Li Yating, Cheng Kexuan, Guo Jiazheng, Jiang Yujia, Kang Qinglin, Wang Rong, Du Peng, Gao Chen, Yu Yunzhou, Yang Zhixin, Wang Wei, Lu Jiansheng
Laboratory of Advanced Biotechnology, Beijing Institute of Biotechnology, Beijing 100071, China.
Department of Occupational Health and Occupational Diseases, College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
Antibodies (Basel). 2025 Jun 13;14(2):48. doi: 10.3390/antib14020048.
Tetanus toxin, produced by , is the second deadliest known toxin. Antibodies capable of neutralizing tetanus toxin (TeNT) are vital for preventing and treating tetanus disease.
Herein, we screened thirty-six single variable domains on a heavy chain (VHHs) binding to the light chain (L) and the translocation domain (HN) (L-HN) fragment of TeNT from a phage-display library. Then, the L-HN-specific clones were identified, humanized, and fused with a human fragment crystallizable region (hFc) to form humanized VHH-hFc fusion proteins.
The humanized VHH-hFc fusion proteins TL-16-h1-hFc, TL-25-h1-hFc, and TL-34-h1-hFc possessed potent efficacy with high binding affinity, specificity, and neutralizing activity. Only 0.3125 μg was required for TL-16-h1-hFc or TL-25-h1-hFc, and 0.625 μg was required for TL-34-h1-hFc to provide full protection against 10 × Lethal Dose 50 (LD) TeNT. In the prophylactic setting, 125 μg/kg of TL-16-h1-hFc or TL-25-h1-hFc provided full protection even when they were injected 12 days before exposure to 10 × LD TeNT, while TL-34-h1-hFc was less effective. In the therapeutic setting, 25 μg/kg of TL-16-h1-hFc or TL-25-h1-hFc could provide complete protection when administered 24 h after exposure to 5 × LD TeNT, while TL-34-h1-hFc required 50 μg/kg.
Our results suggest that TL-16-h1-hFc, TL-25-h1-hFc, and TL-34-h1-hFc provide a bright future for the development of anti-TeNT preventive or therapeutic drugs.
由破伤风梭菌产生的破伤风毒素是已知的第二大致命毒素。能够中和破伤风毒素（TeNT）的抗体对于预防和治疗破伤风疾病至关重要。
在此，我们从噬菌体展示文库中筛选了36个重链单可变结构域（VHHs），它们与破伤风毒素的轻链（L）和转位结构域（HN）（L-HN）片段结合。然后，鉴定出L-HN特异性克隆，进行人源化，并与人源化片段可结晶区（hFc）融合，形成人源化VHH-hFc融合蛋白。
人源化VHH-hFc融合蛋白TL-16-h1-hFc、TL-25-h1-hFc和TL-34-h1-hFc具有强大的功效，具有高结合亲和力、特异性和中和活性。TL-16-h1-hFc或TL-25-h1-hFc仅需0.3125μg，TL-34-h1-hFc需0.625μg即可提供针对10×半数致死剂量（LD）破伤风毒素的完全保护。在预防情况下，即使在接触10×LD破伤风毒素前12天注射，125μg/kg的TL-16-h1-hFc或TL-25-h1-hFc也能提供完全保护，而TL-34-h1-hFc效果较差。在治疗情况下，接触5×LD破伤风毒素24小时后给予25μg/kg的TL-16-h1-hFc或TL-25-h1-hFc可提供完全保护，而TL-34-h1-hFc则需要50μg/kg。
我们的结果表明，TL-16-h1-hFc、TL-25-h1-hFc和TL-34-h1-hFc为抗破伤风毒素预防或治疗药物的开发提供了光明的前景。
