关键词: 利什曼原虫, 内脏利什曼病, 比较蛋白质组学, 差异蛋白, 非标记定量分析

Abstract: Objective To analyze the protein abundance differences between two Leishmania infantum strains isolated from different epidemiological types of visceral leishmaniasis in China by comparative proteomics method. Methods Tryptic digests of total proteins were analyzed by using liquid chromatography?tandem mass spectrometry （LC?MS/MS）， followed by label?free quantitative differential expression analysis. The MS data were analyzed with MaxQuant software （ver 1.3.0.5） against data base. Results This study resulted in the identification of 4 274 proteins across two strains （JIASHI?5 and SC6）. Of these， 1 219 differentially expressed proteins （ratio ＞ 2.0 or ＜ 0.5， P < 0.05）were identified. Considering the proteins differentially or uniquely expressed in the strains， 550 proteins were only found in the JIASHI?5 strain， and 174 proteins were only found in the SC6 strain. Totally 495 differentially proteins were expressed in the two groups， among which 328 proteins were down?regulated and 167 proteins were up?regulated in SC6 strain. Some of the identified differentially expressed proteins were demonstrated and they involved in energy metabolism， stress response， prolonging the lifetime of the infected host cell and survival and proliferation in virulent strains. Conclusion This study reveals a group of differentially expressed proteins and the related biologic function that may lay the foundation for screening and identification of the key Leishmania molecules relative to pathogenicity.

Key words: Leishmania, Visceral leishmaniasis, Comparative proteomics, Differential protein, Label?free quantitative analysis