Oxidative stress in vero cells infected with vesicular stomatitis virus.

Viral-induced apoptosis might be mediated by oxidative stress. It has already been described that cell death in vesicular stomatitis virus (VSV)-infected cells occurs by apoptosis. In this study, oxidative stress parameters present in VSV-infected Vero cells were analyzed. Lipid peroxides (LP) were evaluated in cellular extracts and expressed as thiobarbituric acid-reactive substances. LP levels exhibited a rise at different times post infection, according to the multiplicity of infection (MOI), while the presence of cycloheximide determined a reduction on LP. Also, an increase in protein degradation products and a decrease in polyunsaturated fatty acids content was observed, indicating that cellular proteins and lipids began to be susceptible to degradation during VSV infection. In addition, we analyzed cell viability of VSV-infected Vero cells, which were incubated in the presence of butylated hydroxyanisole. This antioxidant was able to protect Vero cells, at least at MOIs assayed in this study, and to reduce viral yield only when VSV infection was done at MOI 0.05. Further, superoxide dismutases, which occupy the first step within the antioxidant enzyme cascade, also exhibit a rise in VSV-infected Vero cells, at different MOI. These results suggest that both an oxidative stress and an antioxidative cell response precede the induction of apoptosis by VSV.