FIG 4.

Histological analysis and immunohistochemistry of organs from ECTV-infected C57BL/6 mice at day 7 postinfection. Lungs, livers, and spleens were removed, and sections of the organs were routinely stained with hematoxylin and eosin (HE). Bars, 50 μm (A, C, and F) and 100 μm (B, D, and E). (A to C) Micrographs of representative tissues from a mock-vaccinated (PBS) mouse. (A) Lung with necrosis of bronchiolar epithelial cells (arrowhead); (B) liver with hepatocyte necrosis (arrowheads); (C) spleen with areas of red and white pulp necrosis. (D to F) Sections of tissues were immunostained (IHC) with polyclonal rabbit antibody raised against VACV Lister virions to detect ECTV antigen. Micrographs show representative areas of lung (D), liver (E), and spleen (F) from a mock-vaccinated C57BL/6 mouse.