Replication of Venezuelan Equine Encephalomyelitis Virus in Vitro: I. Growth in Suspension Cell Cultures Grown in Serum-Free and Defined Media

Various mammalian cells propagated in serum-free and chemically defined media yielded high titers of Venezuelan equine encephalomyelitis (VEE) virus. Some difference in maximal titers was noted, depending upon the medium employed. Of the two serum-free media tested, lactalbumin hydrolysate medium was more effective than the chemically defined medium in stimulating viral growth. The addition of serum to serum-free cultures at the time of viral inoculation had a pronounced effect characterized first by a delay and then by a burst of viral replication to very high titers. Thus, the levels of Vee virus replication appear to be influenced by a variety of nutritional factors whose mechanisms of action have yet to be elucidated.