Mouse ILC2 cells from wild-type or Gfi1-KO animals

Innate type-2 lymphocytes (ILC2s) are a newly described cell type whose biology and contribution to disease are poorly understood. We are interested in investigating the role of the transcription factor Gfi1 in ILC2s, which appear to be a prominent source of IL-5 and IL-13 during type-2 immune responses. We have compelling evidence demonstrating a critical role for Gfi1 in the development and effector state of ILC2s. We would like to elucidate the molecular role of Gfi1 in ILC2s by identifying Gfi1-regulated genes by microarray analysis. Gfi1+/+ or Gfi1GFP/GFP (a GFP cassette has been 'knocked-in' to the Gfi1 locus and thus functions both as a surrogate for Gfi1 promoter activity and as a loss-of-function allele) mice were injected with IL-25 once daily for 4 days. On day 5, ILC2s (Lin-/Sca-1+/ICOS+/CD127+/c-Kit+) were sorted from the mesenteric lymph nodes of Gfi1+/+ (3 mice/sample were pooled together) or Gfi1-/- mice (6 mice/sample were pooled together) and cultured for 6 days in RPMI 1640, 10% FBS, Gln, P/S, 2ME, IL-2 (50ng/ml), IL-7 (10ng/ml), and IL-25 (50ng/ml). Whole RNA was harvested on day 6 via the RNeasy kit (Qiagen).