Biliary atresia (BA) is a disease of the newborn which results in obstruction of the biliary tree. The cause of BA remains unknown; however, recent studies using the murine model of biliary atresia have found that rotavirus infection of the biliary epithelial cell (cholangiocyte) triggers an inflammatory response. We hypothesized that rotavirus infection of cholangiocytes results in the release of chemokines, important mediators of the host immune response.
In vivo, Balb/c pups were injected with rhesus rotavirus (RRV) or saline, and, their extrahepatic bile ducts were microdissected 2,5, 7, and 14 days after injection. Next, an immortalized cholangiocyte cell line (mCl) was incubated with RRV or serum free media. Qualitative and quantitative chemokine assement was performed using ELISA, PCR, and immunohistchemistry.
In vivo, increased levels of the chemokines MIP-2, MCP-1, KC and RANTES were found in RRV-infected murine bile ducts. In vitro, infected mCl cells produced increasing amounts of these same chemokines in relation to dose and time.
These novel results suggest that chemokine expression by RRV-infected cholangiocytes may trigger a host inflammatory process that causes bile duct obstruction. Understanding how viral infection initiates this response may shed light on the pathogenesis of biliary atresia.