FIG. 4.

(A) C2BBe cell uptake of Y. enterocolitica (blue) and S. aureus (green), colocalized with claudin-4 (red/yellow). (B) Airway epithelial cells (NCI-H292) coincubated with equivalent numbers of S. aureus and Y. enterocolitica particles. Cytokine treatment increased the numbers of cells that took up Yersinia only, or Yersinia and Staphylococcus, but not Staphylococcus only. There were few or no airway cells which took up Yersinia only; TNF/LT treatment enhanced the tendency of cells to ingest Staphylococcus and Yersinia together. The data shown are representative of seven (immunofluorescence) and three (flow cytometry) independent experiments.