Immunophenotyping of immune cells, detection of virus protein and distribution of immune cells and virus protein in the brain of SBV-infected ruminants (n = 15).

<p><b>A)</b> Detection of CD3-positive T cells in the perivascular space and adjacent tissue of a goat kid (animal no 1; asterisks = vessel lumen; bar, 20 µm). <b>B)</b> CD79α-positive B cells are located diffusely in the brain parenchyma and around vessels (asterisks) in a sheep lamb (animal no 11; bar, 20µm). <b>C)</b> SBV-infection caused in some animals pore-associated Gitter cell infiltration. These cells showed prominent CD68-expression (sheep lamb no 4; bar, 20 µm). <b>D)</b> SBV protein was diffusely distributed in the cytoplasm and processes of neurons (goat kid, animal no 1; bar, 20 µm). <b>E)</b> Distribution and percentage of affected brain regions using immunophenotyping of inflammatory cells with special emphasis upon T cells (CD3), B cells (CD79α) and microglia/macrophages (CD68) as well as SBV antigen distribution. Individual numbers within depicted cell types indicate the percentages of animals displaying the specific cell types in the respective brain regions. <b>A–E)</b> Visualization: ABC-method (VECTASTAIN® Elite ABC Kit, Vector Laboratories) with 3, 3′-diaminobezidine-tetrahydrochloride (DAB) as chromogen. <b>F)</b> Occurrence of SBV-antigen in the CNS of 82 naturally infected neonatal ruminants with (n = 15, 14 positive animals, 93.3%) and without inflammation (n = 67, 22 positive animmals, 32.8%). Percentages of animals showing virus protein in the hippocampus (Hippo), mesencephalon (Mes), temporal lobe (Temporal) and parietal lobe (Parietal) are displayed. Absolute numbers of affected animals are given on top of the bar. Note, that one animal may exhibit more than one SBV antigen positive region in the CNS.</p>