Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA.
Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA; Division of Pediatric Hematology and Oncology, Children's Hospital, Boston, MA, USA; Merck Research Laboratories, Boston, MA, USA.
Immunity. 2021 Mar 9;54(3):571-585.e6. doi: 10.1016/j.immuni.2021.01.001. Epub 2021 Jan 25.
CRISPR-Cas9 genome engineering has increased the pace of discovery for immunology and cancer biology, revealing potential therapeutic targets and providing insight into mechanisms underlying resistance to immunotherapy. However, endogenous immune recognition of Cas9 has limited the applicability of CRISPR technologies in vivo. Here, we characterized immune responses against Cas9 and other expressed CRISPR vector components that cause antigen-specific tumor rejection in several mouse cancer models. To avoid unwanted immune recognition, we designed a lentiviral vector system that allowed selective CRISPR antigen removal (SCAR) from tumor cells. The SCAR system reversed immune-mediated rejection of CRISPR-modified tumor cells in vivo and enabled high-throughput genetic screens in previously intractable models. A pooled in vivo screen using SCAR in a CRISPR-antigen-sensitive renal cell carcinoma revealed resistance pathways associated with autophagy and major histocompatibility complex class I (MHC class I) expression. Thus, SCAR presents a resource that enables CRISPR-based studies of tumor-immune interactions and prevents unwanted immune recognition of genetically engineered cells, with implications for clinical applications.
CRISPR-Cas9 基因组工程加快了免疫学和癌症生物学的发现步伐，揭示了潜在的治疗靶点，并深入了解了免疫疗法耐药的机制。然而，Cas9 的内源性免疫识别限制了 CRISPR 技术在体内的适用性。在这里，我们对 Cas9 及其他在几种小鼠癌症模型中引起抗原特异性肿瘤排斥的表达型 CRISPR 载体成分的免疫反应进行了特征描述。为了避免不必要的免疫识别，我们设计了一种慢病毒载体系统，允许从肿瘤细胞中选择性地去除 CRISPR 抗原（SCAR）。SCAR 系统逆转了体内免疫介导的对 CRISPR 修饰的肿瘤细胞的排斥，并能够在以前难以处理的模型中进行高通量遗传筛选。在对 CRISPR 抗原敏感的肾细胞癌中使用 SCAR 进行的 pooled in vivo 筛选揭示了与自噬和主要组织相容性复合体 I 类（MHC I 类）表达相关的耐药途径。因此，SCAR 提供了一种资源，使基于 CRISPR 的肿瘤免疫相互作用研究成为可能，并防止了对基因工程细胞的不必要的免疫识别，这对临床应用具有重要意义。
