Figure 2.

CCR4, but not CCR8, mediates ILC2 migration. (A and B) To assess the migratory behavior of ILC2s, in vitro–expanded WT (A) and Ccr8^−/− or Ccr4^−/− (B) ILC2s were used. Chemotaxis assays were performed using transwell inserts against gradients of the chemokines CCL1, CCL8, CCL17, or CCL22 (100 ng/ml each) as well as an activating CCR8 agonist (5 µM). (C and D) To investigate ILC2 lung homing, WT mice were pretreated with papain, and 10⁶ fluorescent-labeled WT, Ccr4^−/−, or Ccr8^−/− ILC2s (C) or a 50:50 mix (D) were adoptively transferred by i.v. injection. 24 h later, lungs were collected, processed, and analyzed by light-sheet microscopy. (C) One-way ANOVA was applied. Scale bars are 100 µm. Images were acquired with a 10× zoom factor. (D) The pictures show snapshots of Video 1. Scale bars are 200 µm (left) or 100 µm (right). Images were acquired with a 25× zoom factor. (A and B) Each dot represents a technical replicate. One representative experiment out of two independently performed experiments is shown. (C and D) Data represent one out of two independent sorting experiments with one or two mice per group. Data represent mean ± SEM. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001 by Mann-Whitney U tests or, if indicated, one-way ANOVA.