抑制USP7活性对鸡抗沙门菌感染的影响

Correlation between the Expression Level of USP7 and the Immune Response to Salmonella Infection in Chickens

本研究旨在阐明去泛素酶USP7对雏鸡抵抗鼠伤寒沙门菌感染的影响。选用3日龄的白来航鸡40只,随机分为2组,每组20只,隔天腹腔注射USP7抑制剂P5091或对照溶剂,连续注射5次,待最后一次注射结束后第4天,对雏鸡人工口服感染鼠伤寒沙门菌,感染24 h后,采集样品,RT-qPCR检测IL-1β、IL-8、TNFα以及NF-κB的mRNA表达,平板涂布法检测雏鸡肝载菌量,H&E染色观察肝和肺的炎症状况。结果表明,P5091抑制USP7活性后,转录因子NF-κB mRNA水平显著降低,并且下游细胞因子IL-1β、IL-8以及TNF-α的表达均下调,雏鸡载菌量下降,H&E染色显示肝与肺炎症反应加剧。综上表明,USP7可能在机体抗沙门菌感染方面起重要作用。

This research aimed to clarify the effect of ubiquitin-specific protease(USP7)on the resistance of chickens to Salmonella Typhimurium infection.Forty 3-day-old White Leghorns were randomly divided into two groups,and respectively intraperitoneal injected with the USP7 inhibitor P5091 and control solvent every other day for 5 consecutive injections(n=20 in each group).Four days after the last injection,they were artificially orally infected with S.Typhimurium.Samples were collected 24 hours after infection.The mRNA abundances of IL-1β,IL-8,TNF-αand NF-κB were examined by RT-qPCR.The bacteria load in the liver of chickens was measured by the plate coating method.Liver and lung inflammation was checked by H&E staining.Inhibition of the USP7 activity by P5091 treatment significantly downregulated the mRNA level of NF-κB,and its downstream cytokines IL-1β,IL-8 and TNF-α.The bacterial load in the liver of chickens decreased.H&E staining showed aggravated inflammation in the liver and lung in USP7 inhibited chickens.USP7 might have critical role in chicken to resist Salmonella infection.