方大正,吳紅偉,武倫,萬(wàn)光俊,沈豐
(湖北醫(yī)藥學(xué)院附屬東風(fēng)醫(yī)院 肝膽外科,湖北 十堰 442000)
調(diào)節(jié)性T細(xì)胞(regulatory T cells,Tregs)在T細(xì)胞亞群中具有重要免疫調(diào)節(jié)功能,它可以改變機(jī)體免疫內(nèi)環(huán)境,和腫瘤細(xì)胞免疫逃逸與腫瘤形成密切相關(guān)[1]。目前,較為常用的特異性檢測(cè)Tregs分子表面標(biāo)記物的是CD8和CD28,基于CD8+CD28-Tregs的免疫活性調(diào)節(jié),已成為目前腫瘤如黑色素瘤、胰腺癌、卵巢癌等免疫研究的熱點(diǎn)[2-3]。但其在肝細(xì)胞癌(以下簡(jiǎn)稱肝癌)臨床分期、分化程度等方面報(bào)道不一[4]。叉狀頭/翼狀螺旋轉(zhuǎn)錄因子(forkhead/winged helix transcription factor,F(xiàn)oxp3)在胸腺和外周血CD8+CD28-Tregs中特異性表達(dá),抑制機(jī)體增殖與活化腫瘤特異性T效應(yīng)細(xì)胞,與機(jī)體荷瘤時(shí)的免疫抑制狀態(tài)有關(guān)[5]。在T細(xì)胞亞群中,CD4+CD25+Tregs具有免疫負(fù)調(diào)控功能,在原發(fā)性肝癌患者中已有研究[6]。而CD8+CD28-Foxp3+Tregs在肝癌患者外周血中和腫瘤組織中研究較少[7],本研究檢測(cè)肝癌患者外周血和腫瘤組織中CD8+CD28-Foxp3+Tregs的水平,探討其與肝癌的關(guān)系?;谏鲜稣J(rèn)識(shí),本研究應(yīng)用流式細(xì)胞儀檢測(cè)和分析肝癌患者外周血Treg細(xì)胞表面標(biāo)記,觀察肝癌和癌旁組織中CD8+CD28-Foxp3+Tregs的差異性,旨在為肝癌的免疫性治療提供可能的實(shí)驗(yàn)基礎(chǔ)。
72例肝癌標(biāo)本均為湖北醫(yī)藥學(xué)院附屬東風(fēng)醫(yī)院肝膽外科2014—2016年經(jīng)術(shù)后病理確診標(biāo)本,術(shù)前均未經(jīng)過(guò)放、化療處理,術(shù)前取外周血;其中男51例,女21例;年齡41~72歲,平均(49.8±9.5)歲。72例肝癌標(biāo)本按照國(guó)際抗癌聯(lián)盟(International Union Against Cancer,IUCC)分期標(biāo)準(zhǔn),高分化肝癌29例患者,中分化肝癌25例,低分化肝癌18例。22名正常對(duì)照者為同期我院健康體檢中心志愿者外周血,其中男15例,女7例;年齡43~70歲,平均(48.6±9.2)歲,對(duì)照組均無(wú)急、慢性疾病史。兩組均知情同意。
人調(diào)節(jié)性T細(xì)胞(T-reg)檢測(cè)試劑盒包括:抗CD8-PE、CD28-FITC、Foxp3-PE、IgG1-PE、IgG1-FITC等購(gòu)于美國(guó)BD公司;溶血素羊抗人Foxp3多克隆抗體購(gòu)自美國(guó)Bioworld biotechnology公司(工作濃度1:200),即用型免疫組化兔抗羊二抗和3,3-二氨基聯(lián)苯胺(DAB)試劑盒均購(gòu)自北京中杉金橋生物科技有限公司;溶血儀、FACS流式細(xì)胞儀為美國(guó)BD公司產(chǎn)品。
參照文獻(xiàn)[8],抽取入院1 d肝癌患者和健康體檢者(對(duì)照組)外周血1 mL,乙二胺四乙酸(EDTA)抗凝。取血標(biāo)本100 μL,分別加入IgGl-FITC、IgGl-PE、CD8-FITC、CD28-APC、Foxp3-PE各10 μL,室溫下靜置避光孵育15 min后,加紅細(xì)胞裂解液1 mL溶解紅細(xì)胞,震蕩數(shù)秒并靜置5 min后,離心1500 r/min×5 min。選取淋巴細(xì)胞群設(shè)門(mén)流式細(xì)胞儀檢測(cè)Tregs,分析CD8+CD28-Foxp3+Tregs與CD8+T細(xì)胞比值。Cell Quest軟件獲取和分析數(shù)據(jù),每個(gè)樣本檢測(cè)1×104個(gè)/次。
采用免疫組織化學(xué)SP法檢測(cè)肝癌組織中和癌旁組織中Foxp3陽(yáng)性細(xì)胞,嚴(yán)格按照免疫組化試劑盒說(shuō)明書(shū)步驟進(jìn)行操作。組織切片處理如下:常規(guī)取肝癌組織和癌旁10 cm以上組織,10%甲醛溶液固定,梯度酒精脫水,二甲苯透明,石蠟包埋,厚5 μm切片,脫水透明,檸檬酸鈉煮沸,微波抗原修復(fù),山羊血清封閉,滴加一抗,羊抗人Foxp3多克隆抗體4 oC冰箱孵育過(guò)夜,次日PBS緩沖液洗滌后,滴加兔抗羊二抗,37 oC孵育30 min,PBS緩沖液洗滌,DAB顯色,鏡檢觀察染色程度,蘇木精復(fù)染細(xì)胞核,自來(lái)水返藍(lán),梯度酒精脫水脫水,二甲苯透明,中性樹(shù)膠封片。光鏡下觀察、攝片。Foxp3陽(yáng)性細(xì)胞染色呈棕黃色或黃色顆粒,定位為胞質(zhì)。每張切片任意選取高倍鏡下5個(gè)視野,計(jì)數(shù)Foxp3陽(yáng)性細(xì)胞,按照視場(chǎng)面積計(jì)算每mm3Foxp3陽(yáng)性細(xì)胞數(shù)目。陽(yáng)性細(xì)胞計(jì)數(shù)由與本研究無(wú)關(guān)的2位病理醫(yī)師計(jì)算并確認(rèn)取均值。
每例肝癌組織和相應(yīng)癌旁正常肝組織約100 mg,加入1 mL組織細(xì)胞裂解液,冰上剪碎并研磨組織約30 min,研制成組織勻漿,放置于1.5 mL EP管中,4 ℃、離心12000 r/min ×30 min,取上清進(jìn)行蛋白定量,蛋白濃度測(cè)定采取BCA法。100 ℃沸水煮沸變性5 min,取30 μg每個(gè)樣本的總蛋白行SDS-PAGE電泳分離,轉(zhuǎn)膜至PVDF膜上。5%脫脂奶粉室溫封閉1 h,1:1000稀釋的羊抗人Foxp3多克隆抗體4 ℃孵育過(guò)夜,PBS洗滌PVDF膜3次,室溫下放入兔抗羊二抗(1:2000稀釋)孵育2 h,ECL化學(xué)發(fā)光試劑顯色曝光。以β-actin作為上樣內(nèi)參照,所得結(jié)果以灰度掃描并相對(duì)定量分析,用目的蛋白條帶吸光度值/β-actin條帶吸光度值表示Foxp3蛋白的相對(duì)表達(dá)強(qiáng)度。
實(shí)驗(yàn)所得數(shù)據(jù)采用SPSS 17.0軟件處理,計(jì)量資料以均數(shù)±標(biāo)準(zhǔn)差(±s)表示,單因素方差分析和SNK-q檢驗(yàn)進(jìn)行多組數(shù)據(jù)比較,t檢驗(yàn)比較兩組均數(shù),P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
流式細(xì)胞分析結(jié)果顯示,外周血CD8+CD28-Foxp3+Tregs/CD8+T細(xì)胞表達(dá)在肝癌患者明顯高于健康對(duì)照組(P<0.05,P<0.01),且隨著肝癌患者分化級(jí)別的降低,CD8+CD28-Foxp3+Tregs/CD8+T細(xì)胞表達(dá)逐漸升高,但組間差異無(wú)統(tǒng)計(jì)學(xué)意義(圖1)。
圖1 肝癌患者和健康對(duì)照人群外周血CD8+CD28-Foxp3+Tregs/CD8+T檢測(cè)結(jié)果 A:健康對(duì)照組;B:高分化肝癌組;C:中分化肝癌組;D:低分化肝癌組Figure 1 Detection of CD8+CD28–Foxp3+Tregs/CD8+T in peripheral blood of HCC patients and healthy population A: Healthy control group; B: Well diあerentiated HCC group; C: Moderately HCC group; D: Poorly diあerentiated HCC group
流式細(xì)胞分析結(jié)果與肝癌患者臨床病理因素比較顯示,CD8+CD28-Fxop3+Tregs/CD8+T的表達(dá)與性別、年齡無(wú)關(guān)(均P>0.05),與TNM分期、有無(wú)淋巴結(jié)轉(zhuǎn)移、腫瘤分化程度有關(guān)(P<0.05)(表1)。
表1 肝癌患者外周血CD8+CD28-Fxop3+Tregs/CD8+T與臨床病理因素的關(guān)系(%,±s)Table 1 Relations of peripheral blood CD8+CD28–Fxop3+Tregs/CD8+T with clinicopathologic factors of HCC patients(%, ±s)
表1 肝癌患者外周血CD8+CD28-Fxop3+Tregs/CD8+T與臨床病理因素的關(guān)系(%,±s)Table 1 Relations of peripheral blood CD8+CD28–Fxop3+Tregs/CD8+T with clinicopathologic factors of HCC patients(%, ±s)
因素 n C D 8+C D 28-F o x p 3+T r e g s/C D 8+T t P性別男51 8.43±1.18 0.604 0.582女21 8.39±1.20年齡(歲)≤55 39 8.41±1.32 0.862 0.427>55 33 8.43±1.63 T N M分期I/I I 35 7.12±0.99 3.981 0.009 I I I/I V 37 8.01±7.46淋巴結(jié)轉(zhuǎn)移有41 8.77±1.94 4.536 0.007無(wú)31 8.16±1.67分化程度高分化 29 7.96±1.63 3.627 0.042中、低分化 43 8.78±1.76
在肝癌病理組織中有Foxp3陽(yáng)性表達(dá),位于肝癌或癌旁正常組織的細(xì)胞胞質(zhì)中。癌旁組織中Foxp3平均陽(yáng)性細(xì)胞數(shù)為(7.26±1.97)個(gè)/mm2,高分化肝癌平均陽(yáng)性細(xì)胞數(shù)目為(26.02±8.34)個(gè)/mm2,中分化肝癌平均陽(yáng)性數(shù)目為(28.05±8.86)個(gè)/mm2,低分化為(31.65±8.15)個(gè)/mm2;與癌旁正常組織中Foxp3陽(yáng)性細(xì)胞比較,肝癌組織中Foxp3陽(yáng)性細(xì)胞數(shù)明顯升高,差異均有統(tǒng)計(jì)學(xué)意義(均P<0.05);但不同分化程度肝癌組織中Foxp3陽(yáng)性細(xì)胞數(shù)比較差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)(圖2)。
Foxp3蛋白在肝癌和癌旁組織中均有表達(dá),但在肝癌細(xì)胞中的表達(dá)量明顯高于癌旁細(xì)胞(圖3)。由圖像分析可知,與正常組Foxp3蛋白表達(dá)相比,肝癌組織中Foxp3蛋白的表達(dá)明顯增強(qiáng),差異有統(tǒng)計(jì)學(xué)意義(P<0.01);但不同分化程度的肝癌組織中Foxp蛋白表達(dá)間差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)(圖3)。
圖2 免疫組化檢測(cè)Foxp3陽(yáng)性細(xì)胞(×400) A:癌旁組織(距腫瘤邊緣5 cm);B:高分化肝癌組織;C:中分化肝癌組織;D:低分化肝癌組織Figure 2 Immunohistochemical staining for Foxp3 positive cells (×400) A: Tumor adjacent tissue (5 cm away from tumor tissue);B: Well diあerentiated HCC tissue; C: Moderately diあerentiated HCC tissue; D: Poorly diあerentiated HCC tissue
圖3 Western blot檢測(cè)Foxp3蛋白的表達(dá) 1:癌旁組織;2:低分化肝癌組織;3:中分化肝癌組織;4:高分化肝癌組織Figure 3 Western blot analysis of Foxp3 protein expression 1: Tumor adjacent tissue; 2: Well differentiated HCC tissue; 3: Moderately differentiated HCC tissue;4: Poorly differentiated HCC tissue
Tregs是影響腫瘤患者預(yù)后的潛在因素之一,目前,在腫瘤、轉(zhuǎn)移淋巴結(jié)、外周血、惡性腹水,胸腔積液中均有發(fā)現(xiàn)[2-3]。手術(shù)、放療和化療是傳統(tǒng)的腫瘤治療手段,隨著醫(yī)療水平的發(fā)展,對(duì)腫瘤的發(fā)病機(jī)制認(rèn)識(shí)不斷深入,在臨床中,調(diào)動(dòng)患者機(jī)體主動(dòng)免疫功能,進(jìn)行免疫治療已逐步開(kāi)展,但其臨床上對(duì)肝細(xì)胞癌的療效并不確定,可能與患者腫瘤抗原中正常細(xì)胞較多,機(jī)體T細(xì)胞免疫系統(tǒng)對(duì)癌細(xì)胞免疫“豁免”有關(guān)[4]。Tregs的相關(guān)研究如Tregs/CD3、Tregs/CD4、Tregs/CD8等在原發(fā)瘤和轉(zhuǎn)移瘤中的比率已見(jiàn)于很多研究[4-7]。建立Tregs與Foxp3基因或蛋白聯(lián)系,使Tregs的研究有了進(jìn)一步的進(jìn)展[9]。CD8+CD28-Tregs在機(jī)體調(diào)節(jié)機(jī)制中有重要作用,可控制自身反應(yīng)性T細(xì)胞,限制機(jī)體過(guò)度免疫應(yīng)答或破壞自身組織的作用,使機(jī)體免疫平衡穩(wěn)態(tài)得以維持[10-11]。Foxp3在胸腺和外周血CD8+CD28-Tregs中特異性表達(dá),F(xiàn)oxp3基因編碼該蛋白,阻止細(xì)胞因子分泌[12]。CD8+CD28-Tregs可抑制自身免疫性疾病的發(fā)生,參與調(diào)節(jié)腫瘤免疫。本研究表明,與對(duì)照組比較,肝癌患者外周血中CD8+CD28-Foxp3+Tregs的比率明顯升高,且此改變與患者的年齡和性別比較差異無(wú)關(guān),這與王徐等[13]研究T細(xì)胞群和性別無(wú)關(guān)相一致。本研究的肝癌患者中,Tregs的比率較正常健康對(duì)照組明顯升高,且Tregs的比率在有淋巴結(jié)轉(zhuǎn)移的肝癌患者外周血中明顯升高,這與在消化道腫瘤中有淋巴結(jié)轉(zhuǎn)移的Tregs顯著增高相一致[14-17]。
目前,多數(shù)研究對(duì)Tregs的檢測(cè)基于腫瘤患者外周血進(jìn)行,對(duì)腫瘤病理組織同時(shí)進(jìn)行對(duì)照研究較少[18-19]。本研究通過(guò)石蠟包埋免疫組化法和Western blot的研究發(fā)現(xiàn)肝癌患者腫瘤組織中Foxp3陽(yáng)性細(xì)胞數(shù)及Foxp3蛋白表達(dá)水平顯著高于癌旁組織,表明在肝癌患者中,Tregs可能通過(guò)某種途徑向癌周滲透遷移浸潤(rùn)。Foxp3抑制機(jī)體增殖與活化腫瘤特異性T效應(yīng)細(xì)胞,與機(jī)體荷瘤時(shí)的免疫耐受腫瘤抗原和相關(guān)抗原可能有關(guān)[20-21],有文獻(xiàn)[22-25]報(bào)道Tregs通過(guò)趨化因子介導(dǎo)遷移至腫瘤微環(huán)境中。本實(shí)驗(yàn)中,由于肝癌樣本量相對(duì)較少,不利于在單項(xiàng)TNM分期和腫瘤分化級(jí)別中做Tregs的統(tǒng)計(jì)分析,因此基于III/IV期與I/II期、中低分化與高分化肝癌患者Foxp3+Tregs的比率明顯增高,提示Foxp3+Tregs可能在肝癌的發(fā)生、發(fā)展中起著重要作用。
綜上,本實(shí)驗(yàn)通過(guò)對(duì)肝癌患者外周血進(jìn)行檢測(cè),采用病理組織學(xué)和分子生物學(xué)的對(duì)照研究,更加直觀和準(zhǔn)確為臨床檢測(cè)Tregs提供參考。然而,收集遠(yuǎn)期的完整隨訪資料,術(shù)后檢測(cè)早期外周血T細(xì)胞結(jié)果可能受到抗生素使用等多因素的影響,可能會(huì)改變淋巴細(xì)胞亞群,因此,本研究還需要擴(kuò)大樣本量以獲取準(zhǔn)確的研究結(jié)果。
[1] Serrels A, Lund T, Serrels B, et al. Nuclear FAK controls chemokine transcription,Tregs, and evasion of anti-tumorimmunity[J]. Cell,2015, 163(1):160–173.doi: 10.1016/j.cell.2015.09.001.
[2] Tao Q, Pan Y, Wang Y, et al. Regulatory T cells-derived IL-35 promotes the growth of adult acute myeloid leukemia blasts[J].Int J Cancer, 2015, 137(10):2384–2393.doi: 10.1002/ijc.29563.
[3] Ouyang Z, Wu H, Li L, et al. Regulatory T cells in the immunotherapy of melanoma[J].TumourBiol, 2016, 37(1):77–85.doi: 10.1007/s13277–015–4315–0.
[4] Yuan CH, Sun XM, Zhu CL, et al. Amphiregulin activates regulatory T lymphocytes and suppresses CD8+T cell-mediated anti-tumor response in hepatocellular carcinoma cells[J]. Oncotarget, 2015,6(31):32138–32153. doi: 10.18632/oncotarget.5171.
[5] Ichikawa A, Miyoshi H, Arakawa F, et al. Detection of Tax‐specific CTLs in lymph nodes of adult T-cell leukemia/lymphoma patients and its association with Foxp3 positivity of regulatory T-cell function[J].Oncol Lett, 2017, 13(6):4611–4618. doi: 10.3892/ol.2017.6067.
[6] Jó?wicki W, Bro?yna AA, Siekiera J, et al. Frequency of CD4+CD25+Foxp3+cells in peripheral blood in relation to urinary bladder cancer malignancy indicators before and after surgical removal[J]. Oncotarget, 2016, 7(10):11450–11462. doi: 10.18632/oncotarget.7199.
[7] Mishra AK, Kadoishi T, Wang X, et al. Squamous cell carcinomas escape immune surveillance via inducing chronic activation and exhaustion of CD8+T cells co-expressing PD-1 and LAG-3 inhibitory receptors[J]. Oncotarget, 2016, 7(49):81341–81356. doi:10.18632/oncotarget.13228.
[8] 吉順榮, 姚宛彤, 張波, 等. 胰腺癌患者外周血CD8+CD28+和CD8+CD28–T淋巴細(xì)胞亞群的分析[J]. 上海醫(yī)學(xué), 2012,35(4):316–319.Ji SR, Yao WT, Zhang B, et al. Expression of CD8+CD28+and CD8+CD28–in the peripheral blood of pancreatic cancer patients[J].Shanghai Medical Journal, 2012, 35(4):316–319.
[9] Hasanjani Roushan MR, Bayani M, Soleimani Amiri S, et al.Evaluation of CD4+CD25+FoxP3+regulatory T cells during treatment of patients with brucellosis[J]. J Biol Regul Homeost Agents, 2016, 30(3):675–682.
[10] Lexmond WS, Goettel JA, Lyons JJ, et al. FOXP3+Tregs require WASP to restrain Th2- mediated food allergy[J]. J Clin Invest,2016, 126(10):4030–4044. doi: 10.1172/JCI85129.
[11] Chen C, Chen D, Zhang Y, et al. Changes of CD4+CD25+FoxP3+and CD8+CD28–regulatory T cells in non-small cell lung cancer patients undergoing surgery[J]. Int Immunopharmacol, 2014,18(2):255–261. doi:10.1016/j.intimp.2013.12.004.
[12] Assadiasl S, Ahmadpoor P, Nafar M, et al. Regulatory T cell subtypes and TGF‐β1 gene expression in chronic allograft dysfunction[J]. Iran J Immunol, 2014, 11(3):139–152.doi:IJIv11i3A1.
[13] 王徐, 胡明華, 王小明. 原發(fā)性肝癌患者微環(huán)境中CD8+CD28–調(diào)節(jié)性T細(xì)胞表達(dá)變化及意義[J]. 中國(guó)普通外科雜志, 2014,23(7):976–979. doi:10.7659/j.issn.1005–6947.2014.07.022.Wang X, Hu MH, Wang XM. Change and significance of CD8+CD28–Treg cells expression in the patients suffering from primary hepatocellular carcinoma[J]. Chinese Journal of General Surgery, 2014, 23(7):976–979. doi:10.7659/j.issn.1005–6947.2014.07.022.
[14] Chan IH, Wu V, Bilardello M, et al. PEG-rIL-10 treatment decreases FoxP3(+) Tregs despite upregulation of intratumoral IDO[J].Oncoimmunology, 2016, 5(7):e1197458. doi:10.1080/2162402 X.2016.1197458.
[15] Cheng H, Luo G, Lu Y, et al. The combination of systemic inflammation-based marker NLR and circulating regulatory T cells predicts the prognosis of resectable pancreatic cancer patients[J]. Pancreatology, 2016, 16(6):1080–1084. doi: 10.1016/j.pan.2016.09.007.
[16] Beatty PL, van der Geest R, Hashash JG, et al. Immunobiology and immunosurveillance in patients with intraductal papillary mucinous neoplasms(IPMNs), premalignant precursors of pancreatic adenocarcinomas[J]. Cancer Immunol Immunother, 2016,65(7):771–778. doi: 10.1007/s00262–016–1838–1.
[17] Choi HS, Ha SY, Kim HM, et al. The prognostic eあects of tumor infiltrating regulatory T cells and myeloid derived suppressor cells assessed by multicolorflow cytometry in gastric cancer patients[J].Oncotarget, 2016, 7(7):7940–7951. doi: 10.18632/oncotarget.6958.
[18] 薛旦旦, 夏添松, 劉曉安, 等. 乳腺癌腫瘤微環(huán)境中CD8+T細(xì)胞和調(diào)節(jié)性T細(xì)胞的研究[J]. 中華實(shí)驗(yàn)外科雜志, 2014, 31(1):149–151.doi:10.3760/cma.j.issn.1001–9030.2014.01.052.Xue DD, Xia TS, Liu XA, et al. Infiltrating CD8 + T cells and regulatory T cells in breast cancer microenvironment[J]. Chinese Journal of Experimental Surgery, 2014, 31(1):149–151. doi:10.3760/cma.j.issn.1001–9030.2014.01.052.
[19] McCoy MJ, Hemmings C, Miller TJ, et al. Low stromal Foxp3+regulatory T-cell density is associated with complete response to neoadjuvant chemoradiotherapy in rectal cancer[J]. Br J Cancer,2015, 113(12):1677–186. doi: 10.1038/bjc.2015.427.
[20] 毛麗偉, 廖國(guó)清, 王紅梅, 等. 胃癌患者不同區(qū)域淋巴結(jié)和外周血CD4+CD25+FoxP3+調(diào)節(jié)性T細(xì)胞的表達(dá)和臨床意義[J]. 免疫學(xué)雜志, 2016, 32(11):1001–1004.Mao LW, Liao GQ, Wang HM, et al. The expression of CD4+CD25+FoxP3+regulated T cells in different regional lymph nodes of gastric carcinoma and its clinical significance[J].Immunological Journal, 2016, 32(11):1001–1004.
[21] Lee HE, Park DJ, Kim WH, et al. High FOXP3+regulatory T-cell density in the sentinel lymph node is associated with downstream non-sentinel lymph-node metastasis in gastric cancer[J]. Br J Cancer, 2011, 105(3):413–419. doi:10.1038/bjc.2011.248.
[22] 陳中, 倪家連, 劉魯岳, 等. CD4+CD25+調(diào)節(jié)性T細(xì)胞在肝癌微環(huán)境中的分布狀況與局部免疫狀態(tài)的關(guān)系[J]. 中國(guó)普通外科雜志,2007, 16(7):690–692. doi:10.3969/j.issn.1005–6947.2007.07.022.Chen Z, Ni JL, Liu LY, et al. Relationship of the distribution and local immunology of CD4+CD25+ regulartory T cells in tumor microenvironment of hepatocellular carcinoma[J]. Chinese Journal of General Surgery, 2007, 16(7):690–692. doi:10.3969/j.issn.1005–6947.2007.07.022.
[23] Napoletano C, Bellati F, Ruscito I, et al. Immunological and clinical impact of cancer stem cells in vulvar cancer: Role of CD133/CD24/ABCG2-expressing cells[J]. Anticancer Res, 2016, 36(10):5109–5116. doi:10.21873/anticanres.11080.
[24] 王文斌, 劉三光, 劉兵, 等. 肝外膽管癌組織叉狀頭/翅膀狀螺旋轉(zhuǎn)錄因子3陽(yáng)性調(diào)節(jié)性T細(xì)胞浸潤(rùn)及其臨床意義[J]. 中華實(shí)驗(yàn)外科雜志, 2015, 32(5):1156–1158. doi:10.3760/cma.j.issn.1001–9030.2015.05.075.Wang WB, Liu SG, Liu B, et al. Significance of forkhead/winged helix transcription factor P3 + regulatory T cells infiltration in extrahepatic cholangiocarcinoma[J]. Chinese Journal of Experimental Surgery, 2015, 32(5):1156–1158. doi:10.3760/cma.j.issn.1001–9030.2015.05.075.
[25] Wei R, Hu Y, Dong F, Xu X, et al. Hepatoma cell-derived leptin downregulates the immunosuppressive function of regulatory T-cells to enhance the anti-tumor activity of CD8+T-cells[J]. Immunol Cell Biol, 2016, 94(4):388–399. doi: 10.1038/icb.2015.110.