对抗SARS-CoV-2单链抗体中和的可变转化为IgG提供了对RBD表皮质可访问性的洞察力
Matthew R Chang1, Hanzhong Ke1,2, Laura Losada Miguéns1
1Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
Protein engineering, design & selection : PEDS
|August 10, 2023
概括
使用菌体显示识别的中和SARS-CoV-2抗体的单克隆抗体 (mAb) 发现. 然而,将单链可变片段 (scFvs) 转化为全IgG抗体显示出由于抗原选择而导致中和功能的损失,影响了治疗的发展.
科学领域:
- 生物技术是生物技术.
- 免疫学 免疫学 免疫学
- 病毒学 病毒学
背景情况:
- 单克隆抗体 (mAbs) 是癌症和病毒感染的关键疗法.
- 抗体菌体显示是一种成本效益高,快速的mAb发现方法.
- SARS-CoV-2 Omicron 变种已经限制了现有的 mAb 疗法的疗效.
研究的目的:
- 使用大规模的菌体显示库识别中和抗SARS-CoV-2单链可变片段 (scFvs).
- 评估强大的scFvs转化为全免疫球蛋白G (IgG) 抗体,并评估其中和能力.
- 研究在scFv转化为IgG转化过程中中和化功率的潜在损失背后的原因.
主要方法:
- 利用一个拥有27亿成员的天真scFv菌体显示库对SARS-CoV-2受体结合域 (RBD) 进行分析.
- 识别并将强大的scFv克隆转换为IgG格式.
- 进行中和试验,动力测量 (亲和力) 和机制研究,以评估抗体功能.
主要成果:
- 确定了一组针对各种RBD表位的中和抗SARS-CoV-2 scFvs小组.
- 几种强大的scFv克隆在转换到IgG格式时失去了显著的中和能力.
- 观察到类似的结合亲缘关系,但与抗原选择相关的结构限制被确定为减少中和的原因.
结论:
- 在转化为IgG mAbs.时,scFv-菌素泛化带有降低中和功率的风险.
- 选择泛化抗原对于成功开发中和mAbs.至关重要.
- 这凸显了在抗体发现的初始阶段考虑结构性影响的重要性.
相关概念视频
Cross-reactivity
Overview
Antibody Structure and Classes
Antibodies, also known as immunoglobulins, are produced by B cells in response to foreign substances, such as bacteria and viruses. These proteins are critical for recognizing and neutralizing these substances, protecting the body from potential harm.
The basic structure of an antibody consists of four protein chains: two identical heavy chains and two identical light chains. These chains are held together by disulfide bonds and other non-covalent interactions, forming a Y-shaped structure.
The basic structure of an antibody consists of four protein chains: two identical heavy chains and two identical light chains. These chains are held together by disulfide bonds and other non-covalent interactions, forming a Y-shaped structure.


