Effects of intravesical liposome-mediated human beta-defensin-2 gene transfection in a mouse urinary tract infection model

The purpose of this study was to assess human β-defensin-2 (hBD-2) gene transfection in human bladder epithelial cells and its therapeutic efficacy in a rat urinary tract infection (UTI) model via liposome mediated gene transfer. A large amount of hBD2 production (36.5 ± 3.2 ng/10(6) cells) was demonstrated in transfected cells' supernatants. In addition, a detectable amount of hBD-2 was identified in rats' urine (4.77 ± 1.4 ng/mL) by ELISA. Expression of the transgene hBD-2 in transfected cells and rats' bladders was also confirmed by RT-PCR and Western blotting. Immunohistochemistry revealed that the transgene hBD-2 expressed in the entire epithelial layer of the transduced bladders. Numbers of bacterial colony-forming units in urine and bladders from hBD2 gene treated UTI rats were significantly lower than those from the UTI rats administered PBS at 24, 36, and 72 hr after infection (P < 0.05). In addition, in vivo expression of hBD-2 reduced mucosal damage, interstitial edema and inflammatory cell infiltration in UTI animals. The results indicate that successful inhibition of UTI progression can be produced by hBD2 gene therapy. The liposome-mediated hBD2 plasmid DNA transfection system appears to be a promising method for antimicrobial gene therapy of UTI.