Liaoning Key Laboratory of Molecular Recognition and imaging, School of Bioengineering, Dalian University of Technology, No. 2 Linggong Road, Dalian, Liaoning, 116023, PR China.
Liaoning Key Laboratory of Molecular Recognition and imaging, School of Bioengineering, Dalian University of Technology, No. 2 Linggong Road, Dalian, Liaoning, 116023, PR China.
Acta Biomater. 2020 Apr 15;107:232-241. doi: 10.1016/j.actbio.2020.02.028. Epub 2020 Feb 22.
Removing β2-microglobulin (β2M) from blood circulation is considered to be the most effective method to delay the occurrence of dialysis-related amyloidosis (DRA). The ideal extracorporeal β2M removal system should be cost-effective, highly specific and having a high capacity. However, the traditional technologies based on size exclusion do not have an adequate specificity, and alternative immunosorbents have limited applications due to low capacity and their high cost. Nanobodies (Nbs), the smallest functional recombinant antibody fragments, offer several advantages to overcome these obstacles. In this study, an anti-β2M Nb with a C-terminal thiol-tag was successfully prepared from E. coli for site-directed and oriented immobilization and usage as capture ligand in a β2M-selective immunosorbent. The prepared immunosorbent showed a high binding capacity of up to 7 mg β2M per mL resin, which is 17 times higher than that of previous studies using single-chain variable antibody fragments (scFv). Furthermore, an exceptional high specificity has been demonstrated as other human serum proteins were not adsorbed during dynamic adsorption experiments. About 80% of the original binding capacity of the immunosorbent was restored after four consecutive easy regenerations, whereas 90% of the original capacity was retained after 1-month storage of the resin. Moreover, the mathematical model fitted very well the in vitro perfusion. The results with this pioneering immunosorbent confirm its possible clinical application and is expected to reach the required clinical effect of immunoadsorption therapy. STATEMENT OF SIGNIFICANCE: Dialysis-related amyloidosis (DRA), associated with the accumulation of β2-microglobulin (β2M), is a serious complication of end-stage kidney disease. Removing β2M from blood circulation by extracorporeal blood purification is considered to be the most effective method to delay the occurrence of DRA. However, the existing methods are incapable to eliminate sufficient quantities of β2M from circulation, either because of lack of specificity, high cost or for low capacity. In this manuscript, we provide a practical and economic immunosorbent based on anti-β2M nanobody for DRA. The prepared immunosorbent was reusable and storable, and demonstrated high specificity and realized a high binding capacity of up to 7 mg β2M per mL resin, which is 17 times higher than that of the previous studies.
从血液循环中去除β2-微球蛋白（β2M）被认为是延缓透析相关淀粉样变性（DRA）发生的最有效方法。理想的体外β2M 去除系统应该具有成本效益、高度特异性和高容量。然而，基于尺寸排阻的传统技术特异性不足，替代免疫吸附剂由于容量低和成本高而应用有限。纳米抗体（Nbs）是最小的功能性重组抗体片段，具有克服这些障碍的几个优势。在这项研究中，成功地从大肠杆菌中制备了带有 C 末端巯基标签的抗β2M Nb，用于在β2M 选择性免疫吸附剂中进行定向和定向固定以及用作捕获配体。制备的免疫吸附剂表现出高达 7mgβ2M/mL 树脂的高结合容量，比以前使用单链可变抗体片段（scFv）的研究高 17 倍。此外，在动态吸附实验中，其他人体血清蛋白没有被吸附，证明了其具有极高的特异性。经过四次连续的简单再生，免疫吸附剂的原始结合容量约有 80%得到恢复，而在树脂储存 1 个月后，仍保留 90%的原始容量。此外，该数学模型非常适合体外灌注。该免疫吸附剂的结果证实了其可能的临床应用，并有望达到免疫吸附治疗所需的临床效果。
与终末期肾病相关的透析相关淀粉样变性（DRA）与β2-微球蛋白（β2M）的积累有关。通过体外血液净化从血液循环中去除β2M 被认为是延缓 DRA 发生的最有效方法。然而，现有的方法要么缺乏特异性，要么成本高，要么容量低，无法从循环中去除足够数量的β2M。在本文中，我们提供了一种基于抗β2M 纳米抗体的实用且经济的 DRA 免疫吸附剂。所制备的免疫吸附剂可重复使用和储存，表现出高特异性，实现了高达 7mgβ2M/mL 树脂的高结合容量，比以前的研究高 17 倍。
