Gene polymorphisms of interleukin-10 and transforming growth factor beta in allergic rhinitis

Polymorphisms and haplotypes of IL2RA, IL10, IFNG, IRF5, and CCR2 are associated with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children

OBJECTIVE

Cytokine storms are central to the development of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Previous studies have shown that single-nucleotide polymorphisms (SNPs) of cytokine genes may be associated with the development of EBV-HLH in children. As such, we investigated the association between susceptibility to EBV-HLH in children and SNPs and haplotypes of genes encoding interleukin-2 receptor subunit alpha (IL2RA), interleukin-10 (IL10), interferon gamma (IFNG), interferon regulatory factor 5 (IRF5), and C-C chemokine receptor 2 (CCR2).

METHODS

Sixty-six children with EBV-HLH and 58 healthy EBV-seropositive controls were enrolled in this study. SNPs of IL2RA rs2104286, rs12722489, and rs11594656; IL10 rs1800896, rs1800871, and rs1800872; IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were assayed and genotyped using the SNaPshot technique.

RESULTS

Frequencies of the A allele of IL2RA rs2104286 and IL10 rs1800896, and C allele of IL-10 rs1800872 were significantly higher in the EBV-HLH group than in the control group. The AA genotype of IL2RA rs2104286 and IL10 rs1800896, and the CC genotype of IL10 rs1800872 might be associated with a significantly high risk of EBV-HLH. However, the frequencies of genotypes and alleles of IL2RA rs2104286, IL10 rs1800871, IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were similar in both groups. Additionally, IL2RA AGT (rs2104286-rs12722489-rs11594656) and IL10 ACC (rs1800896-rs1800871-rs1800872) haplotypes were also associated with an increased risk of EBV-HLH.

CONCLUSIONS

SNPs of IL2RA rs2104286, IL10 rs1800896 and rs1800872 and the haplotypes of IL2RA AGT and IL10 ACC were highly associated with susceptibility to EBV-HLH in children.

Association of interleukin-12B rs6887695 with susceptibility to allergic rhinitis

Interleukin-12 (IL-12) is a heterodimeric cytokine encoded by two separate genes, IL12A and IL12B, which may play a regulatory role in allergen-induced inflammation through CD4⁺ T-cell subsets polarization. The aim of this study was to investigate the association of single-nucleotide polymorphisms (SNPs) in the IL12B gene with susceptibility to allergic rhinitis (AR). We performed a case-control study including 130 AR patients and 130 healthy controls to evaluate the possible association between IL12B gene SNPs (rs3212227, rs6887695) and the risk of AR using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our results showed no significant association between IL12B rs3212227 A > C polymorphism with AR. In contrast, the GC genotype of rs6887695 G > C was associated with susceptibility to AR in comparison with the GG genotype (p = 0.049, OR = 1.684, 95% CI: 1.002-2.83). We also observed a statistically significant difference in the additive model (GC versus GG + CC, p = 0.03, OR = 1.705, 95% CI: 1.040-2.794) for SNPs rs6887695. Furthermore, haplotypes analysis demonstrated that C-C haplotype was associated with an increased risk of AR (p = 0.01, OR = 1.845, 95% CI: 1.114-3.057). Our findings suggest that IL12B rs6887695 polymorphism may be a potential biomarker for susceptibility to AR in an Iranian population.

Immunomodulatory properties of Schistosoma mansoni proteins Sm200 and SmKI-1 in vitro and in a murine model of allergy to the mite Blomia tropicalis

The prevalence of allergic diseases in Brazil is one of the biggest in the world. Among these pathologies, we highlight asthma as one of the most importance. Asthma is characterized as a chronic inflammatory disease of airways, associated with hyperresponsiveness. Many environmental factors can trigger asthma symptoms, among them house dust mites can stimulate hypersensitivity type I reaction. The most common in house dust mite, in tropical countries, are Dermatophagoides pteronysinus and Blomia tropicalis. Several studies have shown that helminths, especially Schistosoma mansoni, lead to reduction of symptoms of atopy and allergic diseases. Therefore, the present study aims to evaluate the ability of recombinant S. mansoni proteins Sm200, and SmKI-1 to induce immunomodulation in vitro, using peripheral blood mononuclear cells (PBMCs) from atopic and non-atopic individuals, stimulated or not with B. tropicalis extract, and in vivo, in a murine model of allergy to the mite B. tropicalis. As results, we observed that the fragment called rSm200-3 and the protein rSmKI-1 stood out for their immunomodulatory potential, stimulating IL-10 production by human PBMCs in vitro. When these proteins were associated with B. tropicalis extract, it was observed the reduction of the production of the cytokine IL-5, with a statistically significant difference in non-atopic individual's cells. In vivo, both proteins presented similar results, with a reduction of IL-5 and IL-4 levels in lung homogenates and of serum IgE. SmKI-1 was also able to decrease the levels of EPO in lung homogenates and in BAL. These results showed that both proteins were able to downmodulate Th2 cells on human PBMCs, and in a murine model of allergy. However, SmKI-1 also reduced significantly the levels of EPO in BAL and lungs showing that this protein may be a good candidate to be used as a possible replacement or in conjunction with pharmacotherapy in individuals with unregulated immune response in asthma.

Polymorphism -509C/T in TGFB1 Promoter Is Associated With Increased Risk and Severity of Persistent Allergic Rhinitis in a Chinese Population

BACKGROUND

Polymorphism -509C/T in the promoter of transforming growth factor beta1 (TGFB1) gene is implicated in the pathogenesis of asthma. This polymorphism might also act to regulate the development of allergic rhinitis (AR).

OBJECTIVES

To investigate whether -509C/T is associated with AR susceptibility and severity in a Han Chinese population.

METHODS

The study enrolled 263 patients with persistent AR and 249 healthy controls. AR patients were classified as mild or moderate/severe AR groups according to the Allergic Rhinitis and its Impact on Asthma classification. TGFB1 gene polymorphism -509C/T was genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum total Immunoglobulin E (IgE) and specific IgE levels were determined using an ImmunoCAP.

RESULTS

Significant difference was found in the allele frequency of TGFB1 -509C/T between AR patients and healthy controls (P = .027) but not in the genotype frequency (P =.051). However, the genotype frequency of TGFB1 -509C/T showed significant difference between the mild AR group, the moderate/severe AR group, and the control group (P = .012); between the moderate/severe AR group and the control group (P =.036); between the mild AR group and the moderate/severe AR group (P = .038); but not between the mild AR group and the control group (P =.075).

CONCLUSION

TGFB1 promoter polymorphism -509C/T may be associated with the susceptibility and the severity of persistent AR of Han Chinese, but the functional relationship still needs clarification.

Association of IL-10 and TGF-beta cytokine gene polymorphisms with autoimmune hepatitis

BACKGROUND AND AIMS

Autoimmune hepatitis is a chronic immune-mediated liver injury caused by dysregulated immune response to liver antigens. Genetic susceptibility is affected by multiple single nucleotide polymorphisms in immune-related genes. There are few reports on the association of TGF-β and IL-10 genetic variants with autoimmune hepatitis.

METHODS

Allele frequency and genotype status of IL-10 -1082, -819, -592 and TGF-β +869 and +915 polymorphisms were investigated in 57 unrelated patients with autoimmune hepatitis and 140 healthy controls by polymerase chain reaction with sequence-specific primers.

RESULTS

IL-10 -592 and -819 allele frequencies and genotypes were not associated with autoimmune hepatitis in our population, while IL-10 -1082 genotypes were. IL-10 -1082/-819/-592 "high-producing" haplotype GCC was significantly less frequent in patients. TGF-β +869 "high-producing" allele C and genotype CC were significantly more in autoimmune hepatitis, compared to controls; whereas, TGF-β +915 "low-producing" allele C and genotype CC were significantly more in autoimmune hepatitis compared to control. TGF-β +869/+915 haplotype TG was significantly less frequent in patients while CC haplotype was significantly more frequently observed in patients.

CONCLUSION

We identified a significant association between IL-10 -1082/-819 and TGF-β +869/+915 genotypes and haplotypes with autoimmune hepatitis in Iranians.

Significant association of TNF-α, but not other pro-inflammatory cytokines, single nucleotide polymorphisms with intervertebral disc degeneration in Iranian population

OBJECTIVES

As the important role of inflammation in pathophysiology of intervertebral disc degeneration and inconsistency regarding the role of pro-inflammatory cytokine genes SNPs, the current case-control study was designed to assess this in Iranian population.

PATIENTS AND METHODS

The genomic DNA of peripheral leukocytes of 76 patients and 140 healthy controls were investigated to sequence 9 SNPs of pro-inflammatory cytokine genes of interleukin 1 (IL-1), interleukin 6 (IL-6), and Tumor Necrosis Factor α (TNF-α) family.

RESULTS

'GA' and 'GG' genotype of TNF-α -308 G/A SNP were significantly associated with IVDD. While 'GA' was 1.93 times more frequent in patients, the 'GG' genotype was more common among healthy subjects (OR = 0.51, P = 0.03). The 'G' allele of TNF-α -238 G/A was 2.51 times more common in IVDD patients while the 'A' genotype was more frequent in controls with odds ratio of 0.39 (P = 0.001). Interestingly, the homozygote 'GG' genotype was 2.98 times more prevalent in patients (P = 0.001) while the 'GA' heterozygote genotype was more common in healthy individuals (OR = 0.34). The other investigated SNPs were not significantly associated with disease in this study population.

CONCLUSION

Polymorphisms of pro-inflammatory cytokine genes could take part in IVDD pathophysiology as the result of alteration in their expression levels or structures. The current study indicated significant roles of TNF-α -308 G/A and TNF-α -238 G/A SNPs with IVDD among Iranian patients. However, this study did not show any significant association between IVDD and either of SNPs of IL-1 and IL-6 genes.

Association of IL10 and TGFB single nucleotide polymorphisms with intervertebral disc degeneration in Iranian population: a case control study

Background

Considered as one of the major causes of low back pain, Intervertebral disc degeneration (IVDD) is caused by several genetic and environmental factors. As inflammation plays an important role in disc degeneration, the genetic changes in both inflammatory and anti-inflammatory genes may play causative roles in IVDD as well. Therefore, the interactions between inflammatory and anti-inflammatory cytokines and also other components of disc matrix would determine the degree of tissue destruction in disc degeneration. However, there is still controversy regarding the exact role of inflammation and disc homeostasis imbalance in pathophysiology of IVDD. Therefore, current study was conducted to investigate the role of IL-10 and TGF-β single nucleotide polymorphisms (SNP) in Iranian IVDD patients.

Methods

Seventy-six IVDD patients and 140 healthy controls were enrolled in this study. Genomic DNA from peripheral leukocytes was tested for 3 SNPs in IL10 (L-10 -1082G/A (rs1800896), IL-10 -819C/T (rs1800871), IL-10 -592A/C (rs1800872)) and 2 SNPs in TGF-β (TGF-β Codon 10 C/T (rs1982037), and TGF-β Codon 25 C/T (rs1800471) genes through PCR-SSP method. The extracted genomic DNA was genotyped for the aforementioned SNPs of interest using specific primers, which were coated in the cytokines KITs and based on the PCR-SSP method for sequencing.

Results

The ‘T’ allele of IL-10 -819C/T and the ‘C’ allele of IL-10 -592A/C were more prevalent among patients, whereas the ‘C’ and ‘A’ alleles of respective SNPs were significantly more frequent in controls. The genotypes including ‘CT’ of IL-10 -819C/T, ‘CA’ of IL-10 -592A/C, and ‘GA’ of IL-10 -1082A/G were more common among patients, while the ‘CC’ genotype of both IL-10 -819C/T and IL-10 -592A/C SNPs were more frequent in controls. In addition, the IL-10 haplotypes including ‘ACC’, ‘ATA’, and ‘ACA’ were significantly associated with disease. Meanwhile, the ‘TC’ haplotype of TGF-β was more common among patients as well.

Conclusions

The IL-10 SNPs were significantly associated with IVDD in Iranian population; which proposes that genomic alterations of anti-inflammatory cytokines could lead to homeostasis imbalance in intervertebral discs and degenerative changes.

Single nucleotide polymorphisms of the genes encoding IL-10 and TGF-β1 in Iranian children with atopic dermatitis

BACKGROUND

Atopic dermatitis is an inflammatory skin disease in which both genetic and environmental factors interact to determine the susceptibility and severity of the disease.

OBJECTIVE

The aim of this study was to determine the association between atopic dermatitis and IL-10 and TGF-β1 gene polymorphisms.

METHODS

The allele and genotype frequencies of genes encoding for IL-10 and TGF-β1 were investigated in 89 patients with atopic dermatitis in comparison with 138 in the control group using the PCR-SSP method.

RESULTS

A significant increase was found in the frequency of the TGF-β1 codon 10/C allele among patients (p<0.001, OR=6.77), whereas a significant decrease was observed in the frequency of the T allele at the same position (p<0.001, OR=0.14). The frequency of the TGF-β1 codon 25/G allele in the control group was significantly higher than among patients (p<0.001, OR=0.08). A significant positive correlation was seen between CC (p<0.001, OR=15.10) and CG (p<0.001) genotypes and AD at codons 10 and 25, respectively. The most frequent haplotypes among patients was TGF-β1 CG which was significantly higher than in the control subjects (50% in patients vs. 39.9% in controls, p=0.042). A significant increase was found in the frequency of TGF-β CC (36% in patients vs. 7.6% in controls, p<0.001) and TC (14% in patients vs. 0% in controls, p<0.001) haplotypes among patients compared to controls. By contrast, the TGF-β1 TG haplotype was significantly lower in patients than controls (0% in patients vs. 52.5% in controls, p<0.001). There were no significant differences in the frequency of alleles, genotypes and haplotypes of the IL-10 gene.

CONCLUSIONS

We found a strong association between the polymorphisms of the TGF-β1 gene at codon 10 and codon 25 positions and atopic dermatitis.

Is a high-fiber diet able to influence ovalbumin-induced allergic airway inflammation in a mouse model?

Background:

More recently, a large amount of experimental and clinical discovered that dietary- fiber intake would decrease the susceptibility to allergic airway disease (AAD) and respiratory inflammation.

Objective:

To investigate whether a fiber-intake supplement is able to influence the induction of AAD and to elucidate the interactive relationship.

Methods:

AAD model mice and control mice were raised on a fundamental diet with standard 4% fiber content, whereas other mice were fed a 10% fiber-content diet in the high fiber-content group, along with a 25% fiber-content diet instead in very-high fiber-content group. All experimental mice were sensitized and challenged with ovalbumin to induce allergic inflammation in both the upper and lower airways. Hallmarks of AAD were examined in terms of eosinophil infiltration and goblet cell metaplasia in subepithelial mucosa, T-helper type 1 (Th1) to Th2 skewing of the immune response. Furthermore, to elucidate the interrelations, we generated 16S ribosomal DNA from fecal samples and further validated the variation of colony composition in each group.

Results:

The excessive high-fiber supplement induced a promoting effect rather than a suppressive effect, including a rise in nasal rubbing and sneezing, an increase in eosinophil inflammation and goblet cell metaplasia in subepithelial mucosa, and promoted Th2 skewing of the immune response as well as the production of serum levels of ovalbumin-specific immunoglobulin E. Moreover, overconsumption of dietary fiber greatly altered the construction of bacterial flora in the intestinal tract, including an increased proportion of Firmicutes, Actinobacteria, and Proteobacteria, and a decreased proportion of Bacteroidetes.

Conclusion:

Our work indicated that, instead of a protecting impact, excessive fiber intake preformed a negative influence on the induction of AAD. Therefore, we suspected that an excessive supplement of dietary fiber might not be an advisable method for the prevention and treatment of AADs.