Upregulated expression of indoleamine 2, 3-dioxygenase in CHO cells induces apoptosis of competent T cells and increases proportion of Treg cells.
Upregulated expression of indoleamine 2, 3-dioxygenase in CHO cells induces apoptosis of competent T cells and increases proportion of Treg cells.
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CHO 细胞中吲哚胺 2, 3-双加氧酶表达上调可诱导感受态 T 细胞凋亡并增加 Treg 细胞的比例。
DOI：
10.1186/1756-9966-30-82
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发表时间：
2011-09-14
期刊：
影响因子：
--
通讯作者：
Ren X
中科院分区：
文献类型：
--
作者：
Sun J;Yu J;Li H;Yang L;Wei F;Yu W;Liu J;Ren X
炎症酶吲哚胺2,3 -双加氧酶（IDO）参与免疫耐受，促进IDO+肿瘤的免疫逃逸。最近的一项假设表明，IDO可能有助于新T调节细胞（Tregs）从初始CD4+ T细胞分化。在本研究中，我们通过增加T细胞的凋亡和Tregs的比例来研究IDO在乳腺癌中诱导免疫抑制的作用。构建IDO表达质粒，稳定转染人IDO到中国仓鼠卵巢细胞。从乳腺癌患者外周血单核细胞中分离纯化CD3+ T细胞。表达IDO或未转染（对照）CHO细胞与T细胞共培养后，通过流式细胞术分析和膜联蛋白- v和PI染色检测T细胞凋亡。流式细胞术检测调节性T细胞（Tregs [CD4 + CD25 + CD127-]）亚群的比例。分离T细胞总RNA和细胞蛋白，检测Foxp3基因及蛋白表达。IDO转基因CHO细胞产生高水平的IDO酶活性，导致培养基中色氨酸完全耗尽。与IDO+ CHO细胞共培养3 d后，CD3+T细胞凋亡率为79.07±8.13%，CD4 + CD25 + CD127- T细胞比例由3.43±1.07%上升至8.98±1.88% （P < 0.05）。IDO特异性抑制剂1-MT在体外有效逆转T细胞凋亡增强和Tregs扩增。RT-PCR、real-time RT-PCR和Western blot分析同时证实Tregs关键分子标志物Foxp3表达升高。这些结果表明，IDO通过直接诱导T细胞凋亡和增强treg介导的免疫抑制，有助于在乳腺肿瘤中创造耐受性环境。
The inflammatory enzyme indoleamine 2, 3-dioxygenase (IDO) participates in immune tolerance and promotes immune escape of IDO+ tumors. A recent hypothesis suggested that IDO may contribute to the differentiation of new T regulatory cells (Tregs) from naive CD4+ T cells. In this study we investigated the role of IDO in induction of immunosuppression in breast cancer by increasing the apoptosis of T cells and the proportion of Tregs. An IDO expression plasmid was constructed and Chinese hamster ovary (CHO) cells were stably transfected with human IDO. Purified CD3+ T cells were isolated from the peripheral blood monouclear cells of breast cancer patients. After co-culturing IDO expressing or untransfected (control) CHO cells with T cells, T cells apoptosis were determined by flow cytometry analysis and annexin-V and PI staining. The proportion of the regulatory T cell (Tregs [CD4 + CD25 + CD127-]) subset was measured by flow cytometry analysis. T cells total RNA and cellular protein samples were isolated for detecting Foxp3 gene and protein expression. IDO transgenic CHO cells yielded high levels of IDO enzymatic activity, resulting in complete depletion of tryptophan from the culture medium. We found that apoptosis occurred in 79.07 ± 8.13% of CD3+T cells after co-cultured with IDO+ CHO cells for 3 days and the proportion of CD4 + CD25 + CD127- T cells increased from 3.43 ± 1.07% to 8.98 ± 1.88% (P < 0.05) as well. The specific inhibitor of IDO,1-MT efficiently reversed enhancement of T cells apoptosis and amplification of Tregs in vitro. Increased expression of Foxp3, a key molecular marker of Tregs, was confirmed by RT-PCR, real-time RT-PCR and Western blot analysis at the same time. These results suggest that IDO helps to create a tolerogenic milieu in breast tumors by directly inducing T cell apoptosis and enhancing Treg-mediated immunosuppression.
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影响因子：
3.8
作者：
Mansfield AS;Heikkila PS;Vaara AT;von Smitten KA;Vakkila JM;Leidenius MH
通讯作者：
Leidenius MH
影响因子：
4.8
作者：
Astigiano, S;Morandi, B;Frumento, G
通讯作者：
Frumento, G
影响因子：
11.5
作者：
Brandacher, G;Perathoner, A;Amberger, A
通讯作者：
Amberger, A
影响因子：
3.4
作者：
Travers, MT;Gow, IF;Shennan, DB
通讯作者：
Shennan, DB
影响因子：
30.5
作者：
Grohmann, U;Orabona, C;Puccetti, P
通讯作者：
Puccetti, P