VISTA是PSGL-1的酸性pH选择性连接体
Robert J Johnston1, Linhui Julie Su2, Jason Pinckney3
1Immuno-Oncology Discovery, Bristol-Myers Squibb, Redwood City, CA, USA. robert.johnston@bms.com.
Nature
|October 25, 2019
概括
在酸性pH下,瘤微环境通过VISTA与PSGL-1结合来抑制T细胞. 阻断这种相互作用会逆转免疫抑制,
科学领域:
- 免疫学
- 癌症生物学
- 分子生物学
背景情况:
- 同抑制性免疫受体如CTLA-4和PD-1有助于癌症T细胞功能障碍.
- 目前针对CTLA-4和PD-1的疗法显示有效性,但不能完全恢复抗瘤免疫力.
- 瘤创造免疫抑制环境的机制尚未完全理解.
研究的目的:
- 研究V域免疫球蛋白抑制T细胞激活 (VISTA) 在瘤微环境中的T细胞抑制作用.
- 鉴定VISTA驱动免疫抑制的分子相互作用和环境因素.
- 探索VISTA作为增强抗瘤免疫力的潜在治疗点.
主要方法:
- 在不同pH条件下的VISTA与T细胞相互作用的特征.
- 确定参与VISTA-PSGL-1结合的关键氨基酸残留物.
- 在酸性环境中开发和测试针对VISTA-PSGL-1相互作用的阻断抗体.
- 对逆转VISTA介导免疫抑制的抗体有效性的体内评估.
主要成果:
- 在瘤微环境的特征酸性pH值下,VISTA可以选择性地激活和抑制T细胞.
- 在VISTA上存在的特定的歇斯蒂丁残留物中介于与P-选择蛋白糖蛋白连接物-1 (PSGL-1) 的结合.
- 在酸性条件下阻止VISTA- PSGL-1相互作用的抗体有效地逆转了VISTA介导的免疫抑制.
结论:
- 使用瘤微环境中的酸性pH,通过PSGL-1抑制T细胞活动.
- 由pH调节的VISTA-PSGL-1相互作用代表了瘤诱导的免疫抵抗的新机制.
- 针对pH依赖的VISTA-PSGL-1轴为克服癌症治疗中的免疫逃避提供了一个有希望的策略.
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