Description
Recent studies showing involvement of iNKT cells in lung viral infections and airway inflammation suggest that these cells are key players in both prevention and generation of immune-pathology in the lungs. It is not fully understood how iNKT cells are activated in the lungs and if this relied solely on lung dendritic cells. We recently showed that CD1d is expressed on airway epithelium, and now demonstrate that iNKT cells can be activated by primary airway epithelial cells, via both CD1d dependent and independent processes. Transcriptional analysis of human iNKT cells reveals that direct contact with lipid-pulsed primary human airway epithelial cells results in initiation of a programme of activation comprising rapid and concomitant induction of cytokine genes and genes to switch off this response. These findings establish a new mode of activation within the lungs for iNKT cells, and further enhance the role of airway epithelium in innate lung immunity.