| Ticks are a kind of parasitic arthropods that are specialized in blood sucking.The hosts include humans,mammals,birds,reptiles and amphibians.In addition to the host injury,ticks can spread a variety of pathogens,seriously harm human health,and greatly affect livestock production.Ticks are widely distributed around the world.After being bitten,ticks can cause the skin of the host to become red,irritated,and even cause skin ulcers,meanwhile,the hosts are most likely to be infected with Spotted fever,Lyme's disease,Babesiasis,and others.In order to resist ticks,the host's autoimmune mechanism can be quickly activated,which can resist multiple activities proteins in the tick's saliva through T cells,macrophages,eosinophils,and interleukins,IgG antibodies,and IgE antibodies,and as much as possible to stop sucking blood.In order to explore how mammals utilize autoimmune mechanisms to defend against ticks,quantitative proteomics was used to find differentially expressed proteins in New Zealand white rabbits before and after being bitten by Haemaphysalis longicornis,and determine the change of protein-modified phosphorylation and ubiquitination,hoping to elucidate the immune mechanism of mammals to ticks bites and find some of the key proteins in this reaction.The results will lay a foundation for future development of anti-tick vaccines.H.longicornis is widely distributed in China and is one of the most dangerous species.In this study,the skin of white rabbits before and after H.longicornis bite was used as the research object.We use quantitative proteomics and modified proteomics to research the skin bite by ticks,and the differential expressed proteins in the skin of the white rabbits after being bitten were screened,exploring the mechanisms of mammals responding to the skin immune response to ticks.This experiment is divided into three parts:In the first part,iTRAQ quantitative proteomics method was used to study the expression of all proteins in white rabbits before and after H.longicornis bite.A total of 2863 differentially expressed proteins were identified,and 612 proteins with significant expression differences were systematically bioinformatics analysis.The results showed that some of the proteins were involved in the immune response.Through GO function annotations and KEGG bioinformatics methods,it was finally confirmed that some of these immune-related proteins involved in the antagonism of tick signal pathways.By combining with other bioinformatics analysis methods,the role of these proteins in the process of immune bite was finally discussed.In the second part,the phosphoproteome of white rabbit skin before and after the bite was studied.Finally,390 phosphorylation sites were differentially expressed by i TRAQ method,and 287 phosphorylation proteins were involved.Bioinformatics analysis was performed on 184 phosphoproteins involved in the 203 phosphorylation sites with significant differences in expression.Proteins that changed in these phosphorylation sites were classified and functioned by GO functional annotation,KEGG,and other analysis methods.The analysis confirmed some of these proteins were involved in immune regulation,found the signal pathways which they affected,and analyzed the function of these rabbit proteins which play an immunoregulatory role during the H.longicornis bite.In the third part,ubiquitinated proteins were enriched in the bite before and after the bite,and 267 ubiquitination sites were differentially expressed using the unlabeled quantitative proteomics method.There were 119 ubiquitinated proteins involved.Bioinformatics analysis was performed on 62 ubiquitination sites involved in 43 ubiquitinated proteins with significant differences in expression,and these ubiquitination site-changing proteins were analyzed by GO functional annotation,KEGG,and other analytical methods.The classification and functional analysis confirmed that some of these proteins were involved in immune regulation,found the signal pathways which they affected,and analyzed the function of these rabbit proteins which play an immunoregulatory role during the H.longicornis bite.In this dissertation,quantitative proteomics was used to systematically analyze the differential expression of proteins,phosphorylation and ubiquitination of New Zealand white rabbits.The possible molecular functions of these proteins were identified through bioinformatics methods,providing an effective potential target for the accurate design of anti-tick vaccines in the future.This study not only performed the first comprehensive analysis of the proteomes and modified proteomes of mammals subjected to ticks,but also indicated for the first time the role of CD14,BPI,MRC1 and other proteins in this immune response.This study has done some preparatory work for the comprehensive prevention and overall prevention of ticks,and make contribution to the rapid development of this area. |
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