Proteomic analysis of exosomes isolated from saliva and salivary glands of tick Haemaphysalis longicornis
作者单位：key Laboratory of Animal Parasitology of Ministry of AgricultureShanghai Veterinary Research InstituteChinese Academy of Agricultural Sciences
会议名称：《中国畜牧兽医学会兽医寄生虫学分会第一届青年科学家学术论...》
会议日期：2019年
学科分类：090601[农学-基础兽医学] 09[农学] 0906[农学-兽医学]
关 键 词：Haemaphysalis longicornis exosomes salivary glands proteomic analysis
摘 要：Background:Exosomes,the nano-sized membrane vesicles are considered as vehicles of cellular communication.Parasites usually release exosomes in their exeretory-secretory products to modulate host environment.However,a little is known about the secretion of exosomes by ticks.In this study,we showed for the very first time that the tick,Haemaphysalis longicornis,secretes micro vesicles,resembling to exosomes.Methods:Exosomes were purified from saliva and salivary glands of H.longicornis ticks,through serial steps of ultracentrifugation.Presence of exosomes was confirmed by electron microscopy.Liquid chromatography(LC-MS/MS) was used to characterize the proteins within tick-derived exosomes.In addition,GO and KEGG database were mapped to analyse the molecular functions,biological processes,cellular components and pathways associated with salivary-exosomal proteins.Results:Electron microscopy analysis of saliva and culture medium containing salivary glands revealed the presence of exosomes like vesicles within a size range of 50-100 nm.Presence of exosomal markers(Hsp70 and elongation factor 1) as well as parasite specific proteins gave us further confirmation of their release by the ticks.A total of 354 proteins in salivary exosomes whereas 287 proteins in culture medium containing salivary glands were identified.Most of the proteins within tick-derived exosomes have been identified as components of parasitic exosomes.Bioinformatics analysis(Gene Ontology) indicated association of certain biological and molecular functions with salivary exosomal proteins which may be helpful in development of ticks.Likewise,KEGG database revealed involvement of salivary exosomal proteins in proton transport,detoxification,ECM-receptor interaction,Ribosome,RNA transport,ABC transporters and oxidative phosphorylation.Conclusion:Results of this study provide evidence that exosomes are being secreted by the ticks and suggests that tick derived exosomes could play important roles in host parasite relationship.Moreover,exosomes could be useful tool in development of vaccines or therapeutics against ticks.