Characterization of polyclonal antibodies against nonstructural protein 9 from the porcine reproductive and respiratory syndrome virus

Abstract

Porcine reproductive and respiratory syndrome (PRRS) is considered to be one of the most important infectious diseases impacting the swine industry and is characterized by reproductive failure in late term gestation in sows and respiratory disease in pigs of all ages. The nonstructural protein 9 gene, Nsp9, encoding the RNA-dependent RNA polymerase, is generally regarded as fairly conserved when compared to other viral proteins. Antibodies against Nsp9 will be of great importance for the diagnosis and treatment of the causal agent, PRRS virus. A study was undertaken to generate polyclonal antibodies against the immunodominant Nsp9. For this purpose, the Nsp9 was expressed in Escherichia coli and subsequently used as an antigen to immunize New Zealand rabbits. Antiserum was identified via an indirect ELISA, and then verified based on the ability to react with both naturally and artificially expressed Nsp9. Results of virus neutralization test showed that this antiserum could not neutralize the PRRSV. Nevertheless, this antiserum as a diagnostic core reagent should prove invaluable for further investigations into the mechanism of PRRS pathogenesis.

Keywords

PRRSV / Nsp9 / expression / antibody / neutralize

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Acknowledgments

This work was supported by the National Natural Science Foundation of China (31272564), the Modern Agricultural Industry Technology System (CARS-36), and Special Fund for Agro-scientific Research in the Public Interest (201203039).

Compliance with ethics guidelines

Mengmeng Zhao, Juanjuan Qian, Jiexiong Xie, Tiantian Cui, Songling Feng, Guoqiang Wang, Ruining Wang, and Guihong Zhang declare that they have no conflict of interest or financial conflicts to disclose.

All applicable institutional and national guides for the care and use of animals were followed.

RIGHTS & PERMISSIONS

The Author(s) 2016. Published by Higher Education Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0)