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科学家绘制出癌细胞逃避T细胞杀伤的功能基因组图谱
2020-09-25 10:26

加拿大多伦多大学Jason Moffat团队绘制出癌细胞逃避T细胞杀伤的功能基因组图谱。这一研究成果于2020年9月23日在线发表在国际学术期刊《自然》上。

为了确定一个表型上强大的基因和通路核心集,从而使癌细胞能够逃避细胞毒性T淋巴细胞(CTL)介导的杀伤作用,研究人员在一组与CTL共同培养的多种遗传差异小鼠癌细胞系中进行了全基因组CRISPR筛选。研究人员在这些小鼠癌症模型中确定了182个基因的核心集,其单个干扰增加了癌细胞对CTL介导的毒性敏感或抵抗。
 
使用遗传共相似性对这一数据集进行系统的探索揭示出基因和途径在癌细胞中起作用,从而协调其对CTL逃避的分级和协调方式,并显示了控制干扰素反应和肿瘤坏死因子(TNF)的离散功能模块诱导的细胞毒性是主要的亚表型。这些数据为以前被鉴定为II型干扰素应答的负调节剂的基因(例如Ptpn2、Socs1和Adar1)在介导CTL逃逸中建立了核心作用,并表明需要与脂质相关的基因Fitm2用于在暴露于干扰素-γ(IFNγ)后保持细胞健康。
 
此外,研究人员确定自噬途径是癌细胞逃避CTL的保守介导者,并表明该途径需要抵抗细胞因子IFNγ和TNF诱导的细胞毒性。通过基于细胞因子和基于CTL的遗传相互作用定位以及体内CRISPR筛选,研究人员展示了自噬的多效性效应如何控制CTL杀伤癌细胞,并且研究人员强调了这些效应在肿瘤内的重要性微环境。
 
总体而言,这些数据扩展了人们对癌细胞逃避免疫系统相关遗传回路的了解,并突出了有助于与CTL杀伤相关表型的遗传相互作用。
 
据悉,使得癌细胞逃避宿主免疫系统破坏的遗传回路仍然知之甚少。
 
附:英文原文

Title: Functional genomic landscape of cancer-intrinsic evasion of killing by T cells

Author: Keith A. Lawson, Cristovo M. Sousa, Xiaoyu Zhang, Eiru Kim, Rummy Akthar, Joseph J. Caumanns, Yuxi Yao, Nicholas Mikolajewicz, Catherine Ross, Kevin R. Brown, Abdelrahman Abou Zid, Zi Peng Fan, Shirley Hui, Jordan A. Krall, Donald M. Simons, Chloe J. Slater, Victor De Jesus, Lujia Tang, Richa Singh, Joshua E. Goldford, Sarah Martin, Qian Huang, Elizabeth A. Francis, Andrea Habsid, Ryan Climie, David Tieu, Jiarun Wei, Ren Li, Amy Hin Yan Tong, Michael Aregger, Katherine S. Chan, Hong Han, Xiaowei Wang, Patricia Mero, John H. Brumell, Antonio Finelli, Laurie Ailles, Gary Bader, Gromoslaw A. Smolen, Gillian A. Kingsbury, Traver Hart, Charles Kung, Jason Moffat

Issue&Volume: 2020-09-23

Abstract: The genetic circuits that allow cancer cells to evade destruction by the host immune system remain poorly understood1,2,3. Here, to identify a phenotypically robust core set of genes and pathways that enable cancer cells to evade killing mediated by cytotoxic T lymphocytes (CTLs), we performed genome-wide CRISPR screens across a panel of genetically diverse mouse cancer cell lines that were cultured in the presence of CTLs. We identify a core set of 182 genes across these mouse cancer models, the individual perturbation of which increases either the sensitivity or the resistance of cancer cells to CTL-mediated toxicity. Systematic exploration of our dataset using genetic co-similarity reveals the hierarchical and coordinated manner in which genes and pathways act in cancer cells to orchestrate their evasion of CTLs, and shows that discrete functional modules that control the interferon response and tumour necrosis factor (TNF)-induced cytotoxicity are dominant sub-phenotypes. Our data establish a central role for genes that were previously identified as negative regulators of the type-II interferon response (for example, Ptpn2, Socs1 and Adar1) in mediating CTL evasion, and show that the lipid-droplet-related gene Fitm2 is required for maintaining cell fitness after exposure to interferon-γ (IFNγ). In addition, we identify the autophagy pathway as a conserved mediator of the evasion of CTLs by cancer cells, and show that this pathway is required to resist cytotoxicity induced by the cytokines IFNγ and TNF. Through the mapping of cytokine- and CTL-based genetic interactions, together with in vivo CRISPR screens, we show how the pleiotropic effects of autophagy control cancer-cell-intrinsic evasion of killing by CTLs and we highlight the importance of these effects within the tumour microenvironment. Collectively, these data expand our knowledge of the genetic circuits that are involved in the evasion of the immune system by cancer cells, and highlight genetic interactions that contribute to phenotypes associated with escape from killing by CTLs.

DOI: 10.1038/s41586-020-2746-2

Source: https://www.nature.com/articles/s41586-020-2746-2

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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