Nanobodies that block gating of the P2X7 ion channel ameliorate inflammation
Nanobodies that block gating of the P2X7 ion channel ameliorate inflammation
复制标题
DOI：
10.1126/scitranslmed.aaf8463
复制
发表时间：
2016-11-23
影响因子：
17.1
通讯作者：
Koch-Nolte, Friedrich
中科院分区：
文献类型：
--
作者：
Danquah, Welbeck;Meyer-Schwesinger, Catherine;Koch-Nolte, Friedrich
离子通道是理想的治疗靶点，但仍需要具有高选择性和低副作用的离子通道导向药物。与小分子抑制剂不同，抗体对靶抗原具有高度选择性，但大多不能拮抗离子通道功能。纳米抗体——小的单域抗体片段——可以克服这些问题。 P2X7 是一种配体门控离子通道，在检测到受损细胞释放的 5'-三磷酸腺苷后，会启动促炎信号级联反应，包括释放细胞因子，例如白细胞介素 1 β (IL-1 β)。为了进一步探索其功能，我们生成并表征了针对小鼠 P2X7 的纳米抗体，该纳米抗体可有效阻断 (13A7) 或增强 (14D5) 通道的门控。在小鼠体内全身注射纳米抗体 13A7 可阻断体内 T 细胞和巨噬细胞上的 P2X7，并改善实验性肾小球肾炎和过敏性接触性皮炎。我们还生成了纳米抗体 Dano1，它特异性抑制人类 P2X7。在内毒素处理的人血液中，Dano1 阻止 IL-1 β 释放的效力比目前临床开发中的小分子 P2X7 拮抗剂强 1000 倍。我们的结果表明，纳米抗体技术可以产生针对离子通道的有效、特异性疗法，确认 P2X7 作为炎症性疾病的治疗靶点，并表征针对 P2X7 的有效新候选药物。
Ion channels are desirable therapeutic targets, yet ion channel-directed drugs with high selectivity and few side effects are still needed. Unlike small-molecule inhibitors, antibodies are highly selective for target antigens but mostly fail to antagonize ion channel functions. Nanobodies-small, single-domain antibody fragments-may overcome these problems. P2X7 is a ligand-gated ion channel that, upon sensing adenosine 5'-triphosphate released by damaged cells, initiates a proinflammatory signaling cascade, including release of cytokines, such as interleukin-1 beta (IL-1 beta). To further explore its function, we generated and characterized nanobodies against mouse P2X7 that effectively blocked (13A7) or potentiated (14D5) gating of the channel. Systemic injection of nanobody 13A7 in mice blocked P2X7 on T cells and macrophages in vivo and ameliorated experimental glomerulonephritis and allergic contact dermatitis. We also generated nanobody Dano1, which specifically inhibited human P2X7. In endotoxin-treated human blood, Dano1 was 1000 times more potent in preventing IL-1 beta release than small-molecule P2X7 antagonists currently in clinical development. Our results show that nanobody technology can generate potent, specific therapeutics against ion channels, confirm P2X7 as a therapeutic target for inflammatory disorders, and characterize a potent new drug candidate that targets P2X7.