ILC2 phenotype is dictated by the tissue microenvironment. (A) Schematic representation of the adoptive transfer model. ILC2s (sorted as CD45⁺Lin⁻CD127⁺KLRG1⁺) isolated from kidney, lung, and SILP of IL-33–treated (i.p. injection on four consecutive days) C57BL/6 CD45.1 wild type mice were adoptively transferred i.v. into C57BL/6 Rag2^−/−Il2rg^−/− mice. Tissues from the recipient mice were analyzed after 3 wk of reconstitution. (B) Flow cytometry plots of ILC2 sorting purity from A. The numbers represent frequencies of sorted ILC2s in the total lymphocyte population. (C–F) Flow cytometric analysis of leukocytes isolated from the kidney, lung, and SILP of C57BL/6 Rag2^−/−Il2rg^−/− mice after 3 wk of ILC2 transfer and without transfer. (C) Representative plots comparing CD45.1⁺ ILC2s isolated from the three indicated organs of recipient mice (rows) with transferred ILC2 populations derived from different organ origins (columns). Numbers indicate the percentage of cells in each gate. (D) Frequencies and absolute numbers of CD45.1⁺ ILC2s in kidney, lung, and SILP at 3 wk after transfer. Symbols represent individual data points, and bars indicate mean ± SEM (n = 4 per organ analyzed). (E) Representative histogram overlays showing surface marker expression of kidney, lung, and SILP CD45.1⁺ ILC2s isolated after 3 wk of reconstitution. (F) Heat maps of the MFI of various surface markers of ILC2s 3 wk after ILC2 transfer normalized to surface marker expression of kidney ILC2s. All data are representative of two independent experiments with at least three animals per group.