Organ transplantation is an effective alternative treatment for patients with end-stage organ failure. However, the shortage of donor organs has limited the widespread application of clinical transplantation. In recent years, breakthroughs in CRISPR-Cas9 gene editing technology have overcome the barrier of hyperacute rejection in xenotransplantation, offering a potential solution to the organ shortage crisis. Rejection remains a critical factor affecting graft survival. Antigen-presenting cells play a vital role in the initiation and progression of rejection and immune regulation in xenotransplantation. Therefore, in-depth investigation into the role of antigen-presenting cells in xenotransplantation is of great significance. This article summarizes the roles and therapeutic strategies of professional antigen-presenting cells, including macrophages, dendritic cells and B cells in xenotransplantation, aiming to provide insights for future research on immune regulation mechanisms in this field.

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*

Objective To investigate the antigen presentation characteristics of dendritic cells(DC)and B cells in cardiac grafts.Methods The heart of BALB/c mice was transplanted into the abdominal cavity of C57BL/6J mice.CD45+cells in the heart graft were extracted and sorted by flow cytometry at postoperative 5 d,and single cell RNA sequencing was performed.Taking DC and B cell subsets in cardiac grafts as the main study cells,the changing trend,antigen presenting ability and intercellular communication with T cells after heart transplantation were analyzed by bioinformatics analysis and flow cytometry.Gene ontology(GO)function enrichment difference analysis was adopted to prove the specific function and the reliability annotation of cell subsets.Results Germinal center-like B cell(GC-L B)was the B cell subset with the largest increase in quantity during the acute rejection phase,accounting for 87％.Classical DC(cDC)2 was the only DC subset with a significant increase in quantity during acute rejection of heart transplantation,accounting for 44％of DC subset,and it occupied the highest communication intensity with T cells after heart transplantation.Mononucleated DC(moDC)and memory B cell(MBC)were the main transmitters of T cell input signals in non-transplanted hearts,whereas transformed into cDC2 and GC-L B during the acute rejection phase.Among them,MBC and GC-L B were the main sources of T cell input signals in non-transplanted hearts and heart grafts.Conclusions Compared with DC,B cells occupy a higher number and weight in the intercellular communication with T cells in non-transplanted hearts and heart grafts,prompting that the antigen presenting activity of B cells is more active and stronger than DC in the early stage of acute rejection of heart transplantation.

Background::Homoharringtonine (HHT) is an effective anti-inflammatory, anti-viral, and anti-tumor protein synthesis inhibitor that has been applied clinically. Here, we explored the therapeutic effects of HHT in a mouse heart transplant model.Methods::Healthy C57BL/6 mice were used to observe the toxicity of HHT in the liver, kidney, and hematology. A mouse heart transplantation model was constructed, and the potential mechanism of HHT prolonging allograft survival was evaluated using Kaplan–Meier analysis, immunostaining, and bulk RNA sequencing analysis. The HHT-T cell crosstalk was modeled ex vivo to further verify the molecular mechanism of HHT-induced regulatory T cells (Tregs) differentiation. Results::HHT inhibited the activation and proliferation of T cells and promoted their apoptosis ex vivo. Treatment of 0.5 mg/kg HHT for 10 days significantly prolonged the mean graft survival time of the allografts from 7 days to 48 days ( P <0.001) without non-immune toxicity. The allografts had long-term survival after continuous HHT treatment for 28 days. HHT significantly reduced lymphocyte infiltration in the graft, and interferon-γ-secreting CD4 + and CD8 + T cells in the spleen ( P <0.01). HHT significantly increased the number of peripheral Tregs (about 20%, P <0.001) and serum interleukin (IL)-10 levels. HHT downregulated the expression of T cell receptor (TCR) signaling pathway-related genes ( CD4, H2-Eb1, TRAT1, and CD74) and upregulated the expression of IL-10 and transforming growth factor (TGF) -β pathway-related genes and Treg signature genes ( CTLA4, Foxp3, CD74, and ICOS). HHT increased CD4 + Foxp3 + cells and Foxp3 expression ex vivo, and it enhanced the inhibitory function of inducible Tregs. Conclusions::HHT promotes Treg cell differentiation and enhances Treg suppressive function by attenuating the TCR signaling pathway and upregulating the expression of Treg signature genes and IL-10 levels, thereby promoting mouse heart allograft acceptance. These findings may have therapeutic implications for organ transplant recipients, particularly those with viral infections and malignancies, which require a more suitable anti-rejection medication.

Triggering receptor expressed on myeloid cells-1 (TREM-1) is a member of the immunoglobulin superfamily. As an amplifier of the inflammatory response, TREM-1 is mainly involved in the production of inflammatory mediators and the regulation of cell survival. TREM-1 has been studied in infectious diseases and more recently in non-infectious disorders. More and more studies have shown that TREM-1 plays an important pathogenic role in kidney diseases. There is evidence that TREM-1 can not only be used as a biomarker for diagnosis of disease but also as a potential therapeutic target to guide the development of novel therapeutic agents for kidney disease. This review summarized molecular biology of TREM-1 and its signaling pathways as well as immune response in the progress of acute kidney injury, renal fibrosis, diabetic nephropathy, immune nephropathy, and renal cell carcinoma.

Objective To investigate the effects of a 45％high-fat diet(HFD)with isocaloric intake on energy metabolism and endurance exercise capacity in SD rats.Methods Twenty-four male SD rats were randomly divided into normal chow diet group(CON),HFD group,normal chow diet+exercise training group(CONT),and HFD+exercise training group(HFDT).The CON and CONT groups received normal chow diet,while the HFD and HFDT groups received a 45％high-fat diet with isocaloric intake.The HFDT and CONT groups underwent an endurance training of moderate-intensity running for 6 weeks.Body weight,fat mass,and lean mass were measured weekly.Energy expenditure and basal metabolic rate during rest and exercise states were measured using Pheno Master/Calo Treadmill system.Blood glucose,lipids,and creatine kinase levels were detected after the exhaustion test.Results In 6 weeks after intervention,the endurance exercise capacity was significantly enhanced in the HFDT group than the CONT group(P＜0.05).There were no obvious differences in body weight and body composition among the groups under isoenergetic feeding conditions.At rest,no statistical differences were observed in total energy expenditure and basal metabolic rate among the groups.However,prior to the 4th week,the CON group primarily metabolized carbohydrates while the HFD group primarily metabolized fats.But the carbohydrate metabolism was decreased and then increased,and the substrate metabolism rates eventually reached similar levels between the 2 groups on the 5th to 6th week.The HFDT group primarily metabolized fats while the CONT group primarily metabolized carbohydrates,with significant differences persisting after 6 weeks of training(P＜0.05).HFD led to elevated levels of serum cholesterol,triglycerides(TG),and high-density lipoprotein cholesterol(HDL-C),but,endurance training resulted in decreased lipid levels in the HFDT group,accompanied by an increase inβ-hydroxybutyrate(βHB)level(P＜0.05).Isoenergetic diets had no significant differences in their effects on liver and kidney function or muscle damage indicators.Conclusion An isoenergetic HFD can improve fat utilization ability and extend endurance exercise time in rats without altering body composition or affecting liver and kidney function.

Objective To develop a nutritional formula on enhancing the endurance of heavy load exercise,and evaluate its efficacy comprehensively.Methods Sixty C57BL/6J male mice were randomly divided into control group(CON group)and low-,medium-and high-dose nutritional formula groups(LDF,MDF and HDF groups),with 15 mice in each group.Each group received intervention with nutritional formula at corresponding dose for 2 weeks,and underwent adaptive training and heavy load exercise in the 1 st and 2nd weeks,respectively.Exhaustion exercise time,skeletal muscle antioxidant indicators(SOD,MDA,PC and GSH),fatigue related indicators(serum URA,LDH and LA),muscle glycogen,and serum exercise injury related indicators(ALT,AST,CK and CK-MB)were measured and detected in the mice,and comprehensive evaluation was conducted according to relevant evaluation standards.Results The LDF group,MDF group and HDF group had significantly prolonged running exhaustion time than the CON group(P＜0.05),with the HDF group showing the greatest improvement(P＜0.05).Compared with the CON group,the activities of SOD and GSH in the skeletal muscles were significantly increased(P＜0.05),while the levels of MDA and PC in skeletal muscles were obviously decreased in the 3 doses of nutritional formula groups(P＜0.05).PAS staining of the skeletal muscles displayed that the glycogen content was significantly increased in the MDF group and the HDF group than the CON group(P＜0.05),and the highest increase was observed in the HDF group(P＜0.05).Biochemical test revealed that the levels of LDH,LA,ALT,AST,CK,and CK-MB were remarkably lower in the 3 doses of nutritional formula groups than the CON group(P＜0.05).Conclusion The nutritional formula can significantly improve the endurance and skeletal muscle antioxidant capacity in mice under heavy load exercise,and has anti-fatigue and-injury protection effects.This nutritional formula can be used to support physical fitness during heavy load endurance exercise.

Objective:The mouse kidney transplantation model presents challenges in terms of surgical difficulty and low success rate,making it difficult to master.This study aims to provide a crucial model for transplantation immunology research by modifying and developing novel techniques for mouse kidney transplantation. Methods:A total of 57 pairs of mice were used to establish and compare the modified and innovative surgical techniques for mouse kidney transplantation.Three different surgical models were established,including the abdominal suture technique for orthotopic kidney transplantation,the abdominal cuff technique for orthotopic kidney transplantation,and the cervical cuff technique for ectopic kidney transplantation.BALB/c or C57BL/6 male mice,aged 8 to 12 weeks and weighed 20 to 25 g with specified pathogen free-grade were served as the donor mice or the recipient mice.The surgical technique characteristics,key surgical times,complications,and pathological examination in the early postoperative period were summarized and compared. Results:Three different surgical models of mouse kidney transplantation were successfully established.The comparison of warm ischemic time for the 3 groups of mice showed no statistical significance(P=0.510 4).The abdominal suture group had the shortest total operation time of the donor compared with the abdominal cuff group and the cervical cuff group[(18.3±3.6)min vs(26.2±4.7)min and(22.8±2.5)min;both P<0.000 1].There was a significant difference in cold ischemia time among the 3 groups(all P<0.000 1),with(60.8±4.1)min in the cervical cuff group,(43.3±5.0)min in the abdominal suture group,and(88.8±6.7)min in the abdominal cuff group.Due to different anastomosis methods,the cervical cuff group had the shortest time[(17.6±2.7)min],whereas the abdominal cuff group had the longest time[(38.8±5.4)min].The total operation time for the recipients showed significant differences(P<0.000 1),with the abdominal suture group having the shortest time[(44.0±6.9)min],followed by the cervical cuff group[(64.1±5.2)min],and the abdominal cuff group[(80.0±6.0)min]being the longest.In the 32 mice of the abdominal suture group,there were 6 with intraoperative bleeding,including 1 arterial intimal injury bleeding and 5 with bleeding after vessel opening.Six mice had ureteral complications,including ureteral bladder anastomotic stenosis,necrosis,and renal pelvis dilation.Two mice had postoperative abdominal infections.In the abdominal cuff group,there was no intraoperative bleeding,but 6 mice showed mild arterial stenosis and 5 showed venous stenosis,4 arterial injury,4 arterial thrombosis,and 2 ureteral complications.No postoperative infections occurred in the mice.In the cervical cuff group,no intraoperative bleeding,arterial intimal injury,arterial/venous stenosis,or thrombosis were found in 13 mice.Five mice had ureteral complications,including ureteral necrosis and infection,which were the main complications in the cervical cuff group.The renal function in mice of the 3 groups remained stable 7 days after surgery.Hematoxylin and eosin staining and periodic acid-Schiff staining showed no significant differences in terms of acute rejection among the 3 surgical methods(all P>0.05). Conclusion:All 3 surgical methods are able to successfully establish mouse kidney transplantation models,with no significant differences observed in the short-term graft survival and acute rejection.The modified abdominal suture technique and abdominal cuff technique have their respective advantages in research applications.The novel cervical cuff technique for ectopic kidney transplantation model is relatively simple to be prepared and causes less trauma to the mice,providing more options for studies involving xenotransplantation,secondary transplantation,and local lymphatic drainage.However,the difficulty in harvesting the donor kidney and the high incidence of ureteral infections need further validation in long-term survival.This study holds important reference value for choosing the type of mouse kidney transplantation model for different research needs.

Objective: To explore the associations between blood pressure trajectories during pregnancy and risk of future pre-eclampsia in a large cohort enrolling pregnant women at gestational age of ~12 weeks from community hospitals in Tianjin. Latent class growth modeling (LCGM) was used to model the blood pressure trajectories. Methods: This was a large prospective cohort study. The study enrolled pregnant women of ~12 weeks of gestation in 19 community hospitals in Tianjin from November 1, 2016 to May 30, 2018. We obtained related information during 5 antepartum examinations before gestational week 28, i.e., week 12, week 16, week 20, week 24 and week 28. LCGM was used to model longitudinal systolic (SBP) and diastolic blood pressure (DBP) trajectories. For the association study, the predictors were set as SBP and DBP trajectory membership (built separately), the outcome was defined as the occurrence of preeclampsia after 28 weeks of gestation. Results: A total of 5 809 cases with known pregnant outcomes were documented. After excluding 249 cases per exclusion criteria, 5 560 cases with singleton pregnancy were included for final analysis. There were 128 cases preeclampsia and 106 cases gestational hypertension in this cohort. Univariate logistic regression and multivariate logistic regression showed the higher baseline SBP level and DBP level were related with increased risk of preeclampsia. Four distinctive SBP trajectories and DBP trajectories from 12 weeks to 28 weeks of gestation were identified by LCGM. After controlling for potential confounders (baseline BMI, being primipara or not, white blood cell counts, hemoglobin level, platelet counts and alanine aminotransferase level), the OR for SBP latent classification trajectory_ 4 was 4.023 (95%CI: 2.368 to 6.835, P<0.001), and the OR for SBP latent classification trajectory_3 was 1.854 (95%CI: 1.223 to 2.811, P=0.004). Logistic regression showed that: using the DBP latent classification trajectory_1 as the reference group, the OR for DBP latent classification trajectory_4 was 4.100 (95%CI: 2.571 to 6.538, P<0.001), and 2.632 (95%CI: 1.570 to 4.414, P<0.001) for DBP latent classification trajectory_2. After controlling for potential confounders (baseline BMI, being primipara or not, white blood cell counts, hemoglobin level, platelet counts and alanine aminotransferase level), the OR for DBP_traj_4 was 2.527 (95%CI: 1.534 to 4.162, P<0.001), and the OR for DBP_traj_3 was 1.297 (95%CI: 0.790 to 2.128, P=0.303), and 2.238 (95%CI: 1.328 to 3.772, P=0.002) for DBP_traj_2. Therefore, BP trajectories from 12 weeks to 28 weeks identified by LCGM served as novel risk factors that independently associated with the occurrence of preeclampsia. Receiver operating characteristic (ROC) curve analysis showed incremental diagnostic performance by combing baseline blood pressure levels with blood pressure trajectories. Conclusion: By applying LCGM, we for the first time identified distinctive BP trajectories from gestational week 12 to 28, which can independently predict the development of preeclampsia after 28 weeks of gestation.
Female ; Humans ; Pregnancy ; Infant ; Blood Pressure ; Pre-Eclampsia/diagnosis* ; Prospective Studies ; Gestational Age ; Alanine Transaminase ; Hemoglobins

Objective:To explore the clinical efficacy of adult donor dual kidney transplantation.Methods:Retrospective analysis of case data of 13 adult donor kidney dual kidney transplantation (DKT) performed in the The Second Xiangya Hospital of Central South University from September 2016 to December 2020. For 13 donors, the average age and BMI were (53.5±12.4)years and (24.3±2.8) kg/m 2, respectively. Their mean Serum creatinine (SCr) at admission and before procurement was (132.9±54.1)and (228.7±112.4)μmol/L, respectively. 3 of them had diabetes mellitus history, and 8 had hypertension history. 11 met the United Network for Organ Sharing (UNOS) DKT criteria and 6 met Remuzzi score DKT criteria. For 13 recipients, the average age and BMI were (39.3±8.9)years and (20.2±2.4)kg/m 2, respectively. All of them received ABO blood type-matched kidney transplants. 2 of them had their grafts transplanted in the bilateral iliac. In 12 cases, the grafts filled rapidly and urinated immediately when opening blood flow. In 1 case, the grafts were dark in color and vascular showed weak pulsation after opening blood flow. The time to recovery of perioperative graft function (from the day of surgery to the natural reduction of SCr to the normal range 44-133μmol/L), the occurrence of delayed graft function (DGF), acute rejection (AR), ureteral and surgical incision complications, as well as the recipients’ final follow-up SCr, eGFR, urinary protein, and grafts outcome were observed. Risk factors affecting outcomes were assessed by univariate logistic regression analysis. Results:The SCr dropped to the normal range at discharge in 10 recipients, and the average recovery time was (13.8±13.0) days. In other 3 cases SCr at discharge were 300.0, 149.0, 152.5μmol/L. 4 cases had DGF, 4 had AR, 1 experienced urinary fistula, and 1 experienced incisional dehiscence, which were treated with anti-rejection, J-tube implantation, continuous catheterization to maintain bladder void, secondary suturing, respectively. The follow-up time ranged from 4 to 54 months, with a median of 28(15.5, 31.0) months. At the final follow-up time, 10 cases had good graft function, 2 suffered impaired kidney function, and 1 experienced graft failure. The average SCr and eGFR except for graft failure patient were (144.2±101.3)μmol/L and (52.9±21.2)ml/min, respectively. 4 had positive urine protein. Univariate logistic regression analysis showed that donor age, BMI, history of diabetes mellitus and hypertension, and SCr were not significantly correlated with recipients’ DGF and graft impairment ( P>0.05), and due to the small sample size, multifactorial logistic regression analysis was not performed. Conclusion:The short to medium-term effects of adult donor DKT coule be safe and feasible.