Nitric oxide is elicited and inhibits viral replication in pigs infected with porcine respiratory coronavirus but not porcine reproductive and respiratory syndrome virus

作者：Jung Kwonil; Gurnani Ashita; Renukaradhya Gourapura J; Saif Linda J^*

来源：Veterinary Immunology and Immunopathology, 2010, 136(3-4): 335-339.

DOI：10.1016/j.vetimm.2010.03.022

• Coronavirus
• Porcine respiratory coronavirus
• Porcine reproductive and respiratory syndrome virus (PRRSV)
• Nitric oxide
• Antiviral effects

There is little information on the role of nitric oxide ((center dot)NO) in innate immunity to respiratory coronavirus (Coy) infections. We examined (center dot)NO levels by Greiss assay in bronchoalveolar lavage (BAL) of pigs infected with either porcine respiratory coronavirus (PRCV) or porcine reproductive and respiratory syndrome virus (PRRSV), a member of Nidovirales, like Coy. The antiviral effects of (center dot)NO on these two viruses were tested in an in vitro system using a (center dot)NO donor, S-nitroso-N-acetylpenicillamine (SNAP). We detected a large increase in (center dot)NO levels in BAL fluids of PRCV-infected pigs, but not in PRRSV-infected pigs. Pulmonary epithelial cell necrosis induced by PRCV coincided with increased (center dot)NO. Moreover, (center dot)NO levels in cell culture medium of PRRSV-infected alveolar macrophages (AMs) did not differ from that of mock-infected AMs. Antiviral assays showed that (center dot)NO significantly inhibited PRCV replication in swine testicular (ST) cells, whereas PRRSV was not susceptible to (center dot)NO based on the conditions tested. Our study suggests that unlike PRRSV which induces apoptosis in AMs, respiratory CoVs such as PRCV that infect pulmonary epithelial cells and cause cytolysis, induce (center dot)NO production in the respiratory tract. Thus, (center dot)NO may play a role in innate immunity to respiratory CoV infections by inhibiting viral replication.

• 出版日期2010-8-15