International Livestock Research Institute, Box 30709, Nairobi 00100, Kenya.
Ticks Tick Borne Dis. 2012 Jun;3(3):170-8. doi: 10.1016/j.ttbdis.2012.03.003. Epub 2012 Jun 1.
Commercial vaccines based on the tick gut protein Bm86 have been successful in controlling the one-host tick Rhipicephalus (Boophilus) microplus and provide heterologous protection against certain other non-target ixodid tick species. This cross protection, however, does not extend to the three-host tick R. appendiculatus, the vector of the protozoan parasite Theileria parva. When transmitted to cattle, T. parva causes the often fatal disease East Coast fever. Here, we used insect cell-expressed recombinant versions of the R. appendiculatus homologs of Bm86, named Ra86, to vaccinate cattle. We measured multiple fitness characteristics for ticks that were fed on cattle Ra86-vaccinated or unvaccinated. The Ra86 vaccination of cattle significantly decreased the molting success of nymphal ticks to the adult stage. Modeling simulations based on our empirical data suggest that repeated vaccinations using Ra86 could reduce tick populations over successive generations. Vaccination with Ra86 could thus form a component of integrated control strategies for R. appendiculatus leading to a reduction in use of environmentally damaging acaricides.
基于蜱肠道蛋白 Bm86 的商业疫苗已成功控制了单宿主蜱 Rhipicephalus (Boophilus) microplus,并对某些其他非靶标硬蜱物种提供了异源保护。然而,这种交叉保护并不延伸到三宿主蜱 R. appendiculatus,即原生动物寄生虫 Theileria parva 的载体。当传播给牛时,T. parva 会引起通常致命的疾病东海岸热。在这里,我们使用昆虫细胞表达的重组 R. appendiculatus Bm86 同源物 Ra86 版本对牛进行疫苗接种。我们测量了喂食牛 Ra86 疫苗或未接种疫苗的蜱的多个适应度特征。牛 Ra86 疫苗接种显著降低了若虫向成虫阶段的蜕皮成功率。基于我们的经验数据的建模模拟表明,使用 Ra86 进行重复疫苗接种可以减少连续几代的蜱种群。因此,Ra86 疫苗接种可以成为控制 R. appendiculatus 的综合控制策略的一部分,从而减少对环境破坏性杀螨剂的使用。