CD4 and asthma: While DC10 engage CD4+CD25+Foxp3+ natural (n)Treg in a productive fashion and these T cells have a modest role in the asthma tolerance within DC10-treated animals, DC10-induced CD25+Foxp3+ (i)Treg are many-fold more effective than naturally occurring CD25+Foxp3+ regulatory T cells (nTreg) of identical TCR specificity in suppressing the asthma phenotype (217).