门静脉输注供者脾细胞诱导的供者特异性免疫低反应性

目的 探讨经门静脉输注供者脾细胞能否诱导皮肤移植小鼠产生供者特异性的免疫低反应性及其可能机制.方法 取Balb/c小鼠,随机分为空白对照组(经小鼠门静脉输注RPMI 1640培养液)、受者脾细胞组(经小鼠门静脉输注Balb/c小鼠脾细胞)、供者脾细胞组(经小鼠门静脉输注C57BL/6小鼠脾细胞)、空白移植对照组(经小鼠门静脉输注RPMI 1640培养液,7 d后移植C57BL/6小鼠的皮肤)、实验对照组(经小鼠门静脉输注Balb/c小鼠脾细胞,7 d后移植C57BL/6小鼠的皮肤)、实验组(经小鼠门静脉输注C57BL/6小鼠脾细胞,7 d后移植C57BL/6小鼠的皮肤)以及第三方移植组(经小鼠门静脉输注C57BL/6小鼠脾细胞,7 d后移植C3H小鼠的皮肤).记录空白移植对照组、实验对照组、实验组和第三方移植组移植皮肤的存活时间,并观察移植皮肤的病理学变化;脾细胞输注后7 d,分别获取空白对照组、受者脾细胞组和供者脾细胞组小鼠的外周血、脾脏和肝脏,用流式细胞仪测定样本中CD4+CD25+Foxp3+调节性T淋巴细胞(CD4+CD25+Foxp3+Treg细胞)的比例.结果 实验组移植皮肤的存活时间为(19.8±4.6)d,明显长于空白移植对照组、实验对照组和第三方移植组,但仍未达到长期存活.皮肤移植后7 d,空白移植对照组和实验对照组的移植皮肤呈现重度急性排斥反应的病理学改变,而实验组移植皮肤呈现中度急性排斥反应的病理学改变.供者脾细胞组外周血、肝脏和脾脏中CD4+CD25+Foxp3+Treg细胞比例明显高于空白对照组和受者脾细胞组.结论 门静脉输注供者脾细胞可特异性地延长供者皮肤移植物的存活时间,减轻移植物的排斥反应,该效应可能与受者体内的CD4+CD25+Foxp3+Treg细胞增加有关.     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.     

RANTES在CD4+Tm细胞介导小鼠心脏移植急性排斥反应中的表达及意义

目的 探讨趋化因子RANTES在CD4+记忆性T淋巴细胞(Tm细胞)介导的小鼠心脏移植急性排斥反应中表达的变化及意义.方法 以Balb/c小鼠为供鼠,C57BL/6小鼠为受鼠,进行皮肤移植,提取并纯化受鼠脾脏中的CD4+ Tm细胞.分为两组进行实验:实验组,C57BL/6小鼠输注1×106个CD4+ Tm细胞,第2天以Balb/c小鼠为供鼠,进行颈部异位心脏移植;对照组,C57BL/6小鼠未输注CD4 Tm细胞,直接进行心脏移植.观察两组移植心脏存活时间和组织病理学改变,检测移植物中RANTES基因的相对表达量及RANTES在受鼠血清中的浓度.结果 皮肤移植受鼠脾脏中CD4+ Tm细胞达到26.83％.对照组受鼠存活时间为(7.67±0.21)d,实验组为(5.17±0.17) d(P＜0.01).对照组移植心脏急性排斥反应的评级为(2.67±0.14)级,实验组为(3.92±0.08)级(P＜0.01).实验组移植心脏中RANTES基因的相对表达量为对照组的(2.6±0.21)倍(P＜0.01).实验组血清中RANTES浓度为(223.6±16.79) pg/ml,对照组为(120.7±9.47) pg/ml(P＜0.01).结论 接受CD4+ Tm细胞输注的心脏移植受鼠,其体内RANTES的表达量明显增加,加速了急性排斥反应的发生.     

混合培养的供、受者骨髓细胞过继回输延长小鼠移植心脏存活时间

目的 将供、受者骨髓细胞经混合培养后过继回输,以观察其对同种异体移植心脏存活时间和受者免疫功能的影响.方法 取Balb/c小鼠和C57BL/6J小鼠的骨髓细胞,进行混合培养.配制含Balb/c小鼠和C57BL/6J小鼠脾淋巴细胞的混合淋巴细胞反应体系(MLR)以及含Balb/c小鼠和C3H小鼠脾淋巴细胞的MLR,分别加入混合培养的骨髓细胞,观察其对MLR中细胞增殖的影响.以C57BL/6J小鼠为供者,Balb/c小鼠为受者行腹腔异位心脏移植,实验分为4组:(1)移植对照组,受者仅进行心脏移植,不作其他处理;(2)实验对照组,心脏移植后给予西罗莫司灌胃;(3)实验组,移植手术结束前注射混合培养的骨髓细胞1×10~7个,术后给予西罗莫司;(4)第三方对照组,受者接受C3H小鼠的移植心脏,手术结束前注射混合培养的骨髓细胞1×10~7个,术后给予西罗莫司.记录移植心脏存活时间;移植心脏停跳当日,取受者外周血,检测CD4~+ CD25~+ T淋巴细胞的比例及供者来源的H-2K~b细胞的比例.结果 加入混合培养的骨髓细胞后,Balb/c和C57BL/6J的MLR的淋巴细胞增殖率低于Balb/c和C3H的MLR.实验组移植心脏的存活时间长于其他3组(P<0.05).实验组CD4~+CD25~+T淋巴细胞的百分率高于其他3组(P<0.05).实验组外周血中H-2K~b细胞的比例高于其他3组(P<0.05).结论 受者输注混合培养的供、受者骨髓细胞可在一定程度上调节免疫应答,延长小鼠移植心脏的存活时间,该作用具有供者抗原特异性.     

OX40信号调节抑制小鼠CD4+CD25+调节性T淋巴细胞Foxp3的表达

目的 探讨共刺激信号OX40对体外诱导的小鼠CD4+ CD25+适应性调节性T淋巴细胞(iTreg)的Foxp3表达的影响.方法 制备C57BL/6小鼠淋巴细胞悬液,经免疫磁珠法分选,获得CD4+ CD25-静息T淋巴细胞,与抗CD3单克隆抗体、抗CD28单克隆抗体、转化生长因子β1、白细胞介素2共孵育,诱导产生Foxp3+ iTreg.在此基础上,于培养体系中加入OX40激动型抗体及其对照抗体,利用流式细胞仪分析研究OX40信号刺激对iTreg Foxp3表达的影响.结果 C57BL/6小鼠淋巴结中CD4+ CD25+天然调节性T淋巴细胞(Treg)比例为(5.0±0.4)％,体外诱导培养的CD4+CD25+ Treg比例为(71.8±13.4)％,其中Foxp3阳性表达占(74.9±1.9)％.OX40激动型抗体组CD4+ CD25+ Treg细胞比例为(80.0±1.6)％,其中Foxp3表达水平为(59.2±0.7)％;OX40激动型抗体对照抗体组CD4+ CD25+ Treg细胞比例为(86.0±1.4)％,其中Foxp3表达水平为(70.0±0.8)％,两组间差异有统计学意义(P＜0.05).结论 静息T淋巴细胞可以在体外诱导培养获得高纯度iTreg;OX40信号刺激可以显著抑制CD25+ iTreg细胞Foxp3的表达.     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.

Abstract：

Objective To investigate the expression of CXCR6 in allograft rejection and effect of CXCL16/CXCR6 interaction on allograft survival Methods Intra-abdominal heterotopic heart transplantation was performed using wild type (WT) Balb/c mice (H-2d) (allogeneic) as donors or WT C57BL/6 mice (B6, H-2b) (syngeneic) as donors, and using WT B6 mice as recipients. The intragraft expression of CXCR6 and expression of CXCR6 in CD8+ T cells of the spleens from syngeneic and allogeneic recipients were examined. The allogeneic recipients were further divided into the experimental group (n = 5) and control group (n = 6) randomly. The experiment group and control group were injected with anti-CXCL16 mAb or control mAb respectively until rejection occurred. The cardiac allograft survival in experimental group and control group was evaluated. Results Rejected allografts showed higher expression of CXCR6 than syngeneic cardiac grafts. More importantly,expression of CXCR6 in CD8+ T cells was also up-regulated by allograft rejection. However, injection of anti-CXCL16 mAb could not inhibit cytotoxic activity of CD8+ T cells. Moreover, experimental group could not prolong the cardiac graft survival time as compared with control group. Conclusion Expression of CXCR6 in CD8+ T cells is up-regulated in allograft rejection.     

阻断ICOS/B7h信号的供体特异性输血对移植受体CD4+CD25+调节性T细胞的影响

目的 观察阻断ICOS/B7h信号的供体特异性输血(DST)对异基因小鼠心脏移植术后体内CD4+CD25+调节性T细胞(Treg)的影响.方法 按陈氏方法建立小鼠颈部异位心脏移植模型,实验分3组,异基因组及同基因组:供心分别来源于BALB/C和C57BL/6小鼠,受体均为C57BL/6小鼠,未予治疗.治疗组:移植当天给予受体鼠(C57BL/6)尾静脉注射5×106 ICOS-Fc靶定的供体(BALB/C)脾B淋巴细胞,d0～6连续给予受体鼠尾静脉注射ICOS-Fc 200 μg/d.术后统计各组移植物的存活时间,通过流式细胞术检测受体鼠外周血中CD4+CD25+Treg的亚群比例,利用逆转录-聚合酶链反应(RT-PCR)检测移植物中FOXP3的mRNA表达,在混合淋巴细胞反应中检测CD4+CD25+Treg对CD4+CD25-效应T细胞(Teff)的增殖抑制效率.结果 与异基因组比较,治疗组心脏移植物存活时间明显延长[(84.38±29.14)d比(7.00±0.76)d,P＜0.01].各组中,治疗组受体外周血中CD4+CD25+Treg亚群比例显著上调[(15.60±5.69)%,P＜0.01].与其他两组比较,治疗组心脏移植物中FOXP3 mRNA表达显著上调.以正常鼠为对照,耐受鼠脾脏中获取的CD4+CD25+Treg能够更高效地抑制CD4+CD25-Teff在混合淋巴细胞培养中的增殖效应.结论 通过阻断ICOS/B7h信号的DST可以诱导异基因小鼠心脏移植耐受,CD4+CD25+Treg在耐受的形成与维持中均起着重要作用.     

CD4+CD25+调节性T细胞在维持小鼠肝脏移植自发性免疫耐受状态中的作用

目的 探讨CD4+CD25+调节性T细胞在维持小鼠肝脏移植免疫耐受状态中的作用.方法 进行小鼠原位肝脏移植,诱导出移植免疫耐受后,向受体注射抗CD25抗体(PC61)以去除CD4+CD25+T细胞,检测受体内CD4+CD25+T细胞数量及叉状头/翅膀状螺旋转录因子(Foxp3)的表达以确定CD4+CD25+T细胞完全被清除,同时观察受体生存时间.结果 与同种同系小鼠肝脏移植结果 相似,同种异系肝脏移植小鼠的生存时间亦均超过70 d.移植免疫耐受诱导后,PC61不同注射方案均能完全去除受体小鼠肝脏、脾脏及血液中的CD4+CD25+T细胞,且移植肝脏中Foxp3 mRNA的表达也明显降低,表明完全去除了CD4+CD25+调节性T细胞,但肝脏移植动物生存时间并未受到影响.结论 CD4+CD25+调节性T细胞对于小鼠肝脏移植自发性免疫耐受的维持并非必需.     

CD+4CD+25调节性T淋巴细胞的研究进展

CD+4CD+25 Treg细胞(调节性T淋巴细胞)是一类特殊的T淋巴细胞群体,其能够识别自身抗原并抑制自身反应性细胞的免疫反应,是自身免疫耐受不可缺失的一环,同时也可在炎症情况下抑制效应性细胞过度活化,防止免疫反应过强而对机体造成损伤.在CD+4CD+25 Treg 细胞缺失或功能障碍情况下,将导致机体发生自身性疾病,而在细胞过度活化情况下,则机体发生肿瘤的概率大为增加.故研究CD+4CD+25 Treg细胞对于临床疾病的治疗具有重大意义.我们就以下几个方面进行综述.(1)CD+4CD+25 Treg细胞表面特异性分子标志;(2)CD+4CD+25 Treg细胞理想的分离扩增方法;(3)分析其维持免疫耐受可能的分子细胞机制;(4)CD+4CD+25 Treg细胞在自身免疫疾病治疗、肿瘤免疫、以及移植排斥的防治等临床疾方面的作用.     

Human CD8 responder cells can be directly activated to proliferate and to produce IL-2 following stimulation by allogeneic, but not by xenogeneic, porcine blood mononuclear cells

Abstract: In order to determine the precise nature of human T lymphocytes reactivity against porcine stimulator cells, purified CD4₊ and CD8+ human peripheral T lymphocytes have been tested for their responsiveness against porcine stimulator cells. In a xenogeneic mixed lymphocyte reaction (MLR), CD4+ T cells were capable of proliferating as a result of the recognition of porcine peripheral blood lymphocytes (PBL), whereas CD8+ T cells were unresponsive. A proliferative response of CD8+ T cells could be restored by treatment with human IL-2, but not by IL-lα, IL-lβ, or IL-6. Production of IL-2 was not detected in the xenostimulated CD8+ responder cells, nor could IL-2 production be restored by the addition of IL-lα, IL-1β, or IL-6. The presence of human CD4₊ responder cells was crucial both for a xenoproliferative response and for IL-2 synthesis. However, when the expression of the IL-2 receptor (CD25) on the CD8₊ T cells was analyzed, no difference was detected between xenostimulated and allostimulated CD8₊ T cells. When the development of cytotoxic T cells in xenogeneic and allogeneic MLRs was compared, the cytotoxic activity exhibited by purified CD8+ T cells in xenogeneic MLR was significantly lower than that in the allogeneic combination. In the xenogeneic combination, exogenous IL-2 reconstituted the cytotoxicity by purified CD8₊ T cells; however, IL-lα, IL-lβ, or IL-6 did not.
Our results show that purified human CD4₊ T cells respond directly against pig PBMCs, whereas purified CD8₊ T cells do not. Furthermore, responsiveness in CD8₊ T cells is completely restored by the addition of human IL-2.     

CD4+ CD25+ CD62+ T-Regulatory Cell Subset Has Optimal Suppressive and Proliferative Potential

CD4+ CD25+ regulatory T cells (Treg) are potent suppressors, and play important roles in autoimmunity and transplantation. Recent reports suggest that CD4+ CD25+ Treg are not a homogeneous cell population, but the differences in phenotype, function, and mechanisms among different subsets are unknown. Here, we demonstrate CD4+ CD25+ Treg cells can be divided into subsets according to cell-surface expression of CD62L. While both subsets express foxp3 and are anergic, the CD62L+ population is more potent on a per cell basis, and proliferates and maintains suppressive function far better than the CD62L- population and unseparated CD4+ CD25+ Treg. The CD62L+ population preferentially migrates to CCL19, MCP-1 and FTY720. Both CD62L+ and CD62L- subsets prevent the development of autoimmune gastritis and colitis induced by CD4+ CD25-CD45RBhigh cells in severe combined immunodeficiency (SCID) mice. Overall, these results suggest CD4+ CD25+ Treg are not a homogenous cell population, but can be divided into at least two subsets according to CD62L expression. The CD62L+ subset is a more potent suppressor than the CD62L- population or unfractionated CD4+ CD25+ Treg cells, can be expanded far more easily in culture, and is more responsive to chemokine-driven migration to secondary lymphoid organs. These properties may have significant implications for the clinical manipulation of the CD4+ CD25+ CD62L+ cells.     

CD4+CD25+调节性T细胞在肿瘤免疫中的作用研究

CD4+CD25+调节性T细胞(Treg)在自身免疫耐受、免疫自稳、肿瘤免疫中发挥着重要作用,它可以抑制自身抗原或者非自身抗原如肿瘤抗原引起的免疫反应.人们对Treg细胞的免疫抑制作用已进行了相关的研究和临床应用,最新研究表明其能够诱导肿瘤特异性抗原和局部的免疫反应.此综述将讨论Treg细胞的相关表面分子及其在肿瘤免疫...     

Biocompatibility Study Based on Differential Sequestration Kinetics of CD14+CD16+ Blood Monocyte Subsets with Different Dialyzers

The immune defect in hemodialysis (HD) patients is associated with a monocyte dysfunction, including an increase in the production of proinflammatory cytokines. Blood membrane contact leads to an increase in cellular activation and sequestration into the capillary bed of the lung. The influence of the sequestration on the number of mature monocytes was studied by analyzing the fate of monocytes, particularly, the CD14+CD16+ subpopulation, during HD treatment.

In thirty stable HD patients, the distinct cell populations were determined by differential blood counts and flow cytometry. Patients with diabetes or systemic vasculitis, those showing evidence of infectious complications or malignancy, or those taking immunosuppressive medications were excluded from the study. Cells from this study population were analyzed before the start, 30 min thereafter, and at the end of HD treatment, each time using a different dialyzer: hemophan, methylmethacrylate (PMMA), triacetate membrane, cuprophane/vitamin E, acrylonitrile, and sodium methallylsulfonate polymer (AN69).

The CD14+CD16+ subset decreased at 30 min and remained suppressed for the course of dialysis. To examine whether currently used biocompatible membranes differ in their effect on the sequestration of monocyte subpopulations, temporal monocytic changes were comparatively analyzed during HD with a different dialyzer. The drop in the first 30 min until the end of HD treatment was significant (p<0.05), very uniform, and sharp in all patients, and was independent upon membrane type.

The CD14+CD16+ monocyte subpopulation showed increased and longer margination from the blood circulation during HD. Given the fact that CD14+CD16+ monocytes represent a sensitive marker for inflammation or cellular activation, the depletion of these cells may offer an easily accessible parameter that is more sensitive than complement activation for biocompatibility studies on forthcoming, improved dialyzer membranes.     

Further Analysis of the T-Cell Subsets and Pathways of Murine Cardiac Allograft Rejection

The present study examined the role of CD4+ and CD8+ T cells in cardiac allograft rejection when either the direct or indirect pathway was eliminated for the CD4+ portion of the response. To study the pathways in vivo, we used genetically altered mouse strains that lack class II antigens as either the donors or recipients for cardiac transplantation. In contrast to earlier published studies, which used different strain combinations, we found that either CD4- or CD8-depletion prolonged cardiac allograft survival moderately, but not indefinitely, in an MHC-mismatched, minor-matched combination. When the CD4+ indirect pathway was eliminated, rapid graft rejection occurred when both T-cell subsets were present and when either CD4+ or CD8+ T cells were depleted. When the CD4+ direct pathway was eliminated, rapid graft rejection occurred when both T-cell subsets were present, there was slow rejection when CD4+ T cells were eliminated, and no rejection was seen for more than 100 days when CD8+ T cells were eliminated. However, the long-surviving allografts on the recipients with only CD4+ cells and an indirect pathway did show evidence of chronic vasculopathy. Thus, either CD4+ or CD8+ T cells can mediate acute cardiac allograft rejection in these experiments when both pathways are available. In addition, CD4+ T cells can provide help for acute rejection through either the direct or indirect pathway. Finally, recipients who have only CD4+ cells and an indirect pathway do not demonstrate acute rejection, but do show evidence of chronic rejection.     

Successive emergence of two CD 8 subsets in primary CMV infection of allograft recipients

Abstract Allograft recipients with cytomegalovirus (CMV) infection develop increased proportions of circulating CD8 lymphocytes. A longitudinal study of 11 kidney and 5 liver allograft recipients with primary CMV infection but no other aetiological factor to explain graft dysfunction revealed selective imbalances in peripheral blood CD8' T cell subsets. Initially, CMV viraemia was associated with elevated CD8+bright' T cell numbers and T cell activation. Activation markers fell to normal when viral cultures became negative (before the end of the 1st month). During the 2nd-6th months, most (12/16) patients continued to have high CD8⁺ T cell counts (1050–2900 CD8⁺ cells/mm3), comprising an uncommon CD8⁺ T cell subset, as 45–73% of CD8^{+ bright} lymphocytes were CD3⁺ and TCRαβ⁺ but were not stained by anti-CD28, CD11b, CD16, CD56 and CD57 antibody. Unexpectedly, CD 8⁺ CD 57⁺ T cells, a hallmark of CMV infection, did not appear until the 2nd-6th months of primary CMV infection, and their numbers increased progressively thereafter. They became the predominant CD8⁺ T cell subset after about 6 months of infection and their persistence for several (up to 4) years was strongly correlated ( r = 0.87) with expansion of CD8⁺ cells. Persistence of CD 8 lymphocytosis was, thus, directly related to the rate of expansion of an uncommon CD 8⁺CD 57^- subset and its progressive replacement by CD 8⁺CD 57 ⁺ T cells that were chronically elicited by CMV.     

慢性乙型肝炎患者外周血调节性T细胞对树突状细胞功能的抑制作用

目的研究慢性乙型肝炎（CHB）患者外周血CD4＋CD25＋调节性T细胞（Treg）对树突状细胞（DCs）免疫功能的抑制作用,探讨治疗CHB的新方法。方法采用密度梯度离心法获得CHB患者和健康对照组（NC组）外周血单个核细胞（PBMC）;部分PBMC体外诱导培养获得DCs,部分PBMCs用特异性免疫磁珠分选获得CD4＋CD25＋Treg和CD4＋CD25-T细胞;不同来源的DCs和正常对照组CD4＋CD25-T细胞混合为反应细胞,将不同来源和不同比例的Treg分别加入到反应细胞中培养3 d,MTT法检测Treg抑制DCs的抑制指数（SI）,并在培养DCs的不同时间加入Treg,应用流式细胞术检测DCs表面共刺激分子CD80和HLA-DR的表达。结果来源于CHB患者及NC组的Treg均可抑制DCs的免疫作用,来源于CHB患者Treg抑制DCs能力显著高于NC,差异具有统计学意义（P ＜0.01）。不同比例的Treg均可抑制DCs的免疫功能,随着Treg比例的增高抑制作用也越明显,抑制指数亦越高。在DCs培养的不同时间加入相同比例的Treg,发现Treg对DCs表面分子CD80、HLA-DR的表达均有抑制作用,与对照组相比,差异具有统计学意义（P＜0.01）,同时发现加入Treg的时间越早,DCs表面分子表达降低越明显。结论 CHB患者Treg可显著抑制DCs免疫功能且呈时间和量的依赖,抑制DCs表面分子CD80和HLA-DR表达,可能是Treg抑制DC免疫功能的机制之一。     

CD4+CD25+调节性T细胞对小鼠肝脏移植自发性免疫耐受的影响

目的 研究CD4+CD25+调节性T细胞在诱导自发性肝脏免疫耐受中的作用.方法 向受体和供体注射抗CD25抗体(PC61)后进行小鼠原位肝脏移植,观测其生存时间.术后20～30 d切取移植肝脏行HE染色,同时观察CD4+CD25+T细胞对CD4+T细胞和CD8+T细胞功能的影响.结果 去除受体而不是供体小鼠的CD4+CD25+T细胞可以导致肝移植排斥反应.而且,去除CD4+CD25+T细胞使移植物的白细胞浸润明显增多,组织损伤加重.同时,去除CD4+CD25+T细胞导致CD4+T细胞的增殖活性和CD8+T细胞的细胞毒活性明显增强.结论 受体来源的CD4+CD25+调节性T细胞在小鼠肝脏移植免疫耐受诱导中起重要作用.

Abstract：

Objective To examine the contribution of CD4+ CD25+ regulatory T cells to liver transplant tolerance. Methods After injection of anti-CD25 monoclonal antibody (mAb, PC61), mouse orthotopic liver transplantation was performed and survivals were determined. The paraffin-embedded sections of hepatic allografts were cut and stained with hematoxylin and eosin (HE). Furthermore, the effect of CD4+ CD25+ regulatory T cells on proliferative response of CD4+ T cells and cytotoxicity of CD8+ T cells was examined by depleting these regulatory T cells. Results Depletion of these cells in the recipients but not in the donors before liver transplantation caused rejection. Histological analyses of hepatic allografts with PC61 treatment showed extensive leukocyte infiltration and tissue destruction, whereas those in the control group showed minimal changes. Moreover, elimination of CD4+CD25+ T cells resulted in the enhancement of both proliferative response of CD4+ T cells and cytotoxicity of CD8+ T cells against donor-type alloantigen. Conclusions These results suggest that CD4+CD25+ regulatory T cells were important for tolerance induction to hepatic allografts.     

CD4+CD25+FOXP3+T细胞在肝癌肝移植肿瘤复发中的作用

目的 探讨肝癌肝移植病人移植前后外周血和肿瘤组织中CD4+CD25+FOXP3+T细胞比例变化及其临床意义.方法 用流式细胞仪检测肝癌肝移植病人和其他肝移植病人术后外周血中CD4+CD25+FOXP3+T细胞的比例,并采用正常人作对照.用免疫组化法检测肝癌病人和非肝癌病人肿瘤组织中FoxP3的表达及CD8+T细胞浸润的比例.观察肝癌肝移植病人术后及肿瘤复发后调节性T细胞的变化及其对肿瘤复发的影响.结果 流式细胞检测显示肝癌肝移植、非肝癌肝移植的病人术后外周血中CD4+CD25+FOXP3+T细胞占CD4+T细胞的比例较正常人明显升高,分别为(10.15±1.00)%、(5.30±1.64)%和(3.20±1.18)%,P<0.05.肝癌肝移植肿瘤复发病人较未复发病人外周血CD4+CD25+FOXP3+T比例明显升高,分别为(15.15±1.50)%和(6.80±1.50)%,P<0.01.免疫组化检测显示肿瘤组织中FOXP3+T细胞增多,CD8+T细胞浸润明显减少.结论 肝癌肝移植肿瘤复发的病人外周血中CD4+CD25+FOXP3+T细胞比例升高.调节性T细胞可能通过减少CD8+T细胞浸润,加速肿瘤复发.