Flow Cytometric Analysis of Myeloid Cells in Human Blood, Bronchoalveolar Lavage, and Lung Tissues

Am J Respir Cell Mol Biol. 2016 Jan;54(1):13-24. doi: 10.1165/rcmb.2015-0146OC.


Clear identification of specific cell populations by flow cytometry is important to understand functional roles. A well-defined flow cytometry panel for myeloid cells in human bronchoalveolar lavage (BAL) and lung tissue is currently lacking. The objective of this study was to develop a flow cytometry-based panel for human BAL and lung tissue. We obtained and performed flow cytometry/sorting on human BAL cells and lung tissue. Confocal images were obtained from lung tissue using antibodies for cluster of differentiation (CD)206, CD169, and E cadherin. We defined a multicolor flow panel for human BAL and lung tissue that identifies major leukocyte populations. These include macrophage (CD206(+)) subsets and other CD206(-) leukocytes. The CD206(-) cells include: (1) three monocyte (CD14(+)) subsets, (2) CD11c(+) dendritic cells (CD14(-), CD11c(+), HLA-DR(+)), (3) plasmacytoid dendritic cells (CD14(-), CD11c(-), HLA-DR(+), CD123(+)), and (4) other granulocytes (neutrophils, mast cells, eosinophils, and basophils). Using this panel on human lung tissue, we defined two populations of pulmonary macrophages: CD169(+) and CD169(-) macrophages. In lung tissue, CD169(-) macrophages were a prominent cell type. Using confocal microscopy, CD169(+) macrophages were located in the alveolar space/airway, defining them as alveolar macrophages. In contrast, CD169(-) macrophages were associated with airway/alveolar epithelium, consistent with interstitial-associated macrophages. We defined a flow cytometry panel in human BAL and lung tissue that allows identification of multiple immune cell types and delineates alveolar from interstitial-associated macrophages. This study has important implications for defining myeloid cells in human lung samples.

Keywords: alveolar macrophages; interstitial lung disease; interstitial macrophages; interstitial-associated macrophages.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / blood*
  • Bronchoalveolar Lavage Fluid / cytology
  • Bronchoalveolar Lavage Fluid / immunology*
  • Female
  • Flow Cytometry*
  • Humans
  • Immunophenotyping / methods*
  • Lung / cytology
  • Lung / immunology*
  • Macrophages, Alveolar / immunology
  • Male
  • Microscopy, Confocal
  • Myeloid Cells / immunology*
  • Sialic Acid Binding Ig-like Lectin 1 / blood
  • Young Adult


  • Biomarkers
  • SIGLEC1 protein, human
  • Sialic Acid Binding Ig-like Lectin 1