Shen Hua, Chen Wangxue, Conlan J Wayne
National Research Council Canada, Institute for Biological Sciences, 100 Sussex Drive, Room 3065 Ottawa, Ont., Canada K1A OR6.
Microb Pathog. 2004 Aug;37(2):107-10. doi: 10.1016/j.micpath.2004.04.005.
The current study determined the ability of Francisella novicida to act as a live vaccine against the much more virulent, but closely related pathogen, Francisella tularensis. Live attenuated strains of the latter are effective vaccines against human tularemia. However, the molecular cause of their attenuation remains unknown, and this is a regulatory barrier for licensing such vaccines. Moreover, F. tularensis is exceptionally difficult to manipulate genetically. This is hampering the development of rationally attenuated vaccine strains. F. novicida shares a lot of genetic homology with F. tularensis and is more amenable to genetic manipulation. If the former naturally expresses the protective antigens of the latter, it could be used to develop a defined tularemia vaccine. However, the results presented herein show that wild-type F. novicida elicits almost no protection in mice against challenge with virulent F. tularensis.
当前的研究确定了新凶手弗朗西斯菌作为一种活疫苗，抵抗毒性更强但亲缘关系密切的病原体——土拉热弗朗西斯菌的能力。后者的减毒活菌株是预防人类兔热病的有效疫苗。然而，其减毒的分子原因仍然未知，这是此类疫苗获批的一个监管障碍。此外，土拉热弗朗西斯菌极难进行基因操作。这阻碍了合理减毒疫苗株的开发。新凶手弗朗西斯菌与土拉热弗朗西斯菌有许多基因同源性，并且更易于进行基因操作。如果前者能天然表达后者的保护性抗原，那么它可用于开发一种明确的兔热病疫苗。然而，本文给出的结果表明，野生型新凶手弗朗西斯菌在小鼠中几乎不能诱导出抵抗强毒土拉热弗朗西斯菌攻击的保护作用。
