Analysis of the IL28RA locus as genetic risk factor for multiple sclerosis

Association of TNFRSF1A and IFNLR1 Gene Polymorphisms with the Risk of Developing Breast Cancer and Clinical Pathologic Features

Several genes have been associated with breast cancer (BC) susceptibility. The tumor necrosis factor receptor superfamily, member 1A (TNFRSF1A), and interferon lambda receptor 1 (IFNLR1) genes encode receptors that mediate the action of inflammatory cytokines. Previous studies have demonstrated the association of the variants rs1800693 (TNFRSF1A) and rs4649203 (IFNLR1) with some inflammatory diseases. The present study aimed to verify a possible association of these variants with BC, its clinical pathologic features, as well as epidemiological data in a Brazilian population. A total of 243 patients and 294 individuals without history of BC were genotyped for these polymorphisms through TaqMan® SNP genotyping assays by qPCR. For the TNFRSF1A gene, no significant results were found. For IFNLR1, the AA genotype (p = 0.008) and the A allele (p = 0.02) were significantly associated with a lower risk of developing BC. When analyzing the age, it was observed that each increase of one year contributes to the development of BC (p < 0.001). Also, the smoking habit (p < 0.001) and body mass index (p = 0.018) increase the risk of disease development. Analyzing progesterone receptor factor an association was found with the AA genotype of the IFNLR1 (p = 0.02). The findings suggest that polymorphism in the immune-related IFNLR1 gene contribute to BC susceptibility in a Brazilian population. These findings can contribute to the further understanding of the role this gene and pathways in BC development.

Interferon III-related IL28RA variant is associated with rheumatoid arthritis and systemic lupus erythematosus and specific disease sub-phenotypes

BACKGROUND

The interferon pathways have been commonly implicated in autoimmune disease development but the identity of the genes involved has not yet been fully clarified. Variation in genes involved in interferon pathways is expected to have a role in the etiology of these diseases.

METHODS

The potential association of a polymorphism in the IL28RA gene, involved in these pathways, with susceptibility to systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and disease-related phenotypes was investigated in 603 Brazilian individuals (354 well-characterized SLE and RA patients, and 249 controls). IL28RA (rs4649203) variant was genotyped by TaqMan assay. Statistical analysis was performed including both diseases and a comprehensive list of patient clinical manifestations.

RESULTS

The rs4649203-G (minor) allele was associated with SLE and RA occurrence and was shown to be a risk factor for serositis and anemia among SLE patients as well as a protective factor for rheumatoid vasculitis and rheumatoid nodules in RA patients, suggesting an association with a milder form of the disease.

CONCLUSIONS

The IL28RA gene may contribute to SLE and RA susceptibility and to specific clinical manifestations of the diseases.

Protective effects of IL28RA siRNA on cardiomyocytes in hypoxia/reoxygenation injury

Objective:

We demonstrate the protective effects of the siRNA-mediated inhibition of the interleukin-28 receptor alpha (IL28RA) subunit on cardiomyocytes in hypoxia/reoxygenation (H/R) injury and explore the associated mechanism.

Methods:

After designing and synthesizing three pairs of siRNA that effectively reduced IL28RA gene expression in vitro (siRNA-6158, siRNA-6160, and siRNA-6162), primary neonatal rat cardiomyocytes were transfected using a liposome transfection method. Six groups were included based on the siRNA that was used and the treatment simulating reperfusion injury: control group, H/R group, H/R+negative control group, H/R+siRNA-6158 group, H/R+siRNA-6160 group, and H/R+siRNA-6162 group. Cell survival and apoptosis rates were measured along with lactate dehydrogenase levels in the cell culture supernatant. Protein levels of IL28RA, phosphatidylinositol 3-kinase, catalytic subunit gamma (PI3KCG), Bcl-2, Bax, and b-actin were also measured.

Results:

The H/R+siRNA-6158 and H/R+siRNA-6160 groups had significantly higher survival rates and increased PI3KCG-to-b-actin and Bcl-2-to-Bax ratios than the the H/R and H/R+negative control groups (p<0.05). The H/R+siRNA-6158 and H/R+siRNA-6160 groups also exhibited reduced rates of apoptosis and reduced IL28RA-to-b-actin ratios (p<0.05). No significant difference was observed among the H/R+siRNA-6162, H/R, and H/R+negative control groups.

Conclusion:

IL28RA siRNA-6158 and -6160 were able to protect cardiomyocytes from H/R injury by inhibiting apoptosis. This strategy of inhibiting IL28RA gene expression may reduce reperfusion injury in the treatment of patients with acute myocardial infarction.

Targeting IFN-λ: therapeutic implications

INTRODUCTION

Type-III interferons (IFN-λ), the most recently discovered family of IFNs, shares common features with other family members, but also has many distinctive activities. IFN-λ uniquely has a different receptor complex, and a more focused pattern of tissue expression and signaling effects, from other classes of IFNs. Multiple genome-wide association studies (GWAS) and subsequent validation reports suggest a pivotal role for polymorphisms near the IFNL3 gene in hepatitis C clearance and control, as also for several other epithelial cell tropic viruses. Apart from its antiviral activity, IFN-λ possesses anti-tumor, immune-inflammatory and homeostatic functions. The overlapping effects of IFN-λ with type I IFN, with a restricted tissue expression pattern renders IFN-λ an attractive therapeutic target for viral infection, cancer and autoimmune diseases, with limited side effects. Areas covered: This review will summarize the current and future therapeutic opportunities offered by this most recently discovered family of interferons. Expert opinion: Our knowledge on IFN-λ is rapidly expanding. Though there are many remaining questions and challenges that require elucidation, the unique characteristics of IFN-λ increases enthusiasm that multiple therapeutic options will emerge.

Interferon-λ: Immune Functions at Barrier Surfaces and Beyond

When type III interferon (IFN-λ; also known as interleukin-28 [IL-28] and IL-29) was discovered in 2003, its antiviral function was expected to be analogous to that of type I IFNs (IFN-α and IFN-β) via the induction of IFN-stimulated genes (ISGs). Although IFN-λ stimulates expression of antiviral ISGs preferentially in cells of epithelial origin, recent studies have defined additional antiviral mechanisms in other cell types and tissues. Viral infection models using mice lacking IFN-λ signaling and SNP associations with human disease have expanded our understanding of the contribution of IFN-λ to the antiviral response at anatomic barriers and the immune response beyond these barriers. In this review, we highlight recent insights into IFN-λ functions, including its ability to restrict virus spread into the brain and to clear chronic viral infections in the gastrointestinal tract. We also discuss how IFN-λ modulates innate and adaptive immunity, autoimmunity, and tumor progression and its possible therapeutic applications in human disease.

The impact of the interferon-lambda family on the innate and adaptive immune response to viral infections

Type-III interferons (IFN-λ, IFNL) are the most recently described family of IFNs. This family of innate cytokines are increasingly being ascribed pivotal roles in host-pathogen interactions. Herein, we will review the accumulating evidence detailing the immune biology of IFNL during viral infection, and the implications of this novel information on means to advance the development of therapies and vaccines against existing and emerging pathogens. IFNLs exert antiviral effects via induction of IFN-stimulated genes. Common single nucleotide polymorphisms (SNPs) in the IFNL3, IFNL4 and the IFNL receptor α-subunit genes have been strongly associated with IFN-α-based treatment of chronic hepatitis C virus infection. The clinical impact of these SNPs may be dependent on the status of viral infection (acute or chronic) and the potential to develop viral resistance. Another important function of IFNLs is macrophage and dendritic cell polarization, which prime helper T-cell activation and proliferation. It has been demonstrated that IFNL increase Th1- and reduce Th2-cytokines. Therefore, can such SNPs affect the IFNL signaling and thereby modulate the Th1/Th2 balance during infection? In turn, this may influence the subsequent priming of cytotoxic T cells versus antibody-secreting B cells, with implications for the breadth and durability of the host response.

Evaluation of the relationship between IL28B, IL10RB and IL28RA single-nucleotide polymorphisms and susceptibility to hepatitis C virus in Chinese Han population

Hepatitis C virus (HCV) infection is associated with both viral and host factors. Cytokines, such as interferon (IFN)-λ, play a critical role in modulating the innate and adaptive immune systems. This study aims to investigate the association between single-nucleotide polymorphisms (SNPs) of interleukin (IL) 28B, IL10RB, and IL28RA genes and susceptibility to HCV infection in a population from the Liaoning Province of China. We used high resolution melt-polymerase chain reaction (HRM-PCR) analyses for genotype 6 polymorphisms in these genes in 271 chronic HCV-infected patients and in 300 healthy control subjects. The distribution of IL10RB and IL28RA genotypes among the HCV-infected and control groups did not differ significantly. However, we did find that the four IL28B variants were in complete linkage disequilibrium (r(2) = 0.831-0.922), and the frequency of rs8099917 GT genotype was significantly higher among chronic HCV-infected patients than among controls (OR = 2.21, 95% CI = 1.33-3.68, P = 0.00193); the G allele was found more frequently in the chronic HCV-infected group than in the control group (OR = 2.10, 95% CI = 1.28-3.44, P = 0.00276). Haplotype analysis showed that IL28B (rs12980275, rs11881222, rs12979860 and rs8099917) haplotype AACT had a protective effect for HCV infection (OR = 0.52, 95% CI = 0.33-0.83, P = 0.00551). This study indicates that the four SNPs in IL28B are correlated with susceptibility to HCV infection.

IL28RA polymorphism is associated with early hepatitis C virus (HCV) treatment failure in human immunodeficiency virus-/HCV-coinfected patients

Due to the poor rate of response to hepatitis C virus (HCV) with pegylated interferon and ribavirin treatment in HCV/HIV coinfected patients, key factors for predicting failure would be useful. We performed a retrospective study on 291 patients on HCV treatment, who had early virological response (EVR) data. IL28B and IL28RA polymorphisms were performed using the GoldenGate(®) assay. Unfavourable genotypes at IL28B (rs12980275 AG/GG and rs8099917 GT/GG) and an unfavourable allele at IL28RA (rs10903035 G) were associated with early treatment failure. However, only the rs12980275 AG/GG genotype and rs10903035 G allele remained independently associated with early failure in the overall population (OR = 4.15 (95% CI = 1.64-10.54) and OR = 2.00 (95% CI = 1.19-3.36), respectively) as well as in GT1/4 patients (OR = 5.07 (95% CI = 1.81-14.22) and OR = 2.03 (95% CI = 1.13-3.66), respectively). Next, a decision tree showed early treatment failure increased from 37.1% to 65.5% when the unfavourable rs12980275 AG/GG and rs10903035 AG/GG genotypes and HCV-RNA≥ 500.000 IU/mL were taken into account in GT1/4 patients. In contrast, the failure rate decreased from 37.1% to 11.9% when the favourable rs12980275 AA and rs10903035 AA genotypes were detected. The percentage of patients correctly classified was 78.4%, and AUROC was 0.802 ± 0.028. Regarding GT3 patients, the presence of the GCGCA haplotype (all unfavourable alleles) was associated with early treatment failure, while no association was observed for the IL28B polymorphisms. In conclusion, the IL28RA polymorphism was associated with early treatment failure independently of the IL28B SNPs. The combination of IL28B and IL28RA polymorphisms might be a valuable tool for predicting early treatment failure before starting HCV treatment.