van Engelenburg F A, Kaashoek M J, Rijsewijk F A, van den Burg L, Moerman A, Gielkens A L, van Oirschot J T
Department of Virology, Institute for Animal Science and Health, Lelystad, The Netherlands.
J Gen Virol. 1994 Sep;75 ( Pt 9):2311-8. doi: 10.1099/0022-1317-75-9-2311.
A marker vaccine elicits an antibody response in the host that can be distinguished from the antibody response induced by a wild-type strain. To obtain a bovine herpesvirus 1 (BHV-1) marker vaccine, we constructed a glycoprotein E (gE) deletion mutant. This was obtained by removing the complete gE coding region from the BHV-1 genome. To attenuate the gE deletion mutant further, we also introduced a small deletion in the thymidine kinase (TK) gene. We selected three mutants: the gE deletion mutant, a TK deletion mutant and a gE/TK double deletion mutant, and examined their virulence and immunogenicity in calves. After intranasal inoculation, the TK deletion mutant showed some residual virulence, whereas the gE and gE/TK deletion mutants were avirulent. The calves inoculated with the deletion mutants were protected against disease after challenge exposure and shed significantly less virus than control calves. Deleting the gE gene, therefore, has little effect on the immunogenicity of BHV-1, but is sufficient to reduce the virulence of BHV-1 in calves. These findings led us to conclude that the gE deletion mutant is a good candidate for a modified live BHV-1 marker vaccine.
一种标记疫苗能在宿主体内引发抗体反应，这种反应可与野生型毒株诱导产生的抗体反应区分开来。为获得牛疱疹病毒1型（BHV-1）标记疫苗，我们构建了一种糖蛋白E（gE）缺失突变体。这是通过从BHV-1基因组中去除完整的gE编码区而获得的。为进一步减弱gE缺失突变体的毒性，我们还在胸苷激酶（TK）基因中引入了一个小的缺失。我们筛选了三个突变体：gE缺失突变体、TK缺失突变体和gE/TK双缺失突变体，并检测了它们在犊牛中的毒力和免疫原性。经鼻内接种后，TK缺失突变体表现出一些残余毒力，而gE和gE/TK缺失突变体无毒力。接种缺失突变体的犊牛在攻毒后受到疾病保护，且病毒排出量明显低于对照犊牛。因此，删除gE基因对BHV-1的免疫原性影响不大，但足以降低BHV-1在犊牛中的毒力。这些发现使我们得出结论，gE缺失突变体是一种改良活BHV-1标记疫苗的良好候选者。
