T cell phenotypes are associated with serum IgE levels in Amish and Hutterite children

Abstract Objectives Amish children raised on traditional farms have lower atopy and asthma risk than Hutterite children raised on modern farms. In our previous study, we established that the Amish environment affects the innate immune response to lower asthma and atopy risk. Herein we investigated the T cell phenotypes in the same Amish and Hutterite children as in our earlier study to elucidate how this altered innate immunity effects adaptive T cells. Methods Blood was collected from 30 Amish and 30 Hutterite age and sex-matched children; cells were cryopreserved until analysis. Flow cytometry was used to analyze cell subsets. Atopy was determined by allergen-specific and total IgE levels. Results Children exposed to Amish farms had increased activated Treg phenotypes, while conventional CD4 T cell expressed lower levels of co-stimulation molecules and other activation markers. The increase in circulating activated Tregs was associated with increase in inhibitory receptors on monocytes in Amish, but not Hutterite, children. Strikingly, the Amish children had a higher proportion of CD28null CD8 T cells than Hutterite children (non-parametric t test p Conclusion Amish children's blood leukocytes are not only altered in their innate immune status, but additionally have distinct T cell phenotypes that are often associated with increased antigenic exposure.