

Unbalanced inflammatory reactions and oxidative stress are inseparably interconnected, and both may play crucial roles in the pathophysiological mechanisms of preeclampsia (PE). In the published previous studies, we have genotyped for SNPs that related to inflammation (rs2227485, rs153109, rs17855750, rs2027432, rs2275913, rs763780, rs4819554, and rs13015714) and oxidative stress (rs1695, rs4680, rs1800566, rs4807542, rs713041, rs7579, rs230813, rs1004467, rs3824755, and rs9932581) to investigate whether these polymorphisms were associated with susceptibility to PE in a Chinese Han population. In this present study, we collected these data of experimental and clinical from above studies for haplotype analysis of inflammation-related SNPs in 631 PE patients and 720 normal pregnancy and oxidative stress-related SNPs in 342 PE patients and 457 normal pregnancies for susceptibility to PE. The data of genotype distribution and allele frequency comparisons after correction for multiple comparisons (P/8 or P/10) showed 2 among the 8 candidate inflammation-related SNPs have significant differences (rs2027432 genotype χ² = 407.377, p < 0.001, p < 0.00625). Moreover, the minor alleles of rs2027432 T (minor allele χ² = 450.923, p < 0.001, p < 0.00625; OR = 21.439, 95%CI = 15.181‐30.278) and rs4819554 G (minor allele χ² = 163.465, p < 0.001, p < 0.00625; OR = 5.814, 95%CI = 4.380‐7.719) were confirmed as risk allele of PE, respectively. Our analysis revealed rs2027432 (TT) of NLRP3 and rs4819554 (GG) of IL-17RA are risk factors for PE. However, no significant difference was found at the oxidative stress-related SNPs. In the candidate loci for oxidative stress, we also identified 3 SNP matches (rs4807542 and rs713041, rs230813 and rs75799, rs1004467 and rs3824755) that had high linkage disequilibrium (LD) with each other and were selected as a block (r² = 0.98, r² = 0.97, r² = 0.97, r² > 0.9), and the GT and GC haplotypes of rs4807542 and rs713041 in GPX4 showed significant differences between the PE and control groups (χ² = 5.143, p = 0.0233, p < 0.05; χ² = 6.373, p = 0.0116, p < 0.05). So, we inferred that polymorphisms of NLRP3 rs2027432 and IL-17RA rs4819554, which are related to inflammation, and the rs713041 variant of GPX4, which is related to oxidative stress, were associated with susceptibility to PE. The GT and GC haplotypes of rs4807542 and rs713041 in GPX4 may increase the risk of PE in the Chinese Han population.

Interleukin-33 gene expression and rs1342326 polymorphism in Behçet's disease

OBJECTIVE

Behçet's disease (BD) is a chronic multi-factorial inflammatory disease with the important role of genetic in activation of its inflammatory response. Interleukin (IL)-33 is a member of the IL-1 family of cytokines that affects innate and adaptive immune systems to promote inflammatory responses. In the current study, we investigated the association of IL-33 gene rs1342326 polymorphism and expression levels of this gene in peripheral blood mononuclear cells (PBMCs) with the susceptibility to BD in Azari population of Iran.

METHODS

We recruited 44 patients with BD and 61 age and sex-matched healthy controls in this cross-sectional study. The existence of rs1342326 T/G IL-33 gene single nucleotide polymorphism was investigated using Tetra-Amplification Refractory Mutation System (Tetra-ARMS)-PCR. Allele and genotype distributions were evaluated among groups using chi-square or Fisher's test. Moreover, the mRNA levels of IL-33 in PBMCs were assessed through the Real-time PCR.

RESULTS

Patients with BD exhibited a significantly higher prevalence of the T/G genotype of rs1342326 polymorphism compared with the control group. Moreover, the expression level of IL-33 in PBMCs was significantly higher in the BD group compared to the healthy controls. Interestingly, the rs1342326 T/G polymorphism was associated with higher IL-33 expression in patients with BD. There was no association between the clinical manifestation of BD and disease activity with rs1342326 polymorphism and IL-33 expression.

CONCLUSIONS

Our study implies that rs1342326 T/G polymorphism of the IL-33 gene may contribute to the genetic susceptibility to BD in part through regulation of the IL-33 expression.

Genetics and immunodysfunction underlying Behçet's disease and immunomodulant treatment approaches

Behçet's disease (BD) is a chronic autoimmune condition primarily prevalent in populations along the Mediterranean Sea. The exact etiology of BD has not been fully explained yet, but the disease occurrence is associated with a genetic factor, human leukocyte antigen (HLA)-B51 antigen. Among the various immunodysfunctions that are found in BD, patients are increased neutrophil motility and superoxide production, as well as elevated production of tumor necrosis factor (TNF)-α and decreased production of interleukin (IL)-10. Elevated levels of inflammatory cytokines like IL-1 and IL-17 in BD have been found associated with aberrant expression of microRNA. Gene polymorphisms in BD patients have been observed in molecules involved in responses to pathogens that can ultimately modulate the host antimicrobial response. Moreover, several single nucleotide polymorphisms (SNPs) have been reported in genes encoding chemokines and adhesion molecules; many of these changes manifest as increases in vascular inflammation and vascular damage. Lastly, genetic and epigenetic changes have been suggested as involved in the pathogenesis of BD. Modifications in DNA methylation have been found in BD patient monocytes and lymphocytes, leading to adverse function of these cells. This review presents a comprehensive compilation of the literature with regard to the immunodysfunction underlying BD, as well as of the genetics, newly described clinical specifications and novel treatment strategies using immunomodulants based on the current understanding of BD.

Elevated expression of TSLP and IL-33 in Behçet's disease skin lesions: IL-37 alleviate inflammatory effect of TSLP

The release of TSLP and IL-33 affect the skin integrity, which unsettled transcription factor regulators. We investigate TSLP and IL-33 in Behçet disease (BD) and we prove the effect of the anti-inflammatory cytokine IL-37 in BD skin lesions on TSLP production. TSLP, IL-33 and GATA-3/T-bet, were measured using PCR in BD skin lesions. We tested the suppressive effect of IL-37 on skin samples stimulated with a cytokine mixture inducing TSLP expression. TSLP and IL-33 were increased in BD patients particularly in patients having skin manifestations and correlate with indexed skin lesions. TSLP expression in BD with skin lesions correlates significantly with the transcription factors GATA3/Tbet ratio. The anti-inflammatory mediator IL-37 acted as a suppressor of TSLP-skin synthesis. The microenvironment in cutaneous lesions of BD patients' skin lesions is dominated by the expression of IL-33 and TSLP along an inflammatory Th2-type current. IL-37 acts as a booster to restore homeostasis.

IL-33/ST2 Pathway as a Rational Therapeutic Target for CNS Diseases

Interleukin (IL)-33 is a member of the interleukin-1 cytokine family that is produced by many different types of tissues including the central nervous system (CNS). IL-33 mediates its effects via its heterodimeric receptor complex, comprised of ST2 and the IL-1 receptor accessory protein (IL-1RAcp). As a pleiotropic nuclear cytokine, IL-33 is a crucial factor in the development of cardiovascular diseases, allergic diseases, infectious diseases, and autoimmune diseases. Recently, accumulated evidence shows that the IL-33/ST2 axis plays a crucial and diverse role in the pathogenesis of CNS diseases, including neurodegenerative diseases, cerebrovascular diseases, infectious diseases, traumatic CNS injury, chronic pain, etc. In this review, we discuss the recent findings in the cellular signaling of IL-33 and advancement of the role of IL-33 in several CNS diseases, as well as its therapeutic potential for the treatment of those diseases.

Knitting the Threads of Silk through Time: Behçet's Disease-Past, Present, and Future

Behçet's disease (BD) is a chronic relapsing vasculitis that affects vessels of all types and sizes with a broad spectrum of phenotypic heterogeneity and complex immunopathogenesis. Efforts by the scientific community to resolve the unmet needs of BD and gaps in our knowledge have been hampered by considerable challenges that primarily relate to the rare nature of the disease in many parts of the world and its heterogeneity. Controversies remain in many aspects of the disease including the diagnostic criteria, immunopathogenesis and biomarker discovery, geographical variation, and therapeutic considerations. In this review, we highlight recent advances in our scientific understanding of BD, shed new insights into diagnostic and treatment strategies, and discuss residual gaps in our knowledge that will serve as the basis for current and future research.

The potential of genetically guided treatment in Behçet's disease

Continuous identification of specific targets and candidate genes together with novel approaches offers new promises for the future of gene therapy design in Behçet's disease (BD). Personalized medicine based on pharmacogenomics is being developed at the clinical stage to improve treatment response. Screening the whole gene and regulatory regions is important when searching for novel variants associated with such complex diseases. Different host genetic factors play significant roles in susceptibility to BD. Thus, identifying these genes responsible for susceptibility and resistance to BD may offer a notable contribution toward understanding its pathogenesis, and may lead to the development of novel prophylactic and treatment strategies. Evidenced-based treatment strategy is recommended for the management in BD patients. This review sheds light on the immunopathogenesis and pharmacogenetics of BD with special attention to the treatment targeting gene polymorphisms. In conclusion, the potential of genetically guided treatment in BD takes us back to the future for an accurate management strategy of this serious rheumatic disease. The ongoing discovery of pivotal genes related to the susceptibility, manifestations, disease activity and treatment options provide substantial hope to the reduced frequency of BD, effective control and improvement in the prognosis. Targeted gene therapy could be a leading option in the treatment armamentarium of BD.

Anti-inflammatory activity of IL-37 in asthmatic children: Correlation with inflammatory cytokines TNF-α, IL-β, IL-6 and IL-17A

BACKGROUND

The aim of this study was to assess interleukin (IL)-37 production in asthmatic children in serum and induced sputum and to look to the impact of IL-37 on pro-inflammatory cytokines production (TNF-α, IL-6, IL-1β and IL-17).

METHODS

Forty children with well-controlled asthma (20 moderate and 20 mild asthmatics) were studied. IL-37 was measured by ELISA in serum and induced sputum (IS) samples, and compared with 22 age- and sex-matched healthy controls. Real-time quantitative PCR was used to determine IL-37 mRNA expression in induced sputum cells. Induced sputum mononuclear cells from 10 moderate asthmatics and 10 healthy controls were stimulated either with lipopolysaccharides (LPS) or LPS plus recombinant IL-37 (rIL-37) comparing pro-inflammatory cytokines production. TNF-α, IL-1β, IL-6 and IL-17 were measured by RT-PCR and ELISA.

FINDINGS

The expression of IL-37 mRNA in asthmatic patients was significantly lower than that observed in healthy controls (P=0.0001). IL37 mRNA expression depended on asthma severity. Serum and IS IL-37 levels were significantly lower in asthma patients compared to healthy controls. LPS-stimulated sputum cells from asthma patients produced higher levels of IL-1β, IL-6, and TNF-α than those from HC. Adding rIL-37 suppressed TNF-α, IL-1β and IL-6 production in IS cells. In the same way, stimulating IS CD4(+) T cells in the presence of rIL-37 inhibited IL-17 production both in asthma patients and HC. IL-37 effect on IL-17 was more pronounced in patients than controls.

INTERPRETATION

The decrease in IL-37 level observed in IS was found to correlate with disease severity. The increased pro-inflammatory cytokines production from asthma IS cells was abrogated by the addition of rIL-37. IL-37 could be an important cytokine in the control of asthma by suppressing the production of inflammatory cytokines.