Czajka Timothy F, Vance David J, Song Renji, Mantis Nicholas J
Department of Biomedical Sciences, University at Albany, Albany, NY 12201 United States.
Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208.
bioRxiv. 2024 Jul 3:2024.07.02.601761. doi: 10.1101/2024.07.02.601761.
Expression of camelid-derived, single-domain antibodies (VHs) within the cytoplasm of mammalian cells as "intrabodies" has opened-up novel avenues for medical countermeasures against fast-acting biothreat agents. In this report, we describe a heterodimeric intrabody that renders Vero cells virtually impervious to ricin toxin (RT), a potent Category B ribosome-inactivating protein (RIP). The intrabody consists of two structurally defined VHs that target distinct epitopes on RT's enzymatic subunit (RTA): V9E1 targets RTA's P-stalk recruitment site, and V2A11 targets RTA's active site. Resistance to RT conferred by the biparatopic VH construct far exceeded that of either of the VHs alone and effectively inhibited all measurable RT-induced cytotoxicty . We propose that targeted delivery of bispecific intrabodies to lung tissues may represent a novel means to shield the airways from the effects of inhalational RT exposure.
在哺乳动物细胞胞质内表达骆驼科来源的单域抗体(VHs)作为“胞内抗体”,为应对快速起效的生物威胁制剂开辟了新的医学对策途径。在本报告中,我们描述了一种异二聚体胞内抗体,它使Vero细胞几乎对蓖麻毒素(RT)免疫,RT是一种强效的B类核糖体失活蛋白(RIP)。该胞内抗体由两个结构明确的VHs组成,它们靶向RT酶亚基(RTA)上不同的表位:V9E1靶向RTA的P柄招募位点,V2A11靶向RTA的活性位点。双特异性VH构建体赋予的对RT的抗性远远超过单独任何一种VH的抗性,并有效抑制了所有可测量的RT诱导的细胞毒性。我们提出,将双特异性胞内抗体靶向递送至肺组织可能是一种保护气道免受吸入性RT暴露影响的新方法。