中国寄生虫学与寄生虫病杂志

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弓形虫GRA7致密颗粒蛋白与宿主巨噬细胞蛋白的相互作用

薛峰1,2,洪彩玲1,黄敏君1,2,孙岚1,2,甘绍伯1,2,谷俊朝1,2 *   

  1. 1 首都医科大学附属北京友谊医院,北京热带医学研究所,北京 100050;2 北京市热带病防治研究重点实验室,北京 100050
  • 出版日期:2014-10-30 发布日期:2015-01-06

Interaction between Toxoplasma GRA7 Dense Granule Protein and the Protein from Host Macrophages

XUE Feng1,2,HONG Cai-ling1,HUANG Min-jun1,2,SUN Lan1,2,GAN Shao-bo1,2,GU Jun-chao1,2 *   

  1. 1 Beijing Tropical Medicine Research Institute,Beijing Friendship Hospital,Capital Medical University,Beijing 100050,China;2 Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases,Beijing 100050,China
  • Online:2014-10-30 Published:2015-01-06

摘要:

目的  鉴定与弓形虫GRA7致密颗粒蛋白相互作用的宿主巨噬细胞蛋白组分,并研究蛋白相互作用与感染过程的相关性。  方法  建立基于人源THP-1单核巨噬细胞系的弓形虫-巨噬细胞感染模型。以含GST标签的GRA7全长重组蛋白为诱饵,采用GST沉降体外蛋白相互作用方法,捕获与诱饵相互作用的人THP-1单核巨噬细胞系成分,采用液相色谱-两级质谱联用(LC-MS/MS)技术鉴定宿主靶蛋白。采用免疫共沉淀(Co-IP)方法验证其体内的相互作用。采用人碳酸酐酶1(hCA1)抗血清为一抗的蛋白质印迹(Western blotting)验证捕获蛋白为宿主hCA1蛋白组分。采用pcDNA3.1(+)真核质粒过表达宿主靶蛋白的方法研究蛋白相互作用与弓形虫感染巨噬细胞的相关性。  结果  GST沉降实验捕获的THP-1细胞蛋白组分主要为相对分子质量为Mr 29 000的蛋白,质谱鉴定为hCA1。Co-IP实验证明弓形虫GRA7蛋白与宿主hCA1蛋白在感染过程中具有显著体内相互作用。THP-1巨噬细胞内过表达hCA1基因可显著增强弓形虫的繁殖速度和纳虫泡形成速度,但不影响最终繁殖数量。  结论  弓形虫GRA7致密颗粒蛋白与THP-1巨噬细胞的hCA1蛋白具有显著蛋白相互作用,且该相互作用与弓形虫在THP-1巨噬细胞内的繁殖速度呈正相关。

关键词: 刚地弓形虫, 致密颗粒蛋白, 人碳酸酐酶1, 蛋白相互作用, 纳虫泡

Abstract:

Objective  To identify the protein from host macrophages which interacted with GRA7 dense granule protein of Toxoplasma gondii, and reveal the relationship between protein interaction and infection process.  Methods  The recombinant GRA7 protein with N-terminal GST tag were used as a bait in in vitro GST Pull-down experiment, the proteins of THP-1 monocytic macrophage cell line were captured and identified by LC-MS/MS proteomics method. The in vivo protein interaction was verified by Co-IP experiment. The overexpression of the target host protein by pcDNA3.1(+) vector in THP-1 macrophage was further used to analyze the relationship between protein interaction and infection process.  Results  The captured THP-1 cell protein was about Mr 29 000, which was identified as human carbonic anhydrase 1(hCA1). The significant in vivo protein-protein interaction between GRA7 and hCA1 was verified by Co-IP assay. The overexpression of hCA1 gene in THP-1 macrophage induced a higher propagation speed of T. gondii and the formation of the parasitophorous vacuole, but did not influence the number of the parasite.  Conclusion  There is a significant protein interaction between Toxoplasma GRA7 dense granule protein and hCA1 enzyme from host macrophages, which is positively related with the propagation speed of T. gondii.

Key words: Toxoplasma gondii, Dense granule protein, Human carbonic anhydrase 1, Protein interaction, Parasitophorous vacuole