Hasannejad-Asl Behnam, Hashemzadeh Hassan, Pooresmaeil Farkhondeh, Dabiri Mehran, Pooresmaeil Mohammad-Reza, Ahmadvand Davoud, Hosseini Arshad
Department of Medical Biotechnology, School of Allied Medicical Sciences, Iran University of Medical Science, Tehran, Iran.
Department of chemistry, University of Birjand, Birjand, Iran.
Front Mol Biosci. 2024 Sep 2;11:1414119. doi: 10.3389/fmolb.2024.1414119. eCollection 2024.
During the last decade, there has been a significant rise in the use of therapeutic antibodies or passive immunotherapy for treating various conditions like inflammation and cancer. However, these proteins face challenges reaching the brain and often require specialized delivery methods such as single-domain antibodies (sdAbs). Traditional antibodies struggle to efficiently cross the blood-brain barrier (BBB), hindering their effectiveness. Receptor-mediated transcytosis (RMT) offers a promising pathway for transporting large molecules essential for brain function and treatment across the BBB.
SdAbs and peptide ligands with an affinity for RMT receptors are commonly employed to enhance the transport of biotherapeutics compounds across the BBB. This research used a sdAbs phage-displayed library from 13 samples to identify sdABs that specifically bind to and are internalized by human BBB endothelial cells (ECs) through panning.
One sdAb, defined as FB24, was isolated, sequenced, translated into an open reading frame (ORF), and subjected to three-dimensional (3D) modeling. Molecular docking and molecular dynamics simulations were carried out by the HADDOCK web server and GROMACS, respectively, to evaluate the interaction between FB24 and EC receptors . The docking results revealed that FB24 exhibited binding activity against potential EC receptors with -1.7 to -2.7 ranged z score and maintained a stable structure. The docked complex of FB24-RAGE (receptor for advanced glycation end products, also known as advanced glycation end product receptor [AGER]) showed 18 hydrogen bonds and 213 non-bonded contacts. It was chosen for further analysis by molecular dynamics simulations by GROMACS. This complex showed a stable condition, and its root mean square deviation (RMSD) was 0.218 nm. The results suggest that FB24 could serve as a suitable carrier vector for transporting therapeutic and diagnostic agents across the BBB to the brain through a non-invasive route.
在过去十年中，治疗性抗体或被动免疫疗法在治疗炎症和癌症等各种疾病中的应用显著增加。然而，这些蛋白质在进入大脑方面面临挑战，通常需要特殊的递送方法，如单域抗体（sdAbs）。传统抗体难以有效穿过血脑屏障（BBB），从而阻碍了它们的有效性。受体介导的转胞吞作用（RMT）为跨血脑屏障运输对脑功能和治疗至关重要的大分子提供了一条有前景的途径。
对RMT受体具有亲和力的单域抗体和肽配体通常用于增强生物治疗化合物跨血脑屏障的运输。本研究使用来自13个样本的单域抗体噬菌体展示文库，通过淘选来鉴定与人血脑屏障内皮细胞（ECs）特异性结合并被其内化的单域抗体。
分离出一种名为FB24的单域抗体，对其进行测序，将其翻译成开放阅读框（ORF），并进行三维（3D）建模。分别通过HADDOCK网络服务器和GROMACS进行分子对接和分子动力学模拟，以评估FB24与内皮细胞受体之间的相互作用。对接结果显示，FB24对潜在的内皮细胞受体表现出结合活性，z评分为-1.7至-2.7，并且保持稳定结构。FB24与晚期糖基化终产物受体（RAGE，也称为晚期糖基化终产物受体[AGER]）的对接复合物显示出18个氢键和213个非键接触。它被选择通过GROMACS进行分子动力学模拟进一步分析。该复合物显示出稳定状态，其均方根偏差（RMSD）为0.218纳米。结果表明，FB24可作为一种合适的载体，通过非侵入性途径将治疗和诊断药物跨血脑屏障运输到大脑。
