IL-12B Gene Polymorphisms and IL-12 p70 Serum Levels Among Patients with Rheumatoid Arthritis

IL12B and IL17 genes polymorphisms associated with differential susceptibility to juvenile idiopathic arthritis and juvenile-onset systemic lupus erythematosus in Chinese children

Genetic factors play a crucial role in the immune response of juvenile idiopathic arthritis (JIA) and juvenile-onset systemic lupus erythematosus (JSLE). This study aimed to investigate the association of IL12B (rs3212227, rs6887695) and IL17 (rs2275913, rs763780) gene polymorphisms with the susceptibility of JIA and JSLE in Chinese children. A total of 303 healthy controls and 304 patients including 160 JIA and 144 patients were analyzed, and the genetic polymorphisms were genotyped by using a Sequenom MassArray system. There was a significant association between the IL12B rs3212227 genotype and the increased risk of JSLE (P = .01). For rs6887695, the minor allele C was significantly associated with the increased risk of JIA (odds ratio = 1.48, 95% confidence interval [CI] = 1.12-1.95, P = .005). Moreover, rs6887695 genotype was significantly associated with both JIA and JSLE susceptibility (P < .05). Besides, IL12B haplotype GC significantly associated with the increased risk of JIA (P = .016). However, no significant difference was found between the IL17 (rs2275913, rs763780) gene polymorphisms and JIA or JSLE susceptibility (P > .05). And similar genotype distributions of IL12B and IL17 polymorphisms were found between the patients with nephritis and without nephritis in JSLE (P > .05). Our results indicated that IL12B polymorphisms was associated with an increased risk for the development of JIA and JSLE in Chinese children, highlighting the involvement of inflammation in the pathogenesis of JIA and JSLE. Moreover, there was a risk haplotype in IL12B which could increase the risk of JIA.

Receptor tyrosine kinases Tyro3, Axl, and Mertk differentially contribute to antibody-induced arthritis

Tyro3, Axl, and Mertk (abbreviated TAMs) comprise a family of homologous type 1 receptor tyrosine kinases (RTKs) that have been implicated as inhibitory receptors that dampen inflammation, but their roles in the pathogenesis of rheumatoid arthritis remains understudied. Here, to investigate TAMs in an inflammatory arthritis model, antibody-induced arthritis in single TAM-deficient mice (Tyro3- KO, Axl-KO, Mertk-KO) was induced by K/BxN serum injection. Subsequently, joint inflammation and cytokine levels, as well as the expression of Fcγ Rs and complement receptors were assessed in WT and TAM-deficient mice. Compared with littermate control mice, Axl-/- and Mertk-/- mice developed more severe antibody-induced arthritis, while in contrast, Tyro3-/- mice showed diminished joint inflammation. Concomitantly, the levels of cytokines in joints of Axl-/- and Mertk-/- mice were also significantly increased, while cytokines in the Tyro3-/- joint tissues were decreased. At the molecular and cellular level, TAMs showed distinct expression patterns, whereby monocytes expressed Axl and Mertk, but no Tyro3, while neutrophils expressed Axl and Tyro3 but little Mertk. Moreover, expression of Fcγ receptors and C5aR showed different patterns with TAMs expression, whereby FcγRIV was higher in monocytes of Axl-/- and Mertk-/- mice compared to wild-type mice, while Tyro3-/- neutrophils showed lower expression levels of FcγRI, FcγRIII and FcγRIV. Finally, expression of C5aR was increased in Mertk-/- monocytes, and was decreased in Tyro3-/- neutrophils. These data indicate that Axl, Mertk and Tyro3 have distinct functions in antibody-induced arthritis, due in part to the differential regulation of cytokines production, as well as expression of FcγRs and C5aR. Video Abstract.

Elevated expression of interleukin-27, IL-35, and decreased IL-12 in patients with thyroid-associated ophthalmopathy

PURPOSE

Thyroid-associated ophthalmopathy (TAO) is a chronic autoimmune disease. The interleukin-12 (IL-12) family includes IL-12, IL-23, IL-27, and IL-35, all of which play important roles in autoimmunity. Thus far, the relationship between IL-12, IL-27, and IL-35 and the TAO has not been evaluated.

METHODS

Seventy-five serum samples from patients with TAO were collected. Serum samples from 90 healthy controls (HC), 55 patients with Graves' disease (GD), 38 patients with uveitis (UV), 17 patients with Sjogren's syndrome (SS), and 65 patients with rheumatoid arthritis (RA) were collected as controls. The associations between IL-27, IL-35, IL-12, and other clinical parameters were analyzed.

RESULTS

Elevated serum levels of IL-27/IL-35 and decreased serum IL-12 levels were observed in TAO patients compared to those in HC (p < 0.001). For HC, we observed good diagnostic ability to predict TAO (area under the curve = 0.74, 0.78, and 0.78, for IL-27, IL-35, and IL-12, respectively). For other autoimmune diseases, IL-27, IL-35, and IL-12 had the ability to discriminate between UV, RA, and SS (area under the curve = 0.80, 0.83, and 0.85 for IL-27; 0.52, 0.69, and 0.67 for IL-35). The positive detection rates of IL-12 were significantly lower in the TAO group than in the UV and RA groups (p = 0.002, 0.01).

CONCLUSION

IL-12, IL-27, and IL-35 have the potential as biomarkers for TAO.

Association of interleukin-6 (174 G/C) and interleukin-12B (1188 A/C) gene polymorphism with expression and risk of Japanese encephalitis disease in North Indian population

BACKGROUND

Japanese encephalitis is an acute inflammatory disease caused by Japanese encephalitis virus (JEV). In this study we aim to determine the association of IL-6 (174) and IL-12B (1188A/C) gene polymorphisms with JEV susceptibility, disease severity and outcomes in north Indian population.

METHODS

This study was performed an equal number of cases and control individuals (125). Gene polymorphism has been analyzed by PCR-RFLP and expression by ELISA.

RESULTS

Homozygous(C/C) genotypes of IL-12B were significantly associated with protection in JE infection (p = 0.008, OR = 0.368) whereas IL-6 was not associated with JEV infection (p = 0.269, OR = 1.245). The C allele of IL-6 was associated with protection in JE disease and G/C genotype was associated with outcomes with recovered individuals.

CONCLUSION

IL-12B gene polymorphism leads to increase level of IL-12B in JE patients, which can contribute to JE susceptibility and disease severity. IL-6 polymorphism has not been associated with susceptibility of JE. Overall, this is the first information from northern India shows association of IL-6 and IL-12B polymorphisms with JE disease.

Immunology of IL-12: An update on functional activities and implications for disease

As its first identified member, Interleukin-12 (IL-12) named a whole family of cytokines. In response to pathogens, the heterodimeric protein, consisting of the two subunits p35 and p40, is secreted by phagocytic cells. Binding of IL-12 to the IL-12 receptor (IL-12R) on T and natural killer (NK) cells leads to signaling via signal transducer and activator of transcription 4 (STAT4) and subsequent interferon gamma (IFN-γ) production and secretion. Signaling downstream of IFN-γ includes activation of T-box transcription factor TBX21 (Tbet) and induces pro-inflammatory functions of T helper 1 (TH1) cells, thereby linking innate and adaptive immune responses. Initial views on the role of IL-12 and clinical efforts to translate them into therapeutic approaches had to be re-interpreted following the discovery of other members of the IL-12 family, such as IL-23, sharing a subunit with IL-12. However, the importance of IL-12 with regard to immune processes in the context of infection and (auto-) inflammation is still beyond doubt. In this review, we will provide an update on functional activities of IL-12 and their implications for disease. We will begin with a summary on structure and function of the cytokine itself as well as its receptor and outline the signal transduction and the transcriptional regulation of IL-12 secretion. In the second part of the review, we will depict the involvement of IL-12 in immune-mediated diseases and relevant experimental disease models, while also providing an outlook on potential translational approaches.

Associations between hepatocellular carcinoma risk and rs3212227 and rs568408 polymorphisms: a systematic review and meta-analysis

Background

Interleukin-12 (IL-12) is considered to be a risk factor for cancer; however, its role in hepatocellular carcinoma (HCC) remains unknown. This study aimed to explore the impacts of the IL-12 rs3212227 and rs568408 gene polymorphisms on HCC.

Methods

We searched PubMed, Embase, Web of Science, and Chinese Knowledge Infrastructure databases for studies on the associations between HCC and IL-12 rs568408 and rs3212227 polymorphisms published prior to 1 May 2020. The effects of the polymorphisms on HCC susceptibility were presented as odds ratios (ORs) and associated 95% confidence intervals.

Results

Seven studies were ultimately included, including 2375 cases and 3445 controls. The rs3212227 polymorphism was significantly associated with the risk of HCC in both the dominant model (CC+AC vs. AA, OR=1.22) and the allele model (C vs. A, OR=1.12). Combined analysis of rs568408 yielded a significant relative risk for HCC in the dominant (AA+AG vs. GG, OR=1.13), recessive (AA vs. AG+GG, OR=1.72), allele (A vs. G, OR=1.29), heterozygote (AG vs. GG, OR=1.27), and homozygote models (AA vs. GG, OR 1.17).

Conclusion

The IL-12 rs3212227 and rs568408 gene polymorphisms are associated with an increased risk of HCC.

Association between interleukin-21 gene rs6822844 polymorphism and rheumatoid arthritis susceptibility

Controversial results concerning the association between a polymorphism rs6822844 in the interleukin (IL) 21 (IL-21) gene and rheumatoid arthritis (RA) have existed. A meta-analysis to confirm above relationships is necessary to be performed immediately. We conducted a search in the PubMed database, covering all papers published up to 20 October 2018. Overall, six case–control studies with 3244 cases and 3431 healthy controls were included. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of this association. Publication bias was assessed with both Egger’s and Begg’s tests. After calculation, we found that IL-21 rs6822844 polymorphism could decrease RA risk in overall genetic models (allelic contrast: OR = 0.77, 95% CI = 0.62–0.97, P=0.024; TG versus GG: OR = 0.68, 95% CI = 0.50–0.92, P=0.013, and dominant genetic model: OR = 0.72, 95% CI = 0.55–0.94, P=0.016). Similarly, stratified analysis by race, source of control, significantly decreased association was found in Asians, Caucasians and hospital-based (HB) control source. Finally, in the subgroup analysis of rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) status, poorly decreased relationship was detected between IL-21 rs6822844 polymorphism and RF negative and ACPA positive RA risk, respectively. No obvious evidence of publication bias was detected in overall analysis. In summary, our study indicated that IL-21 rs6822844 polymorphism was significantly associated with decreased RA susceptibility.

Impact of IL12B Polymorphisms on Genetic Susceptibility and IL-12p40 and IL-23 Serum Levels in Rheumatoid Arthritis

The aim of this study was to evaluate the possible association of IL12B gene polymorphisms with serum levels of IL-12p40, IL-23 and genetic susceptibility to rheumatoid arthritis (RA) in the Bulgarian population. Genotyping for IL12Bpro (rs17860508) and IL12B A/C - 3' UTR (rs3212227) polymorphisms was performed by polymerase chain reaction (PCR)-based methods in 125 RA patients and 239 healthy controls. The IL-23 and IL-12p40 serum levels were measured by enzyme-linked immunosorbent assay (ELISA). An association was established between the rs17860508 polymorphism and RA susceptibility in Bulgarian population with an increased frequency of rs17860508 minor allele-2 and homozygous genotype-22 in RA patients. The rs17860508 risk RA genotype-22 was also significantly correlated to elevated serum IL-23 in RA patients. Although, there was no association between the rs3212227 and genetic predisposition to RA, significantly increased serum levels of both Il-12p40 and IL-23 were observed in RA patients with the rs3212227 AA genotype. Furthermore, the distribution of haplotypes and genotype combination in our cohort indicated increased RA risk in individuals carrying the rs17860508/rs3212227 2/A haplotype or 2.2/AC+CC combination, while 1/A haplotype or 1.1/AA combination may be protective for RA. In conclusion, our study demonstrates a functional effect of IL12B polymorphisms on IL-12p40 and IL-23 cytokine levels in RA patients and suggests a leading role for IL12B rs17860508 in the genetic predisposition to RA, while IL12B rs3212227 significantly modify the RA risk in Bulgarian population.

Association of interleukin-10 gene single nucleotide polymorphisms with rheumatoid arthritis in a Chinese population

PURPOSE OF THE STUDY

Increasing numbers of studies show that interleukin (IL)-10 plays a key role in the pathogenesis of autoimmune diseases including rheumatoid arthritis (RA) and acts as an immunomodulatory cytokine. The purpose of the present study was to analyse the relationship between gene single nucleotide polymorphisms (SNPs) in the IL-10 gene and RA susceptibility.

STUDY DESIGN

We genotyped three SNPs (rs1800890, rs3024495, rs3024505) of the IL-10 gene in a Chinese population of 354 RA patients and 367 controls. Genotyping was conducted using TaqMan SNP genotyping assays. Plasma IL-10 levels were measured by ELISA.

RESULTS

The A allele of the rs1800890 variant was significantly related to decreased risk for RA compared with the T allele (A vs T: OR 0.580, 95% CI 0.345 to 0.975, P=0.038). No significant association between the genotype distribution of these SNPs and RA susceptibility was detected. The genotype effect of the dominant model was also evaluated, but no statistical difference was found. Further analysis in RA patients demonstrated that none of these SNPs were associated with rheumatoid factor (RF) or anti-citrullinated protein antibody (anti-CCP). In addition, no significant differences in plasma IL-10 levels were observed among RA patients with different genotypes.

CONCLUSIONS

The IL-10 rs1800890 variant might contribute to RA susceptibility in the Chinese population. Replication studies in different ethnic groups are required to further examine the critical role of IL-10 gene variation in the pathogenesis of RA.