title: Identification of myeloid cell subsets in murine lungs using flow cytometry.
abstract: Although the antibody-based recognition of cell-surface markers has been widely used for the identification of immune cells, overlap in the expression of markers by different cell types and the inconsistent use of antibody panels have resulted in a lack of clearly defined signatures for myeloid cell subsets. We developed a 10-fluorochrome flow cytometry panel for the identification and quantitation of myeloid cells in the lungs, including pulmonary monocytes, myeloid dendritic cells, alveolar and interstitial macrophages, and neutrophils. After the initial sorting of viable CD45(+) leukocytes, we detected three leukocyte subpopulations based on CD68 expression: CD68(-), CD68(low), and CD68(hi). Further characterization of the CD68(hi) population revealed CD45(+)/CD68(hi)/F4/80(+)/CD11b(-)/CD11c(+)/Gr1(-) alveolar macrophages and CD45(+)/CD68(hi)/F4/80(-)/CD11c(+)/Gr1(-)/CD103(+)/major histocompatibility complex (MHC) class II(hi) dendritic cells. The CD68(low) population contained primarily CD45(+)/CD68(low)/F4/80(+)/CD11b(+)/CD11c(+)/Gr1(-)/CD14(low) interstitial macrophages and CD45(+)/CD68(low)/F4/80(+)/CD11b(+)/CD11c(-)/Gr1(low)/CD14(hi) monocytes, whereas the CD68(-) population contained neutrophils (CD45(+)/CD68(-)/F4/80(-)/CD11b(+)/Gr1(hi)). The validity of cellular signatures was confirmed by a morphological analysis of FACS-sorted cells, functional studies, and the depletion of specific macrophage subpopulations using liposomal clodronate. We believe our approach provides an accurate and reproducible method for the isolation, quantification, and characterization of myeloid cell subsets in the lungs, which may be useful for studying the roles of myeloid cells during various pathological processes.
authors.affiliation: Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, School of Medicine, Vanderbilt University, Nashville, TN 37232, USA. rinat.z.zaynagetdinov@vanderbilt.edu
authors.forename: Rinat
authors.initials: R
authors.lastname: Zaynagetdinov
authors.forename: Taylor P
authors.initials: TP
authors.lastname: Sherrill
authors.forename: Peggy L
authors.initials: PL
authors.lastname: Kendall
authors.forename: Brahm H
authors.initials: BH
authors.lastname: Segal
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Weller
authors.forename: Robert M
authors.initials: RM
authors.lastname: Tighe
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Blackwell
mesh_terms: D000818:Animals; D050071:Bone Density Conservation Agents / Q000494:pharmacology; D004002:Clodronic Acid / Q000494:pharmacology; D003713:Dendritic Cells / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D008168:Lung / Q000166:cytology* / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects / Q000502:physiology; D016676:Macrophages, Alveolar / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism
chemical_list: D050071:Bone Density Conservation Agents; D000949:Histocompatibility Antigens Class II; D004002:Clodronic Acid