Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Yi Xue Yuan Road, Chongqing, P.R. China.
Int J Oncol. 2010 Jan;36(1):133-40.
Exosome-based immunotherapy for cancer holds promise, but needs improvements, especially for tumor-derived exosomes. We investigated, whether exosomes derived from IL-12-anchored human renal cancer cells could enhance their immunogenicity and increase induction of specific antitumor response. A mammalian co-expression plasmid of glycolipid-anchored-IL-12 (GPI-IL-12) was constructed by subcloning IL-12A chain gene (P35 subunit) and a fusion gene containing GPI-anchor signal sequence of human placental alkaline phosphatase-1 (hPLAP-1) and IL-12B chain gene (P40 subunit) in pBudCE4.1. Then exosomes were prepared from renal cancer cells modified to express GPI-IL-12. The results showed that exosomes derived from IL-12-anchored renal cancer cells expressed renal cell carcinoma-associated antigen G250 and GPI-IL-12. The incorporation of GPI-IL-12 onto exosomes (exosomes-GPI-IL-12, EXO/IL-12) significantly promotes proliferation of T cells, and subsequently increased the release of IFN-gamma. Notably, stimulation with EXOs/IL-12 could efficiently induce antigen-specific cytotoxic T lymphocytes (CTLs), resulting in more significant cytotoxic effects in vitro. These results suggested that exosomes derived from IL-12-anchored renal cancer cells bore GPI-IL-12 and G250, which have tumor rejection antigen with enhanced immunogenicity and antitumor effects, representing a novel strategy of exosomes-based vaccine for renal cell carcinoma.
基于外泌体的癌症免疫疗法具有广阔的前景，但仍需要进一步改进，尤其是针对肿瘤来源的外泌体。本研究旨在探讨负载 IL-12 的人肾癌来源外泌体是否能增强其免疫原性并诱导特异性抗肿瘤反应。通过亚克隆 IL-12A 链基因（P35 亚基）和包含人胎盘碱性磷酸酶-1（hPLAP-1）GPI 锚定信号序列和 IL-12B 链基因（P40 亚基）的融合基因，构建了糖基磷脂酰肌醇（GPI）锚定 IL-12 的哺乳动物共表达质粒（GPI-IL-12）。然后，从表达 GPI-IL-12 的肾癌细胞中提取外泌体。结果显示，负载 IL-12 的肾癌来源外泌体表达肾癌相关抗原 G250 和 GPI-IL-12。GPI-IL-12 被整合到外泌体中（外泌体-GPI-IL-12，EXO/IL-12），可显著促进 T 细胞增殖，并随后增加 IFN-γ的释放。值得注意的是，EXO/IL-12 刺激能有效诱导抗原特异性细胞毒性 T 淋巴细胞（CTL），在体外产生更显著的细胞毒性作用。这些结果表明，负载 IL-12 的肾癌来源外泌体携带 GPI-IL-12 和 G250，这两种物质均具有增强免疫原性和抗肿瘤作用的肿瘤排斥抗原，为肾癌的外泌体疫苗提供了一种新策略。
