Production of labile Newcastle disease virus progeny after infection of chicken embryo cells in the presence of caffeine.

A study was undertaken to examine the effects of caffeine on Newcastle disease virus (NDV) infection of chicken embryo cells. Addition of 10 mM caffeine to the growth medium produced 95% reduction in progeny synthesis, 63% reduction in RNA synthesis, 45% reduction in protein synthesis, and 25% reduction in hemadsorption ability in NDV-infected cultures when compared with untreated, infected cultures. Purified NDV obtained from caffeine-treated, infected cultures was more sensitive to ultraviolet irradiation and to damage by freezing and thawing than was observed in untreated virus cultures. The SDS-polyacrylamide gel electrophoresis revealed that purified virions contained the same complement of polypeptides, but there was a significant variation in the quantities of several of the NDV polypeptides.