调节性T细胞在甲状腺乳头状癌免疫耐受形成中的作用及意义

The effect and significance of regulatory T cells in the formation of immune tolerance of papillary thyroid carcinoma

目的研究调节性T细胞(Treg)在甲状腺乳头状癌(PTC)患者外周血和肿瘤微环境中的分布及意义。方法选择确诊并手术的PTC患者80例作为PTC组,PTC合并桥本氏甲状腺炎(HT)患者80例作为PTC合并HT组,同时选择80例结节性甲状腺肿患者作为对照组。术前用流式细胞仪检测外周血中CD4+CD25+CD127low/-Treg,术后用免疫组化方法检测肿瘤和转移性淋巴结中Foxp3的表达情况。比较各组表达差异及与临床病理特征的关系。结果外周血中CD4+CD25+CD127low/-Treg比例PTC组患者[(9.01±1.82)%]最高,PTC合并HT组患者[(6.94±1.69)%]次之,对照组患者[(6.01±2.33)%]最低,差异有统计学意义(P﹤0.05);有淋巴结转移、有腺外侵犯的PTC患者外周血CD4+CD25+CD127low/-Treg比例和肿瘤组织中Foxp3高表达者比例均高于无淋巴结转移及无腺外侵犯患者(P﹤0.05)。结论 PTC患者外周血及组织微环境中Treg均增加,对癌细胞免疫耐受、组织浸润和转移有促进作用。

Objective To investigate the distribution and significance of regulatory T cells in peripheral blood and tumor microenvironment of papillary thyroid carcinoma（PTC） patients. Method 80 cases of PTC patients who received surgical treatment and 80 cases of PTC and hashimotos thyroiditis（HT） were included in the study, and another 80 cases of nodular goiter patients were included as control. Peripheral blood samples were collected for CD4^＋CD25^＋CD127^low/-Treg detection before surgery by flow cytometry and immunohistochemistry staining was performed to observe the expression of Foxp3 in tumor tissues and metastatic lymph nodes. The difference of expression among the groups and its correlation with clinical features were compared. Result The highest percentage of CD4^＋CD25^＋CD127^low/-Treg in peripheral blood was observed in the PTC patients [（9.01±1.82）%], and then in PTC plus HT patients [（6.94±1.69）%], followed by that in nodular goiter patients [（6.01±2.33）%], the differences were significant（P〈0.05）; the patients who were with lymphatic metastasis and（or） extra-thyroidal invasion had a higher percentage of CD4^＋CD25^＋CD127^low/-Treg in peripheral blood and higher Foxp3 expression in tumor microenvironment than that of patients without metastasis and（or） invasion（P〈0.05）. Conclusion Both in peripheral blood and tumor microenvironment, the Treg of papillary carcinoma in thyroid patients are significantly increased, which contributes to the immune tolerance, tissue infiltration and metastasis of cancer cells.