Epigenetic modification of FOXP3 and IFNγ during asthma.

<p>Treg were purified from the PB (A, n = 21) or bronchoalveolar lavage (BAL) (B, n = 4) of MZT pairs discordant for asthma and methylation of 13 CpG sites within the FOXP3 locus was quantified. A CpG site was considered methylated after exhibiting methylation at that CpG site in ≥70% of the pyrosequencing reactions. Linear regression and Spearman’s correlation analysis of C) FOXP3 protein and % of methylated CpG sites within FOXP3(% calculated as number of methylated CpG sites divided by total number of CpG sites in the FOXP3 locus) or D) FOXP3 transcript (fold expression) and % of methylated CpG sites within FOXP3. E) Teff were purified from asthmatic and non-asthmatic MZT pairs (n = 21) and methylation of 6 CpG sites within the IFNγ locus was quantified. Data points represent individuals and twin pairs are connected via lines, r =  correlation coefficient.</p

Reduction of FOXP3 and IFNγ is augmented with recent SHS exposure.

<p>Peripheral blood Treg or Teff (CD4+CD25neg) were purified from twin pairs discordant for asthma and concordant for no SHS exposure (n = 15) and discordant for both asthma and SHS exposure (n = 6). In A and B, Treg were assessed for FOXP3 transcript (A) and FOXP3 protein (B). In C and D, Teff were assessed for IFNγ transcript (C) and protein (D). Gene expression was determined by QT-PCR and is shown as relative fold expression of candidate genes to expression of the housekeeping gene β-glucuronidase. Protein levels were determined by intracellular flow cytometry and shown as mean fluorescence intensity (MFI). Data points (circles) represent individuals and individual twin pairs are connected via a line, p<.05 for non-asthmatic vs. asthmatic or asthmatic + SHS for all groups.</p

Differential T cell function between asthmatic and non-asthmatic twins.

<p>Function of purified Treg (A) and purified Teff (B) from non-asthmatic twins (n = 21, white bars) and their asthmatic (n = 21, black bars) twin partner was assessed via ³H-thiymidine incorporation. A) Suppressive function of purified CD4+CD25+ Treg to CD4+ CD25neg Teff is presented as % function. B) Proliferation of purified CD4+ Teff to tetanus antigen. Data are presented as mean ± SD, * p<.05.</p

Subject demographics for twins discordant for asthma.

*<p>Significant differences between asthmatic and non-asthmatic twins, P<0.05.</p