MYH9 Key Amino Acid Residues Identified by the Anti-Idiotypic Antibody to Porcine Reproductive and Respiratory Syndrome Virus Glycoprotein 5 Involve in the Virus Internalization by Porcine Alveolar Macrophages

Abstract

MYH9 has been identified as an indispensable cellular protein for porcine reproductive and respiratory syndrome virus (PRRSV) entry into permissive cells using the monoclonal anti-idiotypic antibody (Mab2-5G2) recognizing an antibody that specifically interacts with PRRSV glycoprotein 5 (GP5). More recently, we found that Mab2-5G2 interacted with the MYH9 C-terminal domain, designated PRA, which is required for PRRSV internalization. In this study, we demonstrate that blocking of MYH9 with Mab2-5G2 significantly diminished PRRSV internalization by porcine alveolar macrophage (PAM) via interruption of direct interaction between GP5 and MYH9, and thus remarkably inhibited subsequent infection of PAMs by PRRSV-2 isolates. Moreover, the three-dimensional structure of the Mab2-5G2 Fab-PRA complex determined via homology modeling predicted potential docking sites required for PRRSV internalization. Further analysis of Mab2-5G2-binding sites within PRA highlighted that the amino acids E1670, K1673, E1679, and I1683 in PRA are the key Mab2-5G2-binding residues. Notably, recombinant PRA protein blocked the interaction between PRRSV GP5 and cellular MYH9 by preventing translocation of MYH9 from the cytoplasm to the cell membrane, an essential step for PRRSV virion internalization. Meanwhile, porcine cell line permissive for PRRSV bearing point mutation of E1670A in MYH9 demonstrated reduced susceptibility for PRRSV infection. In conclusion, this work increases understanding of both PRRSV pathogenesis and the mechanistic role played by MYH9 in PRRSV infection.

Use of dual priming oligonucleotide system-based multiplex RT-PCR assay to detect five diarrhea viruses in pig herds in South China

“…Diarrheal virus infection causes diarrhea, high mortality in piglets, and tremendous economic losses for swine farms worldwide. All swine enteric viruses—including TGEV, PEDV, PRV-A, and new variant strains PDCoV and SADS-CoV(Bevins et al 2018 ; Gong et al 2017 ; Pan et al 2017 ; Zhang et al 2015 ; Zhao et al 2019 )—could seriously endanger the development of the pig industry, especially in terms of newborn piglets. The symptoms caused by the above mentioned five viruses are similar, so it is difficult to determine the causative pathogen in clinical diagnosis.…”

Current Status of Genetically Modified Pigs That Are Resistant to Virus Infection

“…Numerous studies have shown that PRRSV entry is mediated by various cell receptors, such as sialoadhesin (Sn, CD169) [67,68], CD151 [69,70], heparin sulfate [71], vimentin [72], MYH9 [73,74], and CD163 (a scavenger receptor) [75]. Recently, CD163 was reported to be the key receptor during the process of PRRSV infection [76].…”

Recent Advances in PRRS Virus Receptors and the Targeting of Receptor–Ligand for Control

“…The ectodomain of GP5 induces aggregation of MYH9 and facilitates viral internalization in both MARC-145 cells and PAMs [62]. Further studies showed that the amino acids E1670, K1673, E1679, and I1683 in the MYH9 C-terminal domain are the key binding residues, and a point mutation in E1670 in PAMs causes reduced permissiveness for PRRSV infection [63]. Overexpression of S100A4, which is an MYH9 disassembly inducer, downregulates the MYH9 aggregation and results in the inhibition of both PRRSV-1 and PRRSV-2 infection [62].…”