Construction of capsid-modified recombinant bovine adenovirus type 3

Adenoviruses have become a popular vehicle for gene transfer into animal and human cells. However, wide prevalence of preexisting immunity to human adenovirus (HAdV) and the promiscuous nature of the virus have made the use of nonhuman adenoviruses an attractive alternative. Moreover, readministration of viral vectors is often required to maintain therapeutic levels of transgene expression, resulting in vector-specific immune responses. Although a number of features of bovine adenovirus (BAdV)-3 make it attractive for use as a vector in human vaccination, BAdV-3 transduces nonbovine cells, including human cells, poorly. However, genetic modification of capsid proteins (e.g., fiber, pIX) has helped in increasing the utility of BAdV-3 as a vector for transducing nonbovine cells. Here, we will describe the methods used to construct recombinant BAdV-3 expressing chimeric fiber or chimeric pIX proteins.