Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA.
Department of Medicine, University of California Los Angeles and Jonsson Comprehensive Cancer Center, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA.
Cell Rep. 2019 Sep 3;28(10):2728-2738.e7. doi: 10.1016/j.celrep.2019.07.106.
Neoantigen-specific T cells are increasingly viewed as important immunotherapy effectors, but physically isolating these rare cell populations is challenging. Here, we describe a sensitive method for the enumeration and isolation of neoantigen-specific CD8+ T cells from small samples of patient tumor or blood. The method relies on magnetic nanoparticles that present neoantigen-loaded major histocompatibility complex (MHC) tetramers at high avidity by barcoded DNA linkers. The magnetic particles provide a convenient handle to isolate the desired cell populations, and the barcoded DNA enables multiplexed analysis. The method exhibits superior recovery of antigen-specific T cell populations relative to literature approaches. We applied the method to profile neoantigen-specific T cell populations in the tumor and blood of patients with metastatic melanoma over the course of anti-PD1 checkpoint inhibitor therapy. We show that the method has value for monitoring clinical responses to cancer immunotherapy and might help guide the development of personalized mutational neoantigen-specific T cell therapies and cancer vaccines.
新抗原特异性 T 细胞被越来越多地视为重要的免疫治疗效应物，但从少量患者肿瘤或血液样本中分离这些稀有细胞群是具有挑战性的。在这里，我们描述了一种从患者肿瘤或血液的小样本中计数和分离新抗原特异性 CD8+T 细胞的灵敏方法。该方法依赖于磁性纳米颗粒，这些颗粒通过带有条形码 DNA 接头的新抗原负载的主要组织相容性复合物 (MHC) 四聚体以高亲和力呈现。磁性颗粒为分离所需的细胞群提供了方便的处理方法，而条形码 DNA 则实现了多重分析。与文献方法相比，该方法显示出对抗原特异性 T 细胞群有更好的回收效果。我们应用该方法来分析接受抗 PD1 检查点抑制剂治疗的转移性黑色素瘤患者肿瘤和血液中的新抗原特异性 T 细胞群。我们表明，该方法对于监测癌症免疫治疗的临床反应具有价值，并且可能有助于指导个性化突变新抗原特异性 T 细胞治疗和癌症疫苗的开发。
