Establishment and Characterization of a High and Stable Porcine CD163-Expressing MARC-145 Cell Line.

Xiangju Wu,Fulin Tian,Jing Qi,Dongwan Yoo,Yijun Du,Zhi Chen,Lihui Guo,Feng Li,Jun Li,Xiaoyan Cong,Lei Chen,Jinbao Wang,Jiaqiang Wu,Wenbo Sun,Guisheng Wang,Yue Hu,Xiaomin Zhao

doi:10.1155/2018/4315861

Abstract

Isolation and identification of diverse porcine reproductive and respiratory syndrome viruses (PRRSVs) play a fundamental role in PRRSV research and disease management. However, PRRSV has a restricted cell tropism for infection. MARC-145 cells are routinely used for North American genotype PRRSV isolation and vaccine production. But MARC-145 cells have some limitations such as low virus yield. CD163 is a cellular receptor that mediates productive infection of PRRSV in various nonpermissive cell lines. In this study, we established a high and stable porcine CD163- (pCD163-) expressing MARC-145 cell line toward increasing its susceptibility to PRRSV infection. Indirect immunofluorescence assay (IFA) and Western blotting assays showed that pCD163 was expressed higher in pCD163-MARC cell line than MARC-145 cells. Furthermore, the ability of pCD163-MARC cell line to propagate PRRSV was significantly increased as compared with MARC-145 cells. Finally, we found that pCD163-MARC cell line had a higher isolation rate of clinical PRRSV samples and propagated live attenuated PRRS vaccine strains more efficiently than MARC-145 cells. This pCD163-MARC cell line will be a valuable tool for propagation and research of PRRSV.

Highlights

Porcine reproductive and respiratory syndrome (PRRS) first appeared in the late 1980s independently but almost simultaneously in North America and Europe
The cell clone of the highest pCD163 expression was identified by immunofluorescence assay (IFA) and Western blotting and designated pCD163MARC
The pCD163 expression level was further examined by Western blotting (Figure 2(a)). porcine CD163- (pCD163-)MARC cells were found to express 8.7 times higher level of pCD163 than MARC-145 cells (Figure 2(b))

Summary

Introduction

Porcine reproductive and respiratory syndrome (PRRS) first appeared in the late 1980s independently but almost simultaneously in North America and Europe. The causative agent is PRRS virus (PRRSV) and two distinct genotypes are found: the European (EU) type (genotype 1) and the North American (NA) type (genotype 2) [2,3,4] Sequence analysis shows they share approximately 60% nucleotide sequence identity at the genome level [5,6,7,8]. Since the emergence, they exhibit distinct genetic and antigenic variations and have been identified as dominating pathogens causing reproductive failures in sows and gilts, respiratory distress, high mortality rates for nursery pigs, and serious economic losses per year [9,10,11,12]. In 2006, a large-scale devastating disease, known locally as “high fever,” broke out in China causing high morbidity of 50–100% and a mortality rate of 20–100% [14]

Methods

Results

Conclusion