Efficient adenovirus-mediated gene transfer to gastric tissue by oral administration

Recombinant adenoviruses (rAd) are well-characterized viral vectors and have been studied in many human diseases. However, there are no detailed methods for transferring genes to the stomach using rAd.

Gastric epithelial cells were infected with rAd encoding green fluorescence protein (AdGFP) for different times, or with AdGFP that had been incubated in artificial gastric juice at different pH values for 1 h. Gene expression was detected by fluorescence microscope and flow cytometry. Mice were infected via oral administration with rAd encoding red fluorescence protein and beta-galactosidase (AdRFP-lacZ) or rAd encoding mouse interleukin-17 (AdmIL-17), and tissues were collected at the indicated times after infection. LacZ expression in different tissues was detected by X-gal staining and IL-17 expression in the stomach was assessed by the real-time polymerase chain reaction and an enzyme-linked immunosorbent assay. Inflammation in the stomach was also assessed.

rAd could infect the gastric epithelial cells and tolerate pH 5 for 1 h in vitro. Adenovirus-mediated genes were specifically expressed in the gastrointestinal tract and transgene expression persisted in gastric tissue for up to 7 days after oral administration of AdRFP-lacZ. Oral administration of AdmIL-17 induced mIL-17 expression in gastric tissue at the mRNA and protein levels and protein level peaked on day 5 post-infection. IL-6, a target protein of IL-17, and gastric inflammation also increased in AdmIL-17-infected mice.

The present study has established a detailed method for transferring adenovirus-mediated gene to the stomach, which may provide a valuable approach for gene therapy or the study of the basic biology of gastric diseases.