Human neutrophils switch to an activated phenotype after homing to the lung irrespective of inflammatory disease

Clin Exp Immunol. 2009 Mar;155(3):559-66. doi: 10.1111/j.1365-2249.2008.03791.x. Epub 2008 Dec 9.

Abstract

Systemic inflammation can be investigated by changes in expression profiles of neutrophil receptors. Application of this technology for analysis of neutrophil phenotypes in diseased tissues is hampered by the absence of information regarding the modulation of neutrophil phenotypes after extravasation to tissues under non-inflammatory conditions. To fill this gap we measured the expression of neutrophil receptors in bronchoalveolar lavage fluid (BALF) and in the peripheral blood of healthy volunteers, which included both smokers and non-smokers. Blood and BALF neutrophils were identified by CD16(bright)/CD45(dim) cells, and triple-stained with antibodies directed against integrins, chemokine- and Fc gamma-receptors. BALF neutrophils of healthy volunteers showed an activated phenotype characterized by Mac-1 (CD11b)(bright), L-selectin (CD62L)(dim), intercellular adhesion molecule 1 (ICAM-1) (CD54)(bright), Fc gamma RII (CD32)(bright), C5a receptor (CD88)(bright) and CD66b(bright). A similar phenotype was observed for BALF neutrophils of patients affected by sarcoidosis. Furthermore, our results demonstrate a modulated expression of C5a receptor (CD88) and ICAM-1 (CD54) in neutrophils of sarcoidosis patients. In conclusion, our data indicate that neutrophils found in the lung exhibit an activated phenotype under both homeostatic and inflammatory conditions.

MeSH terms

  • Adult
  • Antigens, CD / analysis
  • Bronchoalveolar Lavage Fluid / immunology
  • CD11b Antigen / analysis
  • Case-Control Studies
  • Cell Adhesion Molecules / analysis
  • Female
  • Humans
  • Immunophenotyping
  • Intercellular Adhesion Molecule-1 / analysis
  • L-Selectin / analysis
  • Lung / immunology*
  • Male
  • Middle Aged
  • Neutrophil Activation
  • Neutrophils / immunology*
  • Receptor, Anaphylatoxin C5a
  • Receptors, Complement / analysis
  • Sarcoidosis / immunology*

Substances

  • Antigens, CD
  • C5AR1 protein, human
  • CD11b Antigen
  • CD66 antigens
  • Cell Adhesion Molecules
  • Receptor, Anaphylatoxin C5a
  • Receptors, Complement
  • Intercellular Adhesion Molecule-1
  • L-Selectin