Synthetic IL-21 cytokine mimetic promotes T cell function

Synthetic cytokine mimetics of IL-2 have been developed, including neoleukin-2 (Neo2), which has been shown to have enhanced therapeutic efficacy over IL-2, with reduced toxicity. IL-21 has also been used in TIL therapy to promote T cell expansion. Here, we tested the efficacy of Neo2, native IL-21, or synthetic IL-21 (21h10) in treating mice bearing B16 tumors that received ACT with melanoma-specific T cells (TRP1High and TRP1Low ; TCRs recognizing antigen with high or low affinity). We performed single-cell RNA-sequencing on these tumors to analyze cytokine therapy-induced changes in the microenvironment. Two days prior to tumor inoculation, naïve melanoma-specific T cells (TRP1High and TRP1Low) were adoptively transferred to wild-type mice. B16 tumors were inoculated and 5 days post tumor inoculation I.P. cytokine treatments commenced every day until day 15 when tumors from each cohort were labelled with hashtag antibodies and subjected to single-cell RNA-sequencing.

目前已开发出白细胞介素-2（IL-2）的合成细胞因子模拟物，包括新亮蛋白-2（Neo2），研究显示其相较于野生型IL-2具有更优异的治疗疗效且毒性更低。白细胞介素-21（IL-21）也已应用于肿瘤浸润淋巴细胞（Tumor Infiltrating Lymphocytes, TIL）疗法，以促进T细胞扩增。本研究针对接受黑色素瘤特异性T细胞（TRP1High与TRP1Low，即识别高/低亲和力抗原的T细胞受体（TCR））过继细胞治疗（Adoptive Cell Transfer, ACT）的B16黑色素瘤荷瘤小鼠，测试了Neo2、野生型IL-21或合成型IL-21（21h10）的治疗疗效。同时，我们对上述肿瘤样本开展单细胞RNA测序，以分析细胞因子疗法诱导的肿瘤微环境变化。具体实验流程如下：于肿瘤接种前2天，将未致敏的黑色素瘤特异性T细胞（TRP1High与TRP1Low）过继转移至野生型小鼠体内；随后接种B16黑色素瘤，待肿瘤接种后第5天开始每日给予腹腔内（I.P.）细胞因子给药，持续至第15天；最后对每一组别小鼠的肿瘤使用hashtag标签抗体标记，并进行单细胞RNA测序。