Infection of ovine fetal brain cell cultures with cytopathogenic and non-cytopathogenic bovine viral diarrhoea virus.

The in vitro cell tropism of non-cytopathogenic (ncp) and cytopathogenic (cp) bovine viral diarrhoea virus (BVDV) was studied in primary dissociated brain cell cultures derived from ovine fetuses of different gestational ages. The cell types infected were identified by double immunofluorescence using antibodies against BVDV and cell type-specific markers. In cultures infected with ncp BVDV viral antigen was present in neurofilament (NF 200 kDa)-positive neurons, glial fibrillary acidic protein (GFAP)-positive astrocytes and fibronectin-expressing cells. Estimation of the percentages of individual cell types infected with ncp BVDV indicated a tropism for NF 200-positive neurons. In cultures infected with cp BVD virus cytopathic changes were observed beginning at 40 hours post infection. Viral antigen was present in vacuolated NF 200-, GFAP- and fibronectin-positive cells. In comparison with non-infected control cultures a considerable reduction of the number of the different cell types was seen.