Involvement of DPP IV/CD26 in cutaneous wound healing process in mice

Dipeptidyl peptidase IV (DPP IV/CD26) is a widely distributed multifunctional protein that plays a significant role in different physiological as well as pathological processes having a broad spectrum of bioactive substrates and immunomodulative properties. It has potential influence on different processes crucial for wound healing, including cell adhesion, migration, apoptosis, and extracellular matrix degradation. However, despite its known enzymatic and immunomodulative functions, limited data characterize the role of DPP IV/CD26 in cutaneous wound healing mechanisms. The aim of this study was to investigate the process of wound healing in conditions of CD26 deficiency in order to obtain better insights on the role of DPP IV/CD26 in cutaneous regeneration. Experimental wounds were made on the dorsal part of CD26 deficient (CD26^?/?) and wild‐type mice (C57BL/6). The process of cutaneous wound healing was monitored on defined time schedule postwounding by macroscopic, microscopic, and biochemical analyses. Obtained results revealed a better rate of wound closure, revascularization and cell proliferation in CD26^?/? mice, with enhanced local expression of hypoxia‐inducible factor 1α and vascular endothelial growth factor. CD26 deficiency induced prompt macrophage recruitment at the site of skin damage but did not influence mobilization of T‐cells in comparison with wild‐type mice. CD26^?/? mice have significantly higher values of IP‐10 in serum and control skins compared with wild‐type mice but values in wounds did not differ significantly on days 2, 4, and 7 of wound healing. DPP IV/CD26 activity was found to be decreased 4 days postwounding in serum and 2, 4, and 7 days postwounding in wounds of wild‐type animals compared with control skins. These findings contribute to better understanding of wound healing mechanisms and could give a support in finding new therapeutic approaches for wound healing and tissue regeneration.     

Anti-inflammatory effects on ischemia/reperfusion-injured lung transplants by the cluster of differentiation 26/dipeptidylpeptidase 4 (CD26/DPP4) inhibitor vildagliptin

Objectives

We showed previously that stromal cell?derived factor 1 (SDF-1) is a substrate of cluster of differentiation 26/dipeptidylpeptidase 4 (CD26/DPP4) and exerts regenerative properties on acute lung ischemia-reperfusion injury on CD26/DPP4 inhibition. Here, we extend our studies to test whether an intermediate recovery of lung transplants from ischemia/reperfusion injury by CD26/DPP4 inhibition can be achieved for up to 14 days.

Intrathymic immune modulation prevents acute rejection but not the development of graft arteriosclerosis (chronic rejection)

BACKGROUND: We showed previously that our intrathymic immune modulation protocol induces virtually permanent graft survival of simultaneously transplanted cardiac allografts in MHC-incompatible rat strain combinations. It is, however, unknown whether this procedure prevents the development of graft arterial disease (GAD). METHODS: Male AO recipient rats were intrathymically inoculated with 2.5x10(7) PVG splenocytes immediately followed by heterotopic transplantation of a PVG cardiac allograft (day 0). Immunosuppression consisted of 1 ml of antilymphocyte serum i.p. (day 0) and cyclosporine i.m. (15 mg/kg body weight) on days 1, 2, and 3 posttransplantation. Histological analysis, mixed lymphocyte reactions, and intragraft cytokine mRNA expression were performed at several time points after engraftment. RESULTS: Histological analysis revealed that GAD was already present 14 days after transplantation. At 200 days, virtually all vessels were affected and over 80% of the vessels showed severe intimal lesions. Infiltrate analysis displayed massive parenchymatous infiltrates (CD8+ cells and ED1+ macrophages) 2 weeks after transplantation. At later time points, infiltrates became epicardial and/or blood vessel associated and mainly consisted of CD4+, CD8+, and B cells. Mixed lymphocyte reactions showed nonspecifically decreased responses at 60 days but complete restoration of these responses at later time points (120 to 280 days). Intragraft cytokine mRNA expression showed decreased interleukin-2/interferon-gamma and sustained interleukin-10 expression 2 weeks after transplantation. Transforming growth factor-beta mRNA expression was increased >200 days after transplantation. CONCLUSIONS: Intrathymic immune modulation does not abolish alloreactivity, and despite induction of long-lasting graft survival, this procedure does not prevent and may even facilitate the development of GAD.     

Renal expression of CD44 correlates with acute renal allograft rejection

As CD44 is involved in the activation, proliferation, adhesion, and extravasation of lymphocytes, we hypothesized that CD44 could be involved in the pathogenesis of acute renal allograft rejection. Renal biopsies and plasma were collected from patients suffering an episode of acute renal allograft rejection. CD44 and its ligands, hyaluronic acid (HA) and osteopontin, were analyzed retrospectively by immunohistochemistry and, computer-aided, morphometric analysis. Soluble CD44 (sCD44) and osteopontin in the plasma were determined by enzyme-linked immunosorbent assay. During acute rejection episodes, CD44 and its ligands, HA and osteopontin, were upregulated in the renal allograft. Also, increased sCD44 plasma levels were observed, which correlated with both tubular expression of CD44 and the extent of infiltrate. No differences could be detected between the different pathologic grades of rejection. Upregulation of tubular CD44 and increased levels of circulating sCD44 may reflect a common pathogenic mechanism during acute renal rejection and could be useful markers in the diagnosis of acute renal rejection.     

CD44在大鼠肾移植急性排斥反应中的表达

目的:探讨移植肾组织CD44的表达及血清中可溶性CD44的含量与急性排斥反应的关系。方法:雄性Wistar大鼠和SD大鼠分别作为供体和受体,共分为四组,采用改进的Blom法大鼠原位肾移植模型。免疫组织化学染色法检测移植肾组织CD44分子的表达;酶联免疫吸附试验测定术后血清中可溶性CD44水平的变化。结果:移植肾组织CD44分子的表达在同种异体移植组显著高于同品系移植组、手术对照组及药物治疗组(均P<0.05);移植肾组织CD44分子的表达与急性排斥反应呈正相关(皮质:r=0.734,髓质:r=0.670,均P<0.01);发生急性排斥反应的移植肾组织CD44分子的表达与Banff急性排斥反应指数无相关性(P>0.05);血清中可溶性CD44分子各组间差异无统计学意义,与急性排斥反应及Banff指数均无相关性(均P>0.05)。结论:CD44分子在肾移植急性排斥反应的发病机制中起着重要作用,为进一步提高移植排斥反应防治水平提供理论依据。     

Accelerated acute rejection of the intestinal graft in CD28-deficient mice

OBJECTIVE: Multiple in vivo studies have shown that the pace and severity of graft rejection is little or not at all changed by deleting CD28 molecules in the recipient. These findings contrast with the effects of monoclonal antibody therapy aimed the same costimulatory target. The objective of the present study was to evaluate how the acute rejection process is affected in CD28-deficient mice using a fully allogeneic, highly immunologically reactive transplant model. METHODS: Heterotopic vascularized small bowel transplants were performed in 24 recipient mice divided into 4 groups: 2 wild-type and 2 knockout groups. Each group consisted of 5 to 7 animals in which BalbC mice were used as intestinal donors to either wild-type C57BL6 or C57BL6 background CD28-deficient recipient mice. Selected endpoints were 3 and 6 postoperative days (POD). Intestinal rejection was evaluated by mucosal laser Doppler flowmetry (expressed in perfusion units) and histology (expressed in rejection grades). RESULTS: Acute rejection occurred in both wild-type and CD28-deficient groups. At POD 3, no significant difference was noted between groups in terms of mucosal perfusion and histology. At POD 6, significant differences in graft mucosal perfusion and histology revealed a more aggressive rejection in the CD28-deficient group compared to the wild-type group. CONCLUSIONS: The present study showed that the severity of intestinal graft rejection responses was amplified by deleting CD28 molecules. Together with data from other studies, these results suggest a different pattern of distribution and/or activation of CD28/B7 receptors in various organs.     

阻断B7/CD28共刺激通路抑制大鼠肝移植急性排斥反应的研究

目的:建立大鼠原位肝移植(ROLT)急性排斥反应模型,观察细胞毒淋巴细胞抗原4免疫球蛋白(CTLA-4Ig)在大鼠肝移植术后对共刺激分子B7-1/B7-2的影响及其抗排斥反应的作用。方法:采用"二袖套管"法先行建立DA-Lewis大鼠组合肝移植急性排斥反应模型,随机分为对照组(A组)与实验组(B组)两组,于肝移植术后48h每只受体大鼠腹腔内一次性注射CTLA-4Ig 75μg,分别于术后3、5、7和10d采用RT-PCR检测B7-1和B7-2 mRNA在两组肝脏组织中的表达情况,并同时观察其肝功能变化。结果:1)B7-1和B7-2 mRNA在A组高水平表达,而在B组表达明显降低(P<0.01);2)B组动物术后未见明显排斥反应,血清ALT、TBIL和DBIL水平明显低于对照组(P<0.01)。结论:移植术后应用CTLA-4Ig可以降低肝组织中B7-1和B7-2的表达;动态检测B7分子的表达有助于观察肝移植排斥反应的进程。     

Evaluation of posttransplantation soluble CD30 for diagnosis of acute renal allograft rejection

BACKGROUND: Posttransplantation measurement of soluble CD30 (sCD30) may be useful for identifying kidney graft recipients at risk of impending graft rejection in the early posttransplantation period. METHODS: We measured plasma sCD30 levels and evaluated the levels in relation to the diagnosis of rejection. RESULTS: Receiver operating characteristic curves demonstrated that on posttransplantation days 3 to 5, sCD30 allowed a differentiation of recipients who subsequently developed acute allograft rejection (n=25) from recipients with an uncomplicated course (n=20, P<0.0001) (area under the receiver operating characteristic curve 0.96, specificity 100%, sensitivity 88%) and recipients with acute tubular necrosis in the absence of rejection (n=11, P=0.001) (area under the receiver operating characteristic curve 0.85, specificity 91%, sensitivity 72%). CONCLUSIONS: sCD30 measured on posttransplantation days 3 to 5 offers a noninvasive means for differentiating patients with impending acute allograft rejection from patients with an uncomplicated course or with acute tubular necrosis.     

CD103 mRNA levels in urinary cells predict acute rejection of renal allografts

BACKGROUND: CD103 is displayed on the cell surface of alloreactive CD8 cytotoxic T lymphocytes (CTLs) and is a critical component for the intraepithelial homing of T cells. Because intratubular localization of mononuclear cells is a feature of acute cellular rejection of renal allografts, we explored the hypothesis that CD103 messenger (m)RNA levels in urinary cells predict acute rejection. METHODS: We collected 89 urine specimens from 79 recipients of renal allografts. RNA was isolated from the urinary cells, and we measured CD103 mRNA levels and a constitutively expressed 18S ribosomal (r)RNA with the use of real-time quantitative polymerase chain reaction assay. RESULTS: CD103 mRNA levels, but not 18S rRNA levels, were higher in urinary cells from 30 patients with an episode of acute rejection (32 biopsies and 32 urine samples) compared with the levels in 12 patients with other findings on allograft biopsy (12 biopsies and 12 urine samples), 12 patients with biopsy evidence of chronic allograft nephropathy (12 biopsies and 12 urine samples), and 25 patients with stable graft function after renal transplantation (0 biopsies and 33 urine samples) (P = 0.001; one-way analysis of variance). Acute rejection was predicted with a sensitivity of 59% and a specificity of 75% using natural log-transformed value 8.16 CD103 copies per microgram as the cutoff value (P = 0.001). CONCLUSION: CD103 mRNA levels in urinary cells are diagnostic of acute rejection of renal allografts. Because CD103 is a cell surface marker of intratubular CD8 CTLs, a noninvasive assessment of cellular traffic into the allograft may be feasible by the measurement of CD103 mRNA levels in urinary cells.     

CD69 expression on peripheral CD8 T cells correlates with acute rejection in renal transplant recipients

BACKGROUND: The development of a noninvasive method to diagnose renal allograft rejection could prevent the complications associated with graft biopsy and allow more accurate surveillance of allograft function. The present study determines whether expression of CD69 on peripheral T lymphocytes of renal allograft recipients correlates with the presence of acute graft rejection. METHODS: Peripheral blood T lymphocytes from healthy volunteers, renal allograft recipients with elevated creatinine but no evidence of rejection on biopsy, and renal allograft recipients with biopsy-proven rejection were analyzed by flow cytometry for the expression of CD69 and various intracellular cytokines (interleukin-2, interferon-gamma). Results were then compared with the degree of rejection on biopsy. RESULTS: CD69 expression on CD3+, CD4+, and CD8+ T-cell subsets was low in controls and transplant recipients without allograft rejection. In contrast, patients with renal allograft rejection showed significantly elevated percentages of CD69+ cells in the CD3+ (P<0.01) and CD8+ subsets (P<0.01). The fraction of CD69+ and CD8+ T cells was found to be a more clinically useful test based on receiver-operator characteristics. CD69 expression on CD4+ T cells did not correlate with rejection. Significant intracellular cytokine levels were not detected in unstimulated T cells from any of the groups; stimulation with mitogens increased expression equally among the three groups. CONCLUSIONS: We demonstrate that expression of CD69 on CD3+ and CD8+ peripheral blood T cells correlates closely with the presence of acute graft rejection in renal allograft recipients. Measurement of this surface marker may provide a rapid, noninvasive, and accurate means by which graft rejection can be identified.     

大鼠小肠移植排斥反应时外周血T淋巴细胞上CD2分子的表达

目的探讨大鼠小肠移植急性排斥反应时外周血T淋巴细胞上CD2分子的表达。方法实验分3组进行,A组为假手术对照组(n=18),给予普通饲料喂养;B组(n=18)行SD大鼠到SD大鼠的同系小肠移植,术后常规补液,给予抗生素;C组(n=18)行SD大鼠到Wistar大鼠的小肠移植,术后处理同B组。各组于术后3、5、7d取肝素抗凝血,行流式细胞术检测,同时取移植肠组织,进行病理学检查。结果术后C组动物的存活时间为(7.0±2.1)d,B组为(33.3±2.3)d,A组>90d,C组与A、B组相比,差异有统计学意义(P<0.05);术后3、5、7d的外周血CD2阳性T淋巴细胞,A组分别为70.2%、69.8%和70.3%;B组为71.3%、69.7%和70.2%;C组为95.6%、88.1%和81.2%,C组各时点的CD2阳性细胞均高于A、B组相应时点(P<0.05);C组移植肠可见排斥反应的病理改变,且随术后时间的延长逐渐加重。结论小肠移植术后发生急性排斥反应时外周血CD2阳性T淋巴细胞表达率升高;术后早期CD2表达率的突然增高,提示可能发生急性排斥反应。     

肾移植患者急性排斥反应与sCD30的相关性

目的 研究检测肾移植患者手术前后血清溶解性CD30（sCD30）水平的临床意义。方法 采用酶联免疫吸附剂测定法（ELISA）检测69例肾移植患者术前及术后sCD30的水平，并分析sCD30与肾移植受者术后急性排斥发生的关系。结果 术前sCD30阳性患者11例，其中有6例发生急性排斥，sCD30阴性患者58例，发生急性排斥5例。两组相比排斥反应发生率差异有统计学意义（P〈0．01）。术后5dsCD30在发生排斥患者组中的水平与对照组间差异有统计学意义（P〈0．05），而术后1、3d水平两组间差异无统计学意义（P〉0．05）。结论 肾移植手术前后监测sCD30水平，特别是术前及术后第5天左右时的检测水平，对于评估和预测急性排斥反应发生的可能性，具有重要的参考价值。     

Transfection of CD40Ig into liver prevents acute rejection in rat liver transplantation

OBJECTIVE: To investigate the effect of CD40Ig upon acute rejection of rat liver transplants. METHODS: Thirty-two orthotopic liver transplants were performed using Lewis to BN rats with "the two-cuff technique". The rats were randomly divided into three groups. Group A served as controls (n = 10); group B (n = 11) and group C (n = 11); Lipofectamine2000-pcDNA3.1 or Lipofectamine2000-pcDNA3.1. CD40Ig complex was injected into Lewis portal vein ex vivo before cold storage of the liver. On the fifth day after transplantation, three rats in each group were killed to study the pathological changes and TUNEL immune histochemistry performed to examine CD40Ig expression. Lymphocytes were obtained from the spleen. The mixed lymphocyte reaction (MLR) was performed to determine tolerance and sheep anti-human immunoglobulin G (IgG)-FITC-labeled T cells counted by flow cytometry. Postoperative survival times of rats in each group were recorded. The pathological changes of dead rats were observed. RESULTS: The mean survival times of group A and B were 11.00 +/- 4.28 and 12.75 +/- 5.57 days, respectively. There were serious acute rejections in allograft liver in groups A and B. Apoptosis index was 33.67 +/- 5.69 versus 39.00 +/- 5.29. Group C mean survival time was 41.25 +/- 13.70 days (P < .01). Immune histochemistry showed CD40Ig-positive elements in the allograft liver, which revealed light acute rejection and apoptosis index was 0.27 +/- 0.21 (P < .01). The part of the allografted liver in a dead rat showed light acute rejection while the others displayed chronic rejection. Recipients were specifically tolerant to donors in the MLR assay. The IgG-FITC-labeled T cells accounted for 11.57% of all T cells in group C. CONCLUSIONS: CD40Ig transfection inhibited T-cell costimulatory pathway, prevented acute rejection, and prolonged graft survival.     

Prediction of acute renal allograft rejection in early post-transplantation period by soluble CD30

To evaluate the feasibility of serum sCD30 for prediction of acute graft rejection, we analyzed clinical data of 231 patients, whose serum levels of sCD30 were detected by ELISA before and after transplantation. They were divided into three groups: acute rejection group (AR, n = 49), uncomplicated course group (UC, n = 171) and delayed graft function group (DGF, n = 11). Preoperative sCD30 levels of three groups were 183 +/- 74, 177 +/- 82 and 168 +/- 53 U/ml, respectively (P = 0.82). Significant decrease of sCD30 was detected in three groups on day 5 and 10 post-transplantation respectively (52 +/- 30 and 9 +/- 5 U/ml respectively, P < 0.001). Compared with Group UC and DGF, patients of Group AR had higher sCD30 values on day 5 post-transplantation (92 +/- 27 U/ml vs. 41 +/- 20 U/ml and 48 +/- 18 U/ml, P < 0.001). However, sCD30 levels on day 10 post-transplantation were virtually similar in patients of three groups (P = 0.43). Receiver operating characteristic (ROC) curve demonstrated that sCD30 level on day 5 post-transplantation could differentiate patients who subsequently suffered acute allograft rejection from others (area under ROC curve 0.95). According to ROC curve, 65 U/ml may be the optimal operational cut-off level to predict impending graft rejection (specificity 91.8%, sensitivity 87.1%). Measurement of soluble CD30 on day 5 post-transplantation might offer a noninvasive means to recognize patients at risk of impending acute graft rejection during early post-transplantation period.     

Up-regulation of prolactin gene expression and feedback modulation of lymphocyte proliferation during acute allograft rejection.

BACKGROUND. Although recent evidence suggests that prolactin is important in the immune response, bidirectional communication between prolactin and the immune system has not been demonstrated previously. We examined our hypothesis that this communication exists during mouse skin allograft rejection. METHODS. Serum prolactin levels were measured by bioassay, and pituitary prolactin mRNA was examined by use of Northern blots, in BALB/c mice receiving skin allografts from C57BL mice, on days 2, 4, and 6 after grafting. The feedback effects of prolactin on splenic lymphocytes were assessed in one-way mixed lymphocyte reactions, with or without added interleukin-2 (IL-2) or IL-4. RESULTS. Prolactin mRNA was increased significantly in grafted animals compared with sham animals (2.4-fold by day 4). Serum prolactin bioactivity was also elevated on all days tested. Prolactin treatment resulted in dose-dependent modulation of the mixed lymphocyte reaction with lymphocytes from grafted animals but not from sham animals. These effects depended on the time points and the presence of IL-2 or IL-4; the maximal enhancement occurred with day-4 lymphocytes cultured with IL-4 (80%). CONCLUSIONS. This report is the first to implicate in vivo immune regulation of prolactin gene expression. Our observations indicate that bidirectional interaction exists between prolactin and the immune system and provide a rationale for altering prolactin levels to treat allograft rejection.     

CD257/CD256及其受体在排斥反应移植肾组织中的表达

目的研究CD257/CD256及其受体在发生排斥反应移植肾组织中的作用。方法收集1987年1月至2007年7月间因移植肾失功切除的移植肾组织标本46份和2009年行程序性活组织检查的移植肾组织标本10份。运用免疫组织化学法分别检测了CD256、CD257、BAFF-R、BCMA、TACI及CD138、CD3和CD20等分子的表达。采用图像分析软件Histo Quest Analysis和统计分析软件SPSS16.0对表达结果进行统计分析。结果依据Banff 2005标准,对移植肾组织标本进行病理学分组：抗体介导的排斥反应（ABMR）组15例、T细胞介导的排斥反应（TCMR）组16例和未明原因病例（UAC）组15例。免疫组织化学结果显示,CD256、CD257及其受体BAFF-R、BCMA和TACI均表达于ABMR组和TCMR组肾小管上皮细胞的胞膜或胞浆,而UAC组和正常对照组无表达或弱表达。CD257在ABMR组、CD256在ABMR组和TCMR组的表达与其他组比较差异有统计学意义（P〈0.05）。BAFF-R和BCMA在ABMR组的表达与其他组比较差异有统计学意义（P〈0.05）;而TACI在ABMR组和TCMR组的表达与UAC组和正常对照组比较差异有统计学意义（P〈0.05）。CD138＋细胞除浸润于肾组织间质外,也浸润于肾小管上皮细胞胞浆或胞膜。CD138＋细胞在ABMR组的表达水平高于其他组（P〈0.05）。CD3＋细胞主要浸润于肾组织间质,以散在分布为主,在ABMR组和TCMR组均有表达,但在TCMR组表达水平更高。CD20＋细胞亦主要分布于肾组织间质,成簇分布为主,在ABMR组和TCMR组的表达水平相似。相关性分析显示,CD256与BCMA、TACI和CD138＋细胞具有显著相关性;而CD257与BAFF-R、BCMA、TACI和CD138＋细胞均具有显著相关性。结论 CD256信号与CD257信号可能均参与了ABMR进程。