IL-33 promotes transcriptional and metabolic adaptations of tissue-resident Th2 cells.

The polarization of naive CD4+ T cells into Th2 cells is initiated in lymphoid organs and completed as the cells become tissue resident, where they express ST2, the receptor for the alarmin interleukin (IL)-33, which may be a key signal for tissue integration. Cellular metabolic requirements associated with this transition remain poorly understood. To address this, we compared the response of lymphoid tissue (LT) Th2 cells from helminth parasite-infected mice to stimulation by IL-33 versus through the T cell receptor via anti-CD3/CD28. We found that IL-33, but not anti-CD3/CD28, induced the development of tissue-resident like Th2 cells expressing ST2. This was associated with IL-33 induced changes in arginine metabolism linked to mTORC1 activation and polyamine synthesis, which were required for the development of tissue-resident like Th2 cells. Furthermore, IL-33 induced transcriptional changes in genes involved in chemotaxis and cell adhesion that may be critical for tissue integration. Our findings provide insights into adaptations of Th2 cells responding to tissue-integration cues and more broadly support the view that IL-33 promotes the expression of the transcriptional program associated with tissue residency of GATA3-expressing cells in adipose and possibly other tissues.