Plasma Cell Polarization to the Immunoglobulin G Phenotype in Hepatocellular Carcinomas Involves Epigenetic Alterations and Promotes Hepatoma Progression in Mice
Plasma Cell Polarization to the Immunoglobulin G Phenotype in Hepatocellular Carcinomas Involves Epigenetic Alterations and Promotes Hepatoma Progression in Mice
复制标题
肝细胞癌中浆细胞向免疫球蛋白 G 表型的极化涉及表观遗传改变并促进小鼠肝癌进展
DOI：
10.1053/j.gastro.2019.01.250
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发表时间：
2019-05-01
期刊：
影响因子：
29.4
通讯作者：
Kuang，Dong-Ming
中科院分区：
文献类型：
--
作者：
Wei，Yuan;Lao，Xiang-Ming;Kuang，Dong-Ming
背景与目的对肝细胞癌患者浆细胞亚群的组成和产生及其与预后的关系知之甚少。方法对342例在中国中山大学肿瘤中心接受根治性切除的肝癌患者标本中浆细胞亚群的组成和分布进行分析，并以非肿瘤肝组织为对照。我们将浆细胞图谱与患者预后联系起来。用流式细胞仪和实时定量聚合酶链式反应分析组织来源的白细胞。巨噬细胞调节浆细胞分化的能力是在体外培养的人肝癌组织细胞中确定的。给C57BL/6和BALB/c小鼠注射形成肝癌的Hepa1-6细胞或形成腹水型肝癌的H22细胞。用实时聚合酶链式反应分析人肝癌、小鼠肝癌和非肿瘤组织中的基因表达模式。给荷瘤小鼠注射组蛋白H3赖氨酸27甲基转移酶抑制剂GSK126和DNA甲基转移酶抑制剂5-AZA-DC，免疫荧光和免疫组织化学分析肿瘤组织中免疫细胞和细胞因子的存在。结果从肝癌组织分离的B细胞具有非肿瘤组织所没有的体细胞超突变和类转换重组。浆细胞水平升高与患者预后不良相关。活化的CD4+T细胞刺激巨噬细胞产生C-X-C基序趋化因子10(CXCL10)。CXCL10与B细胞表面的CXC趋化因子受体3结合，并通过细胞外信号调节激酶发出信号，使其成为产生免疫球蛋白的浆细胞。免疫球蛋白激活巨噬细胞表面的Fc受体，诱导巨噬细胞产生IL-6、IL-10和C-C基序趋化因子配体20(CCL20)。在患肝癌的小鼠中，B细胞的耗尽阻止了这些巨噬细胞的产生，增加了抗肿瘤T细胞的反应，并减少了肝癌的生长。然而，注射CXC趋化因子受体3阳性浆细胞后，这些作用就消失了。人肝细胞癌和小鼠肝癌组织中DNA甲基转移酶1和EZH2的表达均高于非肿瘤组织。小鼠注射GSK126和5-aza-DC可诱导肿瘤细胞表达CXCL10，并引起浆细胞极化，抑制抗肿瘤T细胞反应，促进肝癌生长。来自肝细胞癌的活化的CD4+T细胞刺激巨噬细胞产生CXCL10；CXCL10与B细胞上的CXC趋化因子受体3结合，使它们成为产生免疫球蛋白的浆细胞。免疫球蛋白能激活巨噬细胞中的Fc受体，产生细胞因子，从而降低抗肿瘤免疫反应。在患肝癌的小鼠中，B细胞的耗尽阻止了这些巨噬细胞的产生，增加了抗肿瘤T细胞的反应，并减少了肝癌的生长。这一途径涉及肝癌和肝癌细胞DNA甲基转移酶1和EZH2的表达增加。
Background & AimsLittle is known about the composition and generation of plasma cell subsets in patients with hepatocellular carcinoma (HCC) and how these associate with outcomes. We investigated whether, or how, plasma cells differentiate and function in patients with HCC and mice with liver tumors.MethodsWe analyzed subset composition and distribution of plasma cells in HCC samples from 342 patients who underwent curative resection at the Cancer Center of Sun Yat-sen University in China; samples of non-tumor liver tissue were used as controls. We associated plasma cell profiles with patient outcomes. Tissue-derived leukocytes were analyzed by flow cytometry and real-time polymerase chain reaction. The ability of macrophages to regulate plasma cell differentiation was determined in ex vivo cultures of cells from human HCC tissues. C57BL/6 and BALB/c mice were given injections of Hepa1-6 cells, which formed hepatomas, or H22 cells, which formed ascitic hepatomas. Gene expression patterns were analyzed in human HCC, mouse hepatoma, and non-tumor tissues by real-time polymerase chain reaction. Mice with hepatomas were given injections of GSK126 (an inhibitor of histone H3 lysine 27 methyltransferase [EZH2]) and 5-AZA-dC (an inhibitor of DNA methyltransferases); tumor tissues were analyzed by immunofluorescence and immunohistochemistry for the presence of immune cells and cytokines.ResultsB cells isolated from HCCs had somatic hypermutations and class-switch recombinations to the IgG phenotype that were not observed in non-tumor tissues. Increased level of plasma cells correlated with poor outcomes of patients. Activated CD4+T cells from HCCs stimulated C-X-C motif chemokine 10 (CXCL10) production by macrophages. CXCL10 bound CXC chemokine receptor 3 on B cells and signaled via extracellular signal–regulated kinase to cause them to become IgG-producing plasma cells. IgG activated Fc receptors on macrophages and induced them to produce interleukin 6, interleukin 10, and C-C motif chemokine ligand 20 (CCL20). In mice with hepatomas, depletion of B cells prevented generation of these macrophage, increased the anti-tumor T cell response, and reduced growth of hepatomas. However, these effects were lost after injection of CXC chemokine receptor 3–positive plasma cells. Human HCC and mouse hepatoma tissues had increased expression of DNA methyltransferase 1 and EZH2 compared with non-tumor tissues. Injection of mice with GSK126 and 5-AZA-dC induced expression of CXCL10 by tumor cells and caused plasma cell polarization, suppression of the anti-tumor T cell response, and hepatoma growth.ConclusionsHuman HCC tissues contain B cells with class-switch recombinations to the IgG phenotype. Activated CD4+T cells from HCCs stimulate CXCL10 production by macrophages; CXCL10 binds CXC chemokine receptor 3 on B cells and causes them to become IgG-producing plasma cells. IgG activates Fc receptor in macrophages to produce cytokines that reduce the anti-tumor immune response. In mice with hepatomas, depletion of B cells prevented generation of these macrophages, increased the anti-tumor T cell response, and reduced growth of hepatomas. This pathway involves increased expression of DNA methyltransferase 1 and EZH2 by HCC and hepatoma cells.