Second Department of Surgery, School of Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-8510, Japan.
Sci Rep. 2022 Feb 28;12(1):3295. doi: 10.1038/s41598-022-07305-1.
Significant efficacy of induced pluripotent stem cells (iPSCs) in generating DCs for cancer vaccine therapy was suggested in our previous studies. In clinical application of DC vaccine therapy, however, few DC vaccine systems have shown strong clinical response. To enhance immunogenicity in the DC vaccine, we transfected patient-derived iPSDCs with in vitro transcriptional RNA (ivtRNA), which was obtained from tumors of three patients with colorectal cancer. We investigated iPSDCs-ivtRNA which were induced by transfecting ivtRNA obtained from tumors of three colorectal cancer patients, and examined its antitumor effect. Moreover, we analyzed neoantigens expressed in colorectal cancer cells and examined whether iPSDCs-ivtRNA induced cytotoxic T lymphocytes (CTLs) against the predicted neoantigens. CTLs activated by iPSDCs-ivtRNA exhibited cytotoxic activity against the tumor spheroids in all three patients with colorectal cancer. Whole-exome sequencing revealed 1251 nonsynonymous mutations and 2155 neoantigens (IC < 500 nM) were predicted. For IFN-γ ELISPOT assay, these candidate neoantigens were further prioritised and 12 candidates were synthesized. IFN-γ ELISPOT assay revealed that the CTLs induced by iPSDCs-ivtRNA responded to one of the candidate neoantigens. In vitro CTLs obtained by transfecting tumor-derived RNA into iPSDCs derived from three patients with colorectal cancer showed potent tumor-specific killing effect.
我们之前的研究表明，诱导多能干细胞（iPSCs）在生成用于癌症疫苗治疗的树突状细胞（DC）方面具有显著疗效。然而，在 DC 疫苗治疗的临床应用中，很少有 DC 疫苗系统表现出强烈的临床反应。为了增强 DC 疫苗的免疫原性，我们使用来自三位结直肠癌患者肿瘤的体外转录 RNA（ivtRNA）转染患者来源的 iPSDCs。我们研究了转染来自三位结直肠癌患者肿瘤的 ivtRNA 诱导的 iPSDC-ivtRNA，并检查了其抗肿瘤作用。此外，我们分析了结直肠癌细胞中表达的新抗原，并检查了 iPSDC-ivtRNA 是否诱导针对预测新抗原的细胞毒性 T 淋巴细胞（CTLs）。由 iPSDC-ivtRNA 激活的 CTLs 对所有三位结直肠癌患者的肿瘤球体均表现出细胞毒性活性。全外显子组测序显示 1251 个非同义突变和 2155 个新抗原（IC < 500 nM）被预测。对于 IFN-γ ELISPOT 测定，进一步对这些候选新抗原进行优先级排序，并合成了 12 个候选物。IFN-γ ELISPOT 测定显示，由 iPSDC-ivtRNA 诱导的 CTLs 对候选新抗原之一有反应。从三位结直肠癌患者中分离的 iPSDC 转染肿瘤衍生 RNA 获得的体外 CTLs 显示出针对肿瘤的强大特异性杀伤作用。
