蜱是畜牧傳染病的最主要傳播者, 給畜牧業(yè)帶來嚴重的危害,，同時它也傳播萊姆病,、流行性出血熱等重大人類疾病,。蜱是專性吸血的節(jié)肢動物,，硬蜱侵入宿主后,，要在體表停留吸血1-2個星期,，這么長的吸血時間內(nèi)完全可以啟動宿主的免疫排斥反應。
為了成功地從其宿主獲得血液,，蜱發(fā)展了完善的免疫抑制系統(tǒng)以逃避宿主的免疫排斥反應。長期以來,，世界多個實驗室都已經(jīng)發(fā)現(xiàn)了蜱唾液腺可以分泌免疫抑制劑,，但一直沒有分離和鑒定到免疫抑制劑多肽分子,。
最近中國科學院昆明動物研究所賴仞研究員領導的研究團隊從硬蜱唾液腺中分離和識別了兩個家族的免疫抑制劑多肽,，并對這些免疫抑制劑多肽的作用機制和相關的信號途徑進行了深入的研究,。發(fā)現(xiàn)這兩個家族的多肽由同一個基因編碼,，它們通過作用于MAPK信號途徑調(diào)節(jié)宿主細胞因子的分泌而發(fā)揮免疫抑制功能。這是世界上從蜱唾液腺中發(fā)現(xiàn)的免疫抑制劑多肽活性分子的首次報道,。該發(fā)現(xiàn)對理解蜱與宿主相互作用的分子機制以及發(fā)展蜱的生物控制策略具有重要意義,。(生物谷Bioon.com)
生物谷推薦原文出處：
JBC doi: 10.1074/jbc.M109.094615
Two immunoregulatory peptides with antioxidant activity from tick salivary glands
Jing Wu1, Yipeng Wang1, Han Liu1, Hailong Yang1, Dongying Ma1, Jianxu Li1, Dongsheng Li1, Ren Lai1 and Haining Yu2,*
1 Kunming Institute of Zoology, Chinese Academy of Sciences, China;
2 Dalian University of Technology, China
Ticks are blood feeding arthropods that may secrete immunosuppressant molecules, which inhibit host inflammatory and immune responses and provide survival advantages to pathogens at tick bleeding sites in hosts. In current work, two families of immunoregulatory peptides, hyalomin A and B were firstly identified from salivary glands of hard tick Hyalomma asiaticum asiaticum. Three copies of them are encoded by identical gene and released from the same protein precursor. Both hyalomin A and B can exert significant antiinflammatory functions, either by directly inhibiting the host secretion of inflammatory factors such as TNF alpha, MCP1 and IFN gamma, or by indirectly increasing the secretion of immunosuppressant cytokine of IL10. Hyalomin A and B were both found to potently scavenge free radical in vitro in a rapid manner, and inhibited adjuvant induced inflammation in mouse models in vivo. The JNK SAPK subgroup of MAPKs signaling pathway was involved in such immunoregulatory functions of hyalomin A and B. These results showed that immunoregulatory peptides of tick salivary glands suppress host inflammatory response by modulating cytokine secretion and detoxifying reactive oxygen species.
