Molecular characterization of adenoviral vector expressing human BPI. (A) Verification of the BPI transgene in AdhBPI viral genomic DNA. 293 cells were infected with AdhBPI or AdDl70.3 as control. Total cellular DNA was extracted and subject to Southern hybridization. (B) BPI mRNA expression in vitro and in vivo. 293 cells or mouse hind leg muscle were infected with AdhBPI in vitro and in vivo, respectively. Total cellular or tissue RNA was extracted and subject to Northern hybridization. BPI mRNA was identified as a 1623-bp product. Samples from control vector–infected cells or tissue gave rise to no signals (not shown). (C) Demonstration of secreted and cell-associated BPI protein in A549 cells infected with AdhBPI (lane 1), control vector AdDl70.3 (lane 2), or without infection (lane 3). S³⁵-labeled newly synthesized protein was separated in SDS-PAGE gel and BPI protein was identified as a 60-kDa product.