Mycophenolic acid inhibits avian reovirus replication.

Avian reoviruses (ARV) are economically important pathogens, especially in the poultry industry, where they cause viral arthritis and tenosynovitis. Mycophenolic acid (MPA) is an inhibitor of inosine monophosphate dehydrogenase (mainly used clinically for immunosuppression) that inhibits the replication of several viruses. We demonstrate in this study that MPA also is capable of inhibiting ARV replication in QM5 quail fibrosarcoma cells. The selectivity index of MPA in QM5 cells was determined as approximately 41. Concentrations of > or =3 microg/ml MPA inhibited infectious ARV progeny production in QM5 cells by more than 100-fold. Inhibition of ARV replication also was seen in other cell lines, including HD-11 and Vero. Addition of exogenous guanosine to MPA-treated ARV-infected QM5 cells restored viral replicative capacity to nearly normal levels.