BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*

BACKGROUND: Pre-transplant exposure to immune checkpoint inhibitors (ICIs) significantly increases the risk of allograft rejection after liver transplantation (LT); however, whether ICI-related rejection leads to increased graft loss remains controversial. Therefore, this study aimed to investigate the association between ICI-related allograft rejection and perioperative graft loss. METHODS: This was a retrospective analysis of adult liver transplant recipients with early biopsy-proven T-cell-mediated rejection (TCMR) at Liver Transplantation Center of Sun Yat-sen Memorial Hospital from June 2019 to September 2024. The pathological features, clinical characteristics, and perioperative graft survival were analyzed. RESULTS: Twenty-eight patients who underwent early TCMR between June 2019 and September 2024 were included. Based on pre-LT ICI exposure, recipients were categorized into ICI-related TCMR (irTCMR, n = 12) and conventional TCMR (cTCMR, n = 16) groups. Recipients with irTCMR had a higher median Banff rejection activity index (RAI) (6 vs . 5, P = 0.012) and more aggressive tissue damage and inflammation. Recipients with irTCMR showed higher proportion of treatment resistance, achieving a complete resolution rate of only 8/12 compared to 16/16 for cTCMR. Graft loss occurred in 5/12 of irTCMR recipients within 90 days after LT, with no graft loss in cTCMRs recipients. Cox analysis demonstrated that irTCMR with an ICI washout period of <30 days was an independent risk factor for perioperative graft loss (hazard ratio [HR], 6.540; 95% confidence interval [CI], 1.067-40.067, P = 0.042). CONCLUSION IrTCMR is associated with severe pathological features, increased resistance to treatment, and higher graft loss in adult liver transplant recipients.
Humans ; Liver Transplantation/adverse effects* ; Male ; Female ; Middle Aged ; Retrospective Studies ; Graft Rejection/immunology* ; Immune Checkpoint Inhibitors/therapeutic use* ; Adult ; T-Lymphocytes/drug effects* ; Graft Survival/immunology* ; Aged

BACKGROUNDImproving islet graft revascularization has become a crucial task for prolonging islet graft survival. Endothelial cells (ECs) are the basis of new microvessels in an isolated islet, and EC coating has been demonstrated to improve the vascularization and survival of an islet. However, the traditional method of EC coating of islets has low efficiency in vitro. This study was conducted to evaluate the effect of a polyglycolic acid (PGA) scaffold on the efficiency of islet coating by ECs and the angiogenesis in the coated islet graft.

METHODSA PGA fibrous scaffold was used for EC coating of islet culture and was evaluated for its efficiency of EC coating on islets and islet graft angiogenesis.

RESULTSIn in vitro experiments, we found that apoptosis index of ECs-coating islet in PGA group (27% ± 8%) was significantly lower than that in control group (83% ± 20%, P < 0.05) after 7 days culture. Stimulation index was significantly greater in the PGA group than in the control group at day 7 after ECs-coating (2.07 ± 0.31 vs. 1.80 ± 0.23, P < 0.05). vascular endothelial growth factor (VEGF) level in the PGA group was significantly higher than the coating in the control group after 7 days culture (52.10 ± 13.50 ng/ml vs. 16.30 ± 8.10 ng/ml, P < 0.05). Because of a tight, circumvallated, adhesive and three-dimensional growth microenvironment, islet cultured in a PGA scaffold had higher coating efficiency showing stronger staining intensity of enzyme than those in the control group after 14 days of culture following ECs-coating. For in vivo study, PGA scaffold significantly prolonged the average survival time of EC-coated islet graft after transplantation compared with control group (15.30 ± 5.60 days vs. 8.30 ± 2.45 days, P < 0.05). The angiogenesis and area of survived grafts were more in the PGA group compared with the control group by measuring the mean microvessel density (8.60 ± 1.21/mm2 vs. 5.20 ± 0.87/mm2, P < 0.05). In addition, expression of VEGF and tyrosin-protein kinase receptor (Tie-2) gene increased in PGA scaffold group than that in control group by real-time reverse transcription-polymerase chain reaction analysis.

CONCLUSIONSThese results demonstrate that the efficiency of EC coating of islets was successfully increased by culturing ECs on a PGA scaffold. This method enhances the function, survival, and vascularization of isolated islets in vitro and in vivo.

Animals ; Apoptosis ; drug effects ; Endothelial Cells ; drug effects ; Enzyme-Linked Immunosorbent Assay ; Graft Survival ; drug effects ; Insulin ; metabolism ; Islets of Langerhans ; drug effects ; Islets of Langerhans Transplantation ; methods ; Neovascularization, Physiologic ; drug effects ; Polyglycolic Acid ; chemistry ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Tissue Scaffolds ; chemistry

Objective: To investigate the effect of exogenous L-Arg on the survival of extended perforator flap in rats. Methods: Sixteen male Sprague Dawley rats were randomly divided into L-Arg group (n=8) and control group(n=8). The extended dorsal three-vascular territory perforator flaps were made in rats. L-Arg (400 mg·kg^-1·d^-1) was injected intraperitoneally in L-Arg group 1d before operation, immediately and 1-7 d after operation, while the same volume of saline was injected intraperitoneally in control group at the same time points. The appearance and distribution of blood vessels were observed, and the flap survival areas were measured 7d after operation. The tissue samples were harvested from choke zone Ⅱ for histological study and the expression of vascular endothelial growth factor (VEGF) was detected by immunohistochemistry and Western blot, respectively. Results: After 7d, the clearer vascular structure and more new vessels in choke zone Ⅱ were observed in L-Arg group. The survival rate of flap in L-Arg group was (88.42±4.19)%, which was significantly higher than that in control group[(76.52±5.37)%, t=3.707, P<0.01]. The microvessel density and caliber of choke zone Ⅱ in L-Arg group was (29.47±5.28)/mm² and(47.27±5.32)μm, which were significantly higher than those in control group (t=2.694 and 2.389, P<0.05 or P<0.01). The immunohistochemistry and Western blot showed that the expression of VEGF in choke zone Ⅱ of L-Arg group was significantly higher than that in control group (t=9.428 and -3.054,P<0.05 or P<0.01). Conclusion: Exogenous L-Arg can increase the survival rate of extended dorsal perforator skin flap through promoting vascularization and dilatation of vessels in choke zone Ⅱ in rats.
Animals ; Arginine ; pharmacology ; Graft Survival ; drug effects ; Male ; Neovascularization, Physiologic ; drug effects ; Perforator Flap ; blood supply ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Skin ; drug effects ; Vascular Endothelial Growth Factor A ; metabolism

BACKGROUND/AIMS: The relationship between patient survival and biopsy-proven acute rejection (BPAR) in liver transplant recipients with hepatitis C remains unclear. The aims of this study were to compare the characteristics of patients with and without BPAR and to identify risk factors for BPAR. METHODS: We retrospectively reviewed the records of 169 HCV-RNA-positive patients who underwent LT at three centers. RESULTS: BPAR occurred in 39 (23.1%) of the HCV-RNA-positive recipients after LT. The 1-, 3-, and 5-year survival rates were 92.1%, 90.3%, and 88.5%, respectively, in patients without BPAR, and 75.7%, 63.4%, and 58.9% in patients with BPAR (P<0.001). Multivariate analyses showed that BPAR was associated with the non-use of basiliximab and tacrolimus and the use of cyclosporin in LT recipients with HCV RNA-positive. CONCLUSION: The results of the present study suggest that the immunosuppression status of HCV-RNA-positive LT recipients should be carefully determined in order to prevent BPAR and to improve patient survival.
Antibodies, Monoclonal/therapeutic use ; Biopsy ; Cyclosporine/therapeutic use ; Drug Therapy, Combination ; Genotype ; Graft Rejection/mortality/*prevention & control ; Hepacivirus/genetics/isolation & purification ; Hepatitis C/drug therapy/*virology ; Humans ; Immunosuppressive Agents/*therapeutic use ; *Liver Transplantation/adverse effects ; Polymerase Chain Reaction ; RNA, Viral/blood ; Recombinant Fusion Proteins/therapeutic use ; Recurrence ; Retrospective Studies ; Survival Rate ; Tacrolimus/therapeutic use

The optimal immunosuppressive strategy for renal transplant recipients at high immunologic risk remains a topic of investigation. This prospective single arm pilot study was undertaken to evaluate the safety and efficacy of a combined tacrolimus and sirolimus regimen in recipients at immunological high risk and to compare outcomes with a contemporaneous control group received tacrolimus and mycophenolate mofetil. Patients that received a renal allograft between 2010 and 2011 at high risk (defined as panel reactive antibodies > 50%, 4 or more human leukocyte antigen mismatches, or retransplantation) were enrolled. All patients received basiliximab induction and corticosteroids. A total of 28 recipients treated with tacrolimus and sirolimus were enrolled in this study and 69 recipients were retrospectively reviewed as a control group. The sirolimus group showed a higher, but not statistically significant, incidence of biopsy proven acute rejection and a lower glomerular filtration rate than the control group. Furthermore, sirolimus group was associated with significant increases in BKV infection (P = 0.031), dyslipidemia (P = 0.004), and lymphocele (P = 0.020). The study was terminated prematurely due to a high incidence of adverse events. A de novo tacrolimus/sirolimus combination regimen may not be an ideal choice for recipients at high immunological risk.
Adult ; Drug Therapy, Combination/methods ; Female ; Graft Rejection/diagnosis/*etiology/*prevention & control ; Humans ; Immunocompromised Host ; Immunosuppressive Agents/administration & dosage/adverse effects ; Kidney Transplantation/*adverse effects ; Longitudinal Studies ; Male ; Middle Aged ; Sirolimus/*administration & dosage/adverse effects ; Survival Rate ; Tacrolimus/*administration & dosage/adverse effects ; Treatment Outcome

BACKGROUND/AIMS: BK virus-associated nephropathy (BKVAN) is an important cause of allograft dysfunction in kidney transplant recipients. It has an unfavorable clinical course, and no definite treatment guidelines have yet been established. Here, we report our center's experience with biopsy-proven BKVAN and investigate factors associated with its progression. METHODS: From January 2004 to April 2013, 25 patients with BKVAN were diagnosed by biopsy at Seoul St. Mary's Hospital. Of the 25 patients, 10 were deceaseddonor transplant recipients and 15 were living-donor transplant recipients. Three of the patients underwent retransplantation. The primary immunosuppressant used was tacrolimus in 17 patients and cyclosporine in eight patients. RESULTS: BKVAN was observed at a mean duration of 22.8 ± 29.1 months after transplantation. The mean serum creatinine level at biopsy was 2.2 ± 0.7 mg/dL. BKVAN occurred with acute rejection in eight patients (28%). Immunosuppression modification was performed in 21 patients (84%). Additionally, leflunomide and intravenous immunoglobulin were administered to 13 patients (52%) and two (8%), respectively. Allograft loss occurred in five patients (27.8%) during the follow- up period at 0.7, 17.1, 21.8, 39.8, and 41.5 months after the BKVAN diagnosis. Advanced stages of BKVAN, increased creatinine levels, and accompanying acute rejection at the time of BKVAN diagnosis increased the risk of allograft failure. CONCLUSIONS: The clinical outcomes in patients with biopsy-proven BKVAN were unfavorable in the present study, especially in patients with advanced-stage BKVAN, poor renal function, and acute allograft rejection.
Adult ; Allografts ; Antiviral Agents/therapeutic use ; BK Virus/*pathogenicity ; Biomarkers/blood ; Biopsy ; Creatinine/blood ; Disease Progression ; Female ; Graft Rejection/diagnosis/drug therapy/immunology/*virology ; Graft Survival ; Humans ; Immunocompromised Host ; Immunosuppressive Agents/adverse effects ; Kaplan-Meier Estimate ; Kidney Transplantation/*adverse effects ; Male ; Middle Aged ; Opportunistic Infections/diagnosis/drug therapy/immunology/*virology ; Polyomavirus Infections/diagnosis/drug therapy/immunology/*virology ; Republic of Korea ; Retrospective Studies ; Risk Factors ; Time Factors ; Treatment Outcome ; Tumor Virus Infections/diagnosis/drug therapy/immunology/*virology

OBJECTIVETo investigate the effects of ursolic acid on corneal graft rejection in a rat model of othotopic corneal allograft transplantation.

METHODSForty-eight recipient Wistar rats were divided into normal control group with saline treatment (group A), autograft group with saline treatment (group B), SD rat allograft group with saline treatment (group C), and SD rat allograft group with intraperitoneal ursolic acid (UA) treatment group (group D). The rats received saline or UC (20 mg·kg(-1)·d(-1)) treatment for 12 days following othotopic graft transplantation. The grafts were evaluated using the Larkin corneal rejection rating system, and the graft survival was assessed with Kaplan-Meier analysis. On day 14, the grafts were harvested for histological examination, Western blotting, and assessment of expressions of interlukin-2 (IL-2), interferon-γ (IFN-γ), nuclear transcription factor-κB (NF-κB) p65, vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1).

RESULTSThe allograft survival was significantly longer in group D than in group C (29.12±9.58 vs 9.67±2.16 days, P<0.05). UC treatment obviously reduced the expression levels of IL-2, IFN-γ, NF-κBp65, ICAM-1 and VEGF and increased inhibitory kappa B alpha (IκB-α) expression in the grafts, where no obvious inflammatory cell infiltration or corneal neovascularization was found.

CONCLUSIONAs a NF-κB inhibitor, ursolic acid can prevent corneal neovascularization and corneal allograft rejection to promote graft survival in rats following orthotopic corneal allograft transplantation.

Animals ; Cornea ; metabolism ; Corneal Neovascularization ; prevention & control ; Corneal Transplantation ; Graft Rejection ; prevention & control ; Graft Survival ; drug effects ; I-kappa B Proteins ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Interferon-gamma ; metabolism ; Kaplan-Meier Estimate ; NF-KappaB Inhibitor alpha ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Transcription Factor RelA ; metabolism ; Transplantation, Homologous ; Triterpenes ; pharmacology ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo investigate the synergistic effect of oleanolic acid (OA) and cyclosporine A (CsA) on the survival of renal allografts in rats.

METHODSRenal allograft transplantation was performed using BN rats as donors and LEW rats as recipients. Forty male LEW rats were randomized into 4 equal groups for interventions with DMSO-PBS (control), OA, CsA, or CsA+OA, starting from 1 day before transplantation. Serum creatinine levels were regularly examined, and the survival of rats were recorded. On day 5 after transplantation, CD4(+) and CD8(+) T-cell infiltration in the renal grafts was analyzed by immunohistochemistry; the concentrations of the proinflammatory cytokines (IL-1β, IFN-γ, IL-2, IL-4, and IL-17), anti-inflammatory cytokine IL-10 and chemokines (IP-10, MCP-1, MIP, and Mig) were analyzed with Luminex; the T-cell phenotypes (IFN-γ, IL-10, IL-4, and IL-17) were analyzed using ELISpot.

RESULTSIn OA+CsA group, renal allograft survival was markedly prolonged and CD4(+) and CD8(+) T cell infiltration in the graft significantly decreased as compared to other groups. A significant decrease in IL-2 was observed in OA group and OA+CsA group, especially the latter. Compared with the control group, all the 3 treated groups showed significantly decreased IL-1β, IP-10 and MCP-1, increased IL-10 levels, decreased percentages of T cells secreting IFN-γ, IL-4 and IL-17, and increased percentage of T cells secreting IL-10. The increments of serum IL-10 level and T cell percentage were more prominent in OA+CsA group than in the other two intervention groups.

CONCLUSIONSOA and CsA synergistically ameliorate renal graft rejection and inflammation and promote allograft survival and function in rats.

Animals ; Cyclosporine ; pharmacology ; Cytokines ; metabolism ; Drug Synergism ; Graft Survival ; Kidney ; drug effects ; Kidney Transplantation ; Male ; Oleanolic Acid ; pharmacology ; Rats ; Rats, Inbred BN ; Rats, Inbred Lew ; T-Lymphocytes ; cytology ; Transplantation, Homologous

Syl948 is a synthesized selective S1P1 agonist with novel structure. HTRF-IP1 test indicated that Syl948-P, the active form of Syl948 in vitro, has strong activity against S1P1 (EC50: 83 +/- 16 nmol x L(-1)), but its effect on S1P3 was very weak (EC50: 1 026 +/- 90 nmol x L(-1)). In SD rats, oral administration of Syl948 10 mg x kg(-1) significantly decreased the peripheral blood lymphocytes (PBL), with the maximal PBL inhibition rate of 63%, which was as similar as equal dose of fingolimod (FTY720). Oral administration of Syl948 10 mg x kg(-1) had no effect on heart rate of SD rats, which was better than FTY720. Daily oral administration with Syl948 (2 or 4 mg x kg(-1)) significantly prolonged the survival time of the allografts of skin slice on mice. In summary, the above results demonstrated that Syl948 has great selectivity in vitro and good activity in vivo, which indicated its potential use as an anti-rejection drug in skin transplantation.
Animals ; Fingolimod Hydrochloride ; Graft Survival ; drug effects ; Immunosuppressive Agents ; pharmacology ; Lymphocytes ; drug effects ; Mice ; Propylene Glycols ; pharmacology ; Rats ; Receptors, Lysosphingolipid ; agonists ; Skin Transplantation ; Sphingosine ; analogs & derivatives ; pharmacology ; Transplantation, Homologous