以伯氏疏螺旋体为载体菌研究梅毒螺旋体的基因功能

Functional study of Treponema pallidum genes using Borrelia burgdorferi as a surrogate system

目的：利用体外可培养的伯氏疏螺旋体作为载体菌，将梅毒螺旋体的基因转入相应的伯氏疏螺旋体菌株进行功能性表达，进而对梅毒螺旋体的基因功能进行研究。方法构建一个携带梅毒螺旋体基因tp0111的大肠埃希菌-伯氏疏螺旋体穿梭质粒，利用电转化法，将质粒转入相应的伯氏疏螺旋体菌株中，通过观察伯氏疏螺旋体的表型和相关基因表达变化，来研究梅毒螺旋体的基因功能。结果成功将梅毒螺旋体基因tp0111转入伯氏疏螺旋体rpoN突变株内，一定程度上回补了伯氏疏螺旋体突变株的表型缺陷。结论首次证明tp0111是梅毒螺旋体的rpoN基因，同时验证了伯氏疏螺旋体可以作为载体来研究梅毒螺旋体的致病因子及其基因调控系统。

Objective To employ Borrelia burgdorferi（ B. burgdorferi） , a culturable and genetical-ly transformable spirochete, as a surrogate system to study Treponema pallidum （ T. pallidum） gene function. Methods Bioinformatic analysis revealed that the T. pallidum gene tp0111 encodes the putative sigma factor RpoN. We constructed a B. burgdorferi shuttle vector harboring tp0111. The shuttle vector was then trans-formed into the B. burgdorferi rpoN mutant strain. The phenotype of the resulting B. burgdorferi strain was then determined. Results We successfully constructed the B. burgdorferi rpoN mutant carrying the T. palli-dum gene tp0111. We found that tp0111 could partially complement the B. burgdorferi rpoN mutant. Con-clusion This work provides the first experimental evidence showing that tp0111 is the rpoN gene of T. palli-dum. It also demonstrates that B. burgdorferi can be used as a surrogate system for studying T. pallidum gene function.