High-level expression of hepatitis C virus (HCV) structural proteins by a chimeric HCV/BVDV genome propagated as a BVDV pseudotype

A chimeric cDNA genome was constructed in which the core, E1 and E2 genes o f hepatitis C virus (HCV) replaced the core, E-rns, E1 and E2 genes of bovi ne viral diarrhea virus (BVDV). High levels of HCV structural proteins were expressed in a small number of human or bovine cells following transfectio n with chimeric RNA. However, in one cell line, bovine embryonic trachea ce lls [EBTr(A)], the number of cells expressing HCV proteins increased to gre ater than 70% following serial passage of culture medium. These cells were persistently infected with a non-cyto pathogenic BVDV helper virus. In thes e cells, the chimeric genome was packaged into infectious particles that ac cumulated in the culture medium at a titer as high as 10(7)-10(9) genome eq uivalents per mi. The virus particles were pseudotypes, because they were n eutralized by anti-BVDV but not by anti-HCV. (C) 2001 Elsevier Science B.V. All rights reserved.