Respiratory syncytial virus infection of human airway epithelial cells is polarized, specific to ciliated cells, and without obvious cytopathology.
Gene therapy for cystic fibrosis (CF) lung disease requires efficient gene transfer to airway epithelial cells after intralumenal delivery. Most gene transfer vectors so far tested have not provided the efficiency required. Although human respiratory syncytial virus (RSV), a common respiratory virus, is known to infect the respiratory epithelium, the mechanism of infection and the epithelial cell type targeted by RSV have not been determined. We have utilized human primary airway epithelial cell cultures that generate a well-differentiated pseudostratified mucociliary epithelium to investigate whether RSV infects airway epithelium via the lumenal (apical) surface. A recombinant RSV expressing green fluorescent protein (rgRSV) infected epithelial cell cultures with high gene transfer efficiency when applied to the apical surface but not after basolateral inoculation. Analyses of the cell types infected by RSV revealed that lumenal columnar cells, specifically ciliated epithelial cells, were targeted by RSV and that cultures became susceptible to infection as they differentiated into a ciliated phenotype. In addition to infection of ciliated cells via the apical membrane, RSV was shed exclusively from the apical surface and spread to neighboring ciliated cells by the motion of the cilial beat. Gross histological examination of cultures infected with RSV revealed no evidence of obvious cytopathology, suggesting that RSV infection in the absence of an immune response can be tolerated for >3 months. Therefore, rgRSV efficiently transduced the airway epithelium via the lumenal surface and specifically targeted ciliated airway epithelial cells. Since rgRSV appears to breach the lumenal barriers encountered by other gene transfer vectors in the airway, this virus may be a good candidate for the development of a gene transfer vector for CF lung disease.
Zhang
Liqun
L
Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina, Chapel Hill, North Carolina 27599-7248, USA. liqun_zhang@med.unc.edu
Peeples
Mark E
ME
Boucher
Richard C
RC
Collins
Peter L
PL
Pickles
Raymond J
RJ
D000914:Antibodies, Viral / Q000276:immunology; D000998:Antiviral Agents / Q000494:pharmacology; D016764:Cell Polarity; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology / Q000821:virology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins; D009500:Neutralization Tests; D020545:Respiratory Mucosa / Q000166:cytology; D018113:Respiratory Syncytial Virus, Human / Q000502:physiology*; D012254:Ribavirin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000914:Antibodies, Viral; D000998:Antiviral Agents; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D012254:Ribavirin