Yang Lin, Wu Xiaohou, Wang Dan, Luo Chunli, Chen Lixue
Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, PR China.
Urol Int. 2013;91(3):363-9. doi: 10.1159/000348747. Epub 2013 Jul 31.
Tumor-derived exosomes usually contain some molecules that can help immune evasion by tumors. This study is aimed at investigating the potential effect of exosomes from human kidney adenocarcinoma cells on a human immortalized line of Jurkat T lymphocytes in vitro.
Exosomes were purified from human kidney adenocarcinoma ACHN cells by sequential centrifugations and ultrafiltrations, and characterized by transmission electron microscopy. The effects of exosomes on the proliferation, cytokine production and apoptosis of Jurkat T cells were determined using flow cytometry and enzyme-linked immunosorbent assay. The relative levels of pro- and anti-apoptotic molecules were determined by Western blotting.
Exosomes were purified from ACHN cells and exhibited typical characteristics. Treatment with exosomes inhibited Jurkat T cell proliferation and induced Jurkat T cell apoptosis in a dose- and time-dependent manner. Treatment with exosomes reduced spontaneous interleukin-2 (IL-2), interferon-γ, IL-6 and IL-10 production by Jurkat T cells. Treatment with exosomes increased the relative levels of cleaved caspase-3, -8 and -9 as well as Bax, but reduced the levels of Bcl-2 in Jurkat T cells. The purified exosomes contained Fas ligand, and treatment with soluble Fas abrogated exosome-mediated Jurkat T cell apoptosis.
Our data indicate that exosomes from kidney adenocarcinoma cells contain Fas ligand and trigger Jurkat T cell apoptosis, contributing to the immune evasion of tumors.
肿瘤来源的外泌体通常含有一些可帮助肿瘤进行免疫逃逸的分子。本研究旨在体外研究人肾腺癌细胞来源的外泌体对人永生化Jurkat T淋巴细胞系的潜在影响。
通过连续离心和超滤从人肾腺癌ACHN细胞中纯化外泌体，并通过透射电子显微镜进行表征。使用流式细胞术和酶联免疫吸附测定法确定外泌体对Jurkat T细胞增殖、细胞因子产生和凋亡的影响。通过蛋白质免疫印迹法测定促凋亡和抗凋亡分子的相对水平。
从ACHN细胞中纯化出的外泌体具有典型特征。外泌体处理以剂量和时间依赖性方式抑制Jurkat T细胞增殖并诱导Jurkat T细胞凋亡。外泌体处理降低了Jurkat T细胞自发产生白细胞介素-2（IL-2）、干扰素-γ、IL-6和IL-10的水平。外泌体处理增加了Jurkat T细胞中裂解的半胱天冬酶-3、-8和-9以及Bax的相对水平，但降低了Bcl-2的水平。纯化的外泌体含有Fas配体，可溶性Fas处理可消除外泌体介导的Jurkat T细胞凋亡。
我们的数据表明，肾腺癌细胞来源的外泌体含有Fas配体并触发Jurkat T细胞凋亡，有助于肿瘤的免疫逃逸。
