Activation of lysosomal enzymes in virus-infected cells and its possible relationship to cytopathic effects.

Activities of the enzymes beta-glucuronidase, acid phosphatase, acid DNAase, acid RNAase, and acid protease have been measured in the lysosomal and supernatant fractions of mouse liver cells and monkey kidney cells before and after infection with mouse hepatitis virus and vaccinia virus, respectively. In the infected cells there was easily measurable release of lysosomal enzymes into the supernatant fraction. Evidence was presented that this is not an artefact of homogenization and precedes cell degeneration demonstrable histologically. It is suggested that release of lysosomal enzymes may explain some of the biochemical changes found in infected cells and may contribute to the cytopathic effects of some viruses.