Germinal centre localization of bovine viral diarrhoea virus in persistently infected animals

Immunohistochemical analysis of peripheral lymph nodes from gnotobiotic cal ves persistently infected with bovine viral diarrhoea virus (BVDV) revealed extensive deposition of E-rns and localization of the viral genome in the light zone of germinal centres. Viral antigen co-localized with immunoglobu lin in the germinal centres and was shown to be extracellular. Despite the presence of viral antigen in germinal centres, circulating anti-BVDV antibo dy was not detected. These findings provide evidence that calves persistent ly infected with BVDV, in the absence of adventitious infection, can genera te a B cell response to the persisting virus. The nature of the tolerance i n calves persistently infected with BVDV is discussed in light of these fin dings.