B16 Melanoma Lung Metastasis Model

B16 cells (2.5 × 10⁵ cells) were grown and injected by tail intravenously (i.v.) into recipient mice in a volume of 100 µL phosphate-buffered saline (PBS). Where indicated, mice were intraperitoneally (i.p.) injected with anti-asialo GM1 or isotype (Wako) every third day (day 0, 3, 6, 9, 12), and/or PD-1 blocking antibody or isotype (500µg/mouse, BioXCell) every fourth day (day 4, 8, 12). After 14 days, mice were euthanized and numbers of tumor colonies on lung surfaces were counted per field. Lungs were then collected and processed for the indicated readout as previously described (28 (link)). Briefly, the lungs were perfused with PBS and digested in Collagenase IV (MP Biomedicals, LLC) for 1 hour at 37°C. Samples were then stained and ILC2s were isolated based on the absence of common lineage markers (CD3, CD5, CD4, TCRβ, CD45R, Gr-1, CD56, CD11c, CD11b, Ter119, FcϵRIα, CD335), and the expression of CD45, ST2 and CD127.