Inhibition of recombinant adeno-associated virus (rAAV) transduction by bronchial secretions from cystic fibrosis patients

Abstract

The conducting airways are the primary target for gene transfer in cystic fibrosis (CF), yet the inflammation associated with CF lung disease could potentially pose a significant barrier to gene transfer vectors, such as recombinant adeno-associated virus (rAAV). In order to investigate this possibility, aliquots of bronchoalveolar lavage (BAL) fluid from eight individuals with CF were tested for their in vitro inhibitory effects on rAAV transduction, along with BAL from non-CF individuals. While the non-CF BAL fluid was not inhibitory, seven of eight CF BAL samples had significant inhibitory activity, resulting in a five- to 20-fold reduction in transduction events. Inhibition of rAAV transduction by CF BAL could be reversed by alpha-1-antitrypsin (AAT), but not by DNase. When neutrophil elastase and neutrophil alpha defensins (human neutrophil peptides, HNP) were measured in these samples, they were elevated by 500- and 10,000-fold, respectively. The levels of HNP correlated inversely with the amount of rAAV transduction. Furthermore, rAAV transduction could be blocked by purified HNP in an AAT-reversible manner at HNP concentrations within the range measured in these fluids. We conclude that products of inflammation in CF BAL fluid are inhibitory to rAAV transduction, and that these effects may be reversible by AAT.

Long noncoding RNA are aberrantly expressed in vivo in the cystic fibrosis bronchial epithelium

“…Differences between studies may be partly explained by different experimental procedures employed. These differences include genotype of the cells used, statistical or normalisation approaches and tissue type; such as bronchial and nasal brushings (Ogilvie et al, 2011, Wright et al, 2006, Clarke et al, 2013, isogenic bronchial cells (Virella-Lowell et al, 2000), primary tracheal and bronchial cell cultures (Zabner et al, 2005) and foetal tracheal cells (Verhaeghe et al, 2007). It remains to be determined what direct contribution mutant CFTR makes to an altered CF transcriptome, and it is highly likely that other factors such as infection and inflammation are major contributors to this altered expression of both lncRNAs and protein coding transcripts.…”

Adeno-associated virus serotype 9-mediated pulmonary transgene expression: effect of mouse strain, animal gender and lung inflammation

“…Bronchoalveolar lavage from cystic fibrosis patients has been shown to inhibit transduction by rAAV2 vectors. 23 Therefore, it becomes imperative to test the efficiency of rAAV2/9 vectors in an inflamed lung before it can be proposed to be used in a therapeutic setting. To achieve this end, we have performed AAV2/9-mediated gene delivery experiments in conditional SPB À/À mice.…”

Gene Therapy Progress and Prospects: Recombinant adeno-associated virus (rAAV) vectors

“…The first potential obstacle is efficient delivery and distribution to the appropriate cell surface. For some cells, such as the airway epithelial cells lining the airways of CF patients with pre-existing lung disease, a complex mixture of cellular and bacterial products is present within the airway lumen potentially providing an important extracellular barrier to gene transfer, 41 although the significance of this effect has recently been called into question. 42 Another important potential extracellular blockade to cellular attachment could be posed by the presence of extracellular neutralizing anti-capsid antibodies.…”