肽聚糖识别蛋白SA参与熊蜂Imd通路免疫应答的机制

熊蜂是一类重要的膜翅目传粉昆虫，而病原微生物侵害是其种群数量下降的重要原因。其肽聚糖识别蛋白（PGRPs）介导的Imd和Toll通路免疫应答在清除病原微生物侵染过程中起着十分重要的作用。熊蜂PGRP-SA以高亲和力结合Dap-type肽聚糖介导Imd通路免疫应答，其不同于双翅目果蝇PGRP-SA识别Lys-type肽聚糖介导Toll通路免疫应答。为了揭示熊蜂PGRP-SA识别Dap-type肽聚糖介导Imd通路免疫应答的机制，本项目拟鉴定PGRP-SA-Dap-type肽聚糖复合物的互作受体，验证互作受体参与PGRP-SA介导Imd通路免疫应答的功能。并解析PGRP-SA-Dap-type肽聚糖与互作受体的三维结构，阐明三者的互作结构基础。研究结果将阐明熊蜂PGRP-SA介导Imd通路免疫应答的互作受体及其与PGRP-SA的互作机制，对进一步研究熊蜂的特殊免疫机制及病害防治均有重要意义。

Bumblebee is a type of important Hymenoptera pollinators. However, the colonies of bumblebees have declined dramatically in recent years, and the invasion of pathogens is one of the key factors resulting in the decline of bumblebee colonies. The immune responses of Imd and Toll signaling pathways mediated by peptidoglycan recognition proteins (PGRPs) in bumblebee play an important role in the clearance of pathogen infections. Bumblebee PGRP-SA mediates the immune response of Imd signaling pathway by binding with high affinity to Dap-type peptidoglycan, which differs from the Diptera drosophila PGRP-SA recognizing Lys-type peptidoglycan and participating in the immune response of Toll signaling pathway. To explain the mechanism of bumblebee PGRP-SA recognizing Dap-type peptidoglycan and activating immune response of Imd signaling pathway. This project aims to identify the interaction receptor of PGRP-SA-Dap-type peptidoglycan complex and verify its function in the immune response of Imd pathway mediated by PGRP-SA. The three-dimensional structure of PGRP-SA-Dap-type peptidoglycan and its receptor will be determined to elucidate the structural basis of interaction between PGRP-SA and its interaction receptor. The results will illustrate the interaction receptor of bumblebee PGRP-SA involved in the immune response of Imd signaling pathway and the interaction mechanism between PGRP-SA and its receptor, which is of great significance for further study of the bumblebee's special innate immune mechanism and disease control.