Rahman Md Khalesur, Saiful Islam Mohammad, You Myungjo
Laboratory of Veterinary Parasitology, College of Veterinary Medicine and Bio-Safety Research Centre, Chonbuk National University, Iksan 54596, Korea.
Department of Microbiology, Faculty of Veterinary and Animal Science, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh.
Insects. 2018 Apr 2;9(2):39. doi: 10.3390/insects9020039.
Currently, multi-antigenic vaccine use is the method of choice for the strategic control of ticks. Therefore, determining the efficacy of combined antigens is a promising avenue of research in the development of anti-tick vaccines. The antigen responsible for blood intake and reproduction has proven suitable as a vaccine antigen. It has been shown to silence salivary cystatin (HlSC-1) and subolesin by RNA interference. Adult unfed female ticks were injected with double-stranded RNA of (A) subolesin, (B) cystatin, (C) subolesin plus cystatin, and (D) injection buffer, then fed alongside normal unfed males up to spontaneous drop-down. The percentage of knockdowns was determined by real-time polymerase chain reaction. Sixty-three percent and 53% knockdown rates were observed in subolesin and cystatin double-stranded RNA-injected ticks respectively, while 32 and 26% knockdown rates of subolesin and cystatin transcript were observed in subolesin plus cystatin double-stranded RNA-injected ticks. Subolesin and/or cystatin knockdown causes a significant ( < 0.05) reduction in tick engorgement, egg mass weight, and egg conversion ratio. Most importantly, combined silencing did not act synergistically, but caused a similarly significant ( < 0.05) reduction in tick engorgement, egg mass weight, and egg conversion ratio. Therefore, the elucidation of multiple antigens may be helpful in the future of vaccines.
目前，使用多抗原疫苗是蜱虫战略防控的首选方法。因此，确定联合抗原的功效是抗蜱疫苗研发中一个很有前景的研究方向。已证实负责吸血和繁殖的抗原适合作为疫苗抗原。通过RNA干扰已证明它能使唾液半胱氨酸蛋白酶抑制剂（HlSC-1）和亚油酸异构酶沉默。将未进食的成年雌性蜱虫分别注射（A）亚油酸异构酶、（B）半胱氨酸蛋白酶抑制剂、（C）亚油酸异构酶加半胱氨酸蛋白酶抑制剂的双链RNA，以及（D）注射缓冲液，然后与正常未进食的雄性蜱虫一起进食直至自然掉落。通过实时聚合酶链反应确定敲低率。在注射亚油酸异构酶双链RNA的蜱虫和注射半胱氨酸蛋白酶抑制剂双链RNA的蜱虫中，分别观察到63%和53%的敲低率，而在注射亚油酸异构酶加半胱氨酸蛋白酶抑制剂双链RNA的蜱虫中，亚油酸异构酶和半胱氨酸蛋白酶抑制剂转录本的敲低率分别为32%和26%。亚油酸异构酶和/或半胱氨酸蛋白酶抑制剂的敲低会导致蜱虫饱血程度、卵块重量和卵转化率显著降低（<0.05）。最重要的是，联合沉默并没有协同作用，但同样会导致蜱虫饱血程度、卵块重量和卵转化率显著降低（<0.05）。因此，阐明多种抗原可能对未来疫苗研发有所帮助。
