Antiviral activity of recombinant porcine surfactant protein A against porcine reproductive and respiratory syndrome virus in vitro.
Porcine reproductive and respiratory syndrome virus (PRRSV) has caused significant economic losses in the swine industry worldwide. However, there is not an ideal vaccine to provide complete protection against PRRSV. Thus, the need for new antiviral strategies to control PRRSV still remains. Surfactant protein A (SP-A) belongs to the family of C-type lectins, which can exert antiviral activities. In this present study, we assessed the antiviral properties of recombinant porcine SP-A (RpSP-A) on PRRSV infection in Marc 145 cells and revealed its antiviral mechanism using a plaque assay, real-time qPCR, western blotting analysis and an attachment and penetration assay. Our results showed that RpSP-A could inhibit the infectivity of PRRSV in Marc 145 cells and could reduce the total RNA and protein level. The attachment assay indicated that RpSP-A in the presence of Ca(2+) could largely inhibit Marc 145 cell attachment; however, in the penetration assay, it was relatively inactive. Furthermore, our study suggested that virus progeny released from infected Marc145 cells were blocked by RpSP-A from infecting other cells. We conclude that RpSP-A has antiviral activity against PRRSV, most probably by blocking viral attachment and the cell-to-cell transmission pathway, and therefore, RpSP-A holds promise as a novel antiviral agent against PRRSV.
College of Veterinary Medicine, China Agricultural University, Beijing, 100193, People's Republic of China.
Lan
L
Li
National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China.
Qisheng
Q
Zheng
National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China.
Yuanpeng
Y
Zhang
National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China.
Pengcheng
P
Li
Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China.
Yanfeng
Y
Fu
National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China. houjibo@jaas.ac.cn.
Jibo
J
Hou
College of Veterinary Medicine, China Agricultural University, Beijing, 100193, People's Republic of China. xiaoxl@cau.edu.cn.
Xilong
X
Xiao
D000818:Animals; D002460:Cell Line; D019318:Porcine Reproductive and Respiratory Syndrome / Q000235:genetics / Q000276:immunology* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013552:Swine; D053585:Virus Attachment; D014779:Virus Replication
D037662:Pulmonary Surfactant-Associated Protein A; D011994:Recombinant Proteins