The transcription factor XBP1 in dendritic cells promotes the TH2 cell response in airway allergy

Editor’s summaryT helper 2 (TH2) cells mediate allergic responses, and their development depends on dendritic cells (DCs) expressing the receptor TIM4. Yang et al. found that the transcription factor XBP1 induced expression of the gene encoding TIM4 in DCs. Production of the cytokine IL-2 in the airways of allergen-exposed mice induced expression of XBP1 and then TIM4 in DCs through a pathway involving the GEF Sos1 and the GTPase Ras. Targeting this pathway in DCs reduced the severity of experimentally induced allergic airway responses in mice, suggesting that these factors could be therapeutic targets for treating TH2 cell–dependent inflammatory or allergic diseases. —John F. Foley