未成熟树突状细胞联合雷帕霉素诱导小鼠肤移植免疫耐受

状细胞组、联合组的皮肤移植物存活时间分别为(6.9±1.9)、(10.3±3.0)、(17.0±3.4)、(20.8±3.6)d.方差分析提示组间差异有统计学意义(P＜0.05);S-N-K检验提示各组之间的差异均有统计学意义(P＜0.05).结论 供者骨髓来源未成熟树突状细胞可诱导小鼠皮肤移植免疫耐受;联合使用雷帕霉素可延长免疫耐受的持续时间.     

Technique for procurement of heart, liver and kidneys from a single donor for transplantation

The purpose of this report is to present a safe, simple technique for procurement of the heart, liver, and kidneys from a single donor with no warm ischemic time. Twenty mongrel dogs were divided into 5 groups of 3 recipients and 1 donor each. Liver and kidney mobilization was performed when the core temperature of the liver reached 27 degrees C, a result of ice slush in the abdominal cavity. As the core temperature of the liver reached 20-22 degrees C, the aorta and inferior vena cava were clamped just above the diaphragm. After excision of the liver and kidneys, another team harvested the heart as it continued to beat. The heart and liver were transplanted orthotopically after simple preservation for 12 and 6 hours, respectively. The kidney was transplanted heterotopically after simple 12-hour preservation. The maximum survival time was 7 hours for heart transplantation and 16 days for liver transplantation. Kidney homogenate ATP levels decreased to 19% of baseline after preservation and were restored to 68% one hour after reperfusion. Our method is simple and safe for harvesting the heart, liver, an kidneys for transplantation and may offer a definite possibility for clinical application.     

Induction of immunologic tolerance to cardiac allograft by simultaneous blockade of inducible co-stimulator and cytotoxic T-lymphocyte antigen 4 pathway

BACKGROUND: Inducible co-stimulator (ICOS) is one of the most recently described members of the CD28 family, and it plays an important role in immune responses. To investigate the role of ICOS in allograft rejection, the authors studied graft survival after cardiac transplantation in mice. METHODS: Hearts from BALB/c mice were transplanted into C3H/He mice. Immunohistochemical staining and flow cytometry were performed. Monoclonal antibody to ICOS or ICOS-immunoglobulin (Ig) was injected intraperitoneally. The authors performed mixed lymphocyte reaction (MLR). RESULTS: ICOS was expressed strongly by graft-infiltrating cells during rejection of the allograft. Blockade of the ICOS pathway with anti-ICOS antibody and ICOSIg significantly prolonged graft survival time relative to that in untreated mice; however, all cardiac allografts were eventually rejected by a single treatment. Treatment with both ICOSIg and cytotoxic T-lymphocyte antigen 4 (CTLA4) Ig induced not only long-term acceptance of the cardiac allograft but also donor-specific tolerance, which was shown by acceptance of donor but not third-party skin. Graft arterial intimal hyperplasia in these cardiac allografts was remarkably less than that in cardiac allografts treated with tacrolimus. Addition of anti-ICOS antibody or ICOSIg to MLR resulted in inhibition of T-cell proliferation. CONCLUSIONS: Inhibition of T-cell proliferation with ICOSIg and CTLA4Ig was more effective than that with ICOSIg alone. Thus, ICOS appears to be an important regulator of T-cell activation, and may be an effective therapy in clinical cardiac transplantation.     

Transplantation of pediatric donor kidneys to adult recipients. Is there a critical donor age?

Cadaver kidneys remain a scarce resource, yet single pediatric donor kidneys are underutilized at some centers. Between 1967 and 1984, 133 single pediatric and 318 adult donor cadaver transplants were performed. Patient and graft survival, renal function, and complications in adult recipients grouped by donor age were compared. Recipient age for all groups was similar (34-36 years). Life table analysis revealed no difference in graft survival in recipients of kidneys from donors aged 2, 3, 4, 5-10, and 11-15 when compared with adult donors. Graft survival in these groups improved over time with current 1-year survival over 75%. Recipients from donors less than 24 months of age demonstrated significantly poorer results, with no kidney surviving greater than 2 months. Serum creatinine of grafts functioning greater than 6 months was similar in all groups. It is concluded that single pediatric kidneys from donors greater than 2 years of age can be successfully transplanted to adults with good long-term results.     

Induction of peripheral tolerance by local delivery of dendritic cell progenitors to cardiac allografts in a murine heterotopic heart transplantation model

Objective Systemic injection of donor-derived dendritic cell (DC) progenitors is reported to prolong cardiac allograft survival in nonimmunosuppressed hosts. Our purpose was to identify whether tolerance limited to the cardiac allograft is inducible by direct delivery of DCs to the myocardium, thus diminishing the potential for systemic side effects. Methods The donors were 8- to 12-week-old male B10/H2b mice. The recipients were 8- to 12-week-old male C3H/H2k mice. For DC culture, DCs were propagated from donor bone marrow with granulocytic/macrophage colony stimulating factor (GM-CSF) (GM-CSF DCs) and/or interleukin-4 (IL-4) (GM-CSF+IL-4 DCs). The phenotypes of DCs were analyzed by flow cytometry (FACScan). For DC assay, the JAM test (a DNA fragmentation assay), the mixed lymphocyte reaction (MLR), and flow cytometry were used. For local DC delivery to the myocardium, DCs were injected retrograde into the ascending aorta, and abdominal heterotopic vascularized heart transplantation was performed. Donor heart survival was recorded. Results JAM assays confirmed the induction of apoptosis in T cells by both DC preparations. Flow cytometry revealed that the GM-CSF DCs expressed diminished co-stimulatory molecules (B7-1 and B7-2) in comparison with the GM-CSF+IL-4 DCs. The mean survival time of cardiac allografts was 13.1 ± 4.32 days for the controls, 35.0 ± 25.7 days for DCs cultured with GM-CSF, and 16.9 ± 7.30 days for DCs cultured with GM-CSF+IL-4. Conclusions Local delivery of GM-CSF DCs may induce graft tolerance and may prove to be more efficient than systemic delivery of DCs. Local delivery of GM-CSF+IL-4 DCs did not prolong cardiac graft survival, suggesting that the immune response elicited may be immunostimulatory. This article was presented at the 100th Annual Congress of the Japan Surgical Society     

胸腺注射转染供者主要组织相容性复合物基因的T淋巴细胞诱导免疫耐受的实验

目的 探讨受者胸腺内注射可表达供者主要组织相容性复合物（MHC）基因的受者T淋巴细胞诱导的免疫耐受的效果。方法 将携带供鼠（C57BL／6，H－2^b）k位点基因cDNA的逆转录病毒载体质粒PXN（N2－B19－H－2K^b）经包装细胞PA317细胞包装为重组病毒后，感染体外培养的受鼠（Balb/c,H-2^d）T淋巴细胞，再将此可表达供者MHC抗原的受者T淋巴细胞（H－2K^db）回输受鼠胸腺内，然后将供鼠（H－2^b）的皮肤移植给受鼠（H－2^d），观察免疫耐受的诱导情况。结果 外源性MHC基因（H－2K^b）整合到靶细胞（H－2^d）染色体DNA，并有效地转录，在细胞膜上有H－2K^b分子表达；对照组移植皮肤平均存活时间（MST）为9d；注射单克隆抗体对照组MST为11d；第三供者组MST为11.5d；实验组（胸腺回输H－2K^db嵌合体T淋巴细胞）MST为35d；实验组脾细胞对刀豆素A（ConA）的增殖反应在正常范围，单向混合淋巴细胞反应对第三供者的脾细胞反应正常，但对特异供者的脾细胞无反应。结论 自身T淋巴细胞在胸腺内表达供者MHC抗原可在成年动物诱导出对供者移植的特异性免疫耐受，无非特异性免疫抑制。     

Ex vivo removal of stones in donor kidneys by pyelotomy prior to renal transplantation: a single-center case series

BackgroundDonors with incidentally discovered asymptomatic renal stones was considered a relative contraindication to the kidney donation because of a potential increased morbidity risk for renal transplant recipients. Stone clearance from the donors should be done before donation to ensure safety of the recipient. This study aimed to observe the safety and efficacy of kidney transplantation from donors with nephrolithiasis who received pyelolithotomy before transplantation.MethodsBetween January 2015 and March 2021, 14 deceased organ donors at The Second Affiliated Hospital of Guangzhou Medical University were found to have kidney stones during predonation evaluation. After donor kidney repair, all of the donor kidneys underwent ex vivo pyelolithotomy. Then the organs were transplanted to the right iliac fossa of 17 patients with end-stage renal failure. Data were analyzed for technical feasibility, intraoperative and postoperative complications, and stone clearance. Ultrasonography and urinal routine were followed at the 1-, 3-, and 6-month postoperatively.ResultsThe stones were successfully removed ex vivo by pyelotomy with an average time of 41.0±12.8 minutes. Seventeen recipients successfully underwent renal transplantation, and their renal function recovered well. Slight gross hematuria occurred in 12 cases after operation, and hematuria disappeared after conservative treatment. Ureteral stents were removed within two months after the procedure. There were no complications such as delayed recovery of renal function, acute rejection, ureteral necrosis, and urinary fistula. The serum creatinine of 17 patients 1 month after the operation was 136.8±26.7 µmol/L. None of the 17 patients included in the study suffered from stone recurrence or graft dysfunction in the follow-up period.ConclusionsEx vivo removal of stones by pyelotomy was a technically feasible means of safely and efficiency rendering a stone-bearing donor kidney stone-free. The procedure obtained good early-middle outcomes in kidney transplantation and is therefore worthy of clinical application.     

Induction of tolerance to composite tissue allograft in a rat model

The goal of this study was to establish a rat model that can be used to determine the variables in influencing induction of tolerance to composite tissue allografts. An anti T-cell depleting agent (R73) and 15-deoxyspergualin were given in different doses and schedule to four groups of Lewis rats receiving a limb transplant from Brown-Norway donors. Graft survival prolongation was maximal combining a single dose of R73 and a 20-day administration of 15-deoxyspergualin. Long-term survivors accepted a skin graft from Brown-Norway donors at 80 days, but rejected grafts from an unrelated donor. Skin grafting did not influence survival of the transplanted limb. Mixed allogeneic chimerism was not detectable in peripheral blood by flow cytometry, but immunohistochemistry identified donor-derived cells in the thymus of tolerant recipients at 100 days. These results suggest a state of donor-specific, dynamic tolerance, with potential for future application in human composite tissue allotransplantation.     

Cross-reactive group matching does not lead to a better allocation and survival of donor kidneys

BACKGROUND: In cadaveric renal transplantation HLA-A, -B, -DR matching of donor and recipient is beneficial for graft survival. However, allocation based on HLA matching seems to favor recipients with more frequently occurring HLA antigens. In this study we investigated whether matching on the basis of cross-reactive groups (CREGs), defined according to the United Network for Organ Sharing (UNOS), would be a good alternative for the allocation of kidneys without negatively influencing graft survival. Theoretically, this approach would provide more recipients with an immunologically well-matched donor organ. METHODS: The influence of CREG matching on graft survival was studied in univariate analyses using the Eurotransplant database. RESULTS: No beneficial effect of CREG matching was observed, whereas a significant HLA matching effect was observed in the 0 CREG mismatched donor/ recipient combinations. Only in the small subgroup with 1 MM for HLA-A, -B and 0 MM for HLA-DR, a significantly better survival was observed, when this mismatch belonged to the 0 or 1 MM CREG group versus two or more MM CREG group. However, this subgroup concerns only 8% of the transplants performed. CONCLUSIONS: In contrast to other reports, our study showed that HLA matching is by far more beneficial than CREG matching. In the homogenous Eurotransplant population, adjusting the matching criteria toward CREG matching would not lead to an improved graft survival.     

Induction therapy by anti-thymocyte globulin (rabbit) versus basiliximab in deceased donor renal transplants and the effect on delayed graft function and outcomes

The use of induction therapy significantly reduces the incidence of acute rejection (AR) episodes posttransplantation and prevents delayed graft function (DGF). In our program, all adult deceased donor kidney transplant (DDKT) recipients receive immunosuppression induction therapy with either Basiliximab (anti-CD25 Ab) or rabbit anti-thymocyte globulin (RATG). Our protocol is risk adjusted such that patients who are at a higher risk for DGF or AR received RATG and all other patients receive anti-CD25 Ab. We hypothesized that treating our higher-risk patients with RATG induction at the time of transplantation would lead to a lower rate of DGF and better outcomes. From August 1, 2005 through August 31, 2010, 116 consecutive adult patients received a DDKT in a single academic transplantation center. All DDKT patients received induction with RATG or anti-CD25 Ab. The induction decision was made prior to transplantation based on donor and recipient risk factors for AR and DGF. Transplants that were deemed at higher risk for DGF or AR based on donor factors or recipient factors received RATG. Medical records and patient databases were reviewed retrospectively. The use of RATG in higher-risk recipients for DGF and AR did not significantly reduce the DGF rate. At 6 months the function of the allograft function measured as creatinine clearance or serum creatinine was lower in the RATG group than the patients who received anti-CD25 Ab induction. The choice of induction therapy did not improve outcomes in high-risk patients in this short-term study.     

Sensitivity of the alpha7 nicotinic acetylcholine receptor to isoflurane may depend on receptor inactivation

In previous studies, we demonstrated that nicotinic acetylcholine receptors (nAChRs) composed of the alpha7 subunit are unaffected by the co-application of isoflurane with agonists at concentrations up to 640 microM (two times the minimum alveolar anesthetic concentration). Modulation of alpha7-nAChR activity by isoflurane might have important behavioral ramifications because these receptors are expressed diffusely in the central and peripheral nervous systems and play pre- and postsynaptic roles in synaptic transmission. Here we have demonstrated that under some potentially physiologically relevant circumstances, the activation of alpha7 nAChRs may be inhibited by clinically relevant concentrations of isoflurane. We evaluated isoflurane inhibition of alpha7 nAChRs from chicks and humans expressed in Xenopus oocytes using two-electrode voltage clamp methodology. We determined the influence of time of preperfusion of isoflurane, agonist concentration, and membrane potential on inhibition by isoflurane. Both activation by a large concentration of agonist and isoflurane preperfusion increased inhibition. The half-maximal inhibitory concentration for isoflurane inhibition of chick alpha7 nAChR with isoflurane preperfusion and activation by 100 microM of acetylcholine was 938 +/- 26, and when activated by 1 mM of acetylcholine, it was 408 +/- 51 microM. The increase in inhibition with isoflurane preexposure and large agonist concentration raises the possibility that isoflurane interacts preferentially with a closed or closed-desensitized state of the channel. IMPLICATIONS: Nicotinic receptors expressed in the brain have been considered a possible target for the actions of isoflurane. We studied the effect of isoflurane on alpha7 type nicotinic receptors expressed in Xenopus oocytes. We find that when activated by large concentrations of acetylcholine, alpha7 nicotinic receptors are inhibited by isoflurane at concentrations near MAC.     

Induction of donor-specific unresponsiveness to rat cardiac allograft by donor leukocytes and cyclosporine

Many recent reports have emphasized the importance of donor antigens in the induction of allograft tolerance. This study examines the effect of pretransplant infusion of 10(8) donor leukocytes (DL) combined with peritransplant cyclosporine (CsA) on W/F cardiac allograft survival in Lewis rats. Peritransplant recipient treatment consisted of CsA 20 mg/kg given i.m. on days 0, +1, and +2 relative to heart transplantation. Lewis recipients, 5-8 per group, were pretreated with 10(8) DL with or without peritransplant CsA. A single DL transfusion on day -3 or day -7 prior to transplantation significantly prolonged the mean survival time (MST) of W/F hearts from 7.0 +/- 0.9 days in controls to 12.2 +/- 4.5 days and 12.4 +/- 1.0 days (P less than 0.01), respectively. Two DL infusions on days -7 and -3 or on days -14 and -7 prolonged the MST to 10.6 +/- 1.3 days (P less than 0.02) and 16.4 +/- 2.8 days (P less than 0.001), respectively. The administration of peritransplant CsA alone significantly prolonged W/F heart allograft survival to 43.1 +/- 2.7 days. When pretransplant DL transfusion on day -3 was combined with CsA treatment, 4/8 animals maintained their grafts indefinitely (greater than 100 days). Similarly, DL infusion on day -7 with peritransplant CsA led to indefinite graft survival in 3/5 animals. Administration of DL on days -7 and -3 combined with CsA resulted in indefinite graft survival (greater than 100 days) in 4/6 animals. Transfusion of DL on day -3 alone or in combination with peritransplant CsA, had no effect on a third-party (ACI) heart allograft survival prolongation compared with appropriate controls. To define the underlying mechanisms responsible for donor-specific unresponsiveness in this model, pooled sera and unseparated spleen cells were passively transferred from recipients of long-term cardiac allografts to syngeneic rats receiving donor-type (W/F) or third-party (ACI) cardiac allografts. Transfer of serum (1 ml on days 0, and 1, 0.5 ml on days +2, +3, and +4) from ungrafted recipients of DL on days -14 and -7 led to significant donor graft survival of 9.8 +/- 0.4 days (P less than 0.02) in unmodified hosts. Similarly, passive transfer of serum obtained at 20 and 100 days after transplantation significantly prolonged the MST of donor-type hearts in syngeneic untreated hosts to 11.3 +/- 0.8 and 10.0 +/- 1.1 days, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)