植物乳杆菌诱导宿主防御肽pBD1表达改善猪肠道先天性免疫的机制研究

仔猪断奶应激引起的的免疫力低下是导致该阶段疾病发生和成活率降低的主要原因。如何通过营养调控手段提高畜禽肠道先天性免疫功能已成为领域内关注的科学问题。宿主防御肽是机体先天免疫系统的重要效应分子，申请人前期证实了L. plantarum ZLP001能够诱导猪宿主防御肽pBD1基因的表达，且不引起炎性损伤，但分子机制还不清楚。在此基础上，本项目通过研究L. plantarum ZLP001调节pBD1基因表达模式识别受体和信号转导途径；明确L. plantarum ZLP001调节pBD1基因表达的转录因子和其结合位点；探究L. plantarum ZLP001通过提高pBD1表达对机体免疫应答的影响，阐明植物乳杆菌增强猪宿主防御肽pBD1表达改善机体免疫功能的分子机制。本项目将有助于评估乳酸菌在缓解仔猪断奶应激中新的作用靶点，为乳酸菌在仔猪断奶阶段的科学利用提供新的依据。

Suppressed immunity after weaning is the main reason which causes disease and decreased survival rate of piglet. How to improve the innate immune function of the intestinal tract by nutritional regulation has become the critical scientific issue highly concerned in field. Host defense peptide is an important effector molecule of the innate immune system of the body. The applicant has previously confirmed that L. plantarum ZLP001 can induce the expression of the porcine host defense peptide pBD1 gene without provoking inflammatory damage. However, the molecular mechanism is still unclear. On this basis, this project will study the pattern recognition receptor and signal transduction pathway through which L. plantarum ZLP001 regulate pBD1 gene expression, investigate the transcription factors regulating pBD1 gene expression and their binding sites, and explore the effect of L. plantarum ZLP001 on the immune response by increasing the expression of pBD1. The molecular mechanism of L. plantarum ZLP001 enhancing the expression of porcine host defense peptide pBD1 will be clarified. The present study will be helpful for evaluating the new targets of probiotics in alleviating weaning stress of piglets and provide a new basis for scientific utilization of probiotics in weaning piglets.