Kaashoek M J, van Engelenburg F A, Moerman A, Gielkens A L, Rijsewijk F A, van Oirschot J T
Department of Bovine Virology, Institute for Animal Science and Health, Lelystad, Netherlands.
Vet Microbiol. 1996 Jan;48(1-2):143-53. doi: 10.1016/0378-1135(95)00137-9.
A deletion was introduced into the thymidine kinase (TK) gene of the BHV1 strain Lam and, or, the complete coding region of the glycoprotein E (gE) gene was deleted to reduce virulence and to make serological differentiation possible. The virulence and immunogenicity of these three BHV1 mutants (TK-, gE- and TK-/gE) were studied in specific-pathogen-free calves. Although inactivation of TK strongly reduced the virulence of the Lam strain, deletion of the gE gene alone sufficed to yield complete attenuation of the Lam strain for seven-week-old calves. The three mutants induced protective immunity against disease after challenge with a virulent BHV1 strain. The reduction of virus shedding after challenge was related to the virulence of the various strains. The immunogenicity of the mutants was also evidenced by the reduction of challenge virus shedding after dexamethasone treatment. None of the mutant viruses could be isolated after dexamethasone treatment. The results demonstrate that the gE- and TK-/gE- mutants are good candidates for incorporation in a BHV1 marker vaccine.
在BHV1毒株Lam的胸苷激酶（TK）基因中引入了一个缺失突变，和/或删除了糖蛋白E（gE）基因的完整编码区，以降低毒力并实现血清学鉴别。在无特定病原体的犊牛中研究了这三种BHV1突变体（TK-、gE-和TK-/gE）的毒力和免疫原性。虽然TK的失活强烈降低了Lam毒株的毒力，但单独删除gE基因就足以使Lam毒株对7周龄犊牛完全减毒。这三种突变体在用强毒BHV1毒株攻毒后诱导了针对疾病的保护性免疫。攻毒后病毒排出量的减少与各毒株的毒力有关。地塞米松处理后攻毒病毒排出量的减少也证明了突变体的免疫原性。地塞米松处理后未分离到任何突变病毒。结果表明，gE-和TK-/gE-突变体是用于制备BHV1标记疫苗的良好候选毒株。
