Yuan-Zhe Bai #,Yue Sun #,Yong-Gang Liu #,Hong-Liang Zhang,Tong-Qing An,Qian Wang,Zhi-Jun Tian,Xinyuan Qiao,Xue-Hui Cai,Yan-Dong Tang

Front Cell Infect Microbiol.2024 Mar 25:14:1376725.doi: 10.3389/fcimb.2024.1376725. eCollection 2024.

Abstract

In China, porcine reproductive and respiratory syndrome virus (PRRSV) vaccines are widely used. These vaccines, which contain inactivated and live attenuated vaccines (LAVs), are produced by MARC-145 cells derived from the monkey kidney cell line. However, some PRRSV strains in MARC-145 cells have a low yield. Here, we used two type 2 PRRSV strains (CH-1R and HuN4) to identify the genes responsible for virus yield in MARC-145 cells. Our findings indicate that the two viruses have different spread patterns, which ultimately determine their yield. By replacing the viral envelope genes with a reverse genetics system, we discovered that the minor envelope proteins, from GP2a to GP4, play a crucial role in determining the spread pattern and yield of type 2 PRRSV in MARC-145 cells. The cell-free transmission pattern of type 2 PRRSV appears to be more efficient than the cell-to-cell transmission pattern. Overall, these findings suggest that GP2a to GP4 contributes to the spread pattern and yield of type 2 PRRSV.

Keywords: PRRSV; cell-free; cell-to-cell; spread pattern; yield.