Department of Immunology, Blavatnik Institute and Ludwig Center at Harvard, Harvard Medical School, Boston, Massachusetts.
Department of Cell Biology, Blavatnik Institute and Ludwig Center at Harvard, Harvard Medical School, Boston, Massachusetts.
Cancer Immunol Res. 2021 Feb;9(2):184-199. doi: 10.1158/2326-6066.CIR-20-0384. Epub 2020 Dec 4.
Metabolic constraints in the tumor microenvironment constitute a barrier to effective antitumor immunity and similarities in the metabolic properties of T cells and cancer cells impede the specific therapeutic targeting of metabolism in either population. To identify distinct metabolic vulnerabilities of CD8 T cells and cancer cells, we developed a high-throughput pharmacologic screening platform and used it to measure the cell type-specific sensitivities of activated CD8 T cells and B16 melanoma cells to a wide array of metabolic perturbations during antigen-specific killing of cancer cells by CD8 T cells. We illustrated the applicability of this screening platform by showing that CD8 T cells were more sensitive to ferroptosis induction by inhibitors of glutathione peroxidase 4 (GPX4) than B16 and MC38 cancer cells. Overexpression of ferroptosis suppressor protein 1 (FSP1) or cytosolic GPX4 yielded ferroptosis-resistant CD8 T cells without compromising their function, while genetic deletion of the ferroptosis sensitivity-promoting enzyme acyl-CoA synthetase long-chain family member 4 (ACSL4) protected CD8 T cells from ferroptosis but impaired antitumor CD8 T-cell responses. Our screen also revealed high T cell-specific vulnerabilities for compounds targeting NAD metabolism or autophagy and endoplasmic reticulum (ER) stress pathways. We focused the current screening effort on metabolic agents. However, this screening platform may also be valuable for rapid testing of other types of compounds to identify regulators of antitumor CD8 T-cell function and potential therapeutic targets.
肿瘤微环境中的代谢限制构成了有效抗肿瘤免疫的障碍，而 T 细胞和癌细胞的代谢特性相似，这阻碍了对这两种细胞群体的代谢进行特异性治疗靶向。为了确定 CD8 T 细胞和癌细胞的独特代谢脆弱性，我们开发了一种高通量的药理筛选平台，并使用该平台来衡量在 CD8 T 细胞特异性杀伤癌细胞过程中，激活的 CD8 T 细胞和 B16 黑色素瘤细胞对广泛的代谢扰动的细胞类型特异性敏感性。我们通过展示 CD8 T 细胞对谷胱甘肽过氧化物酶 4（GPX4）抑制剂诱导的铁死亡的敏感性高于 B16 和 MC38 癌细胞，说明了该筛选平台的适用性。过表达铁死亡抑制剂蛋白 1（FSP1）或胞质 GPX4 可产生对铁死亡具有抗性的 CD8 T 细胞，而不损害其功能，而铁死亡敏感性促进酶酰基辅酶 A 合成酶长链家族成员 4（ACSL4）的基因缺失可保护 CD8 T 细胞免受铁死亡，但会损害抗肿瘤 CD8 T 细胞反应。我们的筛选还揭示了针对 NAD 代谢或自噬和内质网（ER）应激途径的化合物对 T 细胞具有高特异性脆弱性。我们目前的筛选重点是代谢剂。然而，该筛选平台对于快速测试其他类型的化合物以鉴定抗肿瘤 CD8 T 细胞功能的调节剂和潜在治疗靶标也可能具有价值。
