Bluetongue is a ruminant infectious disease that is characterized by hyperpyrexia, leukocyte decrease and mucosal ulcerative inflammation changes. In this study, three segments of Bluetongue virus (BTV)-8 VP2 protein (BTV-8A, 8B, and 8C) were cloned into pET-28a (+) and pMAl-c5X vectors and expressed in Escherichia coli BL21 (DE3) as histidine (His)-tagged (His-8A/8B/8C) and maltose-binding protein (MBP)-tagged (MBP-8A/8B/8C) fusion proteins. After purification, His-8A/8B/8C were used to immunize BALB/mice and MBP-8A/8B/8C were used to screen for monoclonal antibody (mAb)-secreting hybridomas. Two mAbs (8B-5D4 and 8B-3G11) that could recognize BTV-8 were obtained. Two competitive enzyme-linked immunosorbent assays with good specificity and sensitivity using mAbs 8B-5D4 or 8B-3G11 as competitive antibody were established. With the joint reaction of these methods, serum samples containing anti-BTV-7 or anti-BTV-8 antibody could be screened out, suggesting that these methods would be useful for the diagnosis and epidemiological studies of BTV-8.
Keywords: Bluetongue virus; C-ELISA; monoclonal antibody; serotype-specific antigen.