Galectin-9 contributes to the survival of fully allogeneic skin grafts by modulating effector T cells and Tregs imbalance.

Allogeneic skin transplantation is an important clinical treatment for many diseases. Although Galectin-9 demonstrates multifaceted roles in modulating immune cell homeostasis and inflammation, its precise impact on balancing effector T cells and Tregs during allogeneic skin transplantation remains uncertain. This work was performed to evaluate the modulation of the survival time of allogeneic skin grafts by Gal-9 and to explore the critical mechanism involved in this process. Skin graft transplantation was conducted using C57BL/6 and BALB/c mice. Additionally, the levels of IL-2, IFN-γ, IL-4, and IL-17A were measured. Hematoxylin and eosin staining assay was performed to analyze the pathological conditions of skin grafts of experiment mice. The results revealed that Gal-9 noticeably prolonged the survival of the allogeneic skin graft and ameliorated the damage caused by acute immune rejection. Furthermore, Gal-9 resulted in selective reduction of effectors T cells such as Th1, and Th17. Simultaneously, Gal-9 didn't attenuate the protective function for allograft, which alleviated the immune rejection caused by abnormal immune imbalance. Gal-9 exhibited a therapeutic effect on the allogeneic skin graft by selectively reducing CD4+TIM-3+ T effector cells and inducing a shift from a Th1 to an anti-inflammatory Th2 response. Furthermore, Gal-9 did not attenuate the protective function. Our present study may represent a novel therapeutic candidate for modulating effector T cells and Tregs imbalance-based therapy of allograft transplantation.

Characterisation of Tertiary Lymphoid Organs in Explanted Rejected Donor Kidneys.

PURPOSE: Tertiary lymphoid organs (TLOs) have been described within organ allografts, but whether they promote destructive or beneficial alloimmune responses remains controversial. This study aimed to characterize TLO distribution in human chronically rejected renal allografts and to explore their functions. METHODS: A total of 29 explanted chronically rejected and 12 acutely rejected renal allografts were analyzed by immunohistochemistry. The distribution of TLOs, T cells, follicular dendritic cells, B cells, and follicular regulatory T (Tfr) cells, as well as Ki67, peripheral lymph node addressin (PNAd), podoplanin, AID, IL-17, IL-21, IL-10, and C4d expression were detected by immunohistochemistry. Correlations between lymphoid neogenesis and the expression of IL-17, IL-21, C4d, podoplanin, IL-10, and Foxp3 were evaluated. In addition, the duration of graft function was compared between allografts that harbored or lacked TLOs. RESULTS: TLOs were detected in 27.6% of chronically rejected renal grafts, but they rarely had germinal centers. Lymphoid neogenesis negatively correlated with CXCR5 expression, and almost completely correlated with IL-17 expression. Those grafts that harbored a TLO functioned for an average of 5.98 years and those without a TLO lasted only about half as long with an average of 2.91 years. However, in grafts that harbored a TLO, Foxp3(+) cells were comparitively less than those without a TLO. Foxp3(+)CXCR5(+) Tfr cells and IL-10(+) cells were rare in grafts, irrespective of the presence of a TLO. CONCLUSION: TLOs in chronically rejected kidney allografts may be an epiphenomenon of the inflammatory process that is related to graft duration.

Effectiveness and safety of calcineurin inhibitor withdrawal in kidney transplantation: a meta-analysis of randomized controlled trials.

BACKGROUND: The purpose was to compare the effectiveness and safety of calcineurin inhibitors (CNIs) withdrawal and continued therapies in kidney transplant recipients. METHODS: We searched the PubMed, MEDLINE, Springer, Elsevier Science Direct, Cochrane Library and Google Scholar up to May 2014. Risk ratio (RR) or weighted mean difference (WMD) and their 95 % confidence intervals (CIs) were calculated in fixed-effects model or random-effects model when appropriate. Besides, sensitivity analysis was performed based on the addition of sirolimus in initial immunosuppression protocols. RESULTS: Total seven studies with 1071 kidney transplant recipients received CNIs withdrawal therapy (experimental group) and 792 kidney transplant recipients received CNIs continued therapy (control group) were included in the meta-analysis. The overall estimates of acute rejection rate (RR = 1.64, 95 % CI: 1.19-2.27, P = 0.003), mean measured glomerular filtration rate (WMD = 9.50, 95 % CI = 2.96-16.03, P = 0.004), thrombocytopenia (RR = 3.39, 95 % CI: 2.27-5.05, P < 0.00001) and hypertension (RR = 0.56, 95 % CI: 0.40-0.78, P = 0.0006) showed that there were significant differences between the CNIs withdrawal and continued therapies in kidney transplant recipients, while no significant differences were found between groups in survival rate, graft survival rate, diabetes, hypercholesterolemia, hypertriglyceridemia and malignancies. In addition, two studies, in which sirolimus was not used in initial immunosuppression protocol, were excluded in sensitivity analysis and the results were still consistent with the overall analysis. CONCLUSIONS: CNIs withdrawal therapy in kidney transplant recipients could significantly decrease risk of hypertension and improve glomerular filtration rate, accompanying with increased risk of acute rejection and thrombocytopenia, compared with the CNIs continued therapy.

Ketanserin, a serotonin 2A receptor antagonist, alleviates ischemia-related biliary fibrosis following donation after cardiac death liver transplantation in rats.

Biliary fibrosis is a major complication after donation after cardiac death (DCD) liver transplantation. In this process, the roles of serotonin [5-hydroxytryptamine (5-HT)] and the 5-HT2A receptor subtype are still unknown. In this study, we analyzed markers of portal fibroblast (PF)/myofibroblast (MF) transdifferentiation such as transforming growth factor ß1 (TGF-ß1), phosphorylated smad2/3, α-smooth muscle actin (α-SMA), collagen I, and collagen III in a primary culture system of PFs after the administration of 5-HT or 5-HT plus ketanserin (a selective 5-HT2A receptor antagonist). A rat DCD transplant model was established with 30 minutes of warm ischemia and 4 hours of cold ischemia during organ procurement. Recipients were intraperitoneally injected with ketanserin (1 mg·kg(-1)·day(-1)) or normal saline. Grafts without in situ warm ischemia instead of minimal cold storage (30 minutes) served as controls. The serum biochemistry, the liver contents of 5-HT and hydroxyproline (HYP), and the expression of fibrosis-related genes (including TGF-ß1, matrix metalloproteinase 2, procollagen α1, and α-SMA messenger RNA) were determined. The extent of biliary fibrosis was also assessed histopathologically. The results indicated that ketanserin inhibited 5-HT-activated TGF-ß1-smad2/3 signaling in vitro and thereby depressed the MF conversion of PFs. Rats receiving DCD livers showed increased liver contents of 5-HT and HYP, impaired biliary function, up-regulation of fibrosis-related genes, and aggravated biliary fibrosis. However, these phenomena were alleviated by treatment with ketanserin. We concluded that the profibrotic activity of 5-HT occurred through the activation of TGF-ß1 signaling and the 5-HT2A receptor. Thus, these data suggest that the 5-HT2A receptor may be a potential therapeutic target for ischemia-related biliary fibrosis after DCD liver transplantation.

Combination of IL-1 receptor antagonist, IL-20 and CD40 ligand for the prediction of acute cellular renal allograft rejection.

PURPOSE: The outcome of renal transplantation is difficult to predict, even with an allograft biopsy. The aim of this study was to develop a sensitive, specific and noninvasive method for prediction of acute cellular rejection (ACR). METHODS: Luminex analysis was used to determine the levels of 95 cytokines/chemokines and their soluble receptors in sera from recipients with: ACR (in the first month post-transplantation, before and during rejection, and after rejection reversal); stable allograft function; delayed graft function (DGF); pulmonary infection. Evaluation of significant differential protein expression in ACR patients compared with stable allograft controls revealed a three-analyte combination as a marker of renal transplantation outcome. The predictive value of this combination was further validated in DGF and infection groups and in a blind binary code study of 24 additional serum samples. RESULTS: Significant differential expression was detected in 26 proteins expressed in patients during the period preceding an ACR episode compared with stable controls. A blood test for discrimination of such patients was developed based on the simultaneous quantification of three analytes (IL-1 receptor antagonist, IL-20 and sCD40 ligand). This test exhibited 90.9 % sensitivity, 96 % specificity, a positive predictive value (PPV) of 95.2 % and a negative predictive value (NPV) of 92.3 %. Moreover, this combination allowed discrimination between patients with ACR and DGF and pulmonary infection. CONCLUSIONS: With further development and validation, this blood test can be used to predict ACR and direct the treatment of transplant patients in the clinic.

Serum hematopoietic growth factors as diagnostic and prognostic markers of acute renal allograft rejection: a potential role for serum stem cell factor.

OBJECTIVES: Hematopoietic growth factors (HGFs) are proliferative and chemotactic agents for hematopoietic stem cells, although their functions on renal transplantation are rarely reported. This study aimed to investigate the association of HGFs with acute T cell-mediated renal rejection. EXPERIMENTAL DESIGN: A cytokine bead array was used to analyze 10 HGFs in the sera of 32 patients with acute T cell-mediated renal allograft rejection before and during rejection and after rejection reversal. Stable renal allograft recipients (n=38) were also investigated. RESULTS: Serum levels of stem cell factor (SCF), IL-3, flt3 ligand, G-CSF, M-CSF and GM-CSF were elevated during episodes of rejection compared with before and after rejection. Serum concentrations of SCF, G-CSF, flt3 ligand and IL-3 were significantly higher than in the absence of rejection. Moreover, serum SCF levels were significantly higher in patients before rejection versus stable controls. CONCLUSIONS: HGFs are reported to be involved in acute T cell-mediated renal allograft rejection. A direct correlation was observed between SCF levels and the occurrence of acute renal allograft rejection which may represent an effective diagnostic and predictive biomarker for acute cellular renal allograft rejection.

Uptake of donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light by recipient dendritic cells induces CD4+CD25+Foxp3+ regulatory T cells and down-regulates cardiac allograft rejection.

Extracorporeal photopheresis (ECP) is an effective immunomodulatory therapy and has been demonstrated to be beneficial for graft-vs-host disease and solid-organ allograft rejection. ECP involves reinfusion of a patient's autologous peripheral blood leukocytes treated ex vivo with 8-methoxypsoralen and UVA light radiation (PUVA). Previous studies focused only on ECP treatment of recipient immune cells. Our study is the first to extend the target of ECP treatment to donor immune cells. The results of in vitro co-culture experiments demonstrate uptake of donor PUVA-treated splenic lymphocytes (PUVA-SPs) by recipient immature dendritic cells (DCs). Phagocytosis of donor PUVA-SPs does not stimulate phenotype maturation of recipient DCs. In the same co-culture system, donor PUVA-SPs enhanced production of interleukin-10 and interferon-gamma by recipient DCs and impaired the subsequent capability of recipient DCs to stimulate recipient naïve T cells. Phagocytosis of donor PUVA-SP (PUVA-SP DCs) by recipient DCs shifted T-cell responses in favor of T helper 2 cells. Infusion of PUVA-SP DCs inhibited cardiac allograft rejection in an antigen-specific manner and induced CD4(+)CD25(high)Foxp3(+) regulatory T cells. In conclusion, PUVA-SP DCs simultaneously deliver the donor antigen and the regulatory signal to the transplant recipient, and thus can be used to develop a novel DC vaccine for negative immune regulation and immune tolerance induction.

Rapamycin inhibits cholangiocyte regeneration by blocking interleukin-6-induced activation of signal transducer and activator of transcription 3 after liver transplantation.

Cholangiocyte proliferation is necessary for biliary recovery from cold ischemia and reperfusion injury (CIRI), but there are few studies on its intracellular mechanism. In this process, the role of rapamycin, a new immunosuppressant used in liver transplantation, is still unknown. In order to determine whether rapamycin can depress cholangiocyte regeneration by inhibiting signal transducer and activator of transcription 3 (STAT3) activation, rapamycin (0.05 mg/kg) was administered to rats for 3 days before orthotopic liver transplantation. The results indicated that cholangiocytes responded to extended cold preservation (12 hours) with severe bile duct injures, marked activation of the interleukin-6 (IL-6)/STAT3 signal pathway, and increased expression of cyclin D1 until 7 days after transplantation, and this was followed by compensatory cholangiocyte regeneration. However, rapamycin treatment inhibited STAT3 activation and resulted in decreased cholangiocyte proliferation and delayed biliary recovery after liver transplantation. On the other hand, rapamycin showed no effect on the expression of IL-6. We conclude that the IL-6/STAT3 signal pathway is involved in initiating cholangiocytes to regenerate and repair CIRI. Rapamycin represses cholangiocyte regeneration by inhibiting STAT3 activation, which might have a negative effect on the healing and recovery of bile ducts in grafts with extended cold preservation. Insights gained from this study will be helpful in designing therapy using rapamycin in clinical patients after liver transplantation.

[Applications of monitoring human leukocyte antigen G and its inhibitory receptors in post-renal transplantation].

OBJECTIVE: to study the feasibility of human leucocyte antigen-G (HLA-G) as a post-transplantation prognostic biomarker and discuss the correlation of its receptor expression and the mechanisms. METHODS: a total of 215 recipients in our centre from February 2006 to June 2008 were divided into stable kidney function group (n = 173) and acute rejection group (n = 42). The soluble human leucocyte antigen-G5 (sHLA-G5) level in peripheral plasma was detected by ELISA. And the HLA-G receptor ILT-2, KIR2DL4 on T, B, NK lymphocytes were analyzed by flow cytometry (FCM). The sHLA-G5 cutoff level by ROC curve was employed to predict the events of acute post-transplantation rejection. And regression analysis was used to determine the association of sHLA-G5 with acute rejection. RESULTS: an optimal cutoff value of 139.0 microg/L could be defined for sHLA-G5 (sensitivity: 63.6%, specificity: 82.1%, AUC: 0.780). Binary regression analysis showed that sHLA-G5 played an independent role on acute rejection (P = 0.019, OR = 0.039, 95%CI: 2.091 - 5.661). The rate of HLA-G receptor ILT-2 on CD4(+)T cell, CD8(+)T cell and B cell in acute rejection group was statistically lower than that in stable kidney function group (21% ± 7% vs 52% ± 17%, 23% ± 6% vs 39% ± 16%, 21% ± 7% vs 39% ± 16%, all P < 0.05). The expression of KIR2DL4 on NK cells in acute rejection group was statistically lower than that in stable kidney function group (31% ± 10%vs 57% ± 21%, P < 0.05). CONCLUSION: sHLA-G5 level may be predicted for acute rejection with a high sensitivity and specificity. The up-regulated expression of ILT-2 and KIR2DLT may contribute to immunology tolerance in peripheral circulation.

Allograft hemorrhage as a manifestation of carbapenem-resistant Klebsiella pneumonia infection in kidney transplant recipients: Case series.

RATIONALE: Carbapenem-resistant Klebsiella pneumonia (CRKP) infections have been a concerning threat, especially in organ transplant patients with very high mortality. Allograft hemorrhage associated with CRKP infection has never been described. PATIENT CONCERNS: A total of 6 recipients tested positive for CRKP were identified in 297 adult kidney transplant recipients who received kidney from donors according to Chinese type donation after cardiac death (DCD) at our center between January 2006 and December 2017. DIAGNOSES: CRKP identification was performed via Vitek 2 system, and the susceptibility was tested by broth microdilution and disk diffusion. Based on the signs of infection and the positive culture, the diagnosis of CRKP infection was established. INTERVENTIONS: Therapy with antibiotic such as including ceftazidime-avibactam or tigecycline and surgical control of primary infection source including allograft nephrectomy and/or thorough debridement was administrated. OUTCOMES: The most striking aspect was that spontaneous recurrent hemorrhage occurred in all the 6 patients. The mortality of CRKP infection in our study was 50%. LESSONS: CRKP infection possibly due to donor-to-recipient transmission in DCD kidney transplants was essentially a necrotic hemorrhagic inflammation and characterized by recurrent hemorrhage and high mortality. The pre-donation screening for CRKP colonization should be mandatory and, if positive, donation should be contraindicated. And, the effective infection source control such as allograft nephrectomy and/or thorough debridement was important to improve outcomes. Further investigation will be required to further characterize the clinical efficacy of new pharmacotherapeutic schemes including ceftazidime-avibactam.

Activation of interleukin-6/STAT3 in rat cholangiocyte proliferation induced by lipopolysaccharide.

BACKGROUND: Cholangiocytes are exposed to endotoxins (lipopolysaccharide, LPS) in a variety of biliary inflammations. It is known that LPS enhances the release of interleukin (IL)-6, a potent cholangiocyte mitogen. However, the role of LPS in cholangiocyte proliferation in vivo is unknown. Aims To investigate whether LPS stimulates cholangiocyte proliferation in vivo via the IL-6/STAT3 pathway. METHODS: Rats were randomized into four groups: the LPS group (injected intravenously with LPS 2.5 mg/kg), anti-IL-6 group (injected intravenously with anti-IL-6 0.5 mg/kg 1 h after LPS injection), RPM group (treated with RPM 0.4 mg/kg intraperitoneally 30 min before LPS injection), and control group. At 6, 12, 24, 48, and 72 h after LPS injection, LPS in plasma was detected by kinetic turbidimetric limulus test. IL-6 concentrations in liver homogenate and cholangiocyte proliferation were determined by ELISA or immunohistochemistry, respectively. Expression of IL-6 mRNA and phosphorylated-STAT3 (P-STAT3) protein in cholangiocytes was analyzed by real-time RT-PCR and western blotting. RESULTS: Cholangiocytes responded to LPS by a marked increase in cell proliferation, IL-6 secretion, and P-STAT3 expression. Anti-IL-6 neutralizing antibody inhibited LPS-induced proliferation of cholangiocytes and decreased levels of IL-6 and STAT3. Furthermore, after being treated with RPM, STAT3 activation was also depressed, which resulted a decreased proliferation of cholangiocytes. CONCLUSIONS: LPS promotes cholangiocyte proliferation through the IL-6/STAT3 pathway, while RPM shows a depressive effect in this pathway.

[Risk factors of long-term cardiovascular diseases and cerebrovascular diseases in kidney allograft recipients].

OBJECTIVE: To identify the risk factors of cardiovascular diseases and cerebrovascular diseases (CVD) events in kidney allograft recipients. METHODS: We followed up 361 renal transplant recipients who had undergone renal transplantation in our center from January 2000 to December 2003 and evaluated the cumulative incidences and mortalities of CVD complications at baseline and post-transplantation 1, 3, 6, 12, 24, 36, 48, and 60 months. Kaplan-Meier plot was used to assess the incidence and Cox's proportional hazards model to determine the risk factors for cardiovascular complications. RESULTS: The cumulative incidences of CVD were 3.1%, 5.4%, 9.9%, 13.0%, 18.0%, 21.1%, and 24.1%, 1, 6, 12, 36, 48, and 60 months after transplantation, respectively. History of diabetes mellitus (RR 2.19, 95% CI 1.32-3.97, P = 0.009) and CVD (RR 6.34, 95% CI 3.76-14.60, P = 0.002) as well as the post-transplantation hypertension (RR 1.18, 95% CI 1.02-1.34, P = 0.04), diabetes mellitus (RR 2.82, 95% CI 1.33-7.26, P = 0.002), hyperlipidemia (RR 2.04, 95% CI 1.26-5.17, P = 0.008) and abnormal creatinine (> 200 micromol/L, RR 1.81, 95% CI 1.08-3.21, P = 0.03), and proteinuria (> 0.3 g/d , RR 1.56, 95% CI 1.12-3.54, P = 0.05) were independently correlated with the development of cardiovascular events. CONCLUSION: History of diabetes mellitus and CVD, post-transplant hypertension, diabetes mellitus, hyperlipidemia, abnormal creatinine and proteinuria are the independent risk factors of the development of CVD events.

[Pathogenesis of post-transplantation diabetes mellitus in 40 renal transplantation recipients].

OBJECTIVE: To explore pathogenesis of post-transplantation diabetes mellitus (PTDM) in renal transplantation recipients. METHODS: A total of 40 renal transplantation recipients were divided into three groups based on oral glucose tolerance test results: normal glucose tolerance (NGT) group (n = 10), impaired fasting glycaemia + impaired glucose tolerance (IFG + IGT) group (n = 16), and PTDM group (n = 14). Insulin resistance (IR) and beta cell function were assessed by homeostasis model. RESULTS: The differences of the immunosuppressive agents used in these groups were not statistically significant (P > 0.05). Compared with NGT group, insulin area under curve and homeostasis model assessment-insulin resistance index were significantly higher in IGT + IFG group and PTDM group (P < 0.05). Compared with NGT group and IGT + IPG group, insulin secretion index at 30 min and homeostasis model assessment-insulin secretion index were significantly lower in PTDM group (P < 0.05). CONCLUSION: Insulin resistance and beta-cell dysfunction may play a key role in the pathogenesis of PTDM.

[Role of IL-6/STAT3 in rat cholangiocyte proliferation induced by lipopolysaccharide].

OBJECTIVE: To investigate whether lipopolysaccharide (LPS) stimulates cholangiocyte proliferation via the IL-6/STAT3 pathway in vivo. METHODS: Rats were randomized into three groups: LPS group (injected intravenously with LPS 2.5 mg/kg), anti-IL-6 group (injected intravenously with anti-IL-6 0.5 mg/kg 1hr after LPS injection), and control group. At 6, 12, 24, 48 and 72 h after LPS injection, LPS concentration in plasma was detected by kinetic turbidimetric limulus test. IL-6 concentrations in liver homogenate was determinded by ELISA, cholangiocyte proliferation was checked by immunohistochemistry, expression of IL-6 mRNA was quantified by real-time RT-PCR, the level of phophorylated-STAT3 (P-STAT3) protein was analyzed by western blotting. RESULTS: Cholangiocytes responded to LPS by a marked increase in cell proliferation, IL-6 secretion and P-STAT3 expression. Anti-IL-6 neutralizing antibody inhibited LPS-induced cholangiocytes proliferation, and decreased levels of IL-6 and p-STAT3. CONCLUSIONS: LPS promotes cholangiocyte proliferation through the IL-6/STAT3 pathway.

[Role of the activation of interleukin-6/STAT3 in cholangiocyte proliferation induced by cold ischemia reperfusion and injury].

OBJECTIVE: To investigate the role of IL-6/STAT3 pathway in the proliferation of cholangiocyte induced by cold ischemia and reperfusion injury. METHODS: Rats were randomized into CP 1 h and CP 12 h groups (supplied livers were preserved for 1 or 12 h), anti-IL-6R (rats in CP 12 h group were administrated with anti-rat soluble IL-6 receptor antibody), and control group. At 1, 3, 7, 14 d postoperative, IL-6 concentration in liver homogenate and cholangiocyte proliferation were detected by enzyme linked immunosorbent assay and histochemistry respectively. Expressions of IL-6 mRNA, phosphorylated-STAT3 and cyclin D1 protein in cholangiocytes were determined by real-time PCR or Western blot analysis. Serum concentrations of ALP and GGT and histology analysis were also performed. RESULTS: Minimal expressions of IL-6, p-STAT3 and cyclin D1 were detected in CP 1 h group, with a slight cholangiocytes proliferation. Cholangiocytes responded to extended cold preservation with severe bile duct injures and marked increase in IL-6 secretion, p-STAT3 and cyclin D1 protein expression, followed by compensatory cholangiocytes regeneration. Parallel to this observation, biochemical index and morphology indicated that bile duct injury was recovery at 14 d postoperative. However, anti-sIL-6R inhibited cholangiocytes proliferation and reduced the expressions of IL-6, STAT3 and cyclin D, with the cellular injury and increase of serum ALP or GGT. CONCLUSIONS: IL-6/STAT3 pathway might participate to initiate cholangiocytes regeneration after cold ischemia and preservation injury, which might benefit biliary recovery after liver transplantation.

CD4+ T Cell Immune Response to VP1 and VP3 in BK Virus Infected Recipients of Renal Transplantation.

OBJECTIVE: To investigate the characteristics of BK virus (BKV) specific cellular immune response in the recipients who have early infection with BKV after renal transplantation. METHODS: The recipients of renal allografts (n = 30) were divided into groups of BK virus nephropathy (BKVN), viruria, and viremia. The BKV load was observed with real-time fluorescence quantitative polymerase chain reaction in urine and blood every three months. The values of serum creatinine (SCr) were detected. The peripheral blood mononuclear cells (PBMCs) were cultivated with overlapping peptide pool containing BKV structural proteins VP1, VP2, and VP3, and regulatory proteins large tumor antigen (LT-Ag) and small tumor antigen (st-Ag), to stimulate in vitro specific cellular immunoresponse. Flow cytometry was used to measure the proliferation of CD3+/CD4+/CD8+ T and interferon [INF]-γ/interleukin [IL]-2/tumor necrosis factor [TNF]-α T cell subsets. RESULTS: The BKV infection increased SCr values in recipients of renal transplantation. CD4+ T cells were dominant (>90%) in the in vitro cellular immunoresponse to VP1, VP2, VP3, LT-Ag, and st-Ag. At the presence of viremia and BKVN, IL-2/IFN-γ+/TNF-α+ CD4+ T cells showed significantly decreased in vitro cellular immunoresponse to VP1, VP2, and VP3 (p < 0.05), but insignificantly changed to LT-Ag and st-Ag (p > 0.05). For the cases of viruria and viremia, IL-2/IFN-γ+/TNF-α+ CD4+ T cells showed significantly higher in vitro cellular immunoresponse to VP1, VP2, and VP3 than to LT-Ag and st-Ag (p < 0.05). The immunogenicity of VP1 and VP3 was significantly higher than that of VP2 (p < 0.05). CONCLUSIONS: The BKV infection increases SCr values, and CD4+ T cells are dominant in the in vitro BKV specific cellular immunoresponse in the recipients of renal transplantation. Viremia significantly decreased the immunoresponse to VP1, VP2, and VP3. There is the significantly stronger immunoresponse to VP1 and VP3 when compared with that to VP2, LT-Ag, and st-Ag, suggesting that VP1 and VP3 may be the major targets for the BKV specific immune response.

Follicular Helper T Cell Derived Exosomes Promote B Cell Proliferation and Differentiation in Antibody-Mediated Rejection after Renal Transplantation.

Follicular helper T cells (Tfh cells) are closely related to the occurrence and development of antibody-mediated rejection (AMR) after renal transplantation. Exosomes play a key role in the rejection after organ transplantation. However, whether Tfh-derived exosomes are involved in AMR has not been reported. We collected peripheral blood from 42 kidney transplant patients and found no significant differences in CD4+CXCR5+ and CD4+CXCR5+CXCR3+CCR6-exosomes between AMR and non-AMR groups, whereas the proportion of CD4+CXCR5+CXCR3-exosomes was significantly higher in AMR group than that in non-AMR group; CTLA-4 expression of CD4+CXCR5+exosomes was significantly lower in AMR group than that in non-AMR group. HLA-G expression was not significantly different between two groups. We further separated CD4+CXCR5+cells from patients by magnetic beads. Coculture experiments showed that Tfh cell-derived exosomes in AMR patients significantly promoted B cell proliferation and differentiation, compared with non-AMR group, the percentage of B cells and plasma cells increased by 87.52% and 110.2%, respectively. In conclusion, our study found that Tfh cell-derived exosomes could promote the proliferation and differentiation of B cells and they may play an important role in the development of AMR after renal transplantation.

Short-term anti-CD25 monoclonal antibody treatment and neogenetic CD4(+)CD25(high) regulatory T cells in kidney transplantation.

CD4(+)CD25(high) T cells named regulatory T (Treg) cells are generated and play a key role in the induction and maintenance of transplant tolerance in organ recipients. Interleukin-2 (IL-2) enhance the development of effector cells and is essential for generation of Treg cells. The effect of the anti-CD25 monoclonal antibody (anti-CD25mAb) induction therapy on the neogenetic CD4(+)CD25(high)Treg cells is important for therapeutic strategies in kidney transplant. To clarify the question, a prospective study was conducted in 21 living donor kidney transplant recipients who randomly divided into the anti-CD25mAb group (Daclizumab) with 11 patients and the control group with 10 patients. The frequency of CD4(+)CD25(high)Treg cells in total CD4(+) T cells was analyzed by flow cytometry and FoxP3 expression by RT-PCR in peripheral blood, and results were compared at day 0, 3, 13, 17, 27 posttransplantation. There was no significant difference in patient characteristics and allograft survival. The present study showed that in vivo antigen-specific Treg cells population were generated and expanded after transplant. Both groups showed a significant increase in the frequency of CD4(+)CD25(high)Treg cells and higher level of FoxP3 mRNA after transplantation while the serum creatinine declined. Compared with the control group, recipients with anti-CD25mAb injection had significantly lower percentage of CD4(+)CD25(high) in total CD4(+) cells (1.13%+/-0.13% vs 1.94%+/-0.22%, P=0.00; 3.75%+/-0.28% vs 7.11%+/-0.51%, P=0.00) on day 3, 17 after transplantation. While, the percentage was not significantly different on day 10, 27 (3.72%+/-0.19% vs 4.36%+/-0.28%, P=0.08; 7.84%+/-0.35% vs 8.56%+/-0.36%, P=0.16). However, there was not obvious difference in Foxp3 expression level associated with the source of the CD4(+)CD25(high)Treg cells at the different time point after transplant. Our data indicated that CD4(+)CD25(high)Treg cells were transiently affected by anti-CD25mAb, without depletion. In conclusion, the short-term treatment with anti-CD25mAb might not prevent the production, proliferation of neogenetic Treg cells in organ transplant.

Endothelial cell chimerism by fluorescence in situ hybridization in gender mismatched renal allograft biopsies.

BACKGROUND: The blood vessels of a transplanted organ are the interface between donor and recipient. The endothelium in the blood vessels is thought to be the major target for graft rejection. Endothelial cells of a transplanted organ can be of recipient origin after transplantation. In this study, we tested whether endothelial chimerism correlated with the graft rejection and cold ischemia. METHODS: We studied the biopsy samples from 34 renal transplants of female recipients who received the kidney from a male donor for the presence of endothelial cells of recipient origin. We examined the tissue sections of renal biopsy samples by fluorescence in situ hybridization (FISH) for the presence of endothelial cells containing two X chromosomes using a biotinylated Y chromosome probe and digoxigenin labelled X chromosome probe, and then analyzed the relationship between the endothelial cell chimerism and the rejection and cold ischemia. RESULTS: Endothelial chimerism was common and irrespective of rejections (P > 0.05). The cold ischemic time of chimerism group was longer than no chimerism group ((14.83 +/- 4.03) hours vs (11.27 +/- 3.87) hours, P < 0.05). CONCLUSIONS: There is no correlation between the percentage of recipient endothelial cells in vascular endothelial cells and the type of graft rejection. The endothelium damaged by ischemic injury might be repaired by the endothelial cells from the recipient.