LSC Abstract – Cellular crosstalk between airway epithelial and endothelial cells during viral infections

Abstract

Introduction: Respiratory viruses infect the airway epithelial barrier and cause inflammation. This process involves cellular crosstalk between different cell types. By using a dynamic 3D co-culture model of airway epithelial cells (AECs) and endothelial cells we aimed to analyse the cellular crosstalk regulating airway inflammation during viral infections. Methods: Human AECs were cultured on the apical side of permeable filter supports while endothelial cells were cultured on the basolateral side facing the microfluidic flow. The 3D model was challenged apically with double stranded RNA (Poly(I:C)), a mimic of viral infections. Basal supernatants were collected in 2h intervals and mediator secretion determined by ELISA. Results: In contrast to static cultures, the microfluidic systemallowed analysis of airway barrier responses time-dependently at shorter intervals and with greater sensitivity. Poly(I:C) induced release of TNF-α by epithelial cells with a peak 4h after stimulation; this was followed temporally by release of fractalkine (CX3 CL1), a chemokine regulating immune cell migration, from the endothelial cells. Release of fractalkine could be prevented by neutralisation of TNF-α. Conclusion: Using adynamic 3D model offers the potential to investigate mechanisms of airway inflammation and cellular crosstalk under conditions closer to the in vivo situation. During viral infections, endothelial-derived CX3 CL1 release is triggered by epithelial derived TNF-α. This cellular crosstalk might play an important role in the regulation of immune cell infiltration.