Predominant expression of the Th2 response in chronic cardiac allograft rejection

Chronic rejection is the main cause of late allograft failure in patients. CD4+ T cells activated by indirect recognition of alloantigens are implicated in this rejection reaction. However, the type of T cell response (Th1 vs Th2) that contributes to chronic rejection has not been fully investigated. The purpose of this study is to examine whether chronic rejection is associated with a polarized T-cell response in a rat cardiac allograft model, where long-term graft survival is achieved by intrathymic immunomodulation with donor class I, RT1.Aa, allopeptides. All long-surviving allografts showed histological evidence of chronic rejection. Chronic rejection was associated with high levels of intragraft Th2 cytokines and the Th2-regulated alloantibodies. The Th2 response was systemic, since long-surviving allografts with chronic rejection had high levels of serum IL-10. The predominance of the Th2 cytokines demonstrates that the Th2 response was not sufficient for the prevention of chronic rejection in this model. The predominant expression of Th2 cytokines, together with the presence of Th2-regulated alloantibodies, suggests that the Th2 response may play a role in the development of chronic rejection.     

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.     

Th1/Th2细胞因子mRNA的表达与心脏移植免疫耐受的关系

目的探讨Th1/Th2细胞因子信使核糖核酸(mRNA)表达改变与心脏移植免疫耐受的关系. 方法采用大鼠腹部心脏移植模型,将30只大鼠随机分成对照组、排斥反应组、免疫耐受组,每组10只.观察移植心脏存活时间,供心病理学改变,受者脾和心脏中Th1/Th2细胞因子白细胞介素2(IL-2)、γ干扰素(IFN-γ)、白细胞介素4(IL-4)、白细胞介素10(IL-10) mRNA表达水平. 结果免疫耐受组供心存活时间为85.28±7.48天,较排斥反应组的7.33±1.03天显著延长(P＜0.01);排斥反应组供心见大量炎性细胞浸润,免疫耐受组供心仅见少量炎性细胞浸润;排斥反应组Th1细胞因子IL-2、IFN-γ mRNA表达较对照组增强,免疫耐受组减弱;排斥反应组Th2细胞因子IL-4、IL-10 mRNA表达较对照组减弱,免疫耐受组增强. 结论 Th1/Th2细胞因子的动态平衡在移植耐受中起重要作用,Th1向Th2偏离是移植耐受的机制之一.     

猪松质骨支架兔体内移植后周围组织Th1和Th2细胞因子的变化

目的观察猪松质骨支架植入后周围组织Th1和Th2细胞因子的变化,为进一步改进材料和临床应用提供实验依据。方法采用物理化学方法对猪松质骨进行处理得到猪松质骨支架,将松质骨支架植入兔背部近头侧皮下,分别于移植后1、2、4、8、12周5个时间点作支架周围组织的组织学检查（HE）及支架周围组织内Th1和Th2细胞因子mRNA检测（RT-PCR）。结果移植术后1周,植入物周围组织光学显微镜下可见大量炎性细胞浸润,以淋巴细胞和单核细胞为主,2周以后炎性细胞浸润逐渐减轻,4周时未见明显炎性细胞浸润,术后12周,组织内炎性细胞罕见。RT-PCR检测Th1细胞因子IL-2、IFN-γ mRNA1周时就有较高水平表达,2-8周逐渐下降,12周时降至低水平;Th2细胞因子IL-4、IL-10 mRNA1周时低水平表达,2周、4周时表达水平表达逐渐上升,8-12周时维持较高水平表达。结论猪松质骨支架异种松质骨支架材料无明显的免疫原性,植入后表现为一过性或暂时性的轻度炎性细胞反应。     

Xenograft accommodation is accompanied by intragraft Th2 cytokines and vascular expression of protective genes

Abstract: We have studied the accommodation (survival of an organ graft in the presence of anti-graft antibodies and complement) of heterotopic Golden Syrian hamster heart xenografts transplanted to Lewis rat recipients. The rats were treated with cyclosporine A (15 mg/kg/day i.m.) for the duration of the experiment and for 11 days with cobra venom factor. This regimen resulted in long-term xenograft survival in approximately 75% of cases. Analysis of endothelial cells (and smooth muscle cells) in long-surviving grafts showed expression of "protective" genes: A20, Bcl-x_L, Bcl-2, and hemoxygenase, which we define as genes that prevent endothelial cells from undergoing responses that might lead to graft rejection. Surviving xenografts were also associated with intragraft Th2 cytokine expression. Rejected grafts did not express the protective genes and had a Thl pattern of cytokine expression. These studies indicate a potential mechanism linking molecular and cellular responses to development of xenograft accommodation.     

Th1-like and Th2-like cytokines in patients undergoing open versus laparascopic cholecystectomy

The advantages of laparoscopic (LC versus, open cholecystectomy (OC) seems to be related to minimal invasive procedure and to the moderate inflammatory response. The aim of this study is to define the involvement of Th1 (IFN-gamma) and Th2 (IL-4, IL-6, IL-10, IL-13) cytokines production in vivo and in vitro in patients undergoing OC or LC. In 42 patients undergoing LC (n = 22) and OC (n = 20) Th1-like and Th2-like was evaluated before operation and at 6, 24 and 48 hours after operation for white blood cell counting and cytokines (IL-4, IL-6, IL-10, IL-13, IFN-gamma, TNF-alpha) in the sera and in the supernatants from circulating mononuclear cells stimulated with phytohemagglutinin or lipopolysaccharide. The acute phase response cytokine, IL-6, appeared significantly increased following OC than after LC. All other cytokines did not very significantly. In vitro data shows a reduction of IFN-gamma and increase in Th2-like cytokines in OC patients compared with the basal value. In LC subjects we observed an high production of IFN-gamma associated to an increase of Th2-like cytokines, like IL-10 and IL-13, even though IL-4 and IL-6 were unmodified. In contrast to OC, LC did not significantly affect immunocompetence, maintaining a moderate inflammatory response and an adequate balance between Th1 and Th2 cytokine. Furthermore, the strong activation of cells producing Th1-like cytokines in LC patients following mitogen activation indicated a consistent anti-microbial activity, that was not detectable in OC patients, that showed after activation only a Th2 response.     

Th2细胞因子在大鼠心脏移植排斥反应中的变化

目的：探讨Th2细胞因子在移植排斥反应中的作用及意义。方法：用酶联免疫法（ELISA）检测大鼠异位心脏移植术后不同时间外周血中白细胞介素4（IL－4）及白细胞介素10（IL－10）的变化。结果：术后IL－4及IL－10的变化与排斥反应的进程有关,两者的峰值均出现于术后第5d,其中IL－10升高则更为明显,此时移植物排斥反应表现为2－3级。当排斥反应加重,出现明显组织坏死时（4级）,血清IL－4及IL－10水平下降。应用环孢素（A（CsA)后,延援了排斥反应的发生及IL－4、IL－10水平的升高。结论：IL－4及IL－10在排斥反应的较早阶段可能发挥重要作用,动态监测外周血IL－4及IL－10可能有助于对临床移植排斥反应 状态的评价。     

血管内皮生长因子在大鼠心脏移植急性排斥期的表达

目的　观察血管内皮生长因子(VEGF)在大鼠心脏移植急性排斥期中的表达及其和排斥的关系。方法　大鼠分对照组,CSA组,每组12只。分别静脉给予生理盐水及CSA干预,采用颈部心脏异位移植术式建立移植模型。常规监测排斥反应发生情况。每组5只用于观察移植物存活时间,7只用于动态切取标本。应用逆转录 聚合酶链反应(RT PCR)检测移植物局部VEGF的表达水平。结果　CSA组移植心存活时间(2 0 .4±5 .1)d显著长于对照组(8.6±1.5 )d ,CSA组VEGF的表达强度弱于对照组,其时间变化趋势和高峰时间较对照组推迟并和移植心存活延长时间有相关性。病理观察显示移植心局部的炎性细胞和淋巴细胞浸润和VEGF表达有关。结论　VEGF高表达促进排斥反应的发生缩短移植心存活时间,提示VEGF的表达和移植心的炎性浸润以及急性排斥有密切关系     

细胞因子在心脏移植急性排斥反应中的表达及其作用机理

目的观察同种大鼠心脏移植急性排斥反应中,局部细胞因子网络的变化及其机理.方法健康雄性Wistar大鼠(受体)和SD大鼠各48只,将接受移植心脏的Wistar大鼠分4组,每组12只.A组对照组;B组抗白介素2单克隆抗体(IL-2Mab)组;C组环孢菌素A(CsA)组;D组IL-2Mab加CsA组.4组大鼠分别静脉给予生理盐水、抗白介素2单克隆抗体及口服CsA、静脉给予抗白介素2单克隆抗体加口服CsA,采用改良的移植术式建立移植模型.常规监测排斥反应发生情况.应用RT-PCR的方法于术后第1、3、5、7、9、11、14天动态检测移植物局部细胞因子IL-1β、IL-2、CD25、IL-4、IL-5、IL-6、IL-10、TNFα、IFNγ的表达水平.结果移植心脏存活时间,A组为(8.3±1.7)d;B组为(29.2±7.1)d;C组为(26.4±5.7)d;D组为(55.0±11.6)d.B、C、D组移植心脏存活时间显著延长,与A组相比,差异有极显著性意义(P＜0.01).存活时间较长的移植心脏的淋巴细胞浸润和心肌坏死的程度比存活时间较短的心脏明显减轻.IL-1β的表达在各组均较高;IL-4、IL-5、IL-6、IL-10的表达水平在移植心脏存活时间较长的组较高;而IL-2、CD25、IFN-γ、TNFα的表达则相对较低;4组相比差异有显著性意义(P＜0.05).结论细胞因子网络在心脏移植排斥反应中发生了相应的变化,并与干预的因素及移植物存活时间有密切的关系.IL-2Mab、CsA联合用药促使TH1类细胞因子向TH2类细胞因子整体偏离,这种免疫偏离使移植心脏存活时间显著延长.     

Role of the antibody to vascular endothelial cells in hyperacute rejection in patients undergoing cardiac transplantation

Traditionally, the human lymphocyte antigens have been considered to be the major barrier to successful transplantation, and lymphocytes have been used as the target cell in evaluating histocompatibility. The presence in the serum of recipients of preformed antibodies, cytotoxic to donors lymphocytes, is associated with a high probability of hyperacute rejection. We identified 11 patients in whom, despite a compatible direct lymphocytotoxic cross-match, acute failure of the cardiac homograft was associated with histologic and immunologic findings consistent with hyperacute rejection. Direct immunofluorescence and immunohistochemical staining showed the presence of antibodies on the surface of vascular endothelial cells in each of these 11 patients. The serum of these recipients was found to contain antibodies against a panel of endothelial cells. In contrast, cytotoxic antibodies to vascular endothelial cells were not present in a control group of 18 heart transplant recipients who did not experience hyperacute rejection. Thus the presence of antibodies against vascular endothelial cells seems to be related to hyperacute rejection of the cardiac allograft.     

Serum soluble adhesion molecules and cytokines in cardiac allograft rejection

Aims. To examine the relationship between soluble adhesion molecules ICAM-1, E-selectin and VCAM-1, serum cytokines TNFα, IL6 and IL2, the IL2 soluble receptor p55 and cardiac rejection in cardiac allograft recipients.Methods. Seventy-six serum samples from 56 patients were examined. Samples were taken on the day of biopsy. No patient was experiencing concurrent infection. All the samples were examined for ICAM-1, TNFα, IL6 and IL2R p55. A smaller number were examined for E-selectin, VCAM-1 and IL2. Specific enzyme-linked immunosorbent assays were used.Results. When grade 0 and grade 3a rejection groups were compared a significant difference was seen between IL6 levels (means 32 pg/ml vs 51 pg/ml, medians both 32 pg/ml, p = 0.007), and a significant difference between ICAM-1 levels (medians 207 ng/ml vs 250 ng/ml versus 303 ng/ml, p = 0.045). No patient without rejection had detectable levels of IL6. There was a correlation between ICAM-1 and E-selectin levels (R = 0.6, p = 0.003). There was no correlation between the other parameters and rejection or each other.Conclusions. Cytokines and adhesion molecules are of great importance in the mechanisms of transplant rejection and this, in some cases, is reflected in the serum. However, this is not sufficiently consistent to be of diagnostic value.     

Th1/Th2类细胞因子在胰腺癌组织中的表达模式及临床意义

自Th1和Th2的概念提出以来，人们对其在机体免疫应签中的作用进行了大量的体内外实验研究，但未见有胰腺癌组织中T1/Th2偏移的研究报道。我们以IFN-γ和IL-2代表Th1类细胞因子，IL-4和IL-10代表Th2类细胞因子，以免疫组织化学方法检测胰腺癌组织中Th1/Th2类细胞因子的表达，观察Th1/Th2类细胞因子在胰腺癌中的表达特征，探讨胰腺癌的发病的机制。     

Reversible down-regulation of connexin43 expression in acute cardiac allograft rejection.

We tested the hypothesis that cardiac allograft dysfunction in acute cardiac rejection may be related, in part, to diminished expression of connexin43, a gap junction channel protein that facilitates intercellular communication and coordinates electrical and mechanical cardiac function. We measured connexin43 levels using quantitative confocal immunofluorescence microscopy of endocardial biopsies from heart transplant recipients with histologic evidence of either no rejection or acute cellular rejection. Expression of connexin43 diminished significantly during acute cellular rejection and returned to baseline levels following resolution of rejection. Reversible down-regulation of connexin43 may contribute to ventricular dysfunction in allograft rejection.     

Incidence of acute cellular rejection and non-cellular rejection in cardiac transplantation

BACKGROUND: Rejection continues to be one of the leading causes of death during the first year after cardiac transplantation. With the advent of more potent immunosuppressive therapies, the incidence of graft rejection has been reported to be decreasing. Yet, this trend has not been well established due to differences in the interpretation of and the protocols for endomyocardial biopsy specimens. Additionally, the incidence of humoral (noncellular) rejection has not been adequately addressed. METHODS: Six thousand one hundred thirty endomyocardial biopsy specimens in 487 cardiac transplant recipients during the first year posttransplantation from 1990 to 2000 were reviewed to assess the incidences of acute cellular and treated noncellular rejection episodes. Cellular rejection was defined as ISHLT grades 3-4; noncellular rejection as a 20% decrease in echo LVEF, cardiac index <2.0, and/or inotropic support associated with ISHLT grades 0-2 necessitating treatment. RESULTS: The incidence of noncellular rejection has remained relatively unchanged at approximately 20% (P=nonsignificant for all years); in contrast, there has been a significant decrease (P <.001) in the incidence of cellular rejection from 54% to 5%. CONCLUSION: The incidence of noncellular rejection in cardiac transplant recipients has remained unchanged through the 1990s despite improved immunosuppressive therapies, which have significantly decreased the incidence of acute cellular rejection. There appears to be a need for newer immunosuppressive agents to effectively treat noncellular rejection. Clinical trials using allograft rejection as a major endpoint will need to increase the enrollment of patients to achieve adequate power to demonstrate differences between study groups.