Aerosol and Lobar Administration of a Recombinant Adenovirus to Individuals with Cystic Fibrosis. II. Transfection Efficiency in Airway Epithelium

Abstract

A phase I clinical trial was conducted in which recombinant adenovirus containing the cystic fibrosis trans-membrane regulator (CFTR) (Ad2/CFTR) was administered by bronchoscopic instillation or aerosolization to the lungs of cystic fibrosis (CF) patients. In this paper, we evaluate the efficiency of Ad2/CFTR-mediated transduction of bronchial airway cells. The ability of an Ad2/CFTR vector to transduce airway cells was first evaluated in patients to whom the vector was administered by bronchoscopic instillation. Cells at the administration site were collected 2 days after treatment by bronchoscopic brushing. Ad2-specific CFTR DNA was detected in four of five individuals by PCR, and Ad2-specific CFTR RNA was detected in three of five individuals by RT-PCR. Ad2/CFTR-mediated transduction of airway epithelial cells was then determined in CF individuals receiving this vector by aerosol inhalation. Ad2-specific CFTR DNA was detected in 13 of 13 individuals 2 days after aerosolization, and in 3 of 5 individuals 7 days after aerosolization. Ad2-specific RNA was detected in 4 of 13 individuals on day 2, but was not detected in the 5 individuals tested on day 7. The percentage of airway epithelial cells containing nuclear-localized vector DNA was < or =2.4% as determined by fluorescence in situ hybridization (FISH). However, in some cases, a high percentage of nonepithelial mononuclear cells or squamous metaplastic epithelial cells was infected with the adenoviral vector. In conclusion, aerosol administration is a feasible means to distribute adenoviral vectors throughout the conducting airways, but improvements in adenovirus-mediated transduction of airway epithelial cells are necessary before gene therapy for CF will be effective.

Current Status of Gene Therapy for Inherited Lung Diseases

“…A more recent phase I clinical trial using aerosolized lobar administration of recombinant CFTR adenovirus demonstrated by in situ hybridization that nuclear-localized vector DNA was not readily detected in small samples of epithelial brushings. However, high levels of infection occurred in mononuclear cells and squamous metaplastic epithelial cells (135). In summary, clinical trials to date with recombinant adenoviral-mediated delivery of CFTR have demonstrated low levels of transduction, likely because the apical surface of airway epithelia lacks CAR receptors.…”

A randomised, double-blind, placebo-controlled trial of repeated nebulisation of non-viral cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy in patients with cystic fibrosis

“…NIHR Journals Library www.journalslibrary.nihr.ac.uk low, 41,42 and is associated with lung inflammation 43,44 and the development of neutralising immune responses that, to date, has precluded repeated administration. 45 AAV-based CFTR gene transfer appears less proinflammatory, 46-48 although repeated administration is also inhibited by immunological reactivity.…”

Inhalation of Nebulized Perfluorochemical Enhances Recombinant Adenovirus and Adeno-Associated Virus-Mediated Gene Expression in Lung Epithelium

“…Use of a microsprayer device inserted through a bronchoscope does increase vector distribution through the airways, although this remains an invasive technique (Harvey et al, 1999;Cipolla et al, 2000;Beck et al, 2002). Administration of aerosolized vectors, both viral and nonviral, can result in more effective distribution throughout the lungs (Sené et al, 1995;Brown and Chowdhury, 1997;Gautam et al, 2000;Lerondel et al, 2001;Perricone et al, 2001). However, the efficiency of many aerosolization devices remains low, with a significant portion of the vector deposited in the machinery or upper airways.…”