Characterization of the highly immunogenic VP2 protrusion domain as a diagnostic antigen for members of Birnaviridae family
Authors: Aamir Shehzad
Majid Ali Shah
Moazur Rahman
Mudasser Habib
Farhid Hemmatzadeh
Maryam Zafar
Mazhar Iqbal
Muhammad Salahuddin Shah
Anam Tariq
Muhammad Muddassar
Journal: Applied Microbiology and Biotechnology (2020)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Birnavirus; Circular dichroism; Gold nanoparticle-based lateral flow assay; Infectious bursal disease virus; Infrared spectroscopy
Affiliations: Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan., Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad, Pakistan., School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia,, 5371, Australia., Vaccine Development Group, Animal Sciences Division, NIAB, Faisalabad, Pakistan., Department of Biosciences, COMSATS-University Islamabad, Park Road, Islamabad, Pakistan., School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia,, 5371, Australia. ., Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan. ., Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad, Pakistan. .

Abstract:  Birnaviridae is a family of viruses (birnaviruses) which consists of four genera, members of which cause diseases in fish, birds, mollusks, and insects. The genome of birnaviruses encodes the highly immunogenic VP2 capsid protein. In order to demonstrate that the VP2 protein can be exploited as a diagnostic antigen for birnaviruses, we developed a lateral flow assay based on the surface-exposed VP2 protrusion domain of a representative birnavirus, infectious bursal disease virus (IBDV) of serotype 1 which causes the highly devastating infectious bursal disease in chickens. The biophysical characterization of the purified domain reveals that the domain predominantly consists of β-sheets, exists in a trimeric form, and remains folded at high temperatures, making it suitable for diagnostic purposes. Owing to its highly immunogenic nature and excellent biophysical properties, we employed the VP2 protrusion domain in a gold nanoparticle-based lateral flow assay for rapid detection of anti-IBDV antibodies in serum samples of infected chickens. Our results indicate that the domain binds anti-IBDV antibodies with high specificity during laboratory testing and on-site testing. The lateral flow assay reported here yields comparable results in a qualitative manner as obtained through a commercial enzyme-linked immunosorbent assay (ELISA). As VP2 is a common capsid protein of birnaviruses, the lateral flow assay can be generalized for other birnaviruses, and members of Tetraviridae and Nodaviridae families which contain homologous VP2 capsid proteins. 

Retracted: No

PubPeer comments:
 Figure 4D. * Red boxes: The 09 month panel looks remarkably similar to the 21 month panel. ![file] ,