Histopathology of brain sections during acute infection with MHV-A59 compared to MHV-2. 5 m thick serial coronal sections from MHV-A59- and MHV-2-infected mice at day 5 post inoculation were stained with H & E (a, b) or immunostained for LCA (c–h) or CD11b (i, j). Histopathology shows acute meningitis characterized by brisk leptomeningeal inflammatory infiltration in the subarachnoid space of the basal forebrain in both MHV-A59- (a, c) and MHV-2-infected (b, d) mice. Coronal sections stained for LCA show acute encephalitis in MHV-A59-infected mouse brain characterized by the presence of inflammatory infiltrates throughout the parenchyma (e) and formation of perivascular cuffing (g) in high magnification whereas in MHV-2 infection infiltrating inflammatory cells were rarely observed in brain parenchyma (f) and, when present, were restricted to the subependyma (h). The majority of LCA+ inflammatory cells stained positive for the macrophage/microglia marker CD11b in MHV-A59-infected brain parenchyma (i) and the few positive cells in MHV-2-infected brain (j) remained restricted to subependyma (arrows). Original magnifications for (a–d) and (h) are 100x, for (g, i, and j) are 200x, and for (e) and (f) are laser-scanned images. (adapted from the work of [94]).
