First Animal Model Developed for Oral Infection of Human Poliovirus

Poliovirus causes acute disease in the central nervous system in humans often resulting in paralysis. Due to its reemerging presence in developing countries researchers are reexamining the viruses' ability to spread among humans through oral ingestion and develop new preventative therapies accordingly.

Due to the human digestive tracts' low sensitivity to the poliovirus, no previous rodent model tracking oral infection has been developed. In the study mice carrying the human poliovirus receptor gene and lacking the interferon receptor gene (IFNAR) were sensitive to an oral challenge of the poliovirus. Nine days following the challenge the mice had died and the virus was detected in their small intestines and digestive tracts. Mice expressing the interferon receptor gene were found to be much less sensitive to virus.

"These results suggest that IFNAR plays an important role in determining permissivity in the alimentary tract as well as the generation of virus-specific immune responses to poliovirus via the oral route," say the researchers. "Thus, hPVR-Tg/IfnarKO are considered to be the first oral infection model for poliovirus."

These findings are reported in the August 2007 issue of the Journal of Virology.

Reference: S. Ohka, H. Igarashi, N. Nagata, M. Sakai, S. Koike, T. Nochi, H. Kiyono, A. Nomoto. 2007. Establishment of a poliovirus oral infection system in human poliovirus receptor-expressing transgenic mice that are deficient in alpha/beta interferon receptor. Journal of Virology, 81. 15: 7902-7912.