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:Rejection remains the most important factor limiting the survival of transplanted kidneys.Although a pathological biopsy of the transplanted kidney is the gold standard for diagnosing rejection,its limitations prevent it from being used as a routine monitoring method.Recently,peripheral blood lymphocyte subpopulation testing has become an important means of assessing the body's immune system,however,its application value and strategy in the field of kidney transplantation need further exploration.Additionally,the development and utilization of routine test parameters are also important methods for exploring diagnostic strategies and predictive models for kidney transplant diseases.This study aims to explore the correlation between peripheral blood lymphocyte subpopulations and T cell-mediated rejection(TCMR)and antibody-mediated rejection(ABMR),as well as their diagnostic value,in conjunction with routine blood tests. Methods:A total of 154 kidney transplant recipients,who met the inclusion and exclusion criteria and were treated at the Second Xiangya Hospital of Central South University from January to December,2021,were selected as the study subjects.They were assigned into a stable group,a TCMR group,and an ABMR group,based on the occurrence and type of rejection.The basic and clinical data of these recipients were retrospectively analyzed and compared among the 3 groups.The transplant kidney function,routine blood tests,and peripheral blood lymphocyte subpopulation data of the TCMR group and the ABMR group before rejection treatment were compared with those of the stable group. Results:The stable,TCMR group,and ABMR group showed no statistically significant differences in immunosuppressive maintenance regimens or sources of transplanted kidneys(all P>0.05).However,the post-transplant duration was significantly longer in the ABMR group compared with the stable group(P<0.001)and the TCMR group(P<0.05).Regarding kidney function,serum creatinine levels in the ABMR group were higher than in the stable group and the TCMR group(both P<0.01),with the TCMR group also showing higher levels than the stable group(P<0.01).Both TCMR and ABMR groups had significantly higher blood urea nitrogen levels than the stable group(P<0.01),with no statistically significant difference between TCMR and ABMR groups(P>0.05).The estimated glomerular filtration rate(eGFR)was lower in both TCMR and ABMR groups compared with the stable group(both P<0.01).In routine blood tests,the ABMR group had lower hemoglobin,red blood cell count,and platelet count than the stable group(all P<0.05).The TCMR group had higher neutrophil percentage(P<0.05)and count(P<0.05)than the stable group,and the ABMR group had a higher neutrophil percentage than the stable group(P<0.05).The eosinophil percentage and count in the TCMR group were lower than in the stable and ABMR groups(all P<0.05).Both TCMR and ABMR groups had lower basophil percentage and count,as well as lower lymphocyte percentage and count,compared with the stable group(all P<0.05).There were no significant differences in monocyte percentage and count among the 3 groups(all P>0.05).In lymphocyte subpopulations,the TCMR and ABMR groups had lower counts of CD45+cells and T cells compared with the stable group(all P<0.05).The TCMR group also had lower counts of CD4+T cells,NK cells,and B cells than the stable group(all P<0.05).There were no significant differences in the T cell percentage,CD4+T cell percentage,CD8+T cell percentage and their counts,CD4+/CD8+T cell ratio,NK cell percentage,and B cell percentage among the stable,TCMR,and ABMR groups(all P>0.05). Conclusion:The occurrence of rejection leads to impaired transplant kidney function,accompanied by characteristic changes in some parameters of routine blood tests and peripheral blood lymphocyte subpopulations in kidney transplant recipients.The different characteristics of changes in some parameters of routine blood tests and peripheral blood lymphocyte subpopulations during TCMR and ABMR may help predict and diagnose rejection and differentiate between TCMR and ABMR.

Object To determine the amount of cichoric acid in Enchinacea purpurea and its preparation. Methods By the use of HPLC, mobile phase: 400 mmol/L ammonium acetate methanol (95∶ 5), flow rate: 1 mL/min, detection wavelength: 330 nm. Results The mean recovery of cichoric acid was 99 41%, RSD=3 23% (n=5). Conclusion The method can be applied in the determination of cichoric acid in E. purpurea extract and its preparation with satisfactory results.