MARCO Inhibits Porcine Reproductive and Respiratory Syndrome Virus Infection through Intensifying Viral GP5-Induced Apoptosis
Xiaoxiao Zhang, Yongjie Chen, Songbei Li, Jinling Wang, Zhan He, Jiecong Yan, Xiaohong Liu, Chunhe Guo
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has been one of the most serious threats to the global swine industry. Glycoprotein 5 (GP5) exposed on the surface of PRRSV virions is a major glycoprotein, and it is involved in viral entry into host cells. A macrophage receptor with collagenous structure (MARCO), which is a member of the scavenger receptor family, was identified to interact with PRRSV GP5 in a DUALmembrane yeast two-hybrid screening. Further investigation demonstrated that MARCO may not serve as a potential receptor to mediate PRRSV entry. Instead, MARCO was a host restriction factor for the virus, and the N-terminal cytoplasmic region of MARCO was responsible for its anti-PRRSV effect. Mechanistically, MARCO inhibited PRRSV infection through intensifying virus-induced apoptosis in PAMs. The interaction between MARCO and GP5 may contribute to GP5-induced apoptosis. Our work reveals a novel antiviral mechanism of MARCO and advances the development of control strategies for the virus.