IL27 T4730C Polymorphism and Serology in Multiple Sclerosis: A Pilot Study

An updated advancement of bifunctional IL-27 in inflammatory autoimmune diseases

Interleukin-27 (IL-27) is a member of the IL-12 family. The gene encoding IL-27 is located at chromosome 16p11. IL-27 is considered as a heterodimeric cytokine, which consists of Epstein-Barr virus (EBV)-induced gene 3 (Ebi3) and IL-27p28. Based on the function of IL-27, it binds to receptor IL-27rα or gp130 and then regulates downstream cascade. To date, findings show that the expression of IL-27 is abnormal in different inflammatory autoimmune diseases (including systemic lupus erythematosus, rheumatoid arthritis, Sjogren syndrome, Behcet's disease, inflammatory bowel disease, multiple sclerosis, systemic sclerosis, type 1 diabetes, Vogt-Koyanagi-Harada, and ankylosing spondylitis). Moreover, in vivo and in vitro studies demonstrated that IL-27 is significantly in3volved in the development of these diseases by regulating innate and adaptive immune responses, playing either an anti-inflammatory or a pro-inflammatory role. In this review, we comprehensively summarized information about IL-27 and autoimmunity based on available evidence. It is hoped that targeting IL-27 will hold great promise in the treatment of inflammatory autoimmune disorders in the future.

Interleukins (IL-23 and IL-27) serum levels: Relationships with gene polymorphisms and disease patterns in multiple sclerosis patients under treatment with interferon and glatiramer acetate

Background

interleukin 23 (IL-23) is an important factor involved in the survival and proliferation of T helper 17 cells (Th17), known for their implication in multiple sclerosis (MS). By contrast, IL-27 regulates and modulates the function of T lymphocytes, in particular as a suppressor of Th17 differentiation. The aims of the study were i) to test the association of cytokines with the clinical and genetic characteristics in each of the multiple sclerosis groups (CIS - clinically isolated syndrome, RRMS - relapsing-remitting MS and SPMS - Secondary progressive MS) and ii) to evaluate the association between serum levels of IL-23 and IL-27 with T4730C (IL-27), A964G (IL-27) and R381Q (IL-23) gene polymorphisms in RRMS patients.

Methods

Blood samples were obtained from 82 patients diagnosed with MS under treatment with glatiramer acetate (GA), interferon beta (IFN) 1 A and 1 B. IL-23 and IL-27 serum concentrations were measured by enzyme-linked immunosorbant assay (ELISA). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used in order to determine the genotypes for R381Q (IL-23) polymorphisms, T4730C (IL-27) and A964G (IL-27).

Results

Patients with SPMS, RRMS and CIS respectively differed significantly regarding age distribution (p = 0.003) but the studied MS groups were similar regarding age at disease onset (p = 0.528) and treatment type (p = 0.479). A significant increase of mean serum IL-27 was noticed in cases with early onset (age at disease onset <28 years) of RRMS (mean difference: 4.2 pg/ml, 95% CI: 0.8-5.3 pg/ml), compared to cases with later onset of RRMS (age at disease onset ≥28 years). RRMS patients with wild GG genotype of R381Q (IL-23) showed a significant increase of mean serum IL-23 than patients with variant AG genotype (mean difference: 115.1 pg/ml, 95% CI: 8.6-221.6 pg/ml). A trend for a higher increase in means of serum IL-23 (p = 0.086) was observed in RRMS patients carriers of AA genotype of A964G (IL-27) polymorphism in comparison with patients with AG or GG genotypes. We found no significant monotonic correlation of IL-27, IL-23 serum levels with age at disease onset (years) and duration of disease (p > 0.05) in the CIS and SPMS group respectively but a significant correlation between IL-23 and the duration of disease-modifying treatment was noticed only in the SPMS group.

Conclusions

The results of the current study suggest an association between IL-23 levels and the R381Q gene polymorphism and also a relationship between IL-27 serum levels and early age at disease onset in RRMS patients.

Potential Contribution of IL-27 and IL-23 Gene Polymorphisms to Multiple Sclerosis Susceptibility: An Association Analysis at Genotype and Haplotype Level

(1) Background: interleukin 23 (IL-23) and interleukin 27 (IL-27) modulate the activity of T helper 17 cells (Th17) with critical roles in autoimmune diseases and multiple sclerosis (MS). The genes responsible for cytokine generation are highly influenced by the presence of single nucleotide polymorphisms (SNP) in main regions such as regulatory sequences or in promoter regions, contributing to disease susceptibility and evolution. The present study analyzed the associations of IL-23 and IL-27 SNPs with susceptibility to multiple sclerosis. (2) Methods: We performed a case-control study including 252 subjects: 157 patients diagnosed with MS and 95 controls. We used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to determine the genotypes for IL-27 T4730C (rs 181206), IL-27 A964G (rs 153109), and IL-23 receptor gene (IL-23R) G1142A (rs 11209026). (3) Results: The IL27-T4730C gene polymorphism was significantly associated with an increased odds of MS under the dominant genetic model (TC + CC variant genotypes, adjusted odds ratio OR = 4.06, 95% CI: 2.14–7.83, p-value = 0.000007, Q-value = 0.000063). Individuals carrying the IL-27 A924G variant (AG + GG) genotype presented higher odds of MS compared to non-carriers under the dominant model (adjusted OR = 1.93, 95% CI: 1.05–3.51, p-value = 0.0324, Q-value = 0.05832) and the allelic genetic model (unadjusted p-value = 0.015, OR = 1.58, 95% CI: 1.09–2.28), while IL-23-R381Q SNP conferred a decreased odds of MS under a codominant model of inheritance (adjusted OR = 0.26, 95% CI: 0.08–0.92, p-value = 0.0276, Q-value = 0.058) and an allelic model (unadjusted p-value = 0.008, OR = 0.23, 95% CI: 0.07–0.75). In an additive model with adjustment for age group (≤40 years vs. >40 years), sex and smoking, patients carrying the G-C (A964G, T4730C) haplotype had a 3.18 increased risk (95% CI: 1.74–5.81, p < 0.001) to develop multiple sclerosis. (4) Conclusions: The results of the current study showed a significant relationship of IL-27-A964G and IL-27-T4730C polymorphisms with increased risk of MS, and also the protective role of the IL-23-R381Q polymorphism. Moreover, the haplotype-based analysis proposed the mutant G-C (A924G, T4730C) as a significant risk haplotype for the development of MS.