Adenoviral gene delivery can inactivate Kupffer cells: role of oxidants in NF-kappaB activation and cytokine production.

Kupffer cells play a significant role in the pathogenesis of several liver diseases; therefore, a potential therapeutic strategy would be to inactivate the Kupffer cell with a gene-delivery system. Although recombinant adenovirus provides robust, transgene expression in parenchymal cells, whether adenovirus transduces Kupffer cells is unclear. Thus, the purpose of this study was to evaluate this possibility. In animals infected with adenovirus, Kupffer cells were identified positively to express adenoviral transgenes by immunohistochemical techniques and Western blot analysis, indicating that Kupffer cells are transduced in vivo. Indeed, isolated Kupffer cells were transduced in vitro with recombinant adenovirus in a dose-dependent manner. Moreover, adenoviral transduction of Kupffer cells was blocked by inhibitors of alphaVbeta5 integrin, the co-receptor for adenovirus binding, supporting the hypothesis that adenovirus transduces Kupffer cells via an alphaVbeta5 integrin-dependent mechanism. Indeed, it is shown here that Kupffer cells express alphaVbeta5 integrins. In a functional assay, infection of isolated Kupffer cells with adenovirus containing superoxide dismutase or IkappaB alpha super-repressor blunted LPS-induced nuclear transcription factor kappa B (NF-kappaB) activation and tumor necrosis factor alpha (TNF-alpha) production but not IL-10 production. Moreover, superoxide production was blocked by expression of superoxide dismutase. These data support the hypothesis that LPS-induced NF-kappaB activation and TNF-alpha production in Kupffer cells are oxidant-dependent. These findings suggest that Kupffer cell-targeted approaches may be a potential therapeutic strategy against many inflammatory diseases including early alcohol-induced liver injury.