Fig. 2.

17D-204 causes viscerotropic abnormalities in the absence of IFN-γ. H&E sections (a–c) antibody-stained frozen sections (b, d) of spleen (a, b) and liver (c, d) were presented. a Spleen sections from 17D-204-infected animals were indistinguishable at 4 dpi, whereas Angola71-infected animals display loss of white pulp and red pulp architecture and increase in infiltrating macrophages and neutrophils (inset) at 4 dpi. At 11 dpi, 17D-204 infected AGB6 has increased immune infiltration and extramedullary hematopoiesis (inset) but not AB6 mice. b YFV antigen can be detected in the spleen at 4 dpi in both AB6 and AGB6 mice in the red pulp and outer marginal zone area. c 17D-204-infected AB6 mice do not display major histological changes but infected AGB6 mice and Angola71-infected animals had microsteatosis (inset) at 4 dpi. In AGB6 mice, microsteatosis only occurs transiently at 4 dpi and resolved by 11 dpi. Antibody-stained frozen liver sections (d) revealed that YFV antigen could only be detected in infected AGB6 mice at 4 dpi but not AB6 mice, parallel to titer data in Fig. 1g. Original magnification = 40x, n = 4