Immunological Characterization and Neutralizing Ability of Monoclonal Antibodies Directed Against Botulinum Neurotoxin Type H
Immunological Characterization and Neutralizing Ability of Monoclonal Antibodies Directed Against Botulinum Neurotoxin Type H
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DOI：
10.1093/infdis/jiv770
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发表时间：
2016-05-15
影响因子：
6.4
通讯作者：
Arnon, Stephen S.
中科院分区：
文献类型：
--
作者：
Fan, Yongfeng;Barash, Jason R.;Arnon, Stephen S.
背景只有肉毒梭菌菌株IBCA 10 -7060产生最近描述的新型H型肉毒杆菌神经毒素（BoNT/H）。BoNT/H（N-末端与BoNT/F同源性最高的三分之二，C-末端与BoNT/A同源性最高的三分之一）需要抗毒素与毒素的比例= 1190：1才能被现有的抗毒素中和。因此，需要针对BoNT/H的更有效和更安全的抗毒素。方法.aEuro积分因此，我们评估了我们现有的针对BoNT/A和BoNT/F的单克隆抗体（mAb）的BoNT/H结合，产生酵母展示突变体以通过使用流式细胞术选择更高亲和力结合的mAb，并在标准小鼠生物测定中评价mAb中和BoNT/H的能力。H具有高亲和力。然而，6种BoNT/F mAb中只有1种（4E17.2A）结合BoNT/H，但其亲和力（平衡解离结合常数[K-D] = 7.56 x 10（-8）M）比其BoNT/F亲和力（K-D = 9.1 x 10（-11）M）低> 800倍，表明BoNT/H的N-末端三分之二是免疫学独特的。4E17.2A对BoNT/H的亲和力增加> 500倍至K-D = 1.48 × 10（-10）M（mAb 4E17.2D）。mAb RAZ 1、CR2和4E17.2D的组合完全保护了用280小鼠半数致死剂量的BoNT/H攻击的小鼠，mAb剂量低至5 μ g总抗体。结论：aEuro积分该3-mAb组合有效地中和了BoNT/H，并代表了可开发用于预防和治疗H型肉毒中毒的潜在人抗毒素。
Background. Only Clostridium botulinum strain IBCA10-7060 produces the recently described novel botulinum neurotoxin type H (BoNT/H). BoNT/H (N-terminal two-thirds most homologous to BoNT/F and C-terminal one-third most homologous to BoNT/A) requires antitoxin to toxin ratios = 1190: 1 for neutralization by existing antitoxins. Hence, more potent and safer antitoxins against BoNT/H are needed.Methods.aEuro integral We therefore evaluated our existing monoclonal antibodies (mAbs) to BoNT/A and BoNT/F for BoNT/H binding, created yeast-displayed mutants to select for higher-affinity-binding mAbs by using flow cytometry, and evaluated the mAbs' ability to neutralize BoNT/H in the standard mouse bioassay.Results.aEuro integral Anti-BoNT/A H-CC-binding mAbs RAZ1 and CR2 bound BoNT/H with high affinity. However, only 1 of 6 BoNT/F mAbs (4E17.2A) bound BoNT/H but with an affinity > 800-fold lower (equilibrium dissociation binding constant [K-D] = 7.56 x 10(-8) M) than its BoNT/F affinity (K-D = 9.1 x 10(-11) M), indicating that the N-terminal two-thirds of BoNT/H is immunologically unique. The affinity of 4E17.2A for BoNT/H was increased > 500-fold to K-D = 1.48 x 10(-10) M (mAb 4E17.2D). A combination of mAbs RAZ1, CR2, and 4E17.2D completely protected mice challenged with 280 mouse median lethal doses of BoNT/H at a mAb dose as low as 5 A mu g of total antibody.Conclusions.aEuro integral This 3-mAb combination potently neutralized BoNT/H and represents a potential human antitoxin that could be developed for the prevention and treatment of type H botulism.