Objective Pseudorabies virus (PRV), belonging to the herpesviridae family, is a neurotropic virus that spreads infection and causes neurological and respiratory diseases through contact. Pigs are the natural hosts of PRV, and PRV infections and epidemics cause great economic losses to the pig industry. PRV infection of the host central nervous system triggers changes in the expression level of the neuropeptide S (NPS) system, a neuropeptide substance that is widely distributed in the central nervous system as a key member of the neuroendocrine system, and is associated with chronic diseases. NPS mediates diverse physiological functions through the neuropeptide S receptor (NPSR), which participates in the regulation of the neuroendocrine-immune network in the body as the NPS/NPSR system together. In this study, we investigated the role of the NPS/NPSR system in PRV-infected host cells in anticipation of developing new anti-PRV targets.

Method NPS and NPSR knock-out PK15 cell lines were constructed by CRISPR/Cas9 method. The antiviral ability of cell lines infected with PRV virus and the binding ability of NPSR to viral surface glycoproteins were detected by qPCR, immunofluorescence, Western blot and co-immunoprecipitation (CO-IP).

Result NPSR knockout attenuated the infectivity of PRV on PK15 cells, while NPS knockout enhanced the infectivity of PRV on PK15 cells. NPSR knockout cells reduced viral invasion during PRV adsorption, thus NPSR was a potential PRV invasion receptor. The interaction of NPSR with viral envelope proteins gB and gD were demonstrated by CO-IP experiment.

Conclusion NPSR promotes PRV infection by binding to viral surface glycoproteins, and NPSR may be one of the receptor factors for PRV infection of the nervous system. NPSR knockout significantly inhibits the infection of PK15 cells by PRV. NPSR may provide new research targets for the development of drugs and therapeutic strategies for PRV prevention and control.