Impact of FOXP3 gene polymorphisms and gene-environment interactions in asthma and atopy in a Brazilian population.

BACKGROUND: Polymorphisms in genes related to the activation and development of regulatory T cells (Tregs), such as FOXP3, may be associated with asthma and atopy development. Additionally, environmental factors such as exposure to infections can modify the effect of these associations. This study evaluated the impact of polymorphisms in the FOXP3 on the risk of asthma and atopy as also gene-environment interactions in these outcomes. METHODS: This study included 1,246 children from the SCAALA program, between 4 and 11 years of age. DNA was extracted from peripheral blood and eight SNPs (rs2280883, rs11465476, rs11465472, rs2232368, rs3761549, rs3761548, rs2232365 and rs2294021) were genotyped using the 2.5 HumanOmni Beadchip from Illumina (San Diego, California, USA) or TaqMan qRT-PCR. RESULTS: The rs2232368 (Allele T) was positively associated with asthma symptoms (OR = 1.95, CI = 1.04 to 3.66, p = 0.040) and skin prick test (SPT) reactivity to aeroallergens (OR = 2.31, CI = 1.16 to 4.59, p = 0.017). The rs3761549 (Allele T) was positively associated with SPT reactivity (OR = 1.44, CI = 1.03 to 2.02, p = 0.034). The rs2280883 (Allele C) was negatively associated with specific IgE to aeroallergens (OR = 0.83, CI = 0.70 to 0.99, p = 0.040). Furthermore, the rs2280883 played a protective role in the development of atopy only in individuals seropositive to Epstein-Barr virus (EBV) infection (OR = 0.74, CI = 0.60 to 0.92, p = 0.003 and OR = 0.74; 95% CI = 0.61-0.91, p = 0.007 for SPT and slgE respectively), but not in individuals without EBV infection. CONCLUSION: Polymorphisms in the FOXP3 gene were associated with the risk of atopy and asthma development in our population. In addition, EBV infection had an effect modifier of the observed association for rs2280883 variant.

Genetic and epigenetic studies of FOXP3 in asthma and allergy.

Multiple factors interact to trigger allergic diseases, including individual genetic background and factors related to the environment such as exposure to allergens, air pollution and respiratory infections. The FOXP3 transcription factor is constitutively expressed in CD4+CD25+FOXP3+ regulatory T cells (Tregs) and is critical for the maintenance of immune homeostasis. For example, FOXP3 is responsible for the suppression of the Th2 response following exposure to allergens. Studies have shown that expression of the FOXP3 gene is reduced in patients with asthma and allergies compared to healthy controls. Therefore, the impairment of FOXP3 function caused by genetic polymorphisms and/or epigenetic mechanisms may be involved in the etiology of asthma and other allergic diseases. This review discusses some aspects of the role of FOXP3 in the development of asthma and allergy, with a particular emphasis on genetic and epigenetic factors.

IL10 single nucleotide polymorphisms are related to upregulation of constitutive IL-10 production and susceptibility to Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori infection is a strong risk factor for gastric cancer, likely due to the extensive inflammation in the stomach mucosa caused by these bacteria. Many studies have reported an association between IL10 polymorphisms, the risk of gastric cancer, and IL-10 production. The aim of the study was to evaluate the association between IL10 genetic variants, Helicobacter pylori infection, and IL-10 production by peripheral blood leukocytes in children. MATERIALS AND METHODS: We genotyped a total of 12 single nucleotide polymorphisms in IL10 in 1259 children aged 4-11 years living in a poor urban area in Salvador, Brazil, using TaqMan probe based, 5' nuclease assay minor groove binder chemistry. Association tests were performed by logistic regression for Helicobacter pylori infection and linear regression for IL-10 spontaneous production (whole-blood cultures) including sex, age, and principal components for informative ancestry markers as covariates, using PLINK. RESULTS: Our results shown that IL10 single nucleotide polymorphisms rs1800896 (OR = 1.63; 95% CI = 1.11-2.39), rs3024491 (OR = 1.71; 95% CI = 1.14-2.57), rs1878672 (OR = 1.79; 95% CI = 1.19-2.68), and rs3024496 (OR = 1.48; 95% CI = 1.05-2.08) were positively associated with Helicobacter pylori infection. Eight single nucleotide polymorphisms were associated with spontaneous production of IL-10 in culture, of which three (rs1800896 and rs1878672, p = .04; rs3024491, p = .01) were strongly associated with infection by Helicobacter pylori. CONCLUSIONS: Our results indicate that IL10 variants rs1800896, rs3024491, rs1878672, and rs3024496 are more consistently associated with the presence of anti-H. pylori IgG by inducing increased production of IL-10. Further studies are underway to elucidate the role of additional genetic variants and to investigate their impact on the occurrence of gastric cancer.

Ocimum gratissimum Linn. and rosmarinic acid, attenuate eosinophilic airway inflammation in an experimental model of respiratory allergy to Blomia tropicalis.

Allergic asthma has emerged as an important public health problem of urban populations in developed countries. Very often herbal medicine is used to treat this widespread disease, due to the lack of efficacy and the important side effects related to the classical drugs in use. Along this line, Ocimum gratissimum (Og) is a plant widely used in Brazilian folk medicine to treat inflammatory disorders, such as asthma. In the present study we evaluated the immunomodulatory effects of Og and rosmarinic acid (RA, a polyphenolic compound) in a murine model of respiratory allergy induced by the Blomia tropicalis (Bt) mite. The respiratory allergy was induced in A/J mice by administration of Bt extract and the treatment was done using 25, 50 or 100mg/kg of an Og methanolic extract or using 2, 20 or 200mg/kg of RA. We then evaluated the changes induced by these drugs on immunological parameters related to the allergic process, which are up-regulated in this allergic model. The treatment of animals with 100mg/Kg Og and 200mg/Kg RA led to a significant reduction in the numbers of leukocytes/eosinophils in bronchoalveolar lavage (BAL); eosinophil peroxidase activity in BAL; presence of mucus in respiratory tract, histopathological changes in the lung, and IL-4 in BAL. These results suggest that the methanolic extract of Og and the polyphenol RA have therapeutic potential in this murine model of respiratory allergy to a clinically relevant human sensitizer allergen.

Effects of Cissampelos sympodialis Eichl. and its alkaloid, warifteine, in an experimental model of respiratory allergy to Blomia tropicalis.

Asthma is one of the most prevalent chronic diseases worldwide. Medicinal plants are historically used in its treatment. The plant Cissampelos sympodialis, known in Northeastern Brazil as "Jarrinha" or "Milona", is used to treat some inflammatory conditions, including asthma. The objective of this study was to evaluate the potential of Cissampelos sympodialis EICHL. extract (CsE) and its isolated alkaloids, especially warifteine (Wa) on a Blomia tropicalis extract (BtE)-induced experimental model of allergy. The respiratory allergy was induced in AJ mice by the administration of BtE. Mice were orally treated with the 400 mg/kg of CsE or 8 mg/kg of total alkaloids fraction (TAF) or 4 mg/kg of Wa and the following parameters were analyzed: (a) total cell numbers in bronchoalveolar fluid (BAF); (b) differential cell numbers in BAF; (c) eosinophil peroxidase (EPO) activity in BAF; (d) IgE serum levels by passive cutaneous anaphylaxis; (e) IL-5, IL-13, IL-10, and IFN-γ levels in BAF; (f) histopathological alterations in the lung. The treatment of the animals with CsE, Wa or TAF led to a reduction in the numbers of total cells and eosinophils in BAF. The same reduction was observed in EPO levels in the BAF. The levels of IL-5 and IL-13 were also reduced in animals treated with Cissampelos sympodialis, while IL-10 levels were significantly increased in the BAF of CsE-treated animals. The treatment also decreased the density of inflammatory cells in the lung by histopathological examination demonstrating the potential of this medicinal plant as new agent for asthma treatment.