Recombinant pestivirus E2 glycoproteins prevent viral attachment to permissive and non permissive cells with different efficiency

•The article describes significantly improved isolation of highly purified insect cells expressed recombinant pestiviral E2 glycoprotein.•The biochemical characteristics, antigenic authenticity, state of modification and biological activities of the rE2 protein were described.•In vitro infection of susceptible cells with pestiviruses can be blocked by the presence of recombinant E2 glycoprotein.•The efficiency of this blockage is higher when using E2 proteins derived from the infecting pestivirus species.•The sequence and thus structure of E2 is likely to be involved in the host specificity of different pestiviruses at their point of uptake into cells.

Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen, which like other pestiviruses has similar molecular biological features to hepaciviruses, including human Hepatitis C virus. The pestivirus E2 glycoproteins are the major target for virus-neutralising antibodies, as well as playing a role in receptor binding and host range restriction.In this study, recombinant E2 glycoproteins (rE2) derived from three different pestivirus species were examined for their inhibitory effects on pestivirus infectivity in cell culture. Histidine-tagged rE2 glycoproteins of BVDV type 2 strain 178003, BVDV type 1 strain Oregon C24V and CSFV strain Alfort 187 were produced in Spodoptera frugiperda insect cells and purified under native conditions. The ability of rE2 glycoprotein to inhibit the infection of permissive cells by both homologous and heterologous virus was compared, revealing that the inhibitory effects of rE2 glycoproteins correlated with the predicted similarity of the E2 structures in the recombinant protein and the test virus. This result suggests that the sequence and structure of E2 are likely to be involved in the host specificity of pestiviruses at their point of uptake into cells.