biomedicines Article Surface Phenotype Changes and Increased Response to Oxidative Stress in CD4+CD25high T Cells Yoshiki Yamamoto 1,*, Takaharu Negoro 2, Rui Tada 3 , Michiaki Narushima 4, Akane Hoshi 2, Yoichi Negishi 3,* and Yasuko Nakano 2 1 Department of Paediatrics, Tokyo Metropolitan Ebara Hospital, Tokyo 145-0065, Japan 2 Department of Pharmacogenomics, School of Pharmacy, Showa University, Tokyo 142-8555, Japan;
[email protected] (T.N.);
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[email protected] (Y.N.) 3 Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan;
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[email protected] (Y.N.); Tel.: +81-3-5734-8000 (Y.Y.); +81-42-676-3182 (Y.N.) + + + + Abstract: Conversion of CD4 CD25 FOXP3 T regulatory cells (Tregs) from the immature (CD45RA ) to mature (CD45RO+) phenotype has been shown during development and allergic reactions. The relative frequencies of these Treg phenotypes and their responses to oxidative stress during devel- opment and allergic inflammation were analysed in samples from paediatric and adult subjects. The FOXP3lowCD45RA+ population was dominant in early childhood, while the percentage of high + FOXP3 CD45RO cells began increasing in the first year of life. These phenotypic changes were observed in subjects with and without asthma. Further, there was a significant increase in phospho- Citation: Yamamoto, Y.; Negoro, T.; + high rylated ERK1/2 (pERK1/2) protein in hydrogen peroxide (H2O2)-treated CD4 CD25 cells in Tada, R.; Narushima, M.; Hoshi, A.; adults with asthma compared with those without asthma.