本期文章：《自然—免疫学》：Online/在线发表

美国哈佛医学院Arlene H. Sharpe研究组发现，X-CHIME可对免疫系统中的基因进行组合式、可诱导、谱系特异性和顺序敲除。2023年11月27日，国际知名学术期刊《自然—免疫学》杂志在线发表了这一成果。

研究人员之前开发了CHIME（CHimeric IMmune Editing），这是一种CRISPR-Cas9骨髓递送系统，用于单基因的组成型、泛删除。研究人员报道了X-CHIME，这是四种基于CHIME的新系统，可对基因功能进行组合（C-CHIME）、诱导（I-CHIME）、谱系特异性（L-CHIME）或顺序（S-CHIME）的模块化快速检测。研究人员利用C-CHIME和S-CHIME评估了胚胎致死基因对Ptpn1和Ptpn2联合缺失对成年小鼠的影响。

研究人员发现，PTPN1和PTPN2的组成型缺失会导致骨髓发育不良和致死，而免疫发育后的诱导型缺失则会导致肠炎和致死。这些研究结果表明，X-CHIME可用于在不同的体内环境中对基因进行快速的机理评估，而且PTPN1和PTPN2有一些功能冗余，这对成年小鼠的生存能力非常重要。

据了解，注释体内免疫基因功能通常需要产生基因敲除小鼠，这既耗时又低通量。

附：英文原文

Title: X-CHIME enables combinatorial, inducible, lineage-specific and sequential knockout of genes in the immune system

Author: LaFleur, Martin W., Lemmen, Ashlyn M., Streeter, Ivy S. L., Nguyen, Thao H., Milling, Lauren E., Derosia, Nicole M., Hoffman, Zachary M., Gillis, Jacob E., Tjokrosurjo, Qin, Markson, Samuel C., Huang, Amy Y., Anekal, Praju V., Montero Llopis, Paula, Haining, W. Nicholas, Doench, John G., Sharpe, Arlene H.

Issue&Volume: 2023-11-27

Abstract: Annotation of immunologic gene function in vivo typically requires the generation of knockout mice, which is time consuming and low throughput. We previously developed CHimeric IMmune Editing (CHIME), a CRISPR–Cas9 bone marrow delivery system for constitutive, ubiquitous deletion of single genes. Here we describe X-CHIME, four new CHIME-based systems for modular and rapid interrogation of gene function combinatorially (C-CHIME), inducibly (I-CHIME), lineage-specifically (L-CHIME) or sequentially (S-CHIME). We use C-CHIME and S-CHIME to assess the consequences of combined deletion of Ptpn1 and Ptpn2, an embryonic lethal gene pair, in adult mice. We find that constitutive deletion of both PTPN1 and PTPN2 leads to bone marrow hypoplasia and lethality, while inducible deletion after immune development leads to enteritis and lethality. These findings demonstrate that X-CHIME can be used for rapid mechanistic evaluation of genes in distinct in vivo contexts and that PTPN1 and PTPN2 have some functional redundancy important for viability in adult mice.

DOI: 10.1038/s41590-023-01689-6