美国哈佛大学医学院Robert T. Manguso、Kathleen B. Yates等研究人员合作通过选择性CRISPR抗原移除的体内筛选揭示肾细胞癌的免疫依赖性。2021年1月25日，《免疫》杂志在线发表了这一最新研究成果。

研究人员表征了针对Cas9和其他CRISPR载体成分的免疫应答，这些成分在几种小鼠癌症模型中引起抗原特异性肿瘤排斥。为了避免有害的免疫识别，研究人员设计了一种慢病毒载体系统，该系统能够从肿瘤细胞中选择性去除CRISPR抗原（SCAR）。SCAR系统在体内逆转了CRISPR修饰肿瘤细胞的免疫排斥反应，并在以前难以治疗的模型中实现了高通量遗传筛选。

在CRISPR抗原敏感的肾细胞癌中，研究人员使用SCAR进行了汇合体内筛选，并揭示了与自噬和I类主要组织相容性复合体（MHC I类）表达相关的耐药途径。因此，SCAR提供了一个资源库，可实现基于CRISPR的肿瘤-免疫相互作用的研究，并防止对基因工程细胞进行有害的免疫识别，从而对临床应用产生影响。

据悉，CRISPR-Cas9基因组工程提高了免疫学和癌症生物学的发现速度，也揭示了潜在的治疗靶标，并提供了对免疫疗法耐药性潜在机制的见解。但是，Cas9的内源性免疫识别限制了CRISPR技术在体内的适用性。

附：英文原文

Title: In vivo screens using a selective CRISPR antigen removal lentiviral vector system reveal immune dependencies in renal cell carcinoma

Author: Juan Dubrot, Sarah Kate Lane-Reticker, Emily A. Kessler, Austin Ayer, Gargi Mishra, Clara H. Wolfe, Margaret D. Zimmer, Peter P. Du, Animesh Mahapatra, Kyle M. Ockerman, Thomas G.R. Davis, Ian C. Kohnle, Hans W. Pope, Peter M. Allen, Kira E. Olander, Arvin Iracheta-Vellve, John G. Doench, W. Nicholas Haining, Kathleen B. Yates, Robert T. Manguso

Issue&Volume: 2021-01-25

Abstract: CRISPR-Cas9 genome engineering has increased the pace of discovery for immunologyand cancer biology, revealing potential therapeutic targets and providing insightinto mechanisms underlying resistance to immunotherapy. However, endogenous immunerecognition of Cas9 has limited the applicability of CRISPR technologies in vivo. Here, we characterized immune responses against Cas9 and other expressed CRISPRvector components that cause antigen-specific tumor rejection in several mouse cancermodels. To avoid unwanted immune recognition, we designed a lentiviral vector systemthat allowed selective CRISPR antigen removal (SCAR) from tumor cells. The SCAR systemreversed immune-mediated rejection of CRISPR-modified tumor cells in vivo and enabled high-throughput genetic screens in previously intractable models. A pooledin vivo screen using SCAR in a CRISPR-antigen-sensitive renal cell carcinoma revealed resistancepathways associated with autophagy and major histocompatibility complex class I (MHCclass I) expression. Thus, SCAR presents a resource that enables CRISPR-based studiesof tumor-immune interactions and prevents unwanted immune recognition of geneticallyengineered cells, with implications for clinical applications.

DOI: 10.1016/j.immuni.2021.01.001

Source: https://www.cell.com/immunity/fulltext/S1074-7613(21)00001-7