Enhanced activated T cell subsets in prostate cancer patients receiving iodine-125 low-dose-rate prostate brachytherapy
Enhanced activated T cell subsets in prostate cancer patients receiving iodine-125 low-dose-rate prostate brachytherapy
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DOI：
10.3892/or.2017.6095
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发表时间：
2018-01-01
期刊：
影响因子：
4.2
通讯作者：
Obata, Fumiya
中科院分区：
文献类型：
--
作者：
Kubo, Makoto;Satoh, Takefumi;Obata, Fumiya
放射治疗（RT）是前列腺癌最重要的治疗方法之一。虽然RT可以通过辐射的直接和间接作用杀死癌细胞，但它偶尔会诱导远位效应，从而使局部辐射治疗与消除距照射区域一定距离的转移性癌症相关。因此，RT可能诱导有效的抗肿瘤免疫应答，尽管所涉及的机制仍不清楚。本研究旨在评估RT在36例前列腺癌患者中的作用，这些患者在入组本临床试验之前提供了知情同意书。前列腺低剂量率（LDR）近距离放射治疗后定期采集外周血，流式细胞仪分析淋巴细胞亚群。LDR近距离放射治疗后，外周血中活化T细胞（CD 3（+）HLA-DR+、CD 4（+）HLA-DR+和CD 8（+）HLA-DR+）的比例呈双峰逐渐增加，而记忆性CD 8（+）T细胞呈双峰下降。治疗后，活化T细胞和调节性T细胞的比例逐渐增加。因此，LDR近距离放射治疗被证明在患者中诱导有效的免疫应答。这种活化T细胞的增加可能有助于维持缓解和降低复发率。
Radiotherapy (RT) is one of the most important treatments for prostate cancer. Although RT can kill cancer cells through direct and indirect effects of radiation, it occasionally induces an abscopal effect whereby localized radiation treatment is associated with elimination of metastatic cancer at a distance from the irradiated area. Thus, RT may induce an effective antitumor immune response, although the mechanism involved has remained unclear. The present was designed to evaluate this effect of RT in 36 patients with prostate cancer who provided informed consent prior to enrollment in this clinical trial. Peripheral blood samples were collected periodically after low-dose-rate (LDR) prostate brachytherapy, and lymphocyte subsets were analyzed by flow cytometry. The proportion of activated T cells (CD3(+)HLA-DR+, CD4(+)HLA-DR+ and CD8(+)HLA-DR+) in peripheral blood revealed a gradual and bimodal increase after LDR brachytherapy, whereas memory CD8(+)T cells bimodally decreased after treatment. The ratios of activated T cells and regulatory T cells gradually increased after the treatment. Thus, LDR brachytherapy was demonstrated to induce effective immune responses in patients. This increase of activated T cells may contribute to maintenance of remission and reduction of relapse rates.