BAL cells were purified by centrifugation on Percoll to remove surfactant and debris 31 (link). BAL cells or BMDMs were immunostained to detect CD115 (AFS98), F4/80 (BM8) (eBioscience), CD3 (145-2C11), CD11b (M1/70), CD11c HL3), CD16/32 (2.4G2), CD19 (1D3), CD64 (X54-5/7.1.1), CD131 (JORO50), Ly6G (1A8), CD45.1 (A20), CD45.2 (104), MHC class II (I-A/I-E) (M5/114.15.2), SiglecF (E50-2440) (BD Biosciences), CD14 (Sa14-2) (BioLegend), CD68 (FA-11) (AbD Serotec), and MerTK (108928) (R&D Systems), as previously described1 (link), evaluated by flow cytometry using a FACSCaliber or FACSCanto flow cytometers (both from BD Biosciences, San Jose, CA), and the results were analyzed using CellQuest, FACSDiva (BD Biosciences), or FlowJo software (Tree Star). For intracellular staining of CD68, Leucoperm (AbDSerotec) was used as directed by the manufacturer.