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: The primary limitation to kidney transplantation is organ shortage. Recent progress in gene editing and immunosuppressive regimens has made xenotransplantation with porcine organs a possibility. However, evidence in pig-to-human xenotransplantation remains scarce, and antibody-mediated rejection (AMR) is a major obstacle to clinical applications of xenotransplantation. METHODS: We conducted a kidney xenotransplantation in a brain-dead human recipient using a porcine kidney with five gene edits (5GE) on March 25, 2024 at Xijing Hospital, China. Clinical-grade immunosuppressive regimens were employed, and the observation period lasted 22 days. We collected and analyzed the xenograft function, ultrasound findings, sequential protocol biopsies, and immune surveillance of the recipient during the observation. RESULTS: The combination of 5GE in the porcine kidney and clinical-grade immunosuppressive regimens prevented hyperacute rejection. The xenograft kidney underwent delayed graft function in the first week, but urine output increased later and the single xenograft kidney maintained electrolyte and pH homeostasis from postoperative day (POD) 12 to 19. We observed AMR at 24 h post-transplantation, due to the presence of pre-existing anti-porcine antibodies and cytotoxicity before transplantation; this AMR persisted throughout the observation period. Plasma exchange and intravenous immunoglobulin treatment mitigated the AMR. We observed activation of latent porcine cytomegalovirus toward the end of the study, which might have contributed to coagulation disorder in the recipient. CONCLUSIONS 5GE and clinical-grade immunosuppressive regimens were sufficient to prevent hyperacute rejection during pig-to-human kidney xenotransplantation. Pre-existing anti-porcine antibodies predisposed the xenograft to AMR. Plasma exchange and intravenous immunoglobulin were safe and effective in the treatment of AMR after kidney xenotransplantation.
Transplantation, Heterologous/methods* ; Kidney Transplantation/methods* ; Heterografts/pathology* ; Immunoglobulins, Intravenous/administration & dosage* ; Graft Survival/immunology* ; Humans ; Animals ; Sus scrofa ; Graft Rejection/prevention & control* ; Kidney/pathology* ; Gene Editing ; Species Specificity ; Immunosuppression Therapy/methods* ; Plasma Exchange ; Brain Death ; Biopsy ; Male ; Aged

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

OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

OBJECTIVE: To investigate the effectiveness of tibial transverse transport (TTT) in treating Wagner grade 3-4 type 2 diabetic foot ulcers and analyze dynamic changes in immunoglobulin levels. METHODS: The clinical data of 68 patients with Wagner grade 3-4 type 2 diabetic foot ulcers treated with TTT between May 2022 and September 2023 was retrospectively analyzed. The cohort included 49 males and 19 females, aged 44-91 years (mean, 67.3 years), with 40 Wagner grade 3 and 28 grade 4 ulcers. The duration of type 2 diabetes ranged from 5 to 23 years, with an average of 10 years. The number of wound healing cases, healing time, amputation cases, death cases, and complications were observed and recorded. Serum samples were collected at 6 key time points [1 day before TTT and 3 days, 7 days (the first day of upward transverse transfer), 14 days (the first day of downward transverse transfer), 21 days (the first day after the end of transfer), 36 days (the first day after the removal of the transfer device)], and the serum immunoglobulin levels were detected by flow cytometry including immunoglobulin G (IgG), IgA, IgM, IgE, complement C3 (C3), C4, immunoglobulin light chain κ (KAP), immunoglobulin light chain λ (LAM). RESULTS: All the 68 patients were followed up 6 months. Postoperative pin tract infection occurred in 3 cases and incision infection in 2 cases. Amputation occurred in 5 patients (7.4%) at 59-103 days after operation, and 8 patients (11.8%) died at 49-77 days after operation; the wounds of the remaining 55 patients (80.9%) healed in 48-135 days, with an average of 80 days. There was no recurrence of ulcer, peri-osteotomy fracture, or local skin necrosis during follow-up. The serum immunoglobulin levels of 55 patients with wound healing showed that the levels of IgG and IgM decreased significantly on the 3rd and 7th day after operation compared with those before operation ( P<0.05), and gradually returned to the levels before operation after 14 days, and reached the peak on the 36th day. IgA levels continued to decrease with time, and there were significant differences at all time points when compared with those before operation ( P<0.05). The level of IgE significantly decreased at 21 days after operation compared with that before operation ( P<0.05), while it was higher at other time points than that before operation, but the difference was not significant ( P>0.05). The level of C3 showed a clear treatment-related increase, which was significantly higher on the 7th, 14th, and 21st days after operation than that before operation ( P<0.05), and the peak appeared on the 14th day. The change trend of C4 level was basically synchronous with that of C3, but the amplitude was smaller, and the difference was significant at 7 and 14 days after operation compared with that before operation ( P<0.05). There was no significant difference in KAP/LAM between different time points before and after operation ( P>0.05). CONCLUSION TTT can accelerate wound healing, effectively treat diabetic foot ulcer, and reduce amputation rate, and has definite effectiveness. The potential mechanisms of TTT in the treatment of diabetic foot ulcers include the dynamic regulation of IgG, IgA, IgM, and IgE levels to balance the process of inflammation and repair, and the periodic increase of C3 and C4 levels may promote tissue cleaning, angiogenesis, and anti-infection defense.
Humans ; Male ; Female ; Middle Aged ; Aged ; Diabetic Foot/immunology* ; Wound Healing ; Adult ; Retrospective Studies ; Aged, 80 and over ; Treatment Outcome ; Tibia/transplantation* ; Diabetes Mellitus, Type 2/complications* ; Amputation, Surgical ; Immunoglobulins/blood* ; Immunoglobulin G/blood*

Severe combined immunodeficiency (SCID) represents a group of genetically heterogeneous disorders characterized by mutations that lead to profound defects in both humoral and cellular immunity. Transplacental maternal engraftment (TME) is a frequently observed complication in SCID. While most cases of SCID with TME exhibit no substantial impact on disease progression, a subset of patients may encounter diagnostic delays or therapeutic challenges due to TME interference. Furthermore, TME may predispose these individuals to graft-versus-host disease (GVHD) prior to hematopoietic stem cell transplantation, thereby increasing diagnostic complexity and treatment risks. This review systematically examines the etiology and clinical manifestations of SCID associated with TME, analyzes its implications for disease management, and evaluates current detection methodologies. The synthesized evidence provides a theoretical foundation for future research and offers potential insights into the clinical diagnosis and management of SCID associated with TME.
Humans ; Severe Combined Immunodeficiency/diagnosis* ; Pregnancy ; Female ; Hematopoietic Stem Cell Transplantation/adverse effects* ; Maternal-Fetal Exchange/immunology* ; Graft vs Host Disease/etiology* ; Animals ; Placenta/immunology*

OBJECTIVE: To investigate the correlation between the types and quantities of immune cells in the graft and early immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their influence on clinical prognosis. METHODS: The clinical data of 83 patients with hematological diseases who received allo-HSCT in Shanxi Bethune Hospital from September 2020 to June 2023 were retrospectively analyzed. The number of mononuclear cells (MNC), CD34⁺ cells and lymphocyte subsets (including CD3⁺T, CD3⁺CD4⁺T(Th), CD3⁺CD8⁺T(Ts), NK cells and B cells) infused into the recipients was counted, and the peripheral blood lymphocytes were detected before conditioning and on days 14, 30, 60 and 100 post-HSCT. RESULTS: Multivariate analysis showed that the number of MNC in the graft affected the recovery of CD4⁺T lymphocytes after HSCT, and the number of CD4⁺T lymphocytes in the graft affected the recovery of NK cells and B cells after HSCT. The patient age, donor sex, stem cell source, degree of HLA matching, use of ATG before HSCT, the occurrence of acute graft-versus-host disease (aGVHD) after HSCT, and viral infection all affect the early cellular immune reconstitution post-HSCT. The number of infused cells had no significant impact on the median engraftment time for neutrophils and platelets after HSCT. Patients with lower numbers of CD3⁺T, CD4⁺T and B cells in the graft were more prone to viral infection after HSCT. However, the cells in the graft had no significant effect on disease recurrence or mortality. CONCLUSION The recovery rate of lymphocyte count after allo-HSCT varies. The numbers of MNC and CD4⁺T cells in the graft may be related to the cellular immune reconstitution after HSCT, while the numbers of CD34⁺,CD3⁺T,CD8⁺T,NK and B cells have no significant effect on the cellular immune reconstruction. The numbers of CD3⁺T,CD4⁺T and B cells in the graft were negatively correlated with viral infection after HSCT, but the cellular components of the graft have no obvious influence on hematopoietic reconstitution, disease recurrence, death, recurrence-free survival(RFS) and overall survival(OS) after HSCT.
Humans ; Hematopoietic Stem Cell Transplantation ; Immune Reconstitution ; Transplantation, Homologous ; Retrospective Studies ; Graft vs Host Disease/immunology* ; Male ; Female ; Killer Cells, Natural/immunology* ; Adult ; Middle Aged ; B-Lymphocytes/immunology* ; Prognosis ; Lymphocyte Subsets/immunology* ; Adolescent

β-Thalassemia is an autosomal recessive genetic disorder caused by defects in the synthesis of the β-globin chains. Due to ineffective erythropoiesis and premature destruction of red blood cells, patients suffer from anemia, iron overload, organ damage, and impaired immune system. The impairment of the immune system is mainly due to the increase in the levels of reactive oxygen species (ROS) caused by iron overload, which induces DNA oxidation and leads to DNA damage. The treatment strategies for β-thalassemia mainly include gene therapy and allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, iron overload in patients cannot be eliminated promptly after gene therapy and transplantation. Therefore, even if allo-HSCT is performed, the patient's hematopoietic function may still be impaired. Iron chelators and antioxidants have been proven to effectively intervene in the immune damage caused by iron overload. This article aims to review the research progress on the effects of iron overload on the immune system in patients with β-thalassemia, and provides relevant treatment recommendations for immune recovery.
Humans ; beta-Thalassemia/immunology* ; Iron Overload/therapy* ; Immune System ; Hematopoietic Stem Cell Transplantation

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.
Adoptive Transfer ; Alveolar Epithelial Cells ; pathology ; Animals ; Apoptosis ; Betacoronavirus ; Body Fluids ; metabolism ; CD4-Positive T-Lymphocytes ; immunology ; Clinical Trials as Topic ; Coinfection ; prevention & control ; therapy ; Coronavirus Infections ; complications ; immunology ; Disease Models, Animal ; Endothelial Cells ; pathology ; Extracorporeal Membrane Oxygenation ; Genetic Therapy ; methods ; Genetic Vectors ; administration & dosage ; therapeutic use ; Humans ; Immunity, Innate ; Inflammation Mediators ; metabolism ; Lung ; pathology ; physiopathology ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stem Cells ; physiology ; Multiple Organ Failure ; etiology ; prevention & control ; Pandemics ; Pneumonia, Viral ; complications ; immunology ; Respiratory Distress Syndrome, Adult ; immunology ; pathology ; therapy ; Translational Medical Research

As a promising candidate seed cell type in regenerative medicine, mesenchymal stem cells (MSCs) have attracted considerable attention. The unique capacity of MSCs to exert a regulatory effect on immunity in an autologous/allergenic manner makes them an attractive therapeutic cell type for immune disorders. In this review, we discussed the current knowledge of and advances in MSCs, including its basic biological properties, i.e., multilineage differentiation, secretome, and immunomodulation. Specifically, on the basis of our previous work, we proposed three new concepts of MSCs, i.e., "subtotipotent stem cell" hypothesis, MSC system, and "Yin and Yang" balance of MSC regulation, which may bring new insights into our understanding of MSCs. Furthermore, we analyzed data from the Clinical Trials database ( http://clinicaltrials.gov ) on registered clinical trials using MSCs to treat a variety of immune diseases, such as graft-versus-host disease, systemic lupus erythematosus, and multiple sclerosis. In addition, we highlighted MSC clinical trials in China and discussed the challenges and future directions in the field of MSC clinical application.
Cell Differentiation ; Humans ; Immune System Diseases ; immunology ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells ; immunology ; physiology ; Randomized Controlled Trials as Topic ; Regenerative Medicine