Evidence of a humoral immune response against the prokaryotic expressed N-terminal autoprotease (N(pro)) protein of bovine viral diarrhoea virus.
Bovine viral diarrhoea virus (BVDV) is an economically important pathogen of cattle and sheep belonging to the genus Pestivirus of the family Flaviviridae. Although the BVDV non-structural N-terminal protease (N(pro)) acts as an interferon antagonist and subverts the host innate immunity, little is known about its immunogenicity. Hence, we expressed a recombinant BVDV N(pro)-His fusion protein (28 kDa) in E. coli and determined the humoral immune response generated by it in rabbits. The antigenicity of the N(pro) protein was confirmed by western blot using anti-BVDV hyperimmune cattle, sheep and goat serum, and anti-N(pro) rabbit serum. When rabbits were immunized with the N(pro) protein, a humoral immune response was evident by 4 weeks and persisted till 10 weeks post immunization as detected by ELISA and western blot. Despite N(pro)-specific antibodies remaining undetectable in 80 serum samples from BVDV-infected sheep and goats, BVDV hyperimmune sera along with some of the field cattle, sheep and goat sera with high BVDV neutralizing antibody titres were found positive for N(pro) antibodies. Our results provide evidence that despite the low immunogenicity of the BVDV N(pro) protein, a humoral immune response is induced in cattle, sheep and goats only with repeated BVDV exposure.
Mishra
Niranjan
N
High Security Animal Disease Laboratory, Indian Veterinary Research Institute, Anand Nagar, Bhopal 462 021, India. mishranir@rediffmail.com
Rajukumar
Katherukamem
K
Pitale
Shruti Shrikant
SS
Prakash
Anil
A
Nema
Ram Kumar
RK
Behera
Sthita Pragnya
SP
Dubey
Shiv Chandra
SC
D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000276:immunology* / Q000821:virology*; D002417:Cattle; D001908:Diarrhea Viruses, Bovine Viral / Q000201:enzymology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004926:Escherichia coli / Q000378:metabolism; D006041:Goats; D007107:Immune System; D056724:Immunity, Humoral; D008297:Male; D008954:Models, Biological; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000276:immunology; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry
D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D010447:Peptide Hydrolases