a Agency for Defense Development , Yuseong, Daejeon , Republic of Korea.
b Abion R&D Institute , Hanhwa Biz-Metro, Guro-gu, Seoul , Republic of Korea.
Hum Vaccin Immunother. 2018 Feb 1;14(2):329-336. doi: 10.1080/21645515.2017.1405201. Epub 2017 Dec 19.
Botulinum neurotoxins (BoNTs) are the most potent toxins to mammals. A toxoid vaccine was previously used for prevention of botulinum intoxication; however, this vaccine is no longer available. Currently, no approved botulinum vaccines are available from the Food and Drug Administration (FDA). Recently, a recombinant host cell receptor-binding subunit created for use as a potential vaccine completed phase 2 clinical trials. The current study designed a vaccine candidate against BoNT type A (BoNT/A) using a structural design. Our vaccine candidate was the BoNT/A heavy chain C-terminal region (HCR) that contained the point mutation BA15 (R1269A) within the ganglioside-binding site. A Biacore affinity test showed that the affinity of BA15 for ganglioside GT1b was 100 times lower than that of the HCR. A SNAP25 cleavage assay revealed that immunized sera blocked SNAP25 cleavage of the BoNT/A toxin via BA15. In an in vivo experiment, mice and guinea pigs immunized with BA15 produced neutralizing antibodies that protected against 3,000 LD of BoNT/A. In conclusion, the results of both in vitro and in vivo assays showed that our BA15 vaccine candidate was similar to the recombinant host cell receptor-binding subunit vaccine. The inability of BA15to bind ganglioside shows that BA15 is a potential safe vaccine candidate.
肉毒神经毒素（BoNTs）是对哺乳动物最有效的毒素。以前曾使用类毒素疫苗预防肉毒中毒；然而，这种疫苗已不再供应。目前，食品和药物管理局（FDA）没有批准的肉毒疫苗。最近，一种用于潜在疫苗的重组宿主细胞受体结合亚单位完成了 2 期临床试验。本研究设计了一种使用结构设计的针对 BoNT 型 A（BoNT/A）的疫苗候选物。我们的疫苗候选物是 BoNT/A 重链 C 末端区域（HCR），其在神经节苷脂结合位点内包含点突变 BA15（R1269A）。Biacore 亲和力测试表明，BA15 与神经节苷脂 GT1b 的亲和力比 HCR 低 100 倍。SNAP25 切割测定表明，免疫血清通过 BA15 阻断了 BoNT/A 毒素对 SNAP25 的切割。在体内实验中，用 BA15 免疫的小鼠和豚鼠产生了中和抗体，可预防 3000LD 的 BoNT/A。总之，体外和体内试验的结果均表明，我们的 BA15 疫苗候选物与重组宿主细胞受体结合亚单位疫苗相似。BA15 不能结合神经节苷脂表明 BA15 是一种有潜力的安全疫苗候选物。
