The suggestive association of eotaxin-2 and eotaxin-3 gene polymorphisms in Korean population with allergic rhinitis

The regulatory role of SFRP5/WNT5A axis in allergic rhinitis through inhibiting JNK pathway activation and lowering mucin generation in human nasal epithelial cells

Allergic rhinitis (AR) is tightly associated with type 2 inflammation. SFRP5 combined with WNT5A mainly inhibits chronic inflammatory response, atherosclerosis, and other metabolic disorders. However, the effect of SFRP5/WNT5A axis on recombinant human interleukin-13 (rhIL-13)-induced inflammation has not been studied. In this study, we aimed to investigate whether secreted frizzled-related protein 5 (SFRP5) could modulate the production of cytokines relevant to eosinophil infiltration and mucin secretion through blocking the activation of Wnt family 5A (WNT5A) signaling pathway. A mouse model of AR demonstrated low expression of SFRP5 and high expression of WNT5A, and indicated that the number of eosinophil and goblet cells was increased, concomitant with elevated IL-13, colony stimulating factor 2 (CSF2), chemokine ligand 11 (CCL11), Mucin 4, and Mucin 5AC levels. Furthermore, lentivirus-SFRP5 overexpression up-regulated the expression of SFRP5 but down-regulated WNT5A level, and inhibited the activation of JNK pathway via decreasing p-JNK1/2 (Thr183/Tyr185) and p-c-Jun (Ser73) protein expressions in rhIL-13-treated human nasal epithelial cells (HNEpCs). Noticeably, SFRP5 overexpression markedly reduced rhIL-13-induced inflammatory protein and mucin generation through lowered CSF2, CCL11, Mucin 4, as well as Mucin 5AC levels. Taken together, these findings confirmed the regulatory role of SFRP5/WNT5A axis in rhIL-13-mediated inflammatory response in HNEpCs.

Relationship between chemokines and T lymphocytes in the context of respiratory allergies (Review)

Allergic diseases have been classified in the last decades using various theories. The main classes of the newest classification in allergic respiratory diseases focus on the characterization of the endotype (which takes into account biomarkers related to determinant pathophysiological mechanisms) and of the phenotype (based on the description of the disease). Th2, Th1 and Th17 lymphocytes and the type of inflammatory response mediated by them represent the basis for Th2 and non-Th2 endotype classification. In addition, new lymphocytes were also used to characterize allergic diseases: Th9 lymphocytes, Th22 lymphocytes, T follicular helper cells (T_FH) lymphocytes and invariant natural killer T (iNKT) lymphocytes. In the last decade, a growing body of evidence focused on chemokines, chemoattractant cytokines, which seems to have an important contribution to the pathogenesis of this pathology. This review presents the interactions between chemokines and Th lymphocytes in the context of Th2/non-Th2 endotype classification of respiratory allergies.

Comparison of the nasal release of IL-4, IL-10, IL-17, CCL13/MCP-4, and CCL26/eotaxin-3 in allergic rhinitis during season and after allergen challenge

BACKGROUND

Allergic rhinitis is an inflammatory disease characterized by local overproduction of type 2 cytokines and tissue eosinophilia. Recent research suggests the involvement of additional cytokines such as IL-17, chemokine (C-C motif) ligand (CCL) 26/eotaxin-3, and CCL13/monocyte chemoattractant protein-4 (MCP-4) in its pathophysiology. Furthermore, bronchial epithelial cells treated with IL-17 and type 2 cytokines distinctively up-regulated eotaxin-3 gene expression. In this study we investigated the kinetics of IL-4, IL-10, IL-17, eotaxin-3, and MCP-4 in seasonal allergic rhinitis volunteers after nasal allergen challenge (NAC) and their release during natural pollen exposure.

METHODS

The nasal lavages of 15 symptomatic allergic and 14 nonallergic subjects were collected during the pollination season. Additionally, six allergic subjects underwent a single unilateral nasal allergen and control challenge out of season, and nasal secretions were collected. Levels of IL-4, IL-10, IL-17, eotaxin-3, and MCP-4 in nasal lavages and secretions were measured using an electrochemiluminescent assay.

RESULTS

After NAC, allergic subjects had a significant immediate response of nasal symptoms as well as a significant increase at 5 hours of IL-4, IL-10, and IL-17 and at 2, 5, and 24 hours significantly raising levels of eotaxin-3. IL-17 and eotaxin-3 concentrations at 5 hours were correlated (r = 0.94; p = 0.005). During natural pollen exposure, barely detectable levels of IL-17 in allergic subjects were also correlated with eotaxin-3 (r = 0.62; p = 0.01). Eotaxin-3 and MCP-4 levels were significantly elevated 9- or 3.7-fold, respectively, and IL-10 and, unexpectedly, IL-4 were significantly lower in allergic subjects compared with nonallergic subjects.

CONCLUSION

Nasal IL-17, MCP-4, and, possibly, eotaxin-3 may aggravate and IL-10 may alleviate nasal mucosal allergy.

Poor reproducibility of allergic rhinitis SNP associations

Replication of reported associations is crucial to the investigation of complex disease. More than 100 SNPs have previously been reported as associated with allergic rhinitis (AR), but few of these have been replicated successfully. To investigate the general reproducibility of reported AR-associations in candidate gene studies, one Swedish (352 AR-cases, 709 controls) and one Singapore Chinese population (948 AR-cases, 580 controls) were analyzed using 49 AR-associated SNPs. The overall pattern of P-values indicated that very few of the investigated SNPs were associated with AR. Given published odds ratios (ORs) most SNPs showed high power to detect an association, but no correlations were found between the ORs of the two study populations or with published ORs. None of the association signals were in common to the two genome-wide association studies published in AR, indicating that the associations represent false positives or have much lower effect-sizes than reported.

Carbon dioxide-enriched water inhalation in patients with allergic rhinitis and its relationship with nasal fluid cytokine/chemokine release

BACKGROUND AND AIMS

Allergic rhinitis is characterized by eosinophil infiltration and accumulation in the nasal mucosa mainly due to IL-3, IL-5, and eotaxin activities. We undertook this study to investigate a possible in vivo effect of carbon dioxide-enriched water inhalation in patients with allergic rhinitis.

METHODS

Twenty five consecutive patients inhaled carbon dioxide-enriched water at Fonti di Rabbi Spa Centre (Trento, Italy). Symptom scores for nasal obstruction, itching and sneezing were obtained before and after treatment. Nasal lavage was collected, and IL-3, IL-5, and eotaxin levels were assessed using the quantitative sandwich enzyme immunoassay technique. Cytometric analysis was performed on samples to measure total cell count, CD45+ cells, and percentages of polymorphonucleates and lymphocytes.

RESULTS

There were statistically significant differences in chemokine levels and in cell populations between patients and healthy controls before treatment. After carbon dioxide-enriched water inhalation, we observed statistically significant improvements in symptom scores, chemokine levels, and percentages of cell populations.

CONCLUSIONS

Our results seem to confirm the role of IL-3, IL-5, and eotaxin in the pathophysiology of allergy and the beneficial effect of carbon dioxide-enriched water inhalation in patients affected by allergic rhinitis.

A meta-analysis of Th2 pathway genetic variants and risk for allergic rhinitis

There is a significant genetic contribution to allergic rhinitis (AR). Genetic association studies for AR have been performed, but varying results make it challenging to decipher the overall potential effect of specific variants. The Th2 pathway plays an important role in the immunological development of AR. We performed meta-analyses of genetic association studies of variants in Th2 pathway genes and AR. PubMed and Phenopedia were searched by double extraction for original studies on Th2 pathway-related genetic polymorphisms and their associations with AR. A meta-analysis was conducted on each genetic polymorphism with data meeting our predetermined selection criteria. Analyses were performed using both fixed and random effects models, with stratification by age group, ethnicity, and AR definition where appropriate. Heterogeneity and publication bias were assessed. Six independent studies analyzing three candidate polymorphisms and involving a total of 1596 cases and 2892 controls met our inclusion criteria. Overall, the A allele of IL13 single nucleotide polymorphism (SNP) rs20541 was associated with increased odds of AR (estimated OR=1.2; 95% CI 1.1-1.3, p-value 0.004 in fixed effects model, 95% CI 1.0-1.5, p-value 0.056 in random effects model). The A allele of rs20541 was associated with increased odds of AR in mixed age groups using both fixed effects and random effects modeling. IL13 SNP rs1800925 and IL4R SNP 1801275 did not demonstrate overall associations with AR. We conclude that there is evidence for an overall association between IL13 SNP rs20541 and increased risk of AR, especially in mixed-age populations.

Regulation of eotaxin-3/CCL26 expression in human monocytic cells

Eotaxin-3/CCL26 is an agonist for chemokine receptor 3 (CCR3) and a natural antagonist for CCR1, CCR2 and CCR5. CCL26 expression by non-haematopoietic cells has been well documented; however, no studies to date have demonstrated CCL26 expression by leucocytes. In this study, we investigated the ability of human monocytic cells to produce CCL26 in response to cytokines. We found that interleukin-4 (IL-4) increased the expression of CCL26 messenger RNA (mRNA) and protein in U937 cells, in human monocytes and in human monocyte-derived macrophages. Tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) alone did not induce CCL26 expression, yet these pro-inflammatory cytokines synergized with IL-4 to increase CCL26 protein expression. Signal transducer and activator of transcription 6 (STAT6) was not affected by costimulation with TNF-alpha, suggesting that the synergy between IL-4 and TNF-alpha occurs at a step downstream of STAT6 activation. Co-incubation of interferon-gamma (IFN-gamma) with IL-4 had no effect on CCL26 protein release. By contrast, pretreatment with IFN-gamma decreased total STAT6 protein, blocked IL-4-mediated STAT6 phosphorylation and decreased IL-4-mediated CCL26 mRNA expression and protein release. These data show that IL-4 and pro-inflammatory cytokines such as TNF-alpha, IL-1beta and IFN-gamma regulate CCL26 synthesis in human monocytic cells, which may be important in regulating monocyte inflammatory responses.

A network analysis of the single nucleotide polymorphisms in acute allergic diseases

BACKGROUND

Genetics of acute allergies has focused on identifying single nucleotide polymorphisms (SNPs) within genes relevant in the pathogenesis. In this study, we begin a systems biology analysis of the interconnectivity and biological functions of these genes, their transcripts and their corresponding proteins.

METHODS

The literature (Pubmed) was searched for SNPs within genes relevant in acute allergic diseases. The SNP-modified genes were converted to corresponding proteins and their protein-protein interactions were searched from six different databases. This interaction network was analysed with annotated vocabularies (ontologies), such as Gene Ontology, Reactome and Nature pathway interaction database. Time-series transcriptomics was performed with nasal epithelial cells obtained from allergic patients and their healthy control subjects.

RESULTS

A total of 39 genes with SNPs related to acute allergic diseases were found from a literature search. The corresponding proteins were then hooked into a large protein-protein interaction network with the help of various databases. Twenty-five SNP-related proteins had more than one interacting protein and a network contained 95 proteins, and 182 connections could be generated. This network was 10-fold enriched with protein kinases and proteins involved in the host-virus interaction compared with background human proteome. Finally, eight of the 95 nodes on our network displayed nasal epithelial transcriptomal regulation in a time-series analysis collected from birch allergic patients during the spring pollen season.

CONCLUSIONS

Signal transduction with special reference to host-virus interactions dominated in the allergy-related protein interaction network. Systems level analysis of allergy-related mutation can provide new insights into pathogenetic mechanisms of the diseases.

Lack of association with rheumatoid arthritis of selected polymorphisms in 4 candidate genes: CFH, CD209, eotaxin-3, and MHC2TA

OBJECTIVE

To investigate associations with rheumatoid arthritis (RA) of single-nucleotide polymorphisms (SNP) in 4 candidate genes, complement factor H (CFH), CD209 or DC-SIGN, eotaxin-3, and the MHC class II Transactivator (MHC2TA) genes. These SNP have been reported as important for RA (eotaxin-3 and MHC2TA) or for other immune-mediated diseases (CFH and CD209).

METHODS

Genotypes for the 7 selected SNP were obtained from 1587 patients with RA and 1570 controls of Spanish ancestry. Analyses were carried out after stratification for sex, erosions, rheumatoid factor, shared epitope, anti-cyclic citrullinated peptide antibodies, and the R620W PTPN22 SNP.

RESULTS

None of the comparisons between patients with RA and controls or between the different strata of patients according to disease features was significant.

CONCLUSION

None of the SNP in CFH and CD209 showed evidence of association with RA. We did not replicate the association of eotaxin-3 with RA described in Koreans, or that of the MHC2T SNP.

Eosinophil progenitors in allergy and asthma - do they matter?

Allergic inflammation is associated with marked infiltration of eosinophils in affected tissues. The eosinophil is believed to be a key effector cells in allergen induced asthma pathogenesis. However, the role of eosinophils in the clinical manifestation of asthma has recently been questioned, since therapies directed against eosinophil infiltration (i.e. anti-interleukin-5) failed to improve clinical symptoms such as airways hyper-responsiveness (AHR) in patients with asthma. Although eosinophils in peripheral blood and the airways were largely depleted after anti-IL-5 treatment, residual eosinophilia in lung tissue persisted, which permits speculation that the remaining eosinophils may be sufficient to drive the asthma symptomatology. Furthermore, recent findings suggest that primitive eosinophil progenitor cells traffic from the bone marrow to sites of inflammation in response to allergen exposure. These progenitors may then differentiate in situ and thus provide an ongoing supply of mature pro-inflammatory cells and secretory mediators that augment the inflammatory response. In the present article, we will review the evidence for these findings, and discuss the rationale for targeting hematopoiesis and their migration pathways in the treatment of allergic diseases. Furthermore, this review will highlight the hypothesis that both IL-5- and CCR3-mediated signaling pathways may need to be targeted in order to control the inflammation and AHR associated with asthma.

Eosinophils: biological properties and role in health and disease

Eosinophils are pleiotropic multifunctional leukocytes involved in initiation and propagation of diverse inflammatory responses, as well as modulators of innate and adaptive immunity. In this review, the biology of eosinophils is summarized, focusing on transcriptional regulation of eosinophil differentiation, characterization of the growing properties of eosinophil granule proteins, surface proteins and pleiotropic mediators, and molecular mechanisms of eosinophil degranulation. New views on the role of eosinophils in homeostatic function are examined, including developmental biology and innate and adaptive immunity (as well as their interaction with mast cells and T cells) and their proposed role in disease processes including infections, asthma, and gastrointestinal disorders. Finally, strategies for targeted therapeutic intervention in eosinophil-mediated mucosal diseases are conceptualized.

The chemokine network. II. On how polymorphisms and alternative splicing increase the number of molecular species and configure intricate patterns of disease susceptibility

In this second review on chemokines, we focus on the polymorphisms and alternative splicings and on their consequences in disease. Because chemokines are key mediators in the pathogenesis of inflammatory, autoimmune, vascular and neoplastic disorders, a large number of studies attempting to relate particular polymorphisms of chemokines to given diseases have already been conducted, sometimes with contradictory results. Reviewing the published data, it becomes evident that some chemokine genes that are polymorphic have alleles that are found repeatedly, associated with disease of different aetiologies but sharing some aspects of pathogenesis. Among CXC chemokines, single nucleotide polymorphisms (SNPs) in the CXCL8 and CXCL12 genes stand out, as they have alleles associated with many diseases such as asthma and human immunodeficiency virus (HIV), respectively. Of CC chemokines, the stronger associations occur among alleles from SNPs in CCL2 and CCL5 genes and a number of inflammatory conditions. To understand how chemokines contribute to disease it is also necessary to take into account all the isoforms resulting from differential splicing. The first part of this review deals with polymorphisms and the second with the diversity of molecular species derived from each chemokine gene due to alternative splicing phenomena. The number of molecular species and the level of expression of each of them for every chemokine and for each functionally related group of chemokines reaches a complexity that requires new modelling algorithms akin to those proposed in systems biology approaches.

The eosinophil

Eosinophils have been considered end-stage cells involved in host protection against parasites. However, numerous lines of evidence have now changed this perspective by showing that eosinophils are pleiotropic multifunctional leukocytes involved in initiation and propagation of diverse inflammatory responses, as well as modulators of innate and adaptive immunity. In this review, we summarize the biology of eosinophils, focusing on the growing properties of eosinophil-derived products, including the constituents of their granules as well as the mechanisms by which they release their pleiotropic mediators. We examine new views on the role of eosinophils in homeostatic function, including developmental biology and innate and adaptive immunity (as well as interaction with mast cells and T cells). The molecular steps involved in eosinophil development and trafficking are described, with special attention to the important role of the transcription factor GATA-1, the eosinophil-selective cytokine IL-5, and the eotaxin subfamily of chemokines. We also review the role of eosinophils in disease processes, including infections, asthma, and gastrointestinal disorders, and new data concerning genetically engineered eosinophil-deficient mice. Finally, strategies for targeted therapeutic intervention in eosinophil-mediated mucosal diseases are conceptualized.

Eotaxin-3 and a uniquely conserved gene-expression profile in eosinophilic esophagitis

Eosinophilic esophagitis (EE) is an emerging disorder with a poorly understood pathogenesis. In order to define disease mechanisms, we took an empirical approach analyzing esophageal tissue by a genome-wide microarray expression analysis. EE patients had a striking transcript signature involving 1% of the human genome that was remarkably conserved across sex, age, and allergic status and was distinct from that associated with non-EE chronic esophagitis. Notably, the gene encoding the eosinophil-specific chemoattractant eotaxin-3 (also known as CCL26) was the most highly induced gene in EE patients compared with its expression level in healthy individuals. Esophageal eotaxin-3 mRNA and protein levels strongly correlated with tissue eosinophilia and mastocytosis. Furthermore, a single-nucleotide polymorphism in the human eotaxin-3 gene was associated with disease susceptibility. Finally, mice deficient in the eotaxin receptor (also known as CCR3) were protected from experimental EE. These results implicate eotaxin-3 as a critical effector molecule for EE and provide insight into disease pathogenesis.

Identification of single nucleotide polymorphisms in FOXJ1 and their association with allergic rhinitis

Forkhead-box J1 (FOXJ1) is a presumed transcription factor that can suppress T cell activity, at least partially, through the repression of NFkappaB activity. Thus, dysregulation of FOXJ1 is thought to be associated with autoimmune diseases and/or other inflammatory diseases. To investigate the association between single nucleotide polymorphisms (SNPs) of human FOXJ1 and allergic rhinitis, we scanned the whole human FOXJ1 gene, including the promoter region, by direct sequencing of DNA from 32 individuals. We identified seven SNPs, three of which (g.-460C>T, g.1805G>T, and g.3375G>C) were chosen for large sample size genotyping (n=713), and to assess the genotype frequencies of these SNPs between controls and allergic rhinitis patients. We also investigated the relationships of each genotype with serum total IgE levels in allergic rhinitis patients, and compared the frequencies of haplotypes constructed by these SNPs between the two groups. Our results suggest that the SNPs g.-460C>T, g.1805G>T and g.3375G>C in the human FOXJ1 gene might be associated with susceptibility to allergic rhinitis (P=0.0184, 0.0076, and 0.0143, respectively). The main haplotype, CGG, also revealed a significant association with allergic rhinitis (P=0.000018). However, no significant association was found between serum total IgE levels and the genotypes of these polymorphisms.

Eotaxin-3 gene polymorphisms are associated with rheumatoid arthritis in a Korean population

The eotaxin gene family (eotaxin, eotaxin-2, and eotaxin-3) has been implicated in the recruitment of eosinophils, basophiles and Th2 lymphocytes that is a central aspect of allergic diseases. We previously suggested that Eo2+179T>C and Eo2+275C>T of the eotaxin-2, and Eo3+2497T>G of the eotaxin-3 were significantly associated with susceptibility to asthma. To precisely determine whether these single nucleotide polymorphisms (SNPs) are associated with susceptibility to autoimmune disease such as rheumatoid arthritis (RA) in Koreans, we analyzed the genotype and allele frequencies for four SNPs (Eo2+179T>C, Eo2+275C>T, Eo2+304A>C, and Eo2+1272A>G) of the eotaxin-2, and three SNPs (Eo3+77C>T, Eo3+1577G>A, and Eo3+2497T>G) of the eotaxin-3 by single-base extension method. Although the genotype and allele frequencies of the eotaxin-2 SNPs gene between patients with RA and controls were not significantly different, the genotype and allele frequencies of the eotaxin-3SNPs between them were significantly associated. The genotype frequencies of Eo3+1577G>A and Eo3+2497T>G in patients with RA were significantly different from those in the controls (p = 0.0001 and p < 0.0001, respectively). Our results strongly suggest that the polymorphisms of eotaxin-3 might be associated with susceptibility to RA.