Preliminary Study On The Involvement Of IRF3,IRF7 And Caspase-1 Dependent Pyroptosis In The Pathogenesis Of Porcine Contagious Pleuropneumonia

Porcine contagious pleuropneumonia,a highly contagious and highly positive respiratory disease caused by Actinobacillus pleuropneumoniae,is a worldwide epidemic.It is of great significance to reveal the mechanism of lung injury caused by PCP.In this study,mice were infected with App by intranasal inoculation,and the lesion of lung tissues were observed by histopathological methods.The expression of caspase-1 and other related cytokines in lung of mice in each group was detected by q PCR and western blot.The results showed that compared with the control group,the infected mice had severe pulmonary hemorrhage and inflammation,while the lung injury in the inhibitor group was milder,with only inflammatory exudates,and no injury were observed in the inhibitor control group.The expression levels of IL-1beta,IL-6,IL-10,IL-18,TNF-alpha,NLRP-3and caspase-1 P20 in infected mice were significantly increased,while the expression levels of IL-1beta,IL-6,IL-18 and TNF-alpha in inhibitor group were significantly lower than those in infected mice.It can be concluded that after App infection in mice,it causes pulmonary inflammation involving pyroptosis,and inhibits caspase-1-mediated cell pyroptosis,which can play a role in reducing pulmonary inflammation and injury caused by infection.In order to understand the role of interferon regulatory factor-7 in the pathogenesis of PCP.In this study,we constructed a lithium chloride-treated App-infected mice model,and observed the pathological changes as well as the expression levels of IRF-3 and IRF-7.At the cell level,App-infected mouse mononuclear macrophage leukemia RAW 264.7 was treated with lithium chloride.Morphological changes and expression levels of IRF-3,IRF-7,IL-1beta,IL-6,IL-10,TNF-alpha,phosphorylated STAT-1 and IRF-3 were observed.The results showed that lithium chloride alleviated lung injury in infected mice,decreased the expression levels of IRF-3 and IRF-7,and decreased the expression levels of IL-1beta,IL-6,TNF-alpha,phosphorylated STAT-1 and IRF-3.In conclusion,lithium chloride treatment may decrease lung injury induced by App infection in mice by lowering the expression of IRF-7.