In vivo dendritic cell reprogramming for cancer immunotherapy [organoid scRNA]. In vivo dendritic cell reprogramming for cancer immunotherapy [organoid scRNA]

Immunotherapy can lead to long-term survival for some cancer patients, yet generalized success has been hampered by insufficient antigen presentation and exclusion of immunogenic cells from the tumor microenvironment. Here, we developed an approach to reprogram tumor cells in vivo by adenoviral delivery of the transcription factors PU.1, IRF8, and BATF3, which enabled them to present antigens as type 1 conventional dendritic cells. Reprogrammed tumor cells remodeled their tumor microenvironment, recruited, and expanded polyclonal cytotoxic T cells, induced tumor regressions, and established long-term systemic immunity in multiple mouse melanoma models. In human tumor spheroids and xenografts, reprogramming to immunogenic dendritic-like cells progressed independently of immunosuppression, which usually limits immunotherapy. Our study paves the way for human clinical trials of in vivo immune cell reprogramming for cancer immunotherapy. Overall design: To verify that a cDC1 program was established in cancer spheroids and to uncover potential differences in cDC1 reprogramming progressing in 2D or 3D cultures, we FACS-purified CD45+ and HLA-DR+ T98G cells at days 3, 7, and 9 of reprogramming and performed scRNA-seq. This submission includes only 2 of the 2D samples (day 7 and day9). We used 2 of the 2D samples (day 0 and day3) from previous submission GSE224941 (GSM7035968, GSM7035969).

免疫治疗可使部分癌症患者获得长期生存，但其广泛应用仍因抗原呈递不足以及免疫原性细胞被排除在肿瘤微环境（tumor microenvironment）之外而受阻。本研究开发了一种体内重编程肿瘤细胞的方法：通过腺病毒递送转录因子PU.1、IRF8和BATF3，使肿瘤细胞能够发挥1型常规树突状细胞（type 1 conventional dendritic cells，cDC1）的抗原呈递功能。重编程后的肿瘤细胞可重塑肿瘤微环境，招募并扩增多克隆细胞毒性T细胞，诱导肿瘤消退，并在多种小鼠黑色素瘤模型中建立长期系统性免疫。在人类肿瘤球体（tumor spheroids）和异种移植瘤（xenografts）中，向免疫原性树突状样细胞的重编程进程可不受通常限制免疫治疗的免疫抑制因素影响。本研究为癌症免疫治疗领域体内免疫细胞重编程的人类临床试验铺平了道路。

实验设计：为验证癌症球体中是否成功建立cDC1程序，并揭示2D与3D培养中cDC1重编程进程的潜在差异，我们在重编程第3、7、9天通过荧光激活细胞分选术（fluorescence-activated cell sorting，FACS）纯化得到CD45+与HLA-DR+的T98G细胞，并开展单细胞RNA测序（single-cell RNA sequencing，scRNA-seq）。本提交仅包含2份2D培养样本（第7天和第9天）。我们使用了此前提交的GSE224941数据集（包含GSM7035968、GSM7035969两个样本）中的2份2D培养样本（第0天和第3天）。