Abstract
Three Brazilian isolates of bovine viral diarrhea virus (BVDV), antigenically distinct from the standard North American isolates, were selected to immunize BALB/c mice in order to obtain hybridoma cells secreting anti-BVDV monoclonal antibodies (mAbs). Two hybridoma clones secreting mAbs, reacting specifically with BVDV-infected cells (mAbs 3.1C4 and 6.F11), were selected after five fusions and screening of 1001 hypoxanthine-aminopterin-thymidine-resistant clones. These mAbs reacted in an indirect fluorescent antibody (IFA) assay with all 39 South and North American BVDV field isolates and reference strains available in our laboratory, yet failed to recognize other pestiviruses, namely the hog cholera virus. The mAbs reacted at dilutions up to 1:25,600 (ascitic fluid) and 1:100 (hybridoma culture supernatant) in IFA and immunoperoxidase (IPX) staining of BVDV-infected cells but only mAb 3.1C4 neutralized virus infectivity. Furthermore, both mAbs failed to recognize BVDV proteins by IPX in formalin-fixed paraffin-embedded tissues and following SDS-PAGE and immunoblot analysis of virus-infected cells, suggesting they are probably directed to conformational-type epitopes. The protein specificity of these mAbs was then determined by IFA staining of CV-1 cells transiently expressing each of the BVDV proteins: mAb 3. 1C4 reacted with the structural protein E2/gp53 and mAb 6.F11 reacted with the structural protein E1/gp25. Both mAbs were shown to be of the IgG2a isotype. To our knowledge, these are the first mAbs produced against South American BVDV isolates and will certainly be useful for research and diagnostic purposes.
Highlights
Bovine viral diarrhea virus (BVDV) is a small enveloped virus ubiquitous among cattle populations
The fusion experiments that yielded hybridoma cells secreting anti-BVDV monoclonal antibodies (mAbs) were performed using virus antigens from cells infected with the isolate UFSM-1 [12]
Only two hybridoma clones (3.1C4 and 6.F11) were stabilized and found to secrete specific mAbs against BVDV proteins; several other hybridoma clones secreted mAbs that were reactive to cellular components
Summary
Bovine viral diarrhea virus (BVDV) is a small enveloped virus ubiquitous among cattle populations. Direct translation of the viral RNA genome yields a long polyprotein that is co- and post-translationally cleaved by cellular and virus-encoded proteases, giving rise to structural and non-structural viral proteins [1,2]. Because of unique features of the viral genome, the NS23/p125 protein may be occasionally cleaved originating two additional products, NS2/p54 and NS3/p80 [2,3]. According to the nucleotide sequence of the 5' untranslated region of the viral genome, BVDV isolates might be classified as genotype 1 and 2. Both cytopathic and non-cytopathic biotypes are found within each genotype [5,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
