Histopathology of vital organs of euthanized baboons following LD of heat-inactivated S aureus challenge with or without 3G3 pretreatment. Lung (A), liver (B), kidney (C), and spleen (D) were collected at the time of necropsy, embedded in paraffin, and stained with hematoxylin and eosin. Images were acquired on an upright Nikon Eclipse E800M microscope equipped with an Omax high-speed digital camera using the Omax ToupView software. For each organ and experimental condition, representative images showing both low and high magnification insets are shown. Scale bars, 100 µm. av, lung alveoli; F, spleen follicle; G, kidney glomeruli; S, liver sinusoidal capillaries; T, renal tubuli. Black arrows, neutrophils infiltration in the subsinusoidal space; green arrows, tubular necrosis; red arrows, lymphoid apoptosis. *Intravascular leukocyte aggregation.