Protocol for the isolation, purification, and short-term expansion of ILC2s from mouse skin

Group 2 innate lymphoid cells (ILC2s) are rare tissue-resident lymphocytes that are challenging to isolate from mouse skin. We present a protocol for isolating, purifying, and expanding ILC2s from adult mouse skin. We describe steps for collecting skin from the trunk and limbs, generating single-cell suspensions, and performing density-based cleanup. We detail procedures for depleting epithelial and endothelial cells before fluorescence-activated cell sorting (FACS), expanding purified ILC2s in cytokine-supplemented medium, and assessing their phenotype and functional responses.