堆型艾美耳球虫感染对鸡外源性凋亡关键蛋白的影响

Effects of Eimeria acervulina infection on exogenous apoptosis key proteins in chicks

为了探讨感染堆型艾美耳球虫(Eimeria acervulina,E.acervulina)对鸡十二指肠组织外源性凋亡关键蛋白的影响,试验将28日龄健康SPF鸡随机分为对照组和试验组,试验组雏鸡感染强毒株堆型艾美耳球虫,感染剂量为1×10^(5)个/只,周期为7 d。在试验的第24,96,144小时,每组随机取3只鸡的十二指肠进行组织病理学及细胞观察,另取部分肠组织制备组织匀浆,检测外源性凋亡关键蛋白Fas、TNFR1和FADD基因的表达情况。结果表明:感染鸡只平均增重显著低于对照组(P<0.05)。感染球虫96小时时,鸡只精神萎靡,十二指肠绒毛上皮细胞大量坏死;而感染球虫144小时时,鸡只的精神状态逐渐好转,小肠组织逐渐修复。感染球虫96小时时,荧光显微镜下可见坏死和变性的绒毛上皮细胞,且凋亡细胞明显增多,死亡和凋亡细胞的细胞核呈致密浓染,或呈碎块状致密浓染。试验期间,Fas、TNFR1和FADD基因的相对表达量均显著或极显著高于对照组(P<0.05或P<0.01)。说明感染堆型艾美耳球虫可激活宿主细胞死亡受体凋亡信号通路,使细胞凋亡及坏死增加,肠道组织病变加重,鸡的平均增重降低。

In order to investigate the effects of Eimeria acervulina(E.acervulina)infection on exogenous apoptosis key proteins in chicken duodenal tissue,in this experiment 28-day-old healthy SPF chicks were randomized divided into control group and experimental group.The chicks in the experimental group were infected with a virulent strain of E.acervulina at an infection dose of 1×10^(5)/chick for 7 days.At the 24th,96th,and 144th hours of the test,3 chicks in each group were randomly selected for histopathological and cellular observation;another part of the intestinal tissue was taken to prepare tissue homogenate to detect the expression of exogenous apoptosis key proteins Fas,TNFR1 and FADD genes.The results showed that the average weight gain of infected chicks was significantly lower than that of the control group(P<0.05).When infected with coccidia for 96 h,chicks were mentally apathetic and a large number of duodenal villi epithelial cells died;when infected with coccidiosis for 144 h,the mental state of the chicks gradually improved,and the small intestinal tissue was gradually repaired.When infected with coccidia for 96 h,necrotic and degenerative villi epithelial cells were visible under fluorescence microscopy,and apoptotic cells were significantly increased,and the nuclei of dead and apoptotic cells were densely stained,or fragmented and densely stained.During the test,the relative expression of Fas,TNFR1,and FADD genes was significantly or very significantly higher than that of the control group(P<0.05 or P<0.01).The results suggested that the infection with E.acervulina could activate the apoptosis pathway of host cell death receptor,increase apoptosis and necrosis,aggravate intestinal tissue lesions,and decrease the average weight gain of chicks.