Mechanism of restriction of normal and CFTR-deficient human tracheal gland cells to Adenovirus (Ad) infection and Ad-mediated gene transfer.
Résumé
CF-KM4 (cystic fibrosis transmebrane conductance regulator-deficient) and MM-39 (healthy) cells, two serous cell lines from submucosal tracheal glands, were found to be poorly susceptible to adenovirus (Ad)5 infection and Ad5-mediated gene transduction. The major limiting steps apparently resided in the primary events of Ad5 interaction, i.e., cell attachment and entry. Both CF-KM4 and MM-39 cells failed to express the Coxsackie-Ad receptor (CAR), and experimental data suggested that alpha[2-->6]-linked sialic acid residues of sialoglycoproteins (SAGP) in CF-KM4 cells, and heparan sulfate glycosaminoglycans (HS-GAG) in MM-39, were used as receptors by Ad5 virions. Ad5 attached to SAGP and HS-GAG receptors via its fiber knob domain, but entered the cells via a penton base- and Arg-Gly-Asp (RGD)-integrin-independent pathway. The block to Ad5-mediated gene transfer in MM-39 and KM4 cells could be overcome by conferring to the vector a novel cell-binding specificity. Thus, Ad5 vectors carrying a stretch of 7-lysine residues genetically inserted at the C-terminus of the fiber knob were found to transduce MM-39 cells with a 10- to 20-fold higher efficiency than the original vectors, but the transduction of CF-KM4 was not significantly improved. Retargeting Ad5 to integrin receptors via RGD peptide ligands, inserted at the extremity of the fiber shaft, resulted in a transducing efficiency of 20- and 50-fold higher in MM-39 and KM4 cells, respectively, compared with Ad5 vectors carrying fibers terminated by their natural knob domain.
Mots clés
Adenoviridae/*genetics/metabolism
Adenoviridae Infections/genetics
Bronchi/cytology/virology
Carbohydrate Conformation
Cell Adhesion/genetics
Cells
Cultured
Cystic Fibrosis/genetics/pathology
Cystic Fibrosis Transmembrane Conductance Regulator/*genetics
Endocytosis
Gene Transfer Techniques
Heparan Sulfate Proteoglycan/metabolism
Humans
Microscopy
Electron
Oligopeptides/metabolism
Receptors
Cell Surface/metabolism
Virus/genetics/metabolism
Research Support
Non-U.S. Gov't
Sialoglycoproteins/chemistry/metabolism
Trachea/*pathology/physiopathology/virology
Virion/metabolism