Histology and mCMV distribution in NB+6 and NB+12 control, mCMV-infected, GEF-treated, mCMV-infected, and U0126-treated, mCMV-infected SMGs. A-H. NB + 6 SMGs. I-P. NB + 12 SMGs. Control SMGs (A, E) exhibit normal ductal and pro-acinar epithelia and fibromyxoid stroma containing loosely-packed stellate to ovoid fibroblasts; note the absence of β-galactosidase staining (E, M). mCMV-infected NB + 6 SMGs (B, F) exhibit stromal viral CPE in stroma, decreased epithelia with dilated lumina, and β-galactosidase-stained virus in peripheral stromal. In GEF-treated, mCMV-infected NB + 6 SMGs (C, G), an improved phenotype consists of a fibromyxoid stroma, and decreased β-galactosidase-stained virus. However, reduced epithelial branching and occasional viral CPE (double black arrowheads) persists. In U0126-treated, mCMV-infected NB + 6 SMGs (D, H), the greatly improved phenotype approximates controls; these SMGs exhibit regularly branched epithelia, sparse fibromyxoid stroma, and no ductal dilation or viral CPE; little β-galactosidase- is seen (H). I-P. NB + 12 SMGs. mCMV-infected NB + 12 SMGs (J, N) are characterized by poorly-differentiated and dysplastic epithelia (arrows), abnormal stroma composed of sheets of small eosinophilic and larger basophilic, pleiomorphic cells, some exhibiting pathognomonic kidney-shaped nuclei (arrowheads). And densely-packedβ-galactosidase-stained virus throughout abnormal stroma and epithelia. GEF-treated, mCMV-infected SMGs (K, O) lost the improved phenotype seen on day 6 (compare K to C); they exhibit epithelial dysplasia, viral CPE in the stroma, pathognomonic kidney-shaped nuclei (black arrowheads), and β-galactosidase staining throughout abnormal stroma and sparsely in epithelia. U0126-treated, mCMV-infected SMGs (L, P) lost the improved phenotype seen on day 6, with overt evidence of epithelial dysplasia, viral CPE, pathognomonic kidney-shaped nuclei (black arrowheads), and β-galactosidase-staining throughout abnormal stroma and sparsely in epithelia. Reduced β-galactosidase staining is seen in GEF- and U0126-treated SMGs compared to untreated SMGs (compare O, P to N). Bar: A-D, I-L - 50 μm; E-H, M-P- 40 μm.