畜牧兽医学报

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TLR-4介导的鹅β-防御素1抗肠炎沙门菌感染的信号传导机制初探

张名岳1,2,张可心1,2,辛胜男1,2,韩宗玺2,邵昱昊2,刘晓丽2,刘胜旺2,马得莹1*   

  1. (1.东北农业大学动物营养研究所,哈尔滨 150030; 2.中国农业科学院哈尔滨兽医研究所 兽医生物技术国家重点实验室 禽传染病研究室,哈尔滨 150001)
  • 收稿日期:2012-06-14 出版日期:2012-12-26 发布日期:2012-12-26
  • 通讯作者: 马得莹, E-mail: mdy296@yahoo.cn
  • 作者简介:张名岳(1986-),男,河北沧州人,硕士研究生,从事动物营养与分子免疫学方面的研究,E-mail: zmy6611@126.com
  • 基金资助:

    国家自然科学基金(30972110)

Preliminary Exploration of the Signal Transduction Mechanisms of the Goose Beta Defensin 1 Resistance to Salmonella Enteritidis Infection Mediated by Toll-like Receptor 4

ZHANG Ming-yue1,2, ZHANG Ke-xin1,2, XIN Sheng-nan1,2, HAN Zong-xi2, SHAO Yu-hao2, LIU Xiao-li2, LIU Sheng-wang2, MA De-ying1,*   

  1. (1.Institute of Animal Nutrition, Northeast Agricultural University, Harbin, 150030; 2. Division of Avian Infectious Disease, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China)
  • Received:2012-06-14 Online:2012-12-26 Published:2012-12-26

摘要:

为研究鹅β-防御素1(AvBD1)的生物学特性以及初步尝试探寻其抗肠炎沙门菌的作用机理,利用RT-PCR方法从鹅骨髓组织中扩增到鹅AvBD1基因片段,并将该基因亚克隆到原核表达载体pGEX-6p-1的EcoRⅠ和SalⅠ双酶切位点上,构建重组表达质粒pGEX-goose AvBD1。将重组质粒转化大肠杆菌BL21,于37 ℃用IPTG诱导表达, SDS-PAGE电泳表明,重组鹅AvBD1蛋白在原核高效表达(相对分子质量约31 ku)。该重组蛋白经纯化后测定其体外抗菌活性与理化特性。结果显示,鹅AvBD1基因cDNA片段大小为198 bp,编码65个氨基酸残基。经相似性分析发现鹅AvBD1氨基酸序列与鸵鸟AvBD1氨基酸序列相似性最高,为77.1%,而且重组鹅AvBD1蛋白具有广谱的抗菌活性,对12种细菌(包括革兰阳性菌和革兰阴性菌)均具有抑菌作用。高盐离子浓度显著降低重组鹅AvBD1蛋白的抗菌活性,且该重组蛋白的溶血活性极低。试验表明,肠炎沙门菌确实会诱导鹅AvBD1基因在鹅骨髓组织中的表达,说明鹅AvBD1起到了抗肠炎沙门菌感染的作用,而这种作用有可能与TLR4介导的信号转导有关。

Abstract:

The objective of this study was to study the biological characteristics of goose AvBD1 and preliminary attempts to explore its resistance to Salmonella enteritidis mechanism. The mRNA of goose AvBD1 was cloned from bone marrow of the gooses by RT-PCR. The cDNA of goose AvBD1 was sub-cloned into EcoRⅠ and SalⅠ sites of pGEX-6p-1 vector to construct recombinant plasmid pGEX-goose AvBD1. The recombinant plasmid was transformed into E. coli BL21 and the bacteria was induced with IPTG. It was demonstrated by SDS-PAGE that a 31 kDa protein which was equal to goose AvBD1 protein in molecular weight was highly expressed. The sequence analysis showed that the gene fragment of AvBD1 contained 198 bp, and encoded 65 amino acids. Homology analysis showed that goose AvBD1 shared the highest percentage of amino acid homology (77.1%) with ostrich AvBD1.The purified recombinant goose AvBD1 exhibited extensive antimicrobial activity against twelve investigated bacteria strains, including Gram-positive and Gram-negative. At high salt ions conditions, antimicrobial activity of recombinant goose AvBD1 protein against both Staphylococcus aureus and Proteus mirabilis decreased significantly and hemolysis activity of the recombinant protein was extremely low. Experimental results show that Salmonella enteritidis did induced goose AvBD1 gene expression in bone marrow, at the same time goose AvBD1 resistance to Salmonella enteritidis infection induces expression of TLR4 may be mediated signal transduction.

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