Establishment and Application of a Model of Well-differentiated Porcine Airway Epithelial Cells in Vitro / 病毒学报

ABSTRACT

Pigs are increasingly recognized as "natural" hosts of infection by human respiratory viruses because of their similarities to humans in terms of lung physiology, airway morphology, cell types, and distribution of cell receptors in the respiratory tract. We wished to explore the mechanisms of infection by respiratory viruses and screening of drug that could be used to treat respiratory-system diseases. Hence, we developed a model of well-differentiated porcine airway epithelial cells (PAECs) derived from pig-lung tissue and cultured them with serum-free medium under an air-liquid interface condition in vitro. We identified the PAEC model using scanning electron microscopy, electrophysiology, and immunohistology. To evaluate application of gene therapy of adeno-associated virus (AAV)6 on the PAEC model, we generated recombinant adeno-associated virus 6-green fluorescent protein (rAAV6-GFP) using the three-plasmid transfection method and infected PAECs from the apical surface with rAAV6-GFP. Results demonstrated that the PAEC model comprised a multilayer epithelial structure containing ciliated mucous secretory cells, with basal cells located directly beneath the multilayer. rAAV6-GFP could infect PAECs from the apical surface and efficiently transduce PAECs to mediate the long-term expression of the exogenous gene. Establishment of a model of well-differentiated PAECs in vitro could lay a solid foundation for the study of infection by respiratory pathogens, as well as the screening and gene therapy of agents used to treat diseases of the respiratory system.