猪德尔塔冠状病毒感染仔猪引起肠道组织病理学变化及其对致病相关因子的影响

为了探究猪德尔塔冠状病毒(PDCoV)感染仔猪肠道引起的组织病理学变化及其在肠道中复制并导致肠道出现炎症病变的作用机制,本研究使用PDCoV天津地区分离株TJ1经口服感染10日龄仔猪,在攻毒后第4天对仔猪进行剖检,通过病理组织学观察发现,空肠、回肠、结肠、盲肠组织主要病变表现为肠黏膜间质、黏膜固有层、黏膜下层弥漫性炎症细胞浸润,局部黏膜绒毛萎缩等。通过荧光定量PCR试验,对肠道组织中PDCo V M基因、天然免疫基因IFN-α、IFN-β、DDX58、STAT2与炎症因子TNF-α、IL-6的mRNA表达量进行检测,结果显示,PDCoV在4种肠组织中通过抑制宿主细胞天然免疫应答实现自身复制,且在空肠、回肠、结肠中通过增强TNF-α、IL-6的表达促进肠道炎症病变的发生。本研究结果可为猪德尔塔冠状病毒致病机制的研究提供理论依据。

The histopathological changes of piglets intestinal tissues and the effection of pathogenicity-associated factors induced by porcine deltacoronavirus

For exploring the histopathological changes of intestinal tissues and the mechanism of porcine deltacoronavirus(PDCo V)replication and leading to inflammatory lesions of piglets intestine which induced by PDCo V infection,10-day-old piglets were infected by PDCo V strain TJ1 which isolated from Tianjin through oral route in this study.The piglets were necropsied at 4 days post-infection.Through histopathological observation,the main lesions of jejunum,ileum,colon and cecum were investigated.The diffuse inflammatory cell infiltration was found in mesenchyme,lamina propria and submucosa of intestinal mucosa,and the mucosal villi atrophy occurred in response to local tissues.The m RNA expression level of PDCo V M gene,innate immune genes including IFN-α,IFN-β,DDX58 and STAT2 as well as the inflammatory cytoines including TNF-αand IL-6 in intestinal tissues were examined.The results showed that PDCo V replication was achieved by inhibiting host cell innate immune response,and the occurrence of inflammatory lesions in jejunum,ileum and colon were promoted through the enhancement of TNF-αand IL-6 expression.This study can provide a theoretical basis for the pathogenic mechanism study of porcine deltacoronavirus.