Effect of Active and Inactive Vaccinia Virus Preparations on Human Amnion Cell Cultures

Cultures of trypsinized human amnion cells react in a morphologically different manner to the inoculation of active and inactive irradiated preparations of vaccinia virus. The most characteristic changes which accompany virus multiplication are rounding of the cells and degenerative changes in both cytoplasm and nucleus. In pronounced contrast inactive virus preparations lead to an extreme lengthening and thinning of the cytoplasm of the cell whereas the nucleus remains intact. In the latter ease the previously homogenous cell sheet is finally transformed into a netlike structure. As reported previously for mouse macrophage cultures, the inactive virus particles themselves seem to be responsible for these changes which are believed to be the result of a toxic viral effect.