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 expression of heat shock protein 90 (HSP90) and the relationship between the expression of HSP90 and the clinicopathological features or prognosis in patients with lung adenocarcinoma (ADC).Methods:The paraffin specimens of 193 patients with lung adenocarcinoma and 53 non cancerous lung tissues (bullae and bronchiectasis) resected in Xiangya Second Hospital of Central South University were analyzed retrospectively. The expression of HSP90 in the tissue chip was detected by immunohistochemical streptavidin-perosidase (SP) method by high-throughput tissue chip, and the relationship between its expression level and the clinicopathological characteristics of patients was analyzed; Kaplan Meier survival curve was used to analyze the difference between different expression levels of HSP90 and the overall survival time of patients with lung adenocarcinoma.Results:The positive expression of HSP90 in lung adenocarcinoma was significantly higher than that in non cancerous lung tissue ( P<0.001), the expression level of HSP90 in clinical stage Ⅲ patients was higher than that in clinical stage Ⅰ-Ⅱ patients ( P=0.008), and the expression level of HSP90 in patients with lymph node metastasis was higher than that in patients without lymph node metastasis ( P=0.024); The 10-year survival rate of lung adenocarcinoma patients with high expression of HSP90 was significantly lower than that of patients with low expression of HSP90 ( P=0.001). The 10-year survival rate of lung ADC patients with stage Ⅲ and lymph node metastasis was significantly lower than that of patients with stage Ⅰ-Ⅱ and no lymph node metastasis ( P<0.05). Multiple Cox proportional hazard regression analysis further identified that lung ADC patients with overexpression of HSP90 had a poor prognosis ( P=0.010). Conclusions:HSP90 might play an important part in the development and progression of lung ADC and might act as a novel prognostic marker for patients with lung ADC.

Objective: The aim of this study was designed to certify the effects of substance P(SP) on thermo-gonohormonal neuron. Methods: We used the technique of extracellular microelectrode recording, and examined the effects of intravenously injections of SP on electroactiveties of thermo-gonohormonal neurons in PO/AH of rats. Results: Total of 9 warm-estradiol sensitive and 4 cold-estradiol sensitive neurons were recorded in PO/AH, where estradiol excited electroactivities of the warm-estradiol sensitive neurons but inhibited those of the cold-estradiol sensitive ones. While SP reversed the effects of estradiol bezonate on the above mentioned neurons. Conclusion: From our results and related data we may draw conclusions that the thermoregulatory effects of SP may be functioned via hermo-gonohormonal neuron.