Gene delivery to intestinal epithelial cells in vitro and in vivo with recombinant adeno-associated virus types 1, 2 and 5

Intestinal disorders such as inflammatory bowel disease (IBD) result in chronic illness requiring lifelong therapy. Our aim was to evaluate the efficacy of recombinant adeno-associated virus (AAV) vector-mediated gene delivery to intestinal epithelial cells in vitro and in vivo. Human colon epithelial cell lines and colon biopsies were transduced using AAV pseudotypes 2/1, 2/2, and 2/5 encoding green fluorescence protein (GFP). Mice were administered the same vectors through oral, enema, intraperitoneal (IP) injection and superior mesenteric artery (SMA) injection routes. Tropism and efficiency were determined by microscopy, flow cytometry, immunohistochemistry and PCR. Caco2 cells were more permissive to AAV transduction. Human colon epithelial cells in organ culture were more effectively transduced by AAV2/2. SMA injection provided the most effective means of vector gene transfer to small intestine and colonic epithelial cells in vivo. Transgene detection 80 days post AAV treatment suggests transduction of crypt progenitor cells. This study shows the feasibility of AAV-mediated intestinal gene delivery, applicable for the investigation of IBD pathogenesis and novel therapeutic options, but also revealed the need for further studies to identify more efficient pseudotypes.