Phages bearing specific peptides with affinity for porcine reproductive and respiratory syndrome virus GP4 protein prevent cell penetration of the virus

• Published in: Veterinary microbiology 2018-10, Vol.224, p.43-49
• Main Authors: Chen, Wanli, Cui, Jin, Wang, Jingyu, Sun, Yankou, Ji, Chihai, Song, Ruyue, Zeng, Yuchen, Pan, Haoming, Sheng, Jinliang, Zhang, Guihong, Wang, Heng
• Format: Article
• Language: English
• Subjects: Affinity; Animals; Antigens, CD - genetics; Antigens, CD - metabolism; Antigens, Differentiation, Myelomonocytic - genetics; Antigens, Differentiation, Myelomonocytic - metabolism; Bacteriophages - chemistry; Bacteriophages - physiology; Binding Sites; CD163 antigen; Cell Line; Cell membranes; Cell proliferation; Dismantling; GP4 protein; Internalization; N-Terminus; Nucleotide sequence; Peptides; Peptides - metabolism; Phage display; Phages; Porcine reproductive and respiratory syndrome; Porcine Reproductive and Respiratory Syndrome - virology; Porcine respiratory and reproductive syndrome virus - physiology; Protein Binding; Proteins; Reagents; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Receptors, Virus - metabolism; Recombinant Proteins - metabolism; Scavenger receptors; Severe acute respiratory syndrome; Swine; Viral Envelope Proteins - metabolism; Viral inhibition; Virus Internalization; Viruses
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2018.08.027

•Phages displaying specific peptides for PRRSV GP4 protein can distinguish PRRSV.•A peptide with high affinity for GP4 exerts inhibitory effect on PRRSV penetration.•The N-terminus of GP4 is speculated to be the critical receptor binding site.•Beginning of the SRCR5 domain of CD163 is predicted as the ligand recognition site. Porcine reproductive and respiratory syndrome (PRRS) has caused significant economic losses to the pig industry worldwide over the last 30 years. GP4 is a minor highly glycosylated structural protein composed of 187 and 183 amino acids in types I and II porcine reproductive and respiratory syndrome virus (PRRSV), respectively. The GP4 protein co-localizes with cluster of differentiation 163 (CD163), the major receptor on the target cell membrane, to mediate PRRSV internalization and disassembly. However, it remains to be established whether blocking interactions between GP4 and host cells can inhibit viral proliferation. In the present study, recombinant GP4 protein prepared and purified using the Escherichia coli system effectively recognized PRRSV-positive serum. Phage display biopanning on GP4 protein showed that the specific phages obtained could distinguish PRRSV from the other viruses. The exogenous peptide WHEYPLVWLSGY displayed on one of the candidate phages showed high affinity for GP4 protein and exerted a significant inhibitory effect on PRRSV penetration in vitro. Moreover, the N-terminus of GP4 was predicted as the critical receptor binding site and the beginning of the fifth scavenger receptor cysteine-rich domain of CD163 as the critical ligand recognition site based on sequence alignment and model prediction analyses. The current study expands our understanding of PRRSV GP4 and its receptor CD163 and provides a fresh perspective for the development of novel peptide-based viral inhibition reagents.