β防御素2转基因小鼠抗金黄色葡萄球菌感染的研究

目的探讨转基因小鼠抗金黄色葡萄球菌作用。方法用分子克隆方法构建β防御素2（HBD-2）全长cDNA重组质粒,通过显微注射技术,将重组片段注射入小鼠雌原核细胞,聚合酶链反应（PCR）方法检测小鼠HBD2基因整合情况,免疫组化检测转基因小鼠HBD2表达和组织分布。用金黄色葡萄球菌腹腔攻击转基因阳性小鼠观测全身情况和死亡数。结果DNA序列测定证明重组质粒插入HBD-2cDNA片段无误,PCR显示7只小鼠已整合HBD-2基因,PCR阳性小鼠免疫组化显示HBD2基因在肺、肠道、肝、肾、睾丸、小脑等组织广泛表达。腹腔攻击实验显示7只转基因小鼠4只存活,而野生小鼠10只全部死亡。结论HBD-2在体内具有显著抗金色葡萄球菌感染能力。

Effect of human beta defensin 2 on Staphylococcus aureus infection: in vivo study with transgenic mice

Objective To investigate the effect of human beta defensin 2 (HBD-2) on Staphylococcus aureus infection. Methods A minigene of HBD-2 containing pCMV promoter, full length of HBD-2 cDNA, and BGH polyA tail was generated by PCR amplification and introduced into the fertilized oocytes of C57/ICR hybridized mouse by microinjection. After gestation of 3-4 weeks, immunohistochemistry was used to detect the expression of HBD-2 peptide in different tissues of the transgenic young mice. Staphylococcus aureus was cultured and injected intraperitoneally to wild type mice and transgenic mice to observe their surviving status. Results PCR showed that the HBD-2 fragment had been successfully integrated into the chromosome of the mice. A widespread expression of HBD-2 gene was found in many tissues of the transgenic mice: trachea, lung, intestine, esophagus, testis, spleen, skin, endothelium, brain, etc. Four of the 7 transgenic mice survived the Staphylococcus aureus infection, and 10 wild type mice all died within 24 hours. Conclusion HBD-2 may play an important role ion the host defense against Staphylococcus aureus infection.