Monoclonal antibodies to the E2 protein of a new genotype (type 2) of bovine viral diarrhea virus define three antigenic domains involved in neutralization

Bovine viral diarrhea virus (BVDV) has recently been segregated into two ge notypes, namely, BVDV 1 and BVDV 2. Viruses of the BVDV 2 genotype are a ca use of hemorrhagic and acute fatal disease in cattle in the US and Canada. In this study, monoclonal antibodies (mAbs) to the newly described BVDV 2 w ere produced after immunization with virus or a combination of virus and E2 peptide. From an original panel of 17 mAbs, 13 mAbs were identified as E2- specific by reactivity with a BVDV 2 recombinant E2 protein expressed in in sect cells. Nine E2 mAbs were observed to be virus-neutralizing. The E2 epi topes represented by the mAbs were found to be highly conserved among BVDV 2 isolates associated with hemorrhagic or severe disease in cattle. Except for one virus-neutralizing E2 mAb, the mAbs showed few or relatively weak c ross-reactions with BVDV I. Two non-neutralizing E2 mAbs were BVDV 2-specif ic. In contrast to BVDV I for which conserved neutralizing epitopes have be en mapped in one immunodominant domain, the virus-neutralizing E2 mAbs prod uced to BVDV 2 were found to bind to highly conserved epitopes in three ant igenic domains. Crown Copyright (C) 1998 Published by Elsevier Science B.V. All rights reserved.