李艳丽,卜庆
外周T细胞淋巴瘤患者外周血中髓源性抑制细胞的表达及意义
李艳丽,卜庆△
目的探索外周T细胞淋巴瘤(PTCL)患者外周血中髓源性抑制细胞(MDSCs)数量与预后的关系。方法收集PTCL患者23例,选取14例同期健康体检者作为正常对照组,采用流式细胞仪检测其外周血MDSCs/单核细胞比例,分析MDSCs数量与PTCL患者预后及临床特征的关系。结果MDSCs在PTCL患者外周血单核细胞中所占的比例高于正常对照组[(4.59±1.41)%vs(1.36±0.59)%,P<0.01]。PTCL化疗后外周血MDSCs的表达(1.29± 2.95)%较化疗前明显降低。结外侵犯部位、骨髓侵犯、临床分期、IPI评分不同的PTCL患者外周血MDSCs的表达差异有统计学意义(P<0.05)。结论MDSCs在PTCL患者外周血中高表达,提示与肿瘤发生及预后不良有关。
淋巴瘤,T细胞,外周;流式细胞术;髓源性抑制细胞
髓源性抑制细胞(myeloid-derived suppressor cells,MDSCs)是一群来源于骨髓祖细胞和未成熟髓细胞,具有免疫抑制功能的髓系细胞。MDSCs被炎性介质从骨髓募集到外周,经过活化可以抑制机体对肿瘤的免疫功能,使肿瘤细胞免于被免疫系统防御,导致肿瘤的发生和发展[1]。外周T细胞淋巴瘤(peripheral T-cell lymphoma,PTCL)是指所有起源于成熟(胸腺后)T细胞和自然杀伤(NK)细胞的恶性肿瘤,具有侵袭性强、病情迁延、容易复发、预后不良等特征,目前尚无标准治疗方法,常规化疗方案如CHOP、EPOCH等虽近期疗效尚可,但复发率仍较高,远期生存率较低。本研究拟观察PTCL患者外周血MDSC的数量,探讨其作用及与PTCL患者预后的关系,并能否将其作为PTCL的治疗靶点。
1.1研究对象收集2013年10月—2014年5月于桂林医学院附属医院、桂林市人民医院、广西壮族自治区南溪山医院接受治疗的PTCL患者23例。所有患者临床资料齐全,均经病理学确诊证实。其中男13例,女10例,年龄11~75岁,平均(43.52±17.16)岁。选取同期健康体检者14例作为正常对照组,其中男7例,女7例,年龄23~70岁,平均(45.79±14.31)岁。2组性别(χ2=0.149)、年龄(t=0.413)差异无统计学意义(均P>0.05)。全部临床特征资料均来自于患者入院的首次检查结果:包块直径≥10 cm为巨大包块,乳酸脱氢酶(LDH)正常参考值114~240 U/L。入组人员均签署知情同意书,并获得本单位伦理委员会批准。
1.2方法收集患者外周血(肝素钠抗凝)后混匀,取350 μL全血,加入荧光标记抗体CD33-APC、CD11b-FITC、CD14-PE各20 μL,4℃冰箱避光孵育30 min,PBS洗涤,红细胞裂解液裂解、洗涤、固定、重悬后,用FACS Canto(美国BD公司)检测患者外周血MDSCs/单核细胞比例,BD FACS Diva软件分析数据。
1.3统计学方法所有统计学数据采用SPSS 17.0软件进行分析,计量资料若符合正态分布用±s表示,采用独立样本t检验或配对样本t检验,如不符合正态分布用中位数(M)表示,采用Mann-Whitney U检验。计数资料采用卡方(χ2)检验。P<0.05认为差异有统计学意义。
23例患者,随访8个月,有7例进展,尚无死亡病例,中位无进展时间(PFS)为6个月。
2.12组MDSCs表达情况比较PTCL组和正常对照组外周血中均存在CD33+CD14-CD11b+MDSCs,但在PTCL组外周血单核细胞中所占的比例高于正常对照组[(4.59±1.41)%vs(1.36±0.59)%,t= 9.224,P<0.05],见图1。PTCL组化疗后外周血MDSCs的表达(1.29±2.95)%较化疗前明显降低(t= 2.10,P<0.05)
2.2MDSCs与临床特征的分析结果结外侵犯部位、骨髓侵犯、临床分期、国际预后指数(international prognostic index,IPI)评分不同PTCL患者外周血单核细胞中的MDSCs比例差异有统计学意义,年龄、LDH水平、包块大小不同PTCL患者外周血中的MDSCs比例差异无统计学意义,见表1。
Tab.1 The correlation of clinical features in PTCL patients表1MDSCs与PTCL患者临床特征间的关系(%)
Fig.1 Results of flow cytometry showing the expression of MDSCs in the peripheral blood in patients with PTCL group and normal control group图1 在PTCL患者和正常对照组外周血中MDSCs表达的流式结果
人类MDSCs的分子标志目前还未确定,本研究选取的是CD33+CD14-CD11b+标志的MDSCs,与国外报道类似[2]。有研究显示,B细胞淋巴瘤和霍奇金淋巴瘤中的MDSCs表达与不良预后相关[3],而PTCL预后不良,其机制尚未明晰,国外也少见MDSCs与PTCL相关性的研究,笔者推测MDSCs可能与PTCL的不良预后有关。
国内对于MDSCs的研究尚处于起步阶段,与临床相关的研究更是罕见。奉松青等[4]的临床研究显示CD14+HLA-DRlow/-MDSCs在胃癌患者外周血中的表达高于正常对照组;Christiansson等[5]以CD33+CD14-CD11b+为MDSCs的表型研究了慢性粒细胞性白血病(CML),发现CML组外周血中MDSCs的比例也要明显高于对照组(P<0.01),与本研究中MDSCs 在PTCL患者外周血中的比例高于正常对照组的结论一致;Gabitass等[6]证明外周血MDSCs在胰腺癌等实体瘤中显著升高,且与肿瘤的大小和临床分期等众多临床特征有关,与本研究结论相似。这提示MDSCs与肿瘤的发展、演进有着密切的关系[7],并可能与患者预后相关。国内外尚少见关于MDSCs在外周T细胞淋巴瘤中与化疗相关性的文献报道,Wang等[8]报道CD14-CD11b+MDSCs在胃癌Ⅳ期患者化疗前后外周血中比例也不一样,提示其变化与治疗有关;Tu等[9]研究结果显示患者化疗后外周血MDSCs的表达低于化疗前,可能与肿瘤被清除后MDSCs的产生和募集减少有关,这也提示MDSCs有可能作为肿瘤化疗效果的一种评价指标,有待更深入的观察和研究。在本研究中,因随访时间较短,尚未得出MDSCs与PTCL生存期的相关性,作用机制仍需探索,需要扩大样本量进一步开展研究。
总之,MDSCs在维持机体免疫系统平衡中起重要作用[10]。本研究证实了MDSCs在PTCL患者外周血中高表达,与多种临床特征相关,且化疗后较化疗前明显下降,因此可能是影响预后的因素。检测MDSCs的变化有望为PTCL的疗效及预后评价提供依据。
[1]Duffy A,Zhao F,Haile L,et al.Comparative analysis of monocytic and granulocytic myeloid-derived suppressor cell subsets in patients with gastrointestinal malignancies[J].Cancer Immunol Immunother,2013,62(2):299-307.doi:10.1007/s00262-012-1332-3.
[2]Peranzoni E,Zilio S,Marigo I,et al.Myeloid-derived suppressor cell heterogeneity and subset definition[J].Curr Opin Immunol,2010,22(2):238-244.doi:10.1016/j.coi.2010.01.021.
[3]Tadmor T,Fell R,Polliack A,et al.Absolute monocytosis at diagnosis correlates with survival in diffuse large B-cell lymphoma-possible link with monocytic myeloid-derived suppressor cells[J].Hematol Oncol,2013,31(2):65-71.doi:10.1002/hon.2019.
[4]Feng SQ,Liu CX,Zheng SB.Expression of myeloid-derived suppressor cells in the peripheral blood and its clinical significance in renal carcinoma[J]Journal of Southern Medical University,2013,33 (4)550-553.[奉松青,刘春晓,郑少波,等.肾癌患者外周血中CD33+HLA-DR-髓源抑制性细胞的表达及其临床意义[J].南方医科大 学 学 报,2013,33(4):550-553].doi:10.3969/j.issn.1673-4254.2013.04.19.
[5]Christiansson L,Soderlund S,Svensson E,et al.Increased level of myeloid-derived suppressor cells,programmed death receptor ligand 1/programmed death receptor 1,and soluble CD25 in Sokal high risk chronic myeloid leukemia[J].PloS 0ne,2013,8(l):e55818. doi:10.1371/journal.pone.0055818.
[6]Gabitass RF,Annels NE,Stocken DD,et al.Elevated myeloid-derivedtsuppressor cells in pancreatic,esophageal and gastric cancer are an independent prognostic factor and are associated with significant elevation of the Th2 cytokine interleukin-13[J].Cancer Immunol Immunother,2011,60(10):1419-1430.doi:10.1007/s00262-011-1028-0.
[7]Ko Js,Bukowski RM,Fincke JH.Myeloid-derived suppressor cells:a novel therapeutic target[J].Curr Oncol Rep,2009,11(2):87-93. doi:10.1007/s11912-009-0014-6.
[8]Wang L,Chang EWY,Wong SC,et al.Increased myeloid-derived suppressorcells in gastric cancer correlate with cancer stage and plasma S100A8/A9 proinflammatory proteins[J].J Immunol,2013,190(2):794-804.doi:10.4049/jimmunol.1202088.
[9]Tu S,Bhagat G,Cui G.Overexpression of interleukin-1beta induces gastric inflammation and cancer and mobilizes myeloid-derived suppressor cells in mice[J].Cancer Cell,2008,14(5):408-419. doi:10.1016/j.ccr.2008.10.011.
[10]Gabrilovich DI,Nasaraj S.Myeloid-derived suppressor cells as regulators of the immune system[J].Nat Rev Immunol,2009,9(3):162-174.doi:10.1038/nri2506.
(2014-09-09收稿2014-11-17修回)
(本文编辑李国琪)
The expression and significance of MDSCs in peripheral blood in patients with peripheral T cell lymphoma
LI Yanli,Bu Qing△
Department of Medical Oncology,the Affiliated Hospital of Guilin Medical University,Guilin 541000,China
△Corresponding AuthorE-mail:buqing1993@qq.com
ObjectiveTo study the relationship between the number of myeloid-derived suppressor cells(MDSCs)in peripheral blood and prognosis in patients with peripheral T-cell lymphoma(PTCL).MethodsTwenty-three patients with PTCL were selected in this study and 14 healthy persons were used as the normal control.The proportion of MDSCs/mononuclear in peripheral blood was detected by flow cytometry.The correlation between the number of MDSCs and the clinical character and prognosis in patients with PTCL was analyzed.ResultsThe proportion of MDSCs in peripheral blood was significantly higher in patients with PTCL than that of healthy subjects[(4.59±1.41)%vs(1.36±0.59)%,P<0.01].The number of MDSCs in peripheral blood was significantly decreased after chemotherapy compared with that before treatment[(1.29± 2.95)%,P<0.05)].There were significant differences in MDSCs expressions in patients between different extranodal involvement,bone marrow involvement,clinical stage and IPI score(P<0.05).Conclusion The higher expression of MDSCs may be related to the progression in patients with PTCL.
lymphoma,T-cell,peripheral;flow cytometry;myeloid-derived suppressor cells
R733.41
ADOI:10.11958/j.issn.0253-9896.2015.03.016
广西自然科学基金青年基金项目(2011GXNSFB018092)
桂林医学院附属医院肿瘤内科(邮编541004)
李艳丽(1989),女,硕士在读,主要从事各种恶性肿瘤的规范化治疗研究
△E-mail:buqing1993@qq.com