Enhanced epithelial gene transfer by modulation of tight junctions with sodium caprate

The airway epithelium is resistant to infection by gene transfer vectors wh en infected from the luminal surface. One strategy for enhancing airway epi thelial gene transfer is to modify paracellular permeability, thereby permi tting the diffusion of vectors to the basolateral surface, where uptake rec eptors are expressed. We investigated the ability of a medium-chain fatty a cid known to enhance drug absorption, sodium caprate (C10), to increase air way paracellular permeability in comparison with ethyleneglycol-bis-(P-amin oethyl ether)-N,N'-tetraacetic acid (EGTA), Apical application of C10 decre ased transepithelial resistance by > 90% within minutes, whereas EGTA requi red an hour or more to produce a similar effect. C10 increased mannitol and dextran permeability by sevenfold, as compared with a twofold increase pro duced by EGTA. A greater enhancement of adenoviral lacZ gene transfer was m ediated by C10 (50-fold over controls) than by EGTA (10-fold over controls) . This correlated with a significant enhancement of adenoviral CFTR-mediate d correction of Cl- transport in polarized human airway epithelial (HAE) ce lls from cystic fibrosis (CF) patients. Confocal microscopy revealed a redi stribution of claudin-1 following C10 but not EGTA treatment as a possible mechanism of gene-transfer enhancement by C10, These data suggest that C10 may be a better agent for enhancing gene transfer than is EGTA, and that th is effect occurs through disruption of claudin-1.