白介素4及CD40抗体作用下肾小管上皮细胞钙调神经磷酸酶活性及其与RANTES分泌的关系

目的观察小鼠肾小管上皮细胞(TEC)在白介素4(IL-4)及CD40激活状态下钙调神经磷酸酶(CaN)活性,并进一步探讨其与趋化因子RANTES分泌的关系。方法取Ⅱ级6～7周的雌性DBA小鼠,分离肾小管上皮细胞进行培养、刺激。采用RT-PCR检测RANTESmRNA表达;ELISA检测培养上清中RANTES含量;流式细胞仪检测CD40表达。结果(1)常规培养TEC可表达一定量的CD40;用IL-4刺激TEC24h,细胞表面CD40平均荧光强度(MFI)显著高于对照组(7.92±0.56vs4.33±0.30,P<0.001)。(2)常规培养TEC中有一定量的CaN活化(8.98±0.56)nmol/mg.pro;用IL-4、CD40抗体(mAb)及IL-4 CD40mAb刺激细胞,3组CaN活性均显著高于对照组(P<0.05)。(3)常规培养TEC仅分泌极少量的RANTES;在IL-4刺激或CD40mAb激活后TECRANTES蛋白分泌增高,分别为(43.61±13.73)pg/ml和(73.77±4.28)pg/ml,显著高于对照组(14.78±2.20)pg/ml(P<0.001)。(4)常规培养TEC微量表达RANTESmRNA;用IL-4、CD40mAb及IL-4 CD40mAb刺激细胞24h,各刺激组RANTESmRNA表达显著高于对照组(P<0.05)。(5)在IL-4、CD40mAb及IL-4 CD40mAb刺激下,FK506对TEC分泌RANTES蛋白及mRNA有显著抑制作用(P均<0.05)。结论Th2细胞因子IL-4及CD40-CD40配体(CD40L)共刺激信号可通过活化TECCaN,调控RANTES基因表达及分泌、     

妊娠期糖尿病孕妇血清Th1/Th2比值测定及分析

目的测定妊娠期糖尿病(GDM)患者血清中Th1细胞分泌的细胞因子干扰素-γ(IFN-γ)及Th2细胞分泌的细胞因子白介素-4(IL-4)的水平,分析Th1/Th2比值与GDM的关系。方法选取2015年10月至2016年10月间在我院住院治疗的GDM孕妇30例为GDM组,同时随机选取同一时期内在我院住院的正常孕妇30例为对照组。两组对象于早晨抽取空腹静脉血测定糖化血红蛋白,采用ELISA方法测定两组对象血清中的IFN-γ和IL-4水平。比较两组对象的上述实验室指标及IFN-γ/IL-4比值。结果两组孕妇的年龄、孕周、糖化血红蛋白水平比较,均无显著性差异(P0.05)。GDM组患者血清中IFN-γ水平显著低于对照组[(87.38±9.14)vs.(96.27±10.24)pg/ml](P0.05),IL-4水平显著高于对照组[(49.09±1.44)vs.(42.38±1.28)pg/ml](P0.05)。GDM组患者血清中IFN-γ/IL-4比值显著低于对照组[(1.78±0.11)vs.(2.27±1.07)](P0.05)。结论 GDM患者体内存在着Th1/Th2失衡的现象,Th2更加优势表达。     

结直肠癌患者外周血Th1和Th2细胞的检测与临床意义

目的 研究结直肠癌患者外周血CD4+T细胞亚群Th1和Th2细胞的比例以及相关特异性转录因子与细胞因子的表达水平,并观察其与临床分期之间的关系.方法 43名结直肠癌患者(肠癌组)与30名健康体检志愿者(对照组)作为研究对象.结直肠癌患者外周血Th1和Th2细胞占CD4+T细胞的比例运用流式细胞技术进行检测.采用实时荧光定量聚合酶链反应(quantitative Real-time PCR),检测外周血Th1/Th2细胞亚群特异性转录因子的相对基因表达量.血浆细胞因子的表达水平使用液相芯片技术方法定量检测.结果 肠癌组外周血Th2细胞占CD4+T细胞的比例和Th2细胞特异性转录因子GATA-3的mRNA表达量均显著高于对照组(P<0.05).肠癌组外周血Th1细胞特异性转录因子T-bet的mRNA表达量显著低于对照组(P<0.05),但Th1细胞占外周血CD4+T细胞的比例与对照组差异无统计学意义(P>0.05).血浆TNF-α、IL-1β和IL-15表达水平组间无显著差异(P>0.05).结直肠癌患者血浆IFN-γ、IL-4和IL-6的表达水平与病程分期有关(P<0.05).结论 结直肠癌患者外周血中Th1细胞比例变化不明显而Th2细胞比例明显升高.结直肠癌患者血浆细胞因子的不平衡表达可作为机体免疫状态转换与病情判断的指标.     

趋化因子RANTES对人外周血单个核细胞的免疫活化作用

目的　探讨趋化因子RANTES刺激对人外周血单个核细胞 (PMNC)的免疫活化作用及其内在机制。方法　分离人外周血 ,应用不同终浓度的人重组RANTES(rhRANTES)以及抗CD3单克隆抗体 (抗CD3mAb)进行体外刺激 ,并对增殖反应显著者给予吡咯啉烷二甲基硫脲 (PDTC)或CTLA4Ig进行干预。采用3 H 胸腺嘧啶核苷掺入法检测PMNC增殖程度 ,流式细胞仪检测淋巴细胞表型的变化。结果　rhRANTES终浓度为 10 0ng/ml和 5 0 0 0ng/ml时 ,诱导PMNC增殖反应出现两次峰值 ;rhRANTES(10 0ng/ml)刺激产生的增殖反应显著高于抗CD3mAb(5 0ng/ml)的刺激 (P <0 .0 5 ) ,但两者无拮抗或协同作用 ;PDTC和CTLA4Ig对rhRANTES(10 0ng/ml)诱导的增殖反应均能产生抑制作用 ,并呈现剂量依赖性 ;rhRANTES刺激后 ,淋巴细胞CD2 5表达率显著增加 (P <0 .0 5 ) ,而人RANTES的受体CCR5表达率显著降低 (P <0 .0 5 ) ,CD2 8表达率及CD4 /CD8比值无明显改变(P >0 .0 5 )。结论　RANTES趋化信号具有不依赖于CD3信号的独特的诱导PMNC免疫活化的功能。     

抗CD-40L单抗加小剂量、短程CsA对肝移植大鼠生存期和Th1/Th2平衡偏移的影响

目的 采用抗CD-40L单抗加小剂量CsA的联合免疫治疗,观察其对大鼠肝移植受体生存时间和Th1/Th2细胞因子谱变化的影响.方法 在建立稳定大鼠肝移植模型的基础上,将整个实验分为4组.A组(同基因对照组):SD→SD;B组(同种异体基因免疫排斥组):SD→Wistar,不用任何治疗措施;C组:SD→Wistar,CsA应用d1～d5;D组:SD→Wistar,CsA应用d1～d5加抗CD-40L(CD-154)单抗应用d0、d2.观察各组大鼠肝移植受体生存时间,移植后第7天用ELISA法检测外周血细胞因子水平.结果 A组、D组受体大鼠均可长期存活,B组生存时间仅为(13.8±2.4)d.IL-2、IFN-γ在B组的血清水平显著高于其余各组(P＜0.05),TNF-α在B组的表达水平高于不同免疫抑制组,但差异无显著统计学意义.IL-4、IL10较A组均有所增加,尤其D组的IL-10表达水平较B组显著增高(P＜0.05).结论 抗CD-40L单抗加小剂量CsA(伴或不伴DSBT)联合免疫治疗,可有效延长大鼠肝移植受体的生存时间,Th2类细胞因子的高水平表达与诱导移植耐受、抑制排斥反应有重要关联,有助于大鼠肝移植受体和移植肝的长期存活.     

西罗莫司和环孢素A对Th17细胞和调节性T淋巴细胞分化影响的比较

目的 比较西罗莫司(SRL)和环孢素A(CsA)对体外诱导CD4+T淋巴细胞向Th17和调节性T淋巴细胞分化的影响.方法 使用抗CD3和抗CD28单克隆抗体(简称抗CD3单抗和抗CD28单抗)刺激CD4+T淋巴细胞,并在培养体系中分别加入转化生长因子β(TGF-β);TGF-β+白细胞介素6(IL-6);TGF-β+IL-6+SRL;TGF-β+IL-6+CsA.72 h后用流式细胞术检测细胞内Foxp3和IL-17的表达水平,观察CD4+T淋巴细胞的分化情况及SRL和CsA对CD4+T淋巴细胞体外分化的影响.结果 在经抗CD3单抗和抗CD28单抗刺激后,TGF-β可诱导Foxp3+细胞(调节性T淋巴细胞,Treg)的增殖与分化,而TGF-β+ID6可诱导Th17细胞的增殖与分化.在培养体系中加人SRL和CsA,均可使Th17细胞的增殖与分化减少;SRL可促进Treg的增殖与分化,而CsA抑制Treg的增殖与分化.结论 SRL可以促进CD4+T淋巴细胞向Treg增殖与分化,而抑制Th17细胞的增殖与分化;CsA既抑制Treg的增殖与分化,又抑制Th17细胞的增殖与分化.     

体外调节Th1/Th2平衡治疗脑胶质瘤

目的 观察外源性细胞因子白细胞介素( IL)-2、干扰素(IFN)-γ和IL-4单克隆抗体(McAb)、IL-10 McAb在体外能否促使Th2型细胞因子分泌优势向Th1型逆转,抑制胶质瘤细胞生长。方法 体外培养大鼠C6胶质瘤细胞,加入外源性细胞因子共同孵育,光学显微镜观察细胞形态学变化,噻唑蓝(MTT)比色法检测细胞增殖抑制率,逆转录-聚合酶链反应(RT-PCR)检测Th1/Th2类细胞因子表达变化。结果 实验组较对照组细胞体积变小,生长密度低,细胞数目少;实验组与对照组比较细胞增殖抑制率分别为(26.41 ±3.60)％,其A值与对照组比较差异有统计学意义(P＜0.05)。对照组细胞只表达Th2类细胞因子,Th1类细胞因子表达缺如,实验组IFN-γ表达增加,IL-4和IL-10表达减弱,但是未见IL-2表达。结论 外源性细胞因子能够抑制脑胶质瘤细胞的生长,促进Th2型细胞因子分泌优势向Th1型逆转。     

Th1/Th2细胞因子对器官移植排斥反应的影响

目的:研究Th1/Th2细胞因子对同种异系小鼠心脏移植存活时间的影响.方法:使用野生型BALB/c小鼠作为供体,野生型B6小鼠、IL-4基因去除B6小鼠及IFN-γ基因去除B6小鼠作为受体,行腹部异位小鼠心脏移植.部分IL-4基因去除小鼠、IFN-γ基因去除小鼠联合应用α-半乳糖神经酰胺(α-galactosylceramide,α-GalCer),以获得更强的Th1/Th2偏移.比较移植物存活时间.向野生型、IL-4基因去除及IFN-γ基因去除B6小鼠腹腔内注射供体小鼠脾细胞,提取受体小鼠脾脏CD8<'8>T细胞行淋巴细胞毒试验.结果:IFN-γ基因去除组小鼠的移植物存活时间为(6.40±0.55)d,联合应用α-GalCer组移植物存活时间为(8.00±1.15)d.IL-4基因去除组小鼠的移植物存活时间为(8.00±1.00)d,联合应用α-GalCer组移植物存活时间为(8.60±1.34)d.淋巴细胞毒试验显示IFN-γ基因去除小鼠的CD8+T细胞毒性明显增强.结论:Th1/Th2细胞因子与排斥反应之间并不存在简单的对应关系.     

细胞因子诱导的杀伤细胞免疫治疗对非小细胞肺癌患者术后免疫功能的影响

目的 探讨细胞因子诱导的杀伤(CIK)细胞免疫治疗对术后非小细胞肺癌(NSCLC)患者免疫功能的影响. 方法 选取Ⅰ期、Ⅱ期和Ⅲa期NSCLC患者50例,经手术治疗后随机分为两组,常规治疗组和CIK细胞治疗组,每组25例;分别于治疗前、治疗后2周、4周和8周动态监测患者免疫功能指标,包括外周血CD3 、CD4 、CD4 /CD8 比值、NK细胞比率以及Th1/Th2细胞因子水平. 结果 CIK细胞治疗组于CIK细胞治疗后2周,外周血CD3 、CD4 T细胞、NK细胞和CD4 /cD8 的比值、白细胞介素-2(IL-2)、干扰素Y(INF-γ)水平较治疗前升高(P＜0.01),于治疗后4周达高峰,此后逐渐回落;而Th2细胞因子于CIK细胞治疗后2周下降,治疗后4周降至低谷.CIK细胞治疗组于CIK细胞治疗后2、4、8周CD3 、CD4 、CD4 /CD8 、NK细胞、IL-2、INF-7、白细胞介素4(IL-4)和白细胞介素10(IL-10)与常规治疗组各时点比较差异有统计学意义[(P＜0.05),治疗后4周CD3 70.2%±9.1% vs.46.3%±5.8%;CD4 40.2%±7.1% vs.22.9%±4.5%;CD4 /CD8 1.82±0.43 vs.1.09±0.34;NK 15.7%±5.4% vs.10.5%±2.5%;IL-2 34.8±11.7 ng/L vs.19.8±12.1 ng/L;INF-γ 63.7±23.3 ng/L vs.30.8±10.6ng/L;IL-4 10.2±8.6 ng/L vs.25.8±6.3 ng/L;IL-10 10.6±3.4 ng/L vs.21.4±8.6 ng/L]. 结论 CIK细胞免疫治疗能增强NSCLC患者术后的免疫功能.     

RNAi对大鼠T淋巴细胞CD28和OX40基因表达的联合抑制作用

目的 通过RNAi技术干扰T细胞CD28、CD134基因表达后,诱导获得抑制性T细胞(Ts);探讨Ts免疫学特性.方法 设计针对目标基因的siRNA,转染大鼠T淋巴细胞,FCM检测CD28、CD134水平,混合淋巴细胞反应(MLR)检测转染后的T淋巴细胞对异体淋巴细胞的增殖能力的影响,逆转录-聚合酶链反应(RT-PCR)及酶联免疫吸附试验(ELISA)法检测细胞因子水平.结果 siRNA转染大鼠T淋巴细胞后,抑制CD28、CD134分子的表达,siRNA转染24 h后,siRNA组CD28、CD134表达受到抑制[转染后及转染前表达分别为(22.35±4.37)%及(34.76±3.51)%(P<0.05)],T淋巴细胞分泌细胞因子IL-10水平增高,转染组及未转染组表达分别为(77.15±12.60)ng/L及(37.56±5.93)ng/L(P<0.01).而转染组及未转染组的IL-2表达分别为(2.79±0.51)及(4.35±1.11)ng/L(P<0.05);干扰素(IFN)-γ表达分别为(277.15±14.8)、(682.7±53.5)ng/L(P<0.05).结论 siRNA可以特异性抑制大鼠T淋巴细胞共刺激分子CD28、CD134基因表达,抑制了IL-2、IFN-γ的表达,提高了IL-10细胞因子表达水平,从而产生了免疫耐受效应.Ts细胞具有抗原特异性,而且在外源性rrIL-2存在时,不能逆转Ts细胞的功能.     

重组pEGFP-N1-H2Bl质粒载体诱导心脏移植免疫耐受

目的 探讨H2-Bl基因诱导小鼠心脏移植免疫耐受的机制和效果.方法 建立小鼠颈部心脏异位移植模型,供体心脏经主动脉根部灌注H2-Bl质粒真核表达载体后进行心脏移植.实验分4组:对照组、环孢素A(CsA)组、H2-Bl质粒转染组、H2-Bl质粒转染+CsA组.各组于术后1、3和7天各动态枪测供心病理改变,免疫组织化学方法测供心CD40表达情况,流式细胞仪检测供心血清中Th1/Th2细胞因子变化,记录移植心脏存活时间.结果 对照组移植后排斥反应最重,其余组与之比较均有所减轻,以H2-Bl质粒转染+CsA组排斥反应最轻.免疫组化显示术后7天时H2-Bl质粒转染组CD40与对照组相比差异有统计学意义(P＜0.05),CsA组、H2-Bl+CsA组CD40与对照组相比差异有统计学意义(P＜0.01).H2-Bl+CsA组Th2细胞因子表达较其余组增加而Th1细胞因子则减少,到术后7天时各组Th细胞因子与对照组相比差异均有统计学意义(P＜0.05).与对照组相比,其余各组小鼠供心存活天数均延长(P＜0.05).结论 H2-Bl基因干预可一定程度诱导移植心脏免疫耐受,延长同种异体小鼠颈部移植心脏存活时间.     

Prevention of acute allograft rejection in nonhuman primate lung transplant recipients: induction with chimeric anti-interleukin-2 receptor monoclonal antibody improves the tolerability and potentiates the immunosuppressive activity of a regimen using low doses of both microemulsion cyclosporine and 40-O-(2-hydroxyethyl)-rapamycin

BACKGROUND: In previous studies of cynomolgus monkey lung allograft recipients, we demonstrated significant immunosuppressive efficacy but reduced tolerability after combined treatment with high doses of microemulsion cyclosporine (CsA) and SDZ RAD (40-O-(2-hydroxyethyl)-rapamycin). The current study was designed to compare efficacy and tolerability of a combination of low-dose CsA and high-dose SDZ RAD (CTL group) to triple therapy using the chimeric anti-interleukin-2 (IL-2) receptor (CD25) monoclonal antibody (mAb) basiliximab (anti-IL-2 receptor mAb) for induction therapy (basiliximab: 5 mg intravenously on days 0 and 4) plus low-dose CsA and low-dose SDZ RAD for maintenance immunosuppression (CD25 group). CsA and anti-IL-2 receptor mAb are drugs that reduce cytokine synthesis and block IL-2-mediated lymphocyte stimulation, respectively. SDZ RAD blocks lymphocyte stimulation by other cytokines (e.g., IL-15) that are not inhibited by anti-IL-2 receptor mAb. METHODS: Twelve unilateral lung transplants were performed. Recipients were observed for 49 days by daily weight assessment, hemograms, blood chemistries, radiographs, and lung biopsies. Monkeys were euthanized before day 49 in the event of excessive weight loss (>25%) or organ failure. Target CsA trough levels were 100-200 ng/ml. Target SDZ RAD trough levels in the CTL group (no mAb) were 20-40 ng/ml, and 10-20 ng/ml in the CD25 group. RESULTS: None of the monkeys in the CD25 group needed to be euthanized early due to signs of drug toxicity. In contrast, four monkeys in the CTL group were sacrificed on days 28-35 as a result of excessive weight loss (n=3) and renal functional impairment (n=1). Three recipients in the CD25 group were euthanized on days 36, 38, and 46 as a result of persistent high fever associated with severe rejection. The median animal survival in the CTL group was 32 vs. 46 days in the CD25 group (P<0.04). The only two long-term survivors in the CTL group showed moderate rejection at day 49. The median rejection scores at day 14 (A0) and day 28 (A2) were identical in the two groups, despite the fact that the mean SDZ RAD trough level was significantly lower in the CD25 group (CTL: 38+/-3 ng/ml, CD25: 18+/-2 ng/ml, P<0.0001). After basiliximab levels fell below the minimum therapeutic level (1 mg/ml) on day 28, the median rejection score at day 49 increased to A4 in the CD25 group. CONCLUSION: This is the first study to combine an anti-IL-2 receptor mAb with a drug from the rapamycin class plus CsA. Our study shows that induction therapy with basiliximab enabled SDZ RAD blood levels to be significantly reduced, which led to improved tolerability without the penalty of increased rejection.     

Activation-Induced Expression of Cell Surface CD28 on Mouse T Lymphocytes is Inhibited by Cyclosporine A

T-cell activation requires both T-cell receptor signaling and a costimulatory signal provided by CD28 which enhances and prolongs interleukin-2 (IL-2) production. To determine the effect of cyclosporine A (CsA) on constitutive and activation-induced CD28 expression, mouse T cells were exposed to CsA (0.1 microM) in the absence or presence of anti-CD3 monoclonal antibody (mAb). CD28 expression was then determined by flow cytometry. CsA treatment prevented activation-induced CD28 expression but did not affect constitutive CD28 expression. Inhibition of inducible CD28 expression by CsA was not rapidly reversible, requiring 48h of restimulation in the absence of CsA for CD28 expression to return to control levels. T cells activated in the presence of combined anti-IL-2 and anti-CD25 mAb (both 10 microg/mL) also exhibited reduced CD28 expression, suggesting that activation-induced CD28 expression is, at least in part, an IL-2-dependent process. However, the inhibitory effect of CsA on activation-induced CD28 expression was maintained in the presence of exogenous IL-2 (250 U/mL). We conclude that CsA, by inhibiting activation-induced expression of costimulatory CD28 molecules by T lymphocytes, may interfere with the ability of CD28 to provide an optimal costimulatory signal for sustained IL-2 production following T-cell activation.     

Mechanisms of survival prolongation of murine cardiac allografts using the treatment of CTLA4-Ig and MR1

BACKGROUND: [corrected] The present study was undertaken to determine the role of costimulatory blockade in a murine cardiac transplant model. MATERIALS AND METHODS: We blocked the CD28/B7 and CD154/CD40 costimulatory pathways by transient administration of CTLA4-Ig and MR1 antibody to study the effects on allograft survival time, deviation of Th1 and Th2 cytokine secretion, and other mechanisms related to prolonged survival. RESULTS: Costimulatory blockade prolonged the mean survival time (MST) of cardiac allografts to 43 days for the treated group vs 8 days for the untreated group (P < .01). The costimulatory blockade down-regulated the expression of 2 Th1 cytokines (interferon-gamma [IFN-gamma] and interleukin-2 [IL-2]) and 2 Th2 cytokines (IL-4 and IL-10), reduced the numbers of graft-infiltrating CD4+ and CD8+ lymphocytes, and inhibited the expression of both perforin/GrB and FasL in allografts. CONCLUSIONS: Combined administration of CTLA4-Ig/MR1 inhibited acute rejection reactions in murine cardiac allografts, prolonging the survival of cardiac grafts through several mechanisms, including inhibition of Th1 and Th2 cytokine expression, graft infiltration by CD4+ and CD8+ T lymphocytes, and reduced both perforin/GrB and Fas-FasL.     

Human T cell responses to human and porcine endothelial cells are highly sensitive to cyclosporin A and FK506 in vitro

BACKGROUND: Human T cells proliferate in response to both human umbilical vein endothelial cells (HUVEC) and porcine aortic endothelial cells (PAEC) via the second signals LFA-3/CD2 and B7-2 (CD86), respectively. Previous studies have shown that stimulation of T cells via CD28 or phorbol myristate acetate (PMA) activation is highly resistant to inhibition by cyclosporine A (CsA) and tacrolimus (FK506), as is the response of T cells to phytohemmaglutinin in the presence of endothelial cells. We have investigated the inhibitory effects of CsA and FK506 on the direct response of human CD4+ T cells to HUVEC and PAEC and the effect of adding B7-1 transfectants. METHODS: T cell proliferation, interleukin-2 release bioassays and a multiple cytokine bioassay employing the TF-1 cell line were used as indicators of T cell responses to HUVEC and PAEC either in the presence or absence of CsA and FK506. In some experiments, B7-1 transfectants were also added. RESULTS: Proliferative responses and interleukin-2 release were highly sensitive to CsA, the ID50 being significantly less for HUVEC (6.5 ng/ml) than PAEC (15 ng/ml). The ID50 of CsA for the mixed lymphocyte response (MLR) was similar to PAEC (18.6 ng/ml), all these values being significantly less than the T cell activation by phytohemmaglutinin (PHA) (227 ng/ml). Addition of B7-1 transfectants significantly increased interleukin-2 production by T cells/HUVEC and resistance to CsA was greatly increased to an ID50 of > 1000 ng/ml. In contrast, addition of B7-1 transfectants to T cells/PAEC had no effect either on T cell proliferation, IL-2 production, or CsA resistance. Similar results were obtained with FK506. Using the TF-1 cell line, it was determined that cytokines other than IL-2 are released during CD4+ T cell/EC interactions, with similar sensitivity to CsA and FK506. CONCLUSIONS: It is concluded that both allogeneic and xenogeneic T cell/endothelial responses should be inhibited by therapeutic levels of CsA in vivo, assuming the absence of trans-stimulation by B7 molecules.     

Changes in expression of T-cell activation-related molecules and cytokines during tolerance induction in an allogeneic skin transplantation murine model

Bone marrow transplantation after treatment with busulfan and costimulatory blockade with monoclonal antibodies (mAb) cytotoxic T lymphocyte antigen 4 (CTLA4)-Ig and anti-CD154 mAb or two-signal blockade using anti-CD45RB and anti-CD154 mAb are nonmyeloablative treatment regimens for allogeneic transplantation. There may be differences in the mechanisms of donor cell engraftment and reactive cell deletion by which these regimens induce donor-specific tolerance. Therefore, this study was performed to investigate changes in T cells and cytokines during tolerance induction toward allogeneic skin grafts. BALB/c and C57BL/6 mice were used as donors and recipients, respectively. Skin and bone marrow transplantations were performed and busulfan was administered. Three groups were treated with mAb as follows: group 1, anti-CD154 mAb; group 2, anti-CD154 plus anti-CD45RB mAb; and group 3, anti-CD154 mAb plus CTLA4-Ig. The proportions of CD4+ or CD8+ T cells and the expression of CD45RB isoforms on splenocytes were measured using flow cytometry and the production of cytokines by CD4+ T cells using enzyme-linked immunosorbent assay. Group 2 showed a significant reduction in the proportions of CD8+ T cells and CD45RB high isoforms compared with groups 1 and 3. The levels of interleukin (IL)-2 and IL-4 in group 2 were lower and higher than those of groups 1 and 3, respectively. In conclusion, the combined use of anti-CD154 and anti-CD45RB mAb decreases the CD8+ T-cell population and the expression of CD45RB, resulting in a Th2 cytokine profile, which may be a characteristic mechanism leading to donor cell engraftment and reactive cell deletion for donor-specific tolerance.     

Th1/Th2 balance in childhood idiopathic nephrotic syndrome

AIMS: In view of the conflicting evidence of helper T cell type 1 (Th1) or type 2 (Th2) pattern of cytokine synthesis in childhood idiopathic nephrotic syndrome (INS) this study examined the balance of Th1 and Th2 which are characterized by intracellular cytokine production of interferon-gamma (IFNgamma) and interleukin-4 (IL-4), respectively. SUBJECTS AND METHODS: Sixteen children with steroid-sensitive INS (mean age 9.0 years) were included in this study, together with 15 healthy normal children (mean age 7.9 years) for the control group. Intracellular production of both IFNgamma and IL-4 in helper T cell (CD4+ cell) was investigated by a 3-color flow cytometry. RESULTS: The cross-sectional data showed no significant differences of percentages of Th0 (IFNgamma+ IL-4+ CD4+ cell), Th1 (IFNgamma+ lL-4- CD4+ cell) and Th2 (IFNgamma- IL-4+ CD4+ cell) in CD4+ cells (p > 0.05). The Th1/Th2 ratio during nephrotic relapse did not differ from those during nephrotic remission and in normal healthy children (p > 0.05). CONCLUSION: We conclude that there is no significant skew of Th1/Th2 balance in childhood INS and that the cardinal immunological abnormality does not lie in helper T cells but in other cells, such as suppressor/cytotoxic T cells, natural killer cells or monocytes/macrophage. To clarify the pathogenesis of INS, comprehensive studies for these cells would be worthwhile.     

Critical role of proinflammatory cytokine IL-6 in allograft rejection and tolerance

The proinflammatory cytokine IL-6 plays an important role in controlling T-cell differentiation, especially the development of Th17 and regulatory T cells. To determine the function of IL-6 in regulating allograft rejection and tolerance, BALB/c cardiac grafts were transplanted into wild-type or IL-6-deficient C57BL/6 mice. We observed that production of IL-6 and IFN-γ was upregulated during allograft rejection in untreated wild-type mice. In IL-6-deficient mice, IFN-γ production was greater than that observed in wild-type controls, suggesting that IL-6 production affects Th1/Th2 balance during allograft rejection. CD28-B7 blockade by CTLA4-Ig inhibited IFN-γ production in C57BL/6 recipients, but had no effect on the production of IL-6. Although wild-type C57BL/6 recipients treated with CTLA4-Ig rejected fully MHC-mismatched BALB/c heart transplants, treatment of IL-6-deficient mice with CTLA4-Ig resulted in graft acceptance. Allograft acceptance appeared to result from the combined effect of costimulatory molecule blockade and IL-6-deficiency, which limited the differentiation of effector cells and promoted the migration of regulatory T cells into the grafts. These data suggest that the blockade of IL-6, or its signaling pathway, when combined with strategies that inhibit Th1 responses, has a synergistic effect on the promotion of allograft acceptance. Thus, targeting the effects of IL-6 production may represent an important part of costimulation blockade-based strategies to promote allograft acceptance and tolerance.