Th17/Treg ratio derived using DNA methylation analysis is associated with the late phase asthmatic response

Abstract

BackgroundThe imbalance between Th17 and Treg cells has been studied in various diseases including allergic asthma but their roles have not been fully understood in the development of the late phase asthmatic response.ObjectivesTo determine changes in Th17 and Treg cell numbers between isolated early responders (ERs) and dual responders (DRs) undergoing allergen inhalation challenge. To identify gene expression profiles associated with Th17 and Treg cells.Methods14 participants (8 ERs and 6 DRs) with mild allergic asthma underwent allergen inhalation challenge. Peripheral blood was collected prior to and 2 hours post allergen challenge. DNA methylation analysis was used to quantifiy the relative frequencies of Th17, Tregs, total B cells, and total T cells. Gene expression from whole blood was measured using microarrays. Technical replication of selected genes was performed using nanoString nCounter Elements.ResultsThe Th17/Treg ratio significantly increased in DRs compared to ERs post allergen challenge compared to pre-challenge. Genes significantly correlated to Th17 and Treg cell counts were inversely correlated with each other. Genes significantly correlated with Th17/Treg ratio included the cluster of genes of the leukocyte receptor complex located on chromosome 19q 13.4.ConclusionsTh17/Treg imbalance post-challenge may contribute to the development of the late phase inflammatory phenotype.

Blood and nasal epigenetics correlate with allergic rhinitis symptom development in the environmental exposure unit

“…Early epigenetic changes triggered by allergen exposure in symptom‐free individuals are important to isolate, as they represent potential therapeutic targets. One recent allergen challenge study demonstrated DNA methylation in blood to be a useful biomarker of early vs dual response . That study harnessed epigenetics as a signal of underlying changes in lymphocyte subsets, while we focused on changes that were independent of cell composition .…”

Enumerateblood – an R package to estimate the cellular composition of whole blood from Affymetrix Gene ST gene expression profiles

“…While we could not determine the accuracy of the B, CD4+ T, CD8+ T and NK cell predicted proportions directly, the sum of these predicted proportions were well correlated to the lymphocyte proportions obtained from the CBC/Diffs (r = 0.90). Monocyte, B and pan T-cell proportions were known in the smaller asthma cohort (Epiontis qPCR cell quantification assay [19]). There, B-cell predicted proportions were highly correlated to those obtained from the Epiontis assay (Fig.…”

“…The model’s performance was further validated using gene expression profiles obtained from a previously published asthma cohort (GSE40240) for which monocyte, B and T cell proportions were known [18, 19]. …”

“…Instead, the sum of the predicted B, CD4+ T, CD8+ T and NK cell proportions was compared to total lymphocyte proportions from the CBC/Diffs. In addition, we accessed a small asthma cohort from GEO (GSE40240) for which monocyte, B- and pan T-cell (CD3+) proportions were available (Epiontis qPCR cell quantification assay) [19]. This dataset was used to independently validate the performance of the model’s B- and T-cell predictions.…”

Interaction between allergic asthma and atherosclerosis

“…75 DNA methylation analysis determined the changes in Th17 and regulatory T cell (Treg) counts in the peripheral blood of mild allergic asthmatic patients undergoing allergen inhalation challenge, and the blood Th17/Treg ratio increased significantly after allergen challenge compared to pre-challenge, suggesting the participation of Th17 cells in the development of the late phase inflammatory phenotype. 76 A cross-sectional study showed that reduced risk of allergic disease among 149 children who had prenatal and postnatal exposure to farm milk relative to the 149 age-matched reference children was due to their increased Treg cell numbers. Peripheral CD4 + CD25 + Foxp3 + Treg cell numbers associated with doctor-diagnosed asthma and perennial IgE, suggesting a protective effect of Treg cells for the development of childhood allergic asthma.…”