Growth of Virulent and Attenuated Ectromelia Virus in Cultured Macrophages from Normal and Ectromelia-Immune Mice

Abstract

Growth of ectromelia virus in cultured mouse peritoneal macrophages is described. Macrophages in vitro are more susceptible to infection by a virulent than by an attenuated strain of ectromelia virus. Macrophages from susceptible and resistant strains of mouse are equally susceptible to infection in vitro with virulent ectromelia virus. Macrophages from immune mice are more readily infected than are normal macrophages. This effect is attributed to the greater phagocytic activity of the macrophages from immune mice. Even in the presence of immune serum, macrophages from immune mice are more readily infected than are macrophages from normal mice.