Allograft Survival Time Research Articles

Inhibition of accelerated rejection mediated by alloreactive CD4+ memory T cells and prolonged allograft survival by arsenic trioxide

The aim of this study was to evaluate and determine the potential mechanisms of As2O3 in accelerated rejection mediated by alloreactive CD4+ memory T cells. Vascularized heterotopic cardiac transplantation from C57BL/6 mice to nude mice (pre-transferred CD4+ memory T cells) was performed on Day 0, and As2O3 was administered to recipient mice from Day 0 to 10. As a result, As2O3 could reduce the proliferation of allo-primed CD4+ memory T cells in vitro in MLR and the baseline rate of proliferation was restored by the addition of exogenous IL-2. In vivo, compared with the control[+] group, the mean survival time of cardiac allografts in the As2O3 group was prolonged from 5.8 ± 0.7 to 14.2 ± 2.5 days. Five days after transplantation, the relative gene expression of IL-2, IFN-γ and Foxp3 was reduced in the grafts by As2O3 treatment, but the expression of IL-10 and TGF-β was increased. Correspondingly, the proportions of CD4+ T cells, CD4+ memory T cells and regulatory T cells (Tregs), both in recipient spleens and lymph nodes, were lowered. These results indicate the potential of As2O3 as a novel immunosuppressant targeting CD4+ memory T cells.

Adoptive transfusion of tolerance dendritic cells prolongs the survival of skin allografts in mice: a systematic review

We aim to systematically review adoptive transfusion of tolerogenic dendritic cells (Tol-DCs) induced by different ways to affect skin allograft survival in mice. We searched PubMed and EMbase for relevant studies and evaluated the quality of included ones. Taking skin allograft survival time as endpoint outcome, we displayed outcomes of each group using one forest map and dissected possible mechanisms underlying survival prolongation. We included 21 studies, which reported four methods of inducing Tol-DCs with different extents of average allograft survival prolongation: skin allograft survival time was prolonged (the drug intervention group, 63.08 ± 42.92 days, 4.6 folds to control; the cytokine induction group: 26.17 ± 16.20 days, 1.8 folds; the gene modification group: 14.65 ± 17.89 days, 1.5 folds; other derivation group 9.63 ± 24.38 days, 0.5 fold). Possible mechanisms underlying survival prolongation included induction of donor-specific T cell hyporesponsiveness, reduction of cytotoxicity against allografts, Th0 skewing to Th2, and generation or expansion of Treg. Infusion of Tol-DCs in combination with immunosuppressive agents or costimulatory blockade contributed to longer prolongation. Compared to MiHA mismatch, MHCI/II mismatch was a much more important factor to cause skin allograft rejection. For MHC or MiHA mismatched, allogeneic skin transplants inbred recipients, adoptive transfusion of Tol-DCs induced by 4 methods prolong skin allograft survival to different extents. Drug intervened Tol-DCs works best. Immunosuppressive agents and/or co-stimulatory blockade contribute to better outcomes. Yet more rigorous studies with larger sample size are needed and more attention to mechanisms should be paid.

The protective effects of CD4+ CD25+ Treg cell on the allograft after infusion of dendritic cells with low expression of CD40 from donor in mouse heart transplantation

Objective To explore the effects of CD4+CD25+Treg cell on the allograft after infusion of dendritic cells (DCs) with low expression of CD40 from donor in mouse heart transplantation.Methods In vitro,mouse bone marrow-derived DCs were infected by CD40-RNAi lentiviral vector,and tolerogenic DCs (Tol-DCs) with low expression of CD40 were prepared.A heterotopic abdominal heart transplantation model was established in mice,and the other three groups that were control group,noninfected DC group and lentivirus infected DC group were designed correspondingly.Cardiac allograft survival time was recorded and pathological grading for acute rejection was assessed on the 7 d after heterotopic abdominal heart transplantation.Concentrations of CD4+CD25+Treg cells in peripheral blood were analyzed before and after transplantation by flow cytometry.Results After 48 h infection of DCs by CD40-RNAi lentiviral vector in vitro,the expression of CD40 mRNA was down-regulated significantly,whose inhibition rate was 80.9％.The expression of CD40 was decreased from 74.37％ ±4.08％ to 40.07％ ± 4.03％ (P＜0.05) after 48 h infection.Compared with the control group and the noninfected DC group,the cardiac allograft survival time was significantly prolonged in the CD40-RNAi lentivirus infected DC group,which was (14 ± 4) d(P＜0.01) ; concentrations of CD4+CD25+Treg cells in peripheral blood were increased both on the 3 d and the 7 d after transplantation (P＜0.05) ; the pathological grading for acute rejection was decreased on the 7 d after transplantation (P＜0.05).Conclusion The CD4+CD25+Treg cell in peripheral blood was protective to cardiac allograft in prolonging its survival time in mouse heart transplantation. Key words: Regulatory T cell; Costimulatory pathway; Dendritic cell; CD40; Heart transplantation

The Effect of Atorvastatin (Lipitor) on the Duration of Survival of Allogeneic Skin Graft and the Growth of B16F10 Melanoma Cells in Mice

Aims: To evaluate the immunomodulatory effect of using non-cholesterol lowering dose of atorvastatin (AS) on skin allograft survival and on tumor growth in mice. Study Design: Experimental Study. Place and Duration of Study: Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut; 2011-2012. Methodology: BALB/c mice were transplanted with skin allografts from C57BL/6 mice and given either AS alone or in combination with immunosuppressive agents. Average survival days of skin allografts were recorded and serum levels of interleukin-1β (IL-1β) and interferon-γ (IFN-γ) were quantified. BALB/c mice and C57BL/6 mice were challenged intraperitoneally with B16F10 melanoma cancer cells (cancer cell line syngeneic to C57BL/6 mice) and were then treated with AS. They were observed Research Article British Journal of Medicine & Medical Research, 3(4): 1938-1951, 2013 1939 regularly for tumor growth. Results: The results indicated that in transplant mice AS given alone or in combination with immunosuppressive agents prolonged allograft survival time through noncholesterol lowering mechanisms in spite of a non-significant change in serum cytokine levels. Furthermore, AS treatment enhanced tumor growth in C57BL/6 mice and promoted tumor growth in BALB/C mice. Conclusion: It can be speculated that AS down expresses TLR and modifies MHC presentation resulting in hindering the generation of an innate and adaptive immune response.

Using trichosanthin to inhibit the rejection in mouse islet allotransplantation

Objective To understand the inhibition effect of trichosanthin to allograft rejection in mouse islet transplantation and investigate its possible mechanisms.Methods Control group and trichosanthin injection group were set in mice with BALB/C to C57BL/6 islet transplantation.Blood glucose was tested daily to obtain the survival time of allografts.T cell proliferation rate and T cell ratio in spleen were detected to investigate mechanisms of trichosanthin in inhibiting rejection.Results Allograft survival time was (12.2 ± 1.7) d in trichosanthin injection group and (9.7 ± 1.4) d in control group.It was prolonged after trichosanthin injection (P ＜ 0.05).Donor antigen specific T cell proliferation rate was depressed (P ＜ 0.01) and regulatory T cell ratio in recipient spleen was elevated after trichosanthin injection.Conclusion Trichosanthin could inhibit allograft rejection in mouse islet transplantation.Inhibition of antigen specific T cell proliferation and up-regulation of regulatory T cell are possible mechanisms. Key words: Islets of Langerhans transplantation; Trichosanthin; Regulatory T cells

A Novel Cyclosporine A Drug-Delivery System for Prevention of Human Corneal Rejection after High-risk Keratoplasty: A Clinical Study

To evaluate the efficacy of a novel cyclosporine A (CsA) drug-delivery system (DDS) in the anterior chamber for suppressing the occurrence of rejection and improving the survival of corneal allografts after high-risk keratoplasty. Single-center, noncomparative case series. Ninety-two eyes of 92 patients with corneal blindness who required corneal transplantation at Shandong Eye Institute from May 2003 to June 2011. The CsA DDS was implanted into the anterior chamber during high-risk keratoplasty, and subsequent therapeutic effects were evaluated. Occurrence and reversal of graft rejection within 12 months after surgery, long-term survival of corneal grafts (>12 months), biodegradation of the CsA DDS, endothelial cell density by noncontact specular microscopy, and iris status by ultrasound biomicroscopy (UBM). At 6 months, the transplantation was scored as success in 81 eyes (88.0%), partial success in 7 eyes (7.6%), and failure in 4 eyes (4.3%). The mean graft survival time was 36.1 ± 17.7 months (range, 12.3-61.6 months). The carrier of the CsA DDS, polylactide-co-glycolide-co-caprolactone, biodegraded completely at 7.6 ± 4.3 months (range, 5-13 months). The density of endothelial cells was 2154 ± 230 cells/mm(2) (range, 2067-2319 cells/mm(2)) immediately after surgery and 2079 ± 156 cells/mm(2) (range, 1950-2254 cells/mm(2); P > 0.05) at 6 months. No edema of corneal stroma and iris was observed by UBM. The CsA DDS implanted in the anterior chamber seems to be effective for the prophylaxis of immune rejection after high-risk keratoplasty without toxicity to the cornea and the iris of patients. It can decrease the rejection episode and prolong the survival time of allografts. The anterior chamber may be a promising drug-delivery target for treatment or prevention of endothelial graft rejection after corneal transplantation.

Impact of NF-κB gene polymorphism on allograft outcome in Hispanic renal transplant recipients

BackgroundThe dimeric NF-κB transcription factors play critical roles in diverse cellular processes including adaptive and innate immunity, cell differentiation, proliferation and apoptosis. It regulates the expression of numerous genes that play a key role in the inflammatory response during kidney allograft rejection. This study aims to determine the association of NF-κB gene polymorphisms with allograft outcomes in the Hispanic renal transplant recipients. MethodsA total of 607 Hispanic renal transplant recipients at St. Vincent Medical Center between 2001 and 2010 were included in this study. The NF-κB genotypes were studied along with clinical data. In the case of NF-κB genotypes, the following single nucleotide polymorphisms (SNPs) were included: NF-κB1 (rs3774959, rs3774932, rs3774937, rs230526, rs230519), NF-κB2 (rs1056890, rs7897947, rs12769316) and NF-κB inducing kinase (NIK) (rs9908330, rs7222094). The association of each genotype with renal allograft survival and acute rejection was evaluated. ResultsNF-κB1 (rs3774937) CC genotype showed protective association with allograft rejection (OR=0.66, 95% CI=0.44–0.99, p=0.04). There was a significant increase in allograft survival time associated with the NF-κB1 (rs3774959) A allele (OR=0.76, 95% CI=0.60–0.98, p=0.03) while GG genotype was associated with a higher risk of graft failure (OR=1.51, 95% CI=1.02–2.21, p=0.03). There were no associations between polymorphic markers in NF-κB2 and NIK genes with allograft survival or acute rejection. Among non-genetic factors, we found that the use of tacrolimus, a deceased donor, delayed graft function and acute rejection were associated with allograft failure. ConclusionThe result of present study suggests that NF-κB1 gene polymorphisms may determine the incidence of acute rejection or graft survival among Hispanic allograft recipients.

Inhibiting accelerated rejection mediated by alloreactive CD4+ memory T cells and prolonging allograft survival by 1α,25-dihydroxyvitamin D3 in nude mice

Donor-reactive memory T cells are major barriers to long-term survival of transplanted organs due to their capacity to accelerate rejection. In this study we investigated the ability of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] to inhibit accelerated rejection mediated by alloreactive CD4+ memory T cells and to prolong cardiac allograft survival in an adoptive T cell memory/heart transplant model of nude mice. In vitro, the proliferation of CD4+ memory T cells was significantly inhibited by 1,25(OH)2D3 and was restored following addition of exogenous IL-2. Compared with the control group, the mean survival time of cardiac allografts in the 1,25(OH)2D3 group was prolonged from 6.5±0.3 to 20.2±0.8days in vivo. Five days after transplantation, the levels of IL-2 and IFN-γ were reduced in the grafts and the recipient sera by 1,25(OH)2D3 treatment, while that of IL-10 increased. The proportions of CD4+ memory T cells and CD4+Foxp3+ T cells, both in recipient spleen and lymph nodes, were lowered by 1,25(OH)2D3 treatment when compared with the control group. Our data suggests that 1,25(OH)2D3 inhibits expansion of CD4+ memory T cells, possibly by inducing clonal anergy and/or clonal deletion, resulting in prolongation of cardiac allograft survival in nude mice. These results may provide a rational basis for exploiting 1,25(OH)2D3 as a novel immunosuppressant targeting CD4+ memory T cells.

PUK22 Evaluating the Minimum Renal Allograft Survival Time Required for Transplantation to Remain Cost Saving in the UK

PUK22 Evaluating the Minimum Renal Allograft Survival Time Required for Transplantation to Remain Cost Saving in the UK

An Oral Sphingosine 1-Phosphate Receptor 1 (S1P1) Antagonist Prodrug with Efficacy in Vivo: Discovery, Synthesis, and Evaluation

A prodrug approach to optimize the oral exposure of a series of sphingosine 1-phosphate receptor 1 (S1P(1)) antagonists for chronic efficacy studies led to the discovery of (S)-2-{[3'-(4-chloro-2,5-dimethylphenylsulfonylamino)-3,5-dimethylbiphenyl-4-carbonyl]methylamino}-4-dimethylaminobutyric acid methyl ester 14. Methyl ester prodrug 14 is hydrolyzed in vivo to the corresponding carboxylic acid 15, a potent and selective S1P(1) antagonist. Oral administration of the prodrug 14 induces sustained peripheral blood lymphocyte reduction in rats. In a rat cardiac transplantation model coadministration of a nonefficacious dose of prodrug 14 with a nonefficacious dose of sotrastaurin (19), a protein kinase C inhibitor, or everolimus (20), an mTOR inhibitor, effectively prolonged the survival time of rat cardiac allografts. This demonstrates that clinically useful immunomodulation mediated by the S1P(1) receptor can be achieved with an S1P(1) antagonist generated in vivo after oral administration of its prodrug.

Flt3L Combined with Rapamycin Promotes Cardiac Allograft Tolerance by Inducing Regulatory Dendritic Cells and Allograft Autophagy in Mice

The induction of immune tolerance is still a formidable challenge in organ transplantation. Dendritic cells (DCs) play an important role in orchestrating immune responses by either mediating protective immune responses or inducing antigen specific tolerance. Previous studies demonstrated that the fms-like tyrosine kinase 3 receptor (Flt3) and its ligand (Flt3L) play an essential role in the regulation of DC commitment and development. Here, we report a synergic effect between Flt3L and low-dose rapamycin (Rapa) in the protection of allograft rejction. It was found that Flt3L combined with Rapa significantly prolonged murine cardiac allograft survival time as compared with that of untreated recipients or recipients treated with Rapa or Flt3L alone. Mechanistic studies revealed that Flt3L combined with low-dose of Rapa induced the generation of tolerogenic DCs along with the production of CD25+ Foxp3+ regulatory T cells and IL-10 secretion. We also observed enhanced autophagy in the cardiac allograft, which could be another asset contributing to the enhanced allograft survival. All together, these data suggest that Flt3L combined with low-dose of Rapa could be an effective therapeutic approach to induce tolerance in clinical setting of transplantation.

The Soluble Tachyzoite Antigen of Toxoplasma gondii Has a Protective Effect on Mouse Allografts

BackgroundInfection with some types of parasites can significantly prolong allograft survival in mice. It is unknown whether the soluble tachyzoite antigen (STAg) from Toxoplasma gondii has the same effect and by what mechanism it acts. MethodsA mouse model of cardiac and skin allograft transplantation was established between BALB/c (H-2d) and C57BL/6(H-2b) mice. T gondii STAg was prepared, and 5 μg was administered subcutaneously to recipient mice 4 days before transplantation. The graft status was checked daily, and histologic and immunohistochemical assays were used to evaluate rejection. The serum cytokine levels from the recipient mice were analyzed by Luminex. ResultThe administration of 5 μg STAg 4 days before transplantation significantly prolonged the survival time of the heart and skin allografts to 85.17 ± 14.06 and 24.17 ± 2.32 days, respectively. Immunohistochemical staining showed that the CD4+ and CD8+ T lymphocytes were markedly reduced in the allografts at day 7 posttransplantation. Notably, interleukin (IL)-12, IL-2, and IL-17 levels were significantly reduced in the serum of mice treated with STAg compared with untreated mice 7 days after transplantation. In contrast, the levels of the antiinflammatory cytokine IL-10 were elevated. ConclusionA single administration of STAg before transplantation can significantly prolong the allograft survival time, which is accompanied by impaired lymphocyte infiltration and a reduced Th1 response.

Experimental Efficacy of Mycophenolate Mofetil Implant on High-Risk Corneal Allograft Rejection and Its Biocompatibility in the Anterior Chamber of Rabbits

The aim of this study was to investigate the immunosuppressive activity of a mycophenolate mofetil (MMF) intraocular-implantable drug delivery system (IDDS) in a rabbit model of high-risk penetrating keratoplasty and to determine the biocompatibility of such a device when implanted in the anterior chamber. Corneal vascularization was induced in New Zealand white rabbits by passing 5-0 silk sutures through the corneal stroma in each quadrant. The corneal neovascularized rabbits received a unilateral 7-mm-diameter central-penetrating keratoplasty. New Zealand white rabbits were used as donors and were divided into 4 treatment groups: the control group, which received no therapy; the 1% MMF eye drop group; the 1.0 mg cyclosporin A (CsA)-IDDS-implanted group; and the 1.0 mg MMF-IDDS-implanted group. Animals were followed up for 150 days, which involved examination of the corneal allografts (opacity, edema, and neovascularization) by slit-lamp biomicroscopy. The survival time of corneal allografts of these animal models was recorded in 4 groups. Histopathologic studies were carried out on the procured specimens of corneal allografts. The biocompatibility of MMF-IDDS in the anterior chamber in rabbits was also investigated. The mean survival time of corneal allografts in the control and MMF eye drop groups was 18.7±3.0 and 37.5±6.2 days, respectively (P=0.005). Allografts from the CsA-IDDS-implanted group were transparent, except 1 allograft, which showed immune rejection after 130 days. Allografts from the MMF-IDDS-implanted group were transparent throughout the entire observation period. The incidence of allograft rejection was 100% in the control and MMF eye drop groups, respectively. The rejected allografts were much more edematous and more heavily infiltrated with leukocytes than the nonrejected allografts. MMF-IDDS was tolerated well in the anterior chamber, even with 3 MMF-IDDS implanted in the anterior chamber at 1 time. MMF-IDDS was able to prolong high-risk allograft survival time and significantly inhibited corneal immune rejection in the rabbit model of penetrating keratoplasty. The device could safely be implanted in the anterior chamber without adverse effects.

Prolonged survival time of allografts by the oral administration of RDP58 linked to the cholera toxin B subunit

Oral administration, which has been identified as a tool for boosting physiological immunoregulatory mechanisms in an antigen-specific manner, is a more convenient way than classical parenteral injection methods. RDP58 is derived from specific regions of class-I MHC molecules and is known to have immunomodulatory effects after intraperitoneal injection or intravenous administration. To determine whether the oral administration of RDP58 conjugated to the cholera toxin B subunit (CTB) can better induce peripheral tolerance than the use of traditional methods, we used various feeding regimens and methods of administration using equivalent doses of antigen during rat kidney transplantation. The results showed that RDP58-GC/CTB treatment increased the activity of Haem oxygenase-1 (HO-1) in vivo and significantly improved the survival and histopathology of allograft kidney tissue relative to the oral administration of RDP58 alone. These results suggest that the administration of RDP58 linked to CTB outweighs the benefits of oral administration of RDP58 alone for prolonging the survival time of kidney transplantation. This study supports the potential therapeutic use of oral administration of RDP58 linked to CTB as a platform molecule in the treatment of allograft rejection.

Transfusion of Endothelial Cells with Lentivirus-Mediated Expression of Fas Ligand Prolonged Survival of Rat Liver Allograft

BackgroundImmunologically privileged sites have been shown to express Fas ligand (FasL) and may protect themselves by inducing apoptosis of infiltrating inflammatory cells. We asked whether the Fas/FasL interaction could be used to protect liver allograft from acute rejection. We proposed that endothelial cells that are resistant to Fas-mediated killing could be considered as a vehicle for expression of recombinant FasL. MethodsBased on the lenti-rFasl/puro expression system, constructs were designed that allowed endothelial cell-specific and continual expression of FasL. Endothelial cells with expression of FasL or viruses recombinant with FasL gene were transfused into portal vein of recipient rats during liver transplant surgery. Comparing groups of rats after liver transplant surgery using regular dose of FK506 and with no other treatment, we observed the aspartate aminotransferase and BIL value and survival of four groups of rat recipients. ResultsValues of AST and BIL in the cell and virus transfusion groups were between FK506 and contrast groups. The survival of cell and virus transfusion groups were longer than contrast group and shorter than FK506 group. ConclusionThis in vitro model shows that endothelial cells with expression of FasL or viruses recombinant with FasL gene transfusion can preserve liver function and prolong the survival time of liver allografts.

A novel accelerated rejection model for mouse cardiac transplantation involving presensitization with donor splenocytes

BackgroundAccelerated rejection is a type of refractory rejection. Animal models of accelerated rejection are widely employed in research on transplant immunity. MethodsWe divided 36 C57BL/6 mice into six groups that underwent heart transplant. To select the ideal number of splenocytes for the presensitization to induce accelerated rejection, were transferred 0.5 × 107, 1 × 107, 5 × 107, or 10 × 107 donor splenocytes 7 d before transplantation. We confirmed successful presensitization by increases in donor-reactive antibodies. We performed 12 additional heart transplants in the accelerated rejection group and the control groups for a histological examination, immunohistochemical staining for C3d, and a splenocyte test using flow cytometry. ResultsThe transfer of 5 × 107 donor splenocytes effectively and efficiently induced an accelerated rejection in the BALB/c→C57BL/6 heart transplant, with an allograft survival time that was decreased from 7.4 ± 0.5 d to 3.5 ± 0.8 d compared with the allogenic controls (P < 0.05, log-rank test). An analysis of this model indicated that compared with acute rejection, the number of donor-reactive antibodies was significantly increased, and the proportions of effector memory CD8+ T cells and plasmacytes in the spleen were significantly increased (7.81% ± 1.2% versus 2.96% ± 1.0%, P = 0.006; 1.27% ± 0.13% versus 0.71% ± 0.22%, P = 0.018, respectively). We found the histological characteristics of both cellular and humoral rejection in the accelerated rejection model. ConclusionsPresensitization via the transfer of donor splenocytes facilitates the establishment of an accelerated rejection model. Our findings with this model indicate that humoral rejection and cellular rejection are coexistent, and that the proportions of effector memory CD8+ T cells and plasmacytes in the spleen increase significantly during accelerated rejection.

Caroli disease patients have excellent survival after liver transplant

BackgroundCaroli disease (CD) is characterized by dilation of the intrahepatic biliary tree, which may result in malignancy. Treatments include management of symptoms and hepatic resection to decrease disease burden. In patients with CD not amenable to these treatments, orthotopic liver transplantation (OLT) has been used. This study examines if OLT is a reasonable treatment for patients with CD. Materials and methodsThe United Network of Organ Sharing/Organ Procurement and Transplantation Network database between September 30, 1987 and March 31, 2011 was queried. Cases without patient or allograft survival time or without a diagnosis were excluded from analysis. Patients with CD were compared to patients with primary biliary cirrhosis (PBC), secondary biliary cirrhosis (BC), primary sclerosing cholangitis (PSC), and all indications for OLT. Survival analysis was performed by log-rank test and Kaplan-Meier. ResultsOne hundred forty patients with CD were compared to 4797 patients with PBC, 489 patients with secondary BC, 6033 patients with PSC, and 92,210 patients post-OLT. Patient and allograft survivals of CD patients at 1, 3, 5, and 10 y are, respectively, 88.5%, 83.4%, 80.9%, and 77.8%; and 81.2%, 74.8%, 70.6%, and 67.9%. CD patients have significantly improved patient and allograft survivals after OLT compared to patients with secondary BC (P = 0.003, P = 0.015) and all other patients undergoing OLT (P = 0.003, P = 0.026). There is a trend towards long-term improved patient and allograft survival in transplanted patients with CD compared to patients with PBC and PSC. ConclusionsThese results suggest that OLT should be considered an effective treatment modality for patients with CD resulting in excellent long-term outcomes.

Danazol induces prolonged survival of fully allogeneic cardiac grafts and maintains the generation of regulatory CD4+ cells in mice

Danazol, a derivative of testosterone, is useful for treatment of endometriosis as well as pretreatment for in vitro fertilization and embryo transfer, although its mechanisms of action are unclear. The aim of this study was to investigate the effect of danazol on alloimmune responses in murine heart transplantation. CBA male mice (H2(k) ) underwent transplantation of C57BL/6 male (H2(b) ) hearts and received a single dose of danazol (0.4, 1.2 or 4mg/kg/day) by intraperitoneal injection on the day of transplantation and for 6days thereafter. An adoptive transfer study was performed to determine whether regulatory cells were generated. The median survival time (MST) of allografts in danazol-treated (1.2 and 4mg/kg/day) mice was 28 and 63days, respectively, compared with 7days in untreated mice. Moreover, secondary CBA recipients given whole splenocytes or CD4(+) cells from primary danazol-treated (4mg/kg/day) CBA recipients 30days after transplantation had prolonged allograft survival (MSTs, 29 and 60days, respectively). Cell proliferation, interleukin (IL)-2 and interferon-γ were suppressed in danazol-treated mice, whereas IL-4 and IL-10 were up-regulated. Moreover, danazol directly suppressed allo-proliferation in a mixed leukocyte culture. Flow cytometry showed an increased CD4(+) CD25(+) Foxp3(+) cell population in splenocytes from danazol-treated mice. Danazol prolongs cardiac allograft survival and generates regulatory CD4(+) cells.

CD20 Expression in the Transplanted Kidney of Patients with Graft Loss and Transient Allograft Dysfunction

CD20 Expression in the Transplanted Kidney of Patients with Graft Loss and Transient Allograft Dysfunction This study aimed to explore the relationship between the infiltration of CD20+ B cells and the survival time of a renal allograft and to investigate the role of infiltrated B cells in the rejection of the renal allograft. A total of 40 patients with renal allograft loss due to refractory rejection and 20 patients with transient renal allograft dysfunction were recruited. Renal biopsy was done and CD20 expression was detected by immunohistochemistry. In addition, the survival time of the renal allograft was also obtained. The relationships between the CD20 expression and the survival time of the renal allograft and graft loss due to rejection were analyzed. The associations of gender, age and clinicopathogical types with the CD20 expression were also investigated. The proportion of patients positive for CD20 in the transplanted kidney was higher in patients receiving nephrectomy of the allograft due to rejection than in those with transient allograft dysfunction. The diffuse infiltration of CD20+ B cells was considered as positive staining. In 40 samples from patients with graft loss, 19 had diffuse infiltration of CD20+ B cells (47.5%). In 19 patients positive for CD20, hyperacute rejection was found in 1 patient, acute rejection in 5 and chronic rejection in 13. Statistical analysis showed the CD20 expression was not associated with the age and gender of donors and recipients, regimen for immunosuppressive treatment, cold/warm ischemia time and secondary transplantation. CD20+ B cell infiltration predicts a poor prognosis of patients with kidney transplantation and is one of the risk factors of graft loss.

Survival time of cardiac allografts prolonged by isogeneic BMT in mice

To find an approach to prolong the survival time of cardiac allografts in a BALB/c-to-C57/BL6 heterotopic heart transplant model and to try to figure out related chemokines and cytokines, isogeneic and allogeneic BM cells were obtained from pregnant C57/BL6 (♀C57/BL6 × ♂BALB/c) and regular BALB/c mice and injected to the half lethally irradiated C57/BL6 mice 1 day before heart transplantation. Recipients were treated with CsA or phosphate-buffered saline for 7 days. Isogeneic BMT (iBMT) from pregnant C57/BL6 mice was observed to significantly prolong the survival of BALB/c allografts and reduce the lymphocyte infiltration. Allogeneic BMT (aBMT) and iBMT both exhibited signicantly less T-cell proliferation reactivity and the similar degree of chimerism. There was no significant difference in these groups of IFN-γ and IL-4 production. The level of chemokine MIG (CXCL9) dramatically decreased in aBMT and iBMT groups compared with the control group. But there were no significant differences between aBMT and iBMT group. IL-17 and RORγ(t) (receptor-related orphan receptor) production were downregulated in iBMT recipients. These results indicate that iBMT can prolong the survival of cardiac allografts. IL-17 production downregulated in iBMT recipients. This means that iBMT may have important therapeutic implications.