As BATF3-dependent DCs are required for immune tolerance to H. pylori and for the immunomodulatory effects of H. pylori in models of allergen-induced airway inflammation [29], we examined the frequencies of pulmonary Tregs in WT and BATF3-/- mice that were infected with H. pylori. As only mice that have been experimentally infected in the neonatal period benefit from reduced allergy symptoms whereas mice infected as adults do not [25], we compared pulmonary Treg populations of mice infected neonatally and as adults. This evidence concerns the gene BATF3 and Allergy.