Preparation of Equine Immunoglobulin F(ab′) 2 against Smallpox and Evaluation of its Immunoprotective Effect

Smallpox, a severe infectious disease caused by the smallpox virus, causes a death rate as high as 30% within 15-20 days after infection. Therefore, development of anti-Smallpox product as a strategic reserve is urgently needed. We prepared and tested pepsin-digested F(ab′) 2 fragments of serum IgG...

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Bibliographic Details
Main Authors: Bochang Shi, Hui Han, Lingyun Tan, Yuan Liu, Fang Yan, Bo Li, Naxin Zheng, Min Li, Liyan Zhao, Huabin Li, Tietong Fan, Zhiping Zhang, Xinyu Li, Chongyu Tian, Yuanqiang Zheng, Wei He, Zhongpeng Zhao
Format: Article
Language:English
Published: Compuscript Ltd 2023-01-01
Series:Zoonoses
Online Access:https://www.scienceopen.com/hosted-document?doi=10.15212/ZOONOSES-2022-0048
Description
Summary:Smallpox, a severe infectious disease caused by the smallpox virus, causes a death rate as high as 30% within 15-20 days after infection. Therefore, development of anti-Smallpox product as a strategic reserve is urgently needed. We prepared and tested pepsin-digested F(ab′) 2 fragments of serum IgG from horses. Transmission electron microscopy indicated that the purified virus showed morphology consistent with VVTT. The titer was above 1.0 × 10 7 PFU/mL. The purity of the antigen exceeded 90%, according to HPLC. After purification and cleavage, the yield of the purified product F(ab′) 2 was approximately 1.3%, its purity exceeded 90%, and the neutralizing antibody titer exceeded 1:3200. F(ab′) 2 fragments had good preventive and therapeutic effects in mice at antibody doses of 5.2 mg/mL and 2.6 mg/mL. The viral loads of the drug-treated mice were suppressed to varying degrees, and the higher dose groups (5.2 and 2.6 mg/mL) showed a 2-3 fold lower viral load than that in the control group. A process for producing equine immunoglobulin F(ab′) 2 against VVTT was established. The prepared horse anti-smallpox immunoglobulin product had good neutralizing antibody effects on VVTT. The highly purified preparation may serve as a potential candidate for smallpox treatment.
ISSN:2737-7466
2737-7474