Recombinant antibodies against Iranian cobra venom as a new emerging therapy by phage display technology

Abstract Background: The production of antivenom from immunized animals is an established treatment for snakebites; however, antibody phage display technology may have the capacity to delivery results more quickly and with a better match to local need. Naja oxiana, the Iranian cobra, is a medically important species, responsible for a significant number of deaths annually. This study was designed as proof of principle to determine whether recombinant antibodies with the capacity to neutralize cobra venom could be isolated by phage display. Methods: Toxic fractions from cobra venom were prepared by chromatography and used as targets in phage display to isolate recombinant antibodies from a human scFv library. Candidate antibodies were expressed in E. coli HB2151 and purified by IMAC chromatography. The selected clones were analyzed in in vivo and in vitro experiments. Results: Venom toxicity was contained in two fractions. Around a hundred phage clones were isolated against each fraction, those showing the best promise were G12F3 and G1F4. While all chosen clones showed low but detectable neutralizing effect against Naja oxiana venom, clone G12F3 could inhibit PLA2 activity. Conclusion: Therefore, phage display is believed to have a good potential as an approach to the development of snake antivenom.

摘要 背景：免疫动物制备的抗蛇毒血清是治疗蛇咬的传统疗法；然而，抗体噬菌体展示技术可能具备更快地提供结果且更符合当地需求的能力。伊朗眼镜蛇（Naja oxiana）是一种具有重要医学价值的物种，每年导致大量死亡。本研究旨在验证原理，确定是否能够通过噬菌体展示技术从人源单链抗体（scFv）文库中分离出能够中和眼镜蛇毒素的重组抗体。方法：通过色谱法制备眼镜蛇毒素的毒性组分，并将其作为噬菌体展示的目标，以从人源单链抗体文库中分离重组抗体。候选抗体在E. coli HB2151中表达，并通过IMAC色谱法进行纯化。选定的克隆体在体内和体外实验中进行分析。结果：毒素毒性被包含在两个组分中。针对每个组分，分离出约一百个噬菌体克隆，其中G12F3和G1F4展现出最好的前景。虽然所有选定的克隆体对伊朗眼镜蛇毒素均显示出低但可检测的中和效果，但克隆体G12F3能够抑制PLA2活性。结论：因此，噬菌体展示被认为是一种在开发蛇毒抗血清方面具有良好潜力的方法。