Genetic analysis of an allergic rhinitis cohort reveals an intercellular epistasis between FAM134B and CD39

Identification of sensory dysfunction and nervous structure changes in Fam134b knockout mice

OBJECTIVES

Mutation in human FAM134B gene has been implicated in hereditary sensory and autonomic neuropathy type IIB. We aimed to knock out Fam134b in mice and explored its phenotypes to determine whether the genetic impairments and behavioral changes can mirror manifestations noted in humans.

METHODS

We used CRISPR/Cas9 technology to knockout the Fam134b gene in the C57BL/6 J mouse. After confirming the knockout was successful by Sanger sequencing and Western blot, sensory function was measured using the hot plate test and the 50% paw withdrawal threshold test. In addition, standard microscopy and transmission electron microscopy were performed to observe the structural changes of the dorsal root ganglion sensory neuron and the sciatic nerve.

RESULTS

DNA sequencing and Western blot analysis confirmed the mutation in the Fam134b mutation gene and the loss of expression of its products. Fam134b knockout mice exhibited heat pain insensitivity and mechanical hyperalgesia. Interestingly, limb damage was found in some homozygotes. Demyelination in the sciatic nerve was common. Golgi bodies were turgid in dorsal root ganglion neuron.

CONCLUSIONS

These findings indicate that peripheral neuropathy is common in Fam134b KO mice. We believe this novel animal model is likely to have significant future potential as a reliable model for the evaluation of peripheral neuropathy and its complications.

ER-phagy: mechanisms, regulation and diseases connected to the lysosomal clearance of the endoplasmic reticulum

ER-phagy (reticulo-phagy) defines the degradation of portions of the endoplasmic reticulum (ER) within lysosomes or vacuoles. It is part of the self-digestion (i.e., auto-phagic) programs recycling cytoplasmic material and organelles, which rapidly mobilize metabolites in cells confronted with nutrient shortage. Moreover, selective clearance of ER subdomains participates to the control of ER size and activity during ER stress, the re-establishment of ER homeostasis after ER stress resolution and the removal of ER parts, in which aberrant and potentially cytotoxic material has been segregated. ER-phagy relies on the individual and/or concerted activation of the ER-phagy receptors, ER peripheral or integral membrane proteins that share the presence of LC3/Atg8-binding motifs in their cytosolic domains. ER-phagy involves the physical separation of portions of the ER from the bulk ER network, and their delivery to the endolysosomal/vacuolar catabolic district. This last step is accomplished by a variety of mechanisms including macro-ER-phagy (in which ER fragments are sequestered by double-membrane autophagosomes that eventually fuse with lysosomes/vacuoles), micro-ER-phagy (in which ER fragments are directly engulfed by endosomes/lysosomes/vacuoles), or direct fusion of ER-derived vesicles with lysosomes/vacuoles. ER-phagy is dysfunctional in specific human diseases and its regulators are subverted by pathogens, highlighting its crucial role for cell and organism life.

CD39 Regulation and Functions in T Cells

CD39 is an enzyme which is responsible, together with CD73, for a cascade converting adenosine triphosphate into adenosine diphosphate and cyclic adenosine monophosphate, ultimately leading to the release of an immunosuppressive form of adenosine in the tumor microenvironment. Here, we first review the environmental and genetic factors shaping CD39 expression. Second, we report CD39 functions in the T cell compartment, highlighting its role in regulatory T cells, conventional CD4⁺ T cells and CD8⁺ T cells. Finally, we compile a list of studies, from preclinical models to clinical trials, which have made essential contributions to the discovery of novel combinatorial approaches in the treatment of cancer.

Roles of FAM134B in diseases from the perspectives of organelle membrane morphogenesis and cellular homeostasis

Family with sequence similarity 134 member B (FAM134B)/RETREG1/JK1 is a novel gene with recently reported roles in various diseases. Understanding the function and mechanism of action of FAM134B is necessary to develop disease therapies. Notably, emerging data are clarifying the molecular mechanisms of FAM134B function in organelle membrane morphogenesis and the regulation of signaling pathways, such as the Wnt and AKT signaling pathways. In addition, transcription factors, RNA N⁶ -methyladenosine-mediated epigenetic regulation, microRNA, and small molecules are involved in the regulation of FAM134B expression. This review comprehensively considers recent studies on the role of FAM134B and its potential mechanisms in neurodegenerative diseases, obesity, viral diseases, cancer, and other diseases. The functions of FAM134B in maintaining cell homeostasis by regulating Golgi morphology, endoplasmic reticulum autophagy, and mitophagy are also highlighted, which may be the underlying mechanism of FAM134B gene mutation-induced diseases. Moreover, the molecular mechanisms of the FAM134B function during numerous biological processes are discussed. This review provides novel insights into the functions and mechanisms of FAM134B in various diseases, which will inform the development of effective drugs to treat diseases.

Critical roles of FAM134B in ER-phagy and diseases

FAM134B (also called JK-1, RETREG1), a member of the family with sequence similarity 134, was originally discovered as an oncogene in esophageal squamous cell carcinoma. However, its most famous function is that of an ER-phagy-regulating receptor. Over the decades, the powerful biological functions of FAM134B were gradually revealed. Overwhelming evidence indicates that its dysfunction is related to pathophysiological processes such as neuropathy, viral replication, inflammation, and cancer. This review describes the biological functions of FAM134B, focusing on its role in ER-phagy. In addition, we summarize the diseases in which it is involved and review the underlying mechanisms.

Overexpression of family with sequence similarity 134, member B (FAM134B) in colon cancers and its tumor suppressive properties in vitro

This study aims to investigate the overexpression-induced properties of tumor suppressor FAM134B (family with sequence similarity 134, member B) in colon cancer, examine the potential gene regulators of FAM134B expression and its impact on mitochondrial function. FAM134B was overexpressed in colon cancer and non-neoplastic colonic epithelial cells. Various cell-based assays including apoptosis, cell cycle, cell proliferation, clonogenic, extracellular flux and wound healing assays were performed. Western blot analysis was used to confirm and identify potential interacting partners of FAM134B in vitro. Immunohistochemistry and qPCR were employed to determine the expressions of MIF and FAM134B, respectively, on 63 patients with colorectal carcinoma. Results showed that FAM134B is involved in the cell cycle and mitochondrial function of colon cancer. Overexpression of FAM134B was coupled with increased expression levels of APC, p53, and MIF. Increased expression of both APC and p53 further validates the potential role of tumor suppressor FAM134B in regulating cancer progression through the WNT/ß-catenin signaling pathway. In approximately 70% of the patients with colorectal cancer, FAM134B downregulation was correlated with MIF protein overexpression while the remaining 30% showed concurrent expression of FAM134B and MIF (P = .045). High expression of MIF coupled with low expression of FAM134B is associated with microsatellite instability status in colorectal carcinomas (P = .049). FAM134B may exert its tumor suppressive function through affecting cell cycle, mitochondrial function via potentially interacting with MIF and p53.

Ectonucleoside triphosphate diphosphohydrolase 1 and 5'-nucleotidase ecto gene polymorphisms and acute cellular rejection after liver transplantation

The single nucleotide polymorphisms (SNPs) rs11188513, rs7071836, rs10748643, rs9450279, rs4458647, and rs6922 map in the genes of ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1) and 5'-nucleotidase ecto. We investigated whether these SNPs and haplotypes of these SNPs are associated with an acute cellular rejection after liver transplantation. A total of 69 recipients with an acute cellular rejection and 138 recipients without an acute cellular rejection were analyzed. Analyzed individually, no SNP demonstrates an association, but the haplotype rs11188513T-rs7071836G-rs10748643A of the ENTPD1 gene appeared more frequently in recipients without rejection and conversely, the haplotype rs11188513T-rs7071836G-rs10748643G of the ENTPD1 gene was more often represented in recipients with rejection. These two haplotypes seem to be important for the susceptibility of an acute cellular rejection after liver transplantation.

ER-phagy and human diseases

Autophagy regulates the degradation of unnecessary or dysfunctional cellular components. This catabolic process requires the formation of a double-membrane vesicle, the autophagosome, that engulfs the cytosolic material and delivers it to the lysosome. Substrate specificity is achieved by autophagy receptors, which are characterized by the presence of at least one LC3-interaction region (LIR) or GABARAP-interaction motif (GIM). Only recently, several receptors that mediate the specific degradation of endoplasmic reticulum (ER) components via autophagy have been identified (the process known as ER-phagy or reticulophagy). Here, we give an update on the current knowledge about the role of ER-phagy receptors in health and disease.

Curvature induction and membrane remodeling by FAM134B reticulon homology domain assist selective ER-phagy

FAM134B/RETREG1 is a selective ER-phagy receptor that regulates the size and shape of the endoplasmic reticulum. The structure of its reticulon-homology domain (RHD), an element shared with other ER-shaping proteins, and the mechanism of membrane shaping remain poorly understood. Using molecular modeling and molecular dynamics (MD) simulations, we assemble a structural model for the RHD of FAM134B. Through MD simulations of FAM134B in flat and curved membranes, we relate the dynamic RHD structure with its two wedge-shaped transmembrane helical hairpins and two amphipathic helices to FAM134B functions in membrane-curvature induction and curvature-mediated protein sorting. FAM134B clustering, as expected to occur in autophagic puncta, amplifies the membrane-shaping effects. Electron microscopy of in vitro liposome remodeling experiments support the membrane remodeling functions of the different RHD structural elements. Disruption of the RHD structure affects selective autophagy flux and leads to disease states.

FAM134B/RETREG1 is a selective ER-phagy receptor that regulates the size and shape of the endoplasmic reticulum. Here authors use molecular modeling and molecular dynamics simulations to assemble a structural model for the reticulon-homology domain of FAM134B.

Identification of DNA methylation module in seasonal allergic rhinitis

OBJECTIVE

In this study, we aimed to characterize the significant DNA methylation module of seasonal allergic rhinitis.

METHODS

Methylation profiling E-GEOD-50222 was obtained from ArrayExpress database. Differential co-methylation network (DCN) was constructed based on the methylation data. From the DCN, we characterized multiple differential modules (M-DMs). Significant module was mapped to pathways to identify significant enriched pathways.

RESULTS

At the criteria of absolute Pearson coefficient value > 0.8, the edges were chose to construct DCN. In the DCN, 16 seed genes were identified. Seed genes were used to construct M-DMs. After statistical analysis, one significant module with p < 0.05 were obtained. After pathways enrichment analysis, 17 significant pathways with p < 0.05 were obtained, and most of these pathways were associated with DNA replication.

CONCLUSION

One multiple differential module was identified in SAR, and seventeen significant pathways mapped by the module were identified as important factors in SAR. These results may provide new insights into the molecular mechanism of DNA methylation in SAR.

CD39 positive regulatory T cell frequency as a biomarker of treatment response to methotrexate in rheumatoid arthritis

AIM

Nearly one-third of patients with rheumatoid arthritis (RA) do not respond to Methotrexate (MTX), the first-line therapy in RA. CD39, an ectonucleotidase highly expressed on regulatory T cells (Tregs), is responsible for production of adenosine, an important anti-inflammatory mediator of MTX action. Higher expression of CD39 on Tregs improves their suppressive capacity. Therefore, we aimed to study the role of CD39⁺ Treg frequency as a biomarker for MTX treatment response in RA.

METHODS

Patients with active RA who were naive to disease-modifying anti-rheumatic drugs were enrolled. Frequencies of CD39⁺ Tregs (CD4⁺ CD25⁺ FoxP3⁺ CD39⁺ cells) and CD4⁺ CD25⁺ CD39⁺ cells were determined by flow cytometry in peripheral blood before the start of therapy. After 4 months of MTX monotherapy, patients were classified into responders (European League Against Rheumatism [EULAR] good/moderate response) and non-responders (EULAR no response). All samples were genotyped for single nucleotide polymorphisms (SNPs) rs11188513 and rs7071836 in the ENTPD1 (CD39) gene.

RESULTS

After 4 months of MTX monotherapy, 54 patients were classified as responders and 16 as non-responders. The baseline CD39⁺ Treg and CD4⁺ CD25⁺ CD39⁺ cell frequencies were significantly higher in the responder group as compared with the non-responder group (P < 0.05 and P < 0.01, respectively). AA genotype at SNP rs7071836 was associated with poor response to MTX (P < 0.05; odds ratio = 5.67; 95% CI = 1.12-28.75).

CONCLUSION

Higher frequencies of CD39⁺ Tregs and CD4⁺ CD25⁺ CD39⁺ cells in the peripheral blood are associated with response to MTX in RA and hence, these could be considered as potential biomarkers for prediction of response to MTX treatment.

Dynamics of helper CD4 T cells during acute and stable allergic asthma

Asthma comprises heterogeneous clinical subtypes driven by diverse pathophysiological mechanisms. We characterized the modulation of the inflammatory environment with the phenotype, gene expression, and function of helper CD4 T cells among acutely exacerbated and stable asthma patients. Systemic Th2 immune deviation (IgE and Th2 cytokines) and inflammation (IL-6, CRP) were associated with increased Th17 cells during acute asthma. Th2/Th17 cell differentiation during acute asthma was regulated by the enhanced expression of transcription factors (c-MAF, IRF-4). The development of pathogenic Th2 cells during acute asthma was characterized by the secretion of inflammatory cytokines coupled with Th2 molecules and PPARγ expression. The acquisition of CD15S, CD39, CD101, and CCR4 contributed to the increased heterogeneity of Regulatory T cells during asthma. Two clusters were derived from above cytokines, CD4 T cell phenotypes, and clinical data. Cluster 1, characterized by high eosinophils, Th2 and ILC2 frequencies, and higher exacerbation rates, may represent Th2-high subtype. Cluster 2 represents a more complex subtype; it is constituted by higher neutrophils or Th17 frequencies, higher inhaled corticosteroids dose and poor asthma control. In conclusion, we characterized systematically and longitudinally Th2-high and non-Th2 asthma subtypes and the heterogeneity of CD4 T cells in stable and acute asthma.

Promoter hypermethylation inactivate tumor suppressor FAM134B and is associated with poor prognosis in colorectal cancer

The present study aims to examine promoter methylation status of FAM134B in a large cohort of patients with colorectal adenocarcinomas. The clinical significances and correlations of FAM134B promoter methylation with its expression are also analysed. Methylation-specific high-resolution melt-curve analysis followed by sequencing was used to identify FAM134B promoter methylation in colorectal adenomas (N = 32), colorectal adenocarcinomas (N = 164), matched adjacent non-neoplastic colorectal mucosae (N = 83) and colon cancer cell lines (N = 4). FAM134B expression was studied by real-time quantitative polymerase chain reaction, immunohistochemistry, and Western blots. FAM134B promoter methylation was more frequent in adenocarcinomas (52%; 85/164) when compared to that of adenomas (28%; 9/32) and non-neoplastic mucosae (35%; 29/83). Cancer cells exhibited higher methylation when compared to non-neoplastic cells. FAM134B promoter methylation was inversely correlated with low FAM134B copy number and mRNA/protein expressions, whereas in-vitro demethylation has restored FAM134B expression in colon cancer cells. FAM134B promoter methylation was associated with high histological grade (P = .025), presence of peri-neural infiltration (P = .012), lymphovascular invasion (P = .021), lymph node metastasis (P = .0001), distant metastasis (P = .0001) and advanced pathological stages (P = .0001). In addition, FAM134B promoter methylation correlated with cancer recurrence and poor survival rates of patients with colorectal adenocarcinomas. To conclude, FAM134B promoter methylation plays a key role in regulating FAM134B expression in vitro and in vivo, which in turn contributes to the prediction of the biological aggressiveness of colorectal adenocarcinomas. Furthermore, FAM134B methylation might act as a marker in predicting clinical prognosis in patients with colorectal adenocarcinomas.

An electrochemical method for sensitive and rapid detection of FAM134B protein in colon cancer samples

Despite the excellent diagnostic applications of the current conventional immunoassay methods such as ELISA, immunostaining and Western blot for FAM134B detection, they are laborious, expensive and required a long turnaround time. Here, we report an electrochemical approach for rapid, sensitive, and specific detection of FAM134B protein in biological (colon cancer cell extracts) and clinical (serum) samples. The approach utilises a differential pulse voltammetry (DPV) in the presence of the [Fe(CN)₆]^3-/4- redox system to quantify the FAM134B protein in a two-step strategy that involves (i) initial attachment of FAM134B antibody on the surface of extravidin-modified screen-printed carbon electrode, and (ii) subsequent detection of FAM134B protein present in the biological/clinical samples. The assay system was able to detect FAM134B protein at a concentration down to 10 pg μL^-1 in phosphate buffered saline (pH 7.4) with a good inter-assay reproducibility (% RSD = <8.64, n = 3). We found excellent sensitivity and specificity for the analysis of FAM134B protein in a panel of colon cancer cell lines and serum samples. Finally, the assay was further validated with ELISA method. We believe that our assay could potentially lead a low-cost alternative to conventional immunological assays for target antigens analysis in point-of-care applications.

A functional SNP associated with atopic dermatitis controls cell type-specific methylation of the VSTM1 gene locus

BACKGROUND

Expression quantitative trait loci (eQTL) databases represent a valuable resource to link disease-associated SNPs to specific candidate genes whose gene expression is significantly modulated by the SNP under investigation. We previously identified signal inhibitory receptor on leukocytes-1 (SIRL-1) as a powerful regulator of human innate immune cell function. While it is constitutively high expressed on neutrophils, on monocytes the SIRL-1 surface expression varies strongly between individuals. The underlying mechanism of regulation, its genetic control as well as potential clinical implications had not been explored yet.

METHODS

Whole blood eQTL data of a Chinese cohort was used to identify SNPs regulating the expression of VSTM1, the gene encoding SIRL-1. The genotype effect was validated by flow cytometry (cell surface expression), correlated with electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP) and bisulfite sequencing (C-methylation) and its functional impact studied the inhibition of reactive oxygen species (ROS).

RESULTS

We found a significant association of a single CpG-SNP, rs612529T/C, located in the promoter of VSTM1. Through flow cytometry analysis we confirmed that primarily in the monocytes the protein level of SIRL-1 is strongly associated with genotype of this SNP. In monocytes, the T allele of this SNP facilitates binding of the transcription factors YY1 and PU.1, of which the latter has been recently shown to act as docking site for modifiers of DNA methylation. In line with this notion rs612529T associates with a complete demethylation of the VSTM1 promoter correlating with the allele-specific upregulation of SIRL-1 expression. In monocytes, this upregulation strongly impacts the IgA-induced production of ROS by these cells. Through targeted association analysis we found a significant Meta P value of 1.14 × 10^-6 for rs612529 for association to atopic dermatitis (AD).

CONCLUSION

Low expression of SIRL-1 on monocytes is associated with an increased risk for the manifestation of an inflammatory skin disease. It thus underlines the role of both the cell subset and this inhibitory immune receptor in maintaining immune homeostasis in the skin. Notably, the genetic regulation is achieved by a single CpG-SNP, which controls the overall methylation state of the promoter gene segment.

Virus infection drives IL-2 antibody complexes into pro-inflammatory agonists in mice

The use of IL-2/JES6-1 Ab complex (IL-2 Ab Cx) has been considered as a potential therapeutic for inflammatory diseases due to its selective expansion of regulatory T cells (Tregs) in mice. Here, IL-2 Ab Cx was explored as a therapeutic agent to reduce joint inflammation induced by chikungunya virus, an alphavirus causing debilitating joint disease globally. Virus-infected mice treated with IL-2 Ab Cx exhibited exacerbated joint inflammation due to infiltration of highly activated CD4+ effector T cells (Teffs). Virus infection led to upregulation of CD25 on the Teffs, rendering them sensitive towards IL2 Ab Cx. Ready responsiveness of Teffs to IL-2 was further demonstrated in healthy human donors, suggesting that the use of IL-2 Ab Cx in humans is not suitable. Changes in IL-2 sensitivity during active virus infection could change the responsive pattern towards the IL-2 Ab Cx, resulting in the expansion of pro-inflammatory rather than anti-inflammatory responses.

A review on emerging frontiers of house dust mite and cockroach allergy research

Currently, mankind is afflicted with diversified health issues, allergies being a common, yet little understood malady. Allergies, the outcome of a baffled immune system encompasses myriad allergens and causes an array of health consequences, ranging from transient to recurrent and mild to fatal. Indoor allergy is a serious hypersensitivity in genetically-predisposed people, triggered by ingestion, inhalation or mere contact of allergens, of which mite and cockroaches are one of the most-represented constituents. Arduous to eliminate, these aeroallergens pose constant health challenges, mostly manifested as respiratory and dermatological inflammations, leading to further aggravations if unrestrained. Recent times have seen an unprecedented endeavour to understand the conformation of these allergens, their immune manipulative ploys and other underlying causes of pathogenesis, most importantly therapies. Yet a large section of vulnerable people is ignorant of these innocuous-looking immune irritants, prevailing around them, and continues to suffer. This review aims to expedite this field by a concise, informative account of seminal findings in the past few years, with particular emphasis on leading frontiers like genome-wide association studies (GWAS), epitope mapping, metabolomics etc. Drawbacks linked to current approaches and solutions to overcome them have been proposed.

Fine-mapping analysis revealed complex pleiotropic effect and tissue-specific regulatory mechanism of TNFSF15 in primary biliary cholangitis, Crohn's disease and leprosy

Genetic polymorphism within the 9q32 locus is linked with increased risk of several diseases, including Crohn’s disease (CD), primary biliary cholangitis (PBC) and leprosy. The most likely disease-causing gene within 9q32 is TNFSF15, which encodes the pro-inflammatory cytokine TNF super-family member 15, but it was unknown whether these disparate diseases were associated with the same genetic variance in 9q32, and how variance within this locus might contribute to pathology. Using genetic data from published studies on CD, PBC and leprosy we revealed that bearing a T allele at rs6478108/rs6478109 (r² = 1) or rs4979462 was significantly associated with increased risk of CD and decreased risk of leprosy, while the T allele at rs4979462 was associated with significantly increased risk of PBC. In vitro analyses showed that the rs6478109 genotype significantly affected TNFSF15 expression in cells from whole blood of controls, while functional annotation using publicly-available data revealed the broad cell type/tissue-specific regulatory potential of variance at rs6478109 or rs4979462. In summary, we provide evidence that variance within TNFSF15 has the potential to affect cytokine expression across a range of tissues and thereby contribute to protection from infectious diseases such as leprosy, while increasing the risk of immune-mediated diseases including CD and PBC.

Role of the CD39/CD73 Purinergic Pathway in Modulating Arterial Thrombosis in Mice

OBJECTIVE

Circulating blood cells and endothelial cells express ectonucleoside triphosphate diphosphohydrolase-1 (CD39) and ecto-5'-nucleotidase (CD73). CD39 hydrolyzes extracellular ATP or ADP to AMP. CD73 hydrolyzes AMP to adenosine. The goal of this study was to examine the interplay between CD39 and CD73 cascade in arterial thrombosis.

APPROACH AND RESULTS

To determine how CD73 activity influences in vivo thrombosis, the time to ferric chloride-induced arterial thrombosis was measured in CD73-null mice. In response to 5% FeCl3, but not to 10% FeCl3, there was a significant decrease in the time to thrombosis in CD73-null mice compared with wild-type mice. In mice overexpressing CD39, ablation of CD73 did not inhibit the prolongation in the time to thrombosis conveyed by CD39 overexpression. However, the CD73 inhibitor α-β-methylene-ADP nullified the prolongation in the time to thrombosis in human CD39 transgenic (hC39-Tg)/CD73-null mice. To determine whether hematopoietic-derived cells or endothelial cell CD39 activity regulates in vivo arterial thrombus, bone marrow transplant studies were conducted. FeCl3-induced arterial thrombosis in chimeric mice revealed a significant prolongation in the time to thrombosis in hCD39-Tg reconstituted wild-type mice, but not on wild-type reconstituted hCD39-Tg mice. Monocyte depletion with clodronate-loaded liposomes normalized the time to thrombosis in hCD39-Tg mice compared with hCD39-Tg mice treated with control liposomes, demonstrating that increased CD39 expression on monocytes protects against thrombosis.

CONCLUSIONS

These data demonstrate that ablation of CD73 minimally effects in vivo thrombosis, but increased CD39 expression on hematopoietic-derived cells, especially monocytes, attenuates in vivo arterial thrombosis.

The genes and the environment in nasal allergy

PURPOSE OF REVIEW

In this review, we summarize the latest publications on the genetic and environmental determinants of allergic rhinitis.

RECENT FINDINGS

Recent advances in genetic technology and bioinformatics have enabled simultaneous unbiased analysis of the entire genome regarding DNA sequence variants, epigenetic modifications and gene expression, providing functional correlates for DNA variants and phenotypes. As a result, new genes of mitochondrial and B-lymphocyte metabolism have been associated with allergic rhinitis phenotypes. Epidemiological studies recently showed an increased risk to develop allergic rhinitis in all age groups with reduction in farm exposure and in children with few older siblings. Climate changes seem to have also influenced pollen exposure and pollen-induced allergic disease. Lastly, occupational rhinitis has been increasingly recognized as a large burden to society.

SUMMARY

In summary, new high throughput genetics research technologies have pointed to new previously unsuspected pathways that may modulate the risk of developing allergic rhinitis such as mitochondrial metabolism. In addition, recent environmental factors found to influence the risk of developing allergic rhinitis include exposure to farm, pollution, occupational agents, and changes in climate.

Association between the Interaction of Key Genes Involved in Effector T-Cell Pathways and Susceptibility to Develop allergic Rhinitis: A Population-Based Case-Control Association Study

Background

Evidence suggests that interaction between key genes mediating signaling and transcriptional networks involving effector T-cell responses may influence an individual’s susceptibility to develop allergic rhinitis(AR).

Objective

The aim of this study was todetermine whether specific interactions between key genes involved in effector T-cell pathways are associated with an individual’s susceptibility to develop AR in Han Chinese subjects.

Method

A cohort of 489 patients with AR and 421 healthy controls was enrolled from the Han Chinese population in Beijing, China. AR was established by questionnaire and clinical examination, and peripheral blood was drawn from all subjects for DNA extraction. A total of 96 single nucleotide polymorphisms (SNPs) in 26 reprehensive candidate genes involved in T helper 1 (Th1), Th2, Th17, Th9 and T regulatory cell pathways were selected from the International Haplotype Mappingdatabase for Han Chinese in Beijing (CHB) population, and IlluminaGoldenGate assay was conducted for SNP genotyping. The PLINK software package was used to perform statistical analyses.

Results

Simple SNP-phenotype association analysis using logistic regression showed SNP rs8193036 in IL17A gene, rs2569254 in IL-12 and rs1898413 in RORα weresignificantlyassociatedwith AR.Simple SNP-phenotype association analysis with genetic models demonstrated thatrs2569254 in IL-12, rs1031508 in STAT4, and rs3741809 in IL-26 were likely to be recessive, rs8193036 in IL17A allelic, rs897200in STAT4 genotypic, and rs1898413 in RORα dominant. Epistasis analyses exhibited that 83 SNPs in 23 genes were significantly interactive; of which 59 interactions/SNP pairs demonstrated OR values higher than 2 or lower than 0.5, and 12 interactions/SNP pairs OR values higher than 4 or lower than 0.25. STAT3, RORα and IL-26, involved in Th17 pathway,were the mostfrequentlyinteractive genes.

Conclusion

This study suggests that interactions between several SNPs in key genes involved in effector T-cell pathways are likely to influence an individual’s susceptibility to develop AR.