中文摘要
鉴于TLRs在人和实验动物天然免疫中的重要作用，本项目比较研究了不同抗病力仔猪（荣昌仔猪和DLY仔猪）TLRs基因在不同生理状态下表达的时空和品种规律，并在此基础上通过体内和体外模型进一步探索了维生素A（VA）和精氨酸（Arg）对TLRs表达的影响及可能机制。结果发现，TLRs的表达具有显著的日龄依赖性和品种差异性，肠淋巴结、肝脏等组织器官TLRs的表达量随仔猪日龄的增加而增加，且无论在正常生理状态或病原微生物攻击时TLRs在荣昌仔猪上的表达量均高于DLY杂交仔猪。病源微生物攻击（蓝耳病活疫苗和沙门氏菌活疫苗）均可不同程度上调TLRs的表达；而额外补充一定剂量的VA或Arg可下调TLRs及相关信号分子的表达和炎性细胞因子的产生，表明VA和Arg的营养状况可通过影响TLRs的表达进而影响机体的先天性和获得性免疫应答。此外，研究揭示Arg主要通过NO途径抑制TLR4-Myd88信号通路的过度活化进而缓减沙门氏菌活疫苗注射导致的仔猪免疫应激。研究结果，不仅有助于从天然免疫层面深入认识不同品种猪疾病抵抗力差异的分子基础，而且也为探索通过营养调控技术提高猪天然疾病抵抗力提供了理论依据和技术参数。
英文摘要
Toll-like receptors (TLRs) play a most important role in innate immune response of human and experimental animals. However, little is known about the expression and regulation of TLRs in different breeds pigs. This project was carried out to compare the expression profile of TLRs mRNA in different tissues and breeds（Rongchang piglet vs DLY piglet）of piglets, which were exposed or not to pathogenic bacteria or virus. Furthermore, the effect of vitamin A (VA) and arginine (Arg) on TLRs mRNA expression and the underlying pathway were explored in vivo and in vitro. The results showed that the mRNA expression of TLRs in the liver, spleen, lung, and mesentery lymph follicle of Rongchang pigs were significantly higher than those of DLY pigs. And the abundance of TLRs mRNA in liver and mesentery lymph follicle was enhanced with the increase of piglet age. TLRs mRNA expression was upregulated when piglets were chanllenged with attenuated porcine reproductive and respiratory syndorme virus vaccine or attenuated Salmonella enterica serovar Choleraesuis bacterin, however, the upregulation was inhibited when piglets diets were supplemented with optimal dose of VA or Arg. At the same time, the serum pro-inflammatory cytokines concentration were reduced. Furthermore, Arg supplementation could inhibit the excessive activation of the TLR4-Myd88 signalling pathway by degraded to NO, and thus attenuated the negative effects caused by the immune challenge of attenuated Salmonella enterica serovar Choleraesuis bacterin. The results indicated that VA and Arg could regulate innate and adaptive immune response through TLRs pathway.
结题摘要
鉴于TLRs在人和实验动物天然免疫中的重要作用，本项目比较研究了不同抗病力仔猪（荣昌仔猪和DLY仔猪）TLRs基因在不同生理状态下表达的时空和品种规律，并在此基础上通过体内和体外模型进一步探索了维生素A（VA）和精氨酸（Arg）对TLRs表达的影响及可能机制。结果发现，TLRs的表达具有显著的日龄依赖性和品种差异性，肠淋巴结、肝脏等组织器官TLRs的表达量随仔猪日龄的增加而增加，且无论在正常生理状态或病原微生物攻击时TLRs在荣昌仔猪上的表达量均高于DLY杂交仔猪。病源微生物攻击（蓝耳病活疫苗和沙门氏菌活疫苗）均可不同程度上调TLRs的表达；而额外补充一定剂量的VA或Arg可下调TLRs及相关信号分子的表达和炎性细胞因子的产生，表明VA和Arg的营养状况可通过影响TLRs的表达进而影响机体的先天性和获得性免疫应答。此外，研究揭示Arg主要通过NO途径抑制TLR4-Myd88信号通路的过度活化进而缓减沙门氏菌活疫苗注射导致的仔猪免疫应激。研究结果，不仅有助于从天然免疫层面深入认识不同品种猪疾病抵抗力差异的分子基础，而且也为探索通过营养调控技术提高猪天然疾病抵抗力提供了理论依据和技术参数。