TNF alpha receptor signaling and IL-10 gene therapy regulate the innate and humoral immune responses to recombinant adenovirus in the lung

Recombinant adenovirus-mediated gene therapy has demonstrated great promise for the delivery of genes to the pulmonary epithelium. However, dose-depen dent inflammation and local immune responses abbreviate transgene expressio n. The purpose of these studies was to determine the role of TNF-alpha and individual TNF receptor signaling to adenovirus clearance and immune respon ses, and whether coexpression of human IL-10 could reduce inflammation and extend the duration of transgene expression in the lung. beta-Galactosidase expression in mice receiving intratracheal instillation of Adv/beta-gal (a denovirus construct expressing beta-galactosidase) was transient (less than 14 days), but a significant early increase of beta-galactosidase expressio n was seen in mice lacking either or both TNF-alpha receptors, Absence of T NF-alpha or the p55 receptor significantly attenuated the iib response to b oth adenovirus and beta-galactosidase, Human IL-10 expression in the lung s uppressed local TNF-alpha production following AdV/hIL-10 (adenovirus const ruct expressing human IL-10) delivery, but did not lead to increased or pro longed transgene expression when coexpressed with beta-galactosidase. Expre ssion of human IL-10 following AdV/hIL-10 instillation extended at least 14 days, was nonimmunogenic, and suppressed the development of neutralizing A bs against adenoviral proteins as well as against human IL-10, We conclude that TNF-alpha signaling through both the p55 and p75 receptor plays import ant roles in the clearance of adenoviral vectors and the magnitude of the h umoral immune response. Additionally, although coexpression of human IL-10 with beta-galactosidase had only modest effects on transgene expression, we demonstrate that AdV/hIL-10 is wed tolerated, has extended expression comp ared with beta-galactosidase, and is nonimmunogenic in the lung.