Tetraspanin CD81 serves as a functional entry factor for porcine circovirus type 2 infection

Abstract

Porcine circovirus type 2 (PCV2), a significant economic pathogen in the swine industry, presents persistent challenges in its prevention and treatment. Despite extensive research, the mechanism of PCV2 invading host cells remains unclear. In this study, we found and identified a novel interaction between the tetraspanin CD81 and the viral Cap protein during the PCV2 invading PK-15 cells. The transmembrane proteoglycan Syndecan-1 and RhoA are involved in the infection process through the CD81. Moreover, this is the first time that the role of Syndecan-1 in the PCV2 infection process has been demonstrated. Also, a polyclonal antibody against the CD81 extracellular domain significantly inhibits PCV2 infection in PK-15 cells. It not only enriches our understanding of PCV2 life cycle but also offers new perspectives for the development of antiviral therapeutics against circovirus.