Development of a Monoclonal Antibody Against Porcine CD163 SRCR5 Domain Which Partially Blocks Infection of PRRSV

• Main Authors: Yujiao Zhang, Kuan Zhang, Hao Zheng, Changlong Liu, Yifeng Jiang, Nannan Du, Liwei Li, Guoxin Li, Lingxue Yu, Yanjun Zhou, Wu Tong, Kuan Zhao, Guangzhi Tong, Fei Gao
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-11-01
• Series: Frontiers in Veterinary Science
• Subjects: PRRSV; epitope; SRCR5; CD163; monoclonal antibody
• Online Access: https://www.frontiersin.org/articles/10.3389/fvets.2020.597843/full
• ISSN: 2297-1769

Porcine reproductive and respiratory syndrome virus (PRRSV), which seriously endangers the world pig industry, invades host cells through receptor-mediated endocytosis involving clathrin. CD163 is an essential receptor for PRRSV during its infection of cells. The scavenger receptor cysteine-rich 5 (SRCR5) domain of the CD163 molecule is necessary for PRRSV infection, and interacts with glycoproteins GP2a and GP4 of PRRSV, allowing the virus to infect the host cells. In this study, a monoclonal antibody (mAb) against the SRCR5-6 region of porcine CD163 was developed, and the target epitope of the mAb was determined as 497TWGTVCDSDF506, which is directly adjacent to the ligand-binding pocket (LBP) domain (487-495aa) of CD163. Further study indicated that the mAb could partially block PRRSV infection of its target cells, pulmonary alveolar macrophages. The mAb developed in the study may provide a foundation of antiviral therapy for PRRSV.