Ozone exposed epithelial cells modify cocultured natural killer cells

Am J Physiol Lung Cell Mol Physiol. 2013 Mar 1;304(5):L332-41. doi: 10.1152/ajplung.00256.2012. Epub 2012 Dec 14.

Abstract

Ozone (O3) causes significant adverse health effects worldwide. Nasal epithelial cells (NECs) are among the first sites within the respiratory system to be exposed to inhaled air pollutants. They recruit, activate, and interact with immune cells via soluble mediators and direct cell-cell contacts. Based on our recent observation demonstrating the presence of natural killer (NK) cells in nasal lavages, the goal of this study was to establish a coculture model of NECs and NK cells and examine how exposure to O3 modifies this interaction. Flow cytometry analysis was used to assess immunophenotypes of NK cells cocultured with either air- or O3-exposed NECs. Our data show that coculturing NK cells with O3-exposed NECs decreased intracellular interferon-γ (IFN-γ), enhanced, albeit not statistically significant, IL-4, and increased CD16 expression on NK cells compared with air controls. Additionally, the cytotoxicity potential of NK cells was reduced after coculturing with O3-exposed NECs. To determine whether soluble mediators released by O3-exposed NECs caused this shift, apical and basolateral supernatants of air- and O3-exposed NECs were used to stimulate NK cells. While the conditioned media of O3-exposed NECs alone did not reduce intracellular IFN-γ, O3 enhanced the expression of NK cell ligands ULBP3 and MICA/B on NECs. Blocking ULBP3 and MICA/B reversed the effects of O3-exposed NECs on IFN-γ production in NK cells. Taken together, these data showed that interactions between NECs and NK cells in the context of O3 exposure changes NK cell activity via direct cell-cell interactions and is dependent on ULBP3/MICA/B expressed on NECs.

Publication types

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

MeSH terms

  • Adult
  • Cell Communication*
  • Coculture Techniques
  • Epithelial Cells / drug effects*
  • Epithelial Cells / physiology
  • GPI-Linked Proteins / biosynthesis
  • Histocompatibility Antigens Class I / biosynthesis
  • Humans
  • Intercellular Signaling Peptides and Proteins / biosynthesis*
  • Interferon-gamma / biosynthesis
  • Interleukin-4 / biosynthesis
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Nasal Lavage Fluid / cytology
  • Nasal Mucosa / drug effects*
  • Ozone / toxicity*
  • Receptors, IgG / biosynthesis

Substances

  • GPI-Linked Proteins
  • Histocompatibility Antigens Class I
  • Intercellular Signaling Peptides and Proteins
  • MHC class I-related chain A
  • Receptors, IgG
  • ULBP3 protein, human
  • Interleukin-4
  • Ozone
  • Interferon-gamma