Eight new spiropolycyclic polyprenylated acylphloroglucinols, named spiropatuols A-H (1-8), were isolated from the traditional Chinese medicinal herb Hypericum patulum. The structures of compounds 1-8 were characterized using spectroscopic analysis, calculations of nuclear magnetic resonance chemical shifts with DP4+ probability analysis, and electronic circular dichroism calculations. Compounds 2-4 exhibited immunosuppressive activities in an in vitro model of concanavalin A (Con A)-induced murine splenocyte proliferation, with half-maximal inhibitory concentrations of 50, 70, and 200 nM, respectively. Furthermore, in a Con A-challenged autoimmune hepatitis mouse model, compound 2 inhibited Con A-induced activation of mice splenic lymphocytes and alleviated Con A-induced acute liver injury. These results indicate that the metabolites isolated in this study can inform the design of novel immunosuppressors for treating autoimmune hepatitis.

Abstract Liver inflammation is a key driver of nonalcoholic fatty liver disease (NAFLD) and its progressive subtype, nonalcoholic steatohepatitis (NASH). Macrophages, as central players in the innate immune response, are crucial to disease pathogenesis; however, the upstream events that initiate their activation remain poorly defined. Here, we employed a cell-based chimeric receptor screening system and identified CD1d as a surface ligand for PIRA2. We subsequently demonstrated that CD1d stimulation activated macrophages both in vitro and in vivo. Co-immunoprecipitation assays further confirmed a direct interaction between CD1d and PIRA2. Using Pira2-deficient (Pira2 −/− ) mice, we observed significantly reduced hepatic inflammation and lipid accumulation compared to wild-type controls. Importantly, macrophage-specific Pira2 conditional knockout mice similarly exhibited reduced macrophage activation and inflammatory cytokine production in vivo, confirming a macrophage-intrinsic role of PIRA2. Mechanistically, CD1d-PIRA2 interaction involves the α1 and α2 domains of CD1d and the D1 and D2 domains of PIRA2, leading to FcRγ ITAM tyrosine phosphorylation and downstream inflammatory signaling-events that are impaired in Pira2 −/− macrophages. Additionally, CD1d and LILRA2 protein levels were elevated in NAFLD patients, and CD1d stimulation induced proinflammatory cytokine expression in human macrophages, which was attenuated by LILRA2 blockade. A recombinant LILRA2/Fc fusion protein effectively blocked CD1d-induced inflammatory gene expression in human macrophages, highlighting its potential as a therapeutic strategy for NAFLD. Collectively, our findings identify CD1d as a functional ligand of PIRA2 that promotes macrophage activation and inflammation, contributing to inflammatory progression in NAFLD.

Eight new brefeldins, penifeldins A–H (1–8), and two known analogues, brefeldins A (9) and C (10), were isolated from the culture of the endophytic fungus Penicillium soli TJ507 collected from Hypericum perforatum, through a Mass Spectrometry Query Language (MassQL)-enhanced molecular networking strategy. The structures of these isolates were confirmed through spectral experiments, single crystal X-ray diffraction analysis and electronic circular dichroism calculations. In bioactivity assays, compound 9 demonstrated significant immunosuppressive activity in concanavalin A (Con A)-induced T lymphocyte proliferation, with the IC50 value of 0.78 ± 0.05 μM. More significantly, pretreatment with 9 in the Con A treated autoimmune hepatitis mice obviously improved liver injury, as evidenced by a marked amelioration of hepatic histopathological alterations, including necrosis and inflammatory infiltration, that proved 9 may serve as a potential lead compound for the treatment of autoimmune hepatitis.

Suppressing immune responses promotes allograft survival but also favours tumour progression and recurrence. Selectively suppressing allograft rejection while maintaining or even enhancing antitumor immunity is challenging. Here, we show loss of allograft-related rejection in mice deficient in Setdb1, an H3K9 methyltransferase, while antitumor immunity remains intact. RNA sequencing shows that Setdb1-deficiency does not affect T-cell activation or cytokine production but induces an increase in Treg-cell-associated gene expression. Depletion of Treg cells impairs graft acceptance in Setdb1-deficient mice, indicating that the Treg cells promote allograft survival. Surprisingly, Treg cell-specific Setdb1 deficiency does not prolong allograft survival, suggesting that Setdb1 may function prior to Foxp3 induction. Using single-cell RNA sequencing, we find that Setdb1 deficiency induces a new Treg population in the thymus. This subset of Treg cells expresses less IL-1R2 and IL-18R1. Mechanistically, during Treg cell induction, Setdb1 is recruited by transcription factor ATF and altered histone methylation. Our data thus define Setdb1 in T cells as a hub for Treg cell differentiation, in the absence of which suppressing allograft rejection is uncoupled from maintaining antitumor immunity.

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Hepatic ischemia-reperfusion injury (HIRI) is a common and inevitable complication of liver surgery that induces severe hepatic functional impairment and can trigger multiple organ dysfunction syndrome. From the rice culture of Paraconiothyrium sp. H-B collected from Hypericum wilsonii N. Robson, 11 novel bergamotane-type sesquiterpenoids, paramotanes A-K (1-11), along with three known congeners, were obtained by the guidance of the DeepSAT system (a neural network-based tool for HSQC spectrum analysis). The structures and configurations of these compounds were confirmed via spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Notably, compound 1 is the first reported 10-nor-bergamotane sesquiterpenoid. The pharmacodynamics assays demonstrated that compound 12 exhibits hepatoprotective effects and can ameliorate liver function in HIRI mice, positioning it as a promising leading compound for developing novel hepatoprotective agents for the clinical management of HIRI.

BACKGROUND:Induction therapy is necessary to prevent acute rejection of xenografts. At present, basiliximab is rarely used as an induction therapy agent in solid organ xenotransplantation. In this study, we conducted in vitro experiments to investigate the inhibitory effect of basiliximab on human anti-porcine xenogeneic immune responses. METHODS:A xenogeneic and allogeneic mixed lymphocyte reaction (MLR) system was established using peripheral blood mononuclear cells (PBMCs) isolated from GTKO/CMAHKO/β4GalNT2KO (triple-knockout, TKO) pigs or humans as stimulator cells, and another group of human PBMCs as responder cells. Various concentrations of basiliximab were added to the MLR systems as interventions. The inhibitory effects of basiliximab on the proliferation and cytokine production of human T cells were compared. RESULTS:PBMCs from TKO pigs or humans stimulated significant proliferation of human T cells. Basiliximab inhibited human CD4+ and CD8+ T-cell proliferation in a typical dose-dependent manner in both xenogeneic and allogeneic MLR. When the concentration of basiliximab reached 1 µg/mL, the proliferation rates of xenoreactive CD4+ and CD8+ T cells decreased by more than 72%, which was quite similar to the effect in the allogeneic MLR. The inhibitory effects of basiliximab on xenogeneic T-cell responses were further confirmed by the detection of CD25 expression and supernatant cytokines (IFN-γ, TNF-α), and the results were similar to those for allogeneic MLR. CONCLUSIONS:Basiliximab can significantly reduce the xenoreactivity of human lymphocytes against TKO pig cells, and its inhibitory effect is no less than that on allogeneic T cell responses, supporting its potential as induction therapy in xenotransplantation.

Chronic allograft rejection is mainly mediated by indirect recognition. Dendritic cells (DCs), as the major antigen-presenting cells in indirect recognition, exhibit an enhanced antigen-presenting ability in chronic rejection, but the specific mechanism is still unclear. Here, we found that pretreatment with high mobility group box-1 protein (HMGB1) in vivo can induce trained immunity in DCs. These trained DCs demonstrated an enhanced ability to present alloantigen, accelerating allograft rejection in a CTLA4-Ig-induced chronic rejection model by upregulating the expression of major histocompatibility complex (MHC)-II and class II major histocompatibility complex transactivator (CIITA) molecules. Mechanistically, we found that HMGB1 promoted the formation of superenhancers (SEs) of CIITA, epigenetically reprogramming DCs and promoting trained immunity. The SE inhibitor JQ1 reduced the expression of CIITA and MHC-II in DCs, thereby delaying the occurrence of chronic rejection. Interestingly, we identified HMGB1 as a specific inducer of SE formation in a newly named SEa region of CIITA. Targeted knockout of the CIITA's SEa region inhibited HMGB1-induced trained immunity in DCs. Taken together, our data confirm that HMGB1 can induce the formation of the SEs of CIITA, promote trained immunity in DCs, and accelerate allograft rejection, thus offering a new potential target for the treatment of chronic rejection.

Mucosal-associated invariant T (MAIT) cells exert multifaceted effects such as anti-microbial activity, tissue repair, and pro-fibrotic effects across various disease settings. Nonetheless, their role in liver injury and hemostasis remains debated. Here, we report a significant depletion and functional dysregulation of MAIT cells, which is associated with disease severity and accumulated bile acids in HBV-infected patients with varying degree of liver injury. Liver transplantation facilitates a gradual recovery of recipient-originated MAIT cells. Transcriptome analysis reveals enhanced MAIT cell activation, while TCR mining demonstrates clonotype overlap between circulating and hepatic MAIT cells during significant liver injury. TCR-activated MAIT cells from transplant recipients display higher protective capacity but reduced pathological potential than those from liver failure patients. Compromised recovery of MAIT cells is linked to post-transplantation complications, whereas prompt recovery predicates favorable clinical outcome. These findings underscore the intricate interplay between MAIT cells and the hepatic environment, highlighting MAIT cells as potential therapeutic targets and sensitive predictors for clinical outcome in individuals experiencing liver failure and post liver transplantation.

Hepatic ischemia/reperfusion injury(IRI)remains a critical complication contributing to graft dysfunction following liver surgery.As part of an ongoing search for hepatoprotective natural products,five previously unreported homoadamantane-type polycyclic polyprenylated acyl-phloroglucinols(PPAPs),named hyperhomanoons A-E(1-5),and one known analog,hyper-sampsone O(6),were isolated from Hypericum patulum.Among these,compound 6 demon-strated potent protective effects against CoCl2-induced hypoxic injury in hepatocytes.Further-more,in a murine model of hepatic IRI induced by vascular occlusion,pretreatment with 6 markedly alleviated liver damage and reduced hepatocyte apoptosis.This study is the first to identify PPAPs as promising scaffolds for the development of therapeutic agents targeting hepatic IRI,underscoring their potential as lead compounds in drug discovery efforts for ischemic liver diseases.

Tissue fibrosis is commonly associated with organ malfunction and is strongly associated with the development of chronic rejection, cardiovascular diseases, and other chronic diseases. Fibrosis also contributes to immune exclusion in tumor tissues. Targeting fibrosis might be a strategy for prolonging allograft survival while suppressing cancer development. Here, single-cell transcriptomes of human and mouse heart allografts showed that macrophages accumulated in grafts with fibrosis were reprogrammed via histone methylation regulated by Setdb1, an H3K9 methyltransferase. Myeloid-specific deletion of Setdb1 prolonged heart allograft survival but reversed immune exclusion in tumor tissues. Interestingly, myeloid-specific Setdb1-knockout led to lower fibrosis in heart allografts and tumor tissues in mice. Our single-cell sequencing data showed that Setdb1 ablation impaired Fn1+ and SPP1+ profibrogenic macrophage reprogramming. Mechanistically, Fn1, which was induced by the CCR2-Creb/Setdb1 axis, upregulated the expression of genes related to fibrosis in fibroblasts and macrophages via ITGA5 and PIRA receptors. Blocking the interaction between FN1 and these receptors inhibited fibrosis in allograft and tumor tissues. Our results reveal a target, histone methylation in macrophages, for the treatment of fibrosis-related disease.

Liver inflammation is a key driver of nonalcoholic fatty liver disease (NAFLD) and its progressive subtype, nonalcoholic steatohepatitis (NASH). Macrophages, as central players in the innate immune response, are crucial to disease pathogenesis; however, the upstream events that initiate their activation remain poorly defined. Here, we employed a cell-based chimeric receptor screening system and identified CD1d as a surface ligand for PIRA2. We subsequently demonstrated that CD1d stimulation activated macrophages both in vitro and in vivo. Using Pira2-deficient (Pira2⁻/⁻) mice, we observed significantly reduced hepatic inflammation and lipid accumulation compared to wild-type controls. Mechanistically, CD1d–PIRA2 interaction involves the α1 and α2 domains of CD1d and the D1 and D2 domains of PIRA2, leading to FcRγ ITAM tyrosine phosphorylation and downstream inflammatory signaling—events that are impaired in Pira2⁻/⁻ macrophages. Additionally, CD1d and LILRA2 protein levels were elevated in NAFLD patients, and CD1d stimulation induced proinflammatory cytokine expression in human macrophages, which was attenuated by LILRA2 blockade. A recombinant LILRA2/Fc fusion protein effectively blocked CD1d-induced inflammatory gene expression in human macrophages, highlighting its potential as a therapeutic strategy for NAFLD. Collectively, our findings identify CD1d as a functional ligand of PIRA2 that promotes macrophage activation and inflammation, contributing to NAFLD progression.

Background Tumor-infiltrating T cells enter an exhausted or dysfunctional state, which limits antitumor immunity. Among exhausted T cells, a subset of cells with features of progenitor or stem-like cells has been identified as TCF1+ CD8+ T cells that respond to immunotherapy. In contrast to the finding that TCF1 controls epigenetic and transcriptional reprogramming in tumor-infiltrating stem-like T cells, little is known about the regulation of TCF1. Emerging data show that elevated body mass index is associated with outcomes of immunotherapy. However, the mechanism has not been clarified.Methods We investigated the proliferation of splenic lymphocytes or CD8+ T cells induced by CD3/CD28 stimulation in vitro. We evaluated the effects of low-density lipoprotein (LDL) and LRP11 inhibitors, as well as MAPK13 inhibitors. Additionally, we used shRNA technology to validate the roles of LRP11 and MAPK13. In an in vivo setting, we employed male C57BL/6J injected with B16 cells or MC38 cells to build a tumor model to assess the effects of LDL and LRP11 inhibitors, LRP11 activators, MAPK13 inhibitors on tumor growth. Flow cytometry was used to measure cell proportions and activation status. Molecular interactions and TCF1 status were examined using Western blotting. Moreover, we employed RNA sequencing to investigate the effects of LDL stimulation and MAPK13 inhibition in CD8+ T cells.Results By using a tumor-bearing mouse model, we found that LDL-induced tumor-infiltrating TCF1+PD1+CD8+ T cells. Using a cell-based chimeric receptor screening system, we showed that LRP11 interacted with LDL and activated TCF1. LRP11 activation enhanced TCF1+PD1+CD8+ T-cell-mediated antitumor immunity, consistent with LRP11 blocking impaired T-cell function. Mechanistically, LRP11 activation induces MAPK13 activation. Then, MAPK13 phosphorylates TCF1, leading to increase of stem-like T cells.Conclusions LRP11-MAPK13-TCF1 enhanced antitumor immunity and induced tumor-infiltrating stem-like T cells.

Hyparillums A (1) and B (2), two previously unidentified polycyclic polyprenylated acylphloroglucinols (PPAPs) with intricate architectures, were isolated from Hypericum patulum Thunb. Hyparillum A was the first PPAP with eight-carbon rings based on an unprecedented 6/6/5/6/6/5/6/4 octocyclic system featuring a rare heptacyclo[10.8.1.11,10.03,8.08,21.012,19.014,17]docosane core. In contrast, hyparillum B featured a novel heptacyclic architecture (6/6/5/6/6/5/5) based on a hexacyclo[9.6.1.11,9.03,7.07,18.011,16]nonadecane motif. Furthermore, hyparillums A and B demonstrated promising inhibitory effects on the proliferation of murine splenocytes stimulated by anti-CD3/anti-CD28 monoclonal antibodies and lipopolysaccharide, exhibiting half-maximal inhibitory concentration (IC50) values ranging from 6.13 ± 0.86 to 12.69 ± 1.31 μmol·L−1.

Objective:The current study is conducted to investigate the potential prognostic value of the age-male-albumin-bilirubin-platelets (aMAP) score in breast cancer patients with liver metastasis after surgery. Methods:This is a retrospective study of 178 breast cancer patients who developed liver metastasis after surgery. These patients were treated and followed up from 2000 to 2018 at our hospital. The aMAP risk score was estimated in accordance with the following formula: . The optimal cutoff value of the aMAP was evaluated via X-tile. Kaplan-Meier, Log-rank and Cox proportional hazards regression models were applied to determine the clinical influence of the aMAP score on the survival outcomes. The nomogram models were established by multivariate analyses. The calibration curves and decision curve analysis were applied to evaluate the estimated performance of the nomogram models. Results:A total of 178 breast cancer patients were divided into low aMAP score group (<47.6) and high aMAP score group (≥47.6) via X-tile plots. The aMAP score was a potential prognostic factor in multivariate analysis. The median disease free survival (p=0.0013) and overall survival (p=0.0003) in low aMAP score group were longer than in high aMAP score group. The nomograms were constructed to predict the DFS with a C-index of 0.722 (95% CI, 0.673-0.771), and the OS with a C-index of 0.708 (95% CI, 0.661-0.755). The aMAP-based nomograms had good predictive performance. Conclusion:The aMAP score is a potential prognostic factor in breast cancer with liver metastasis after surgery. The aMAP score-based nomograms were conducive to discriminate patients at high risks of liver metastasis and develop adjuvant treatment and prevention strategies.

Mucosal-associated invariant T (MAIT) cells exert multifaceted effects such as anti-microbial activity, tissue repair, and pro-fibrotic effects across various disease settings. Nonetheless, their role in liver injury and hemostasis is a current topic of debate. Here, we presented a MAIT cell-centered profiling in chronic HBV-infected patients with varying degree of liver injury and those who underwent liver transplantation. Liver transplantation facilitated a gradual recovery of recipient-originated MAIT cells from dysregulation associated with disease severity and accumulated bile acids in liver failure. Transcriptome analysis and T cell receptor (TCR) mining indicated an upregulation in MAIT cell migration during liver injury and post liver transplantation, characterized by elevated liver egress in the former and rescued liver homing receptors in the latter. TCR activation exacerbated the pathological potency of MAIT cells from liver failure patients, but conferred a protective potential in those from transplant recipients. Compromised recovery of MAIT cells was linked to post-transplantation complications, whereas prompt recovery predicated a more favorable clinical outcome. These findings underscore the intricate interplay between MAIT cells and the hepatic environment, highlighting MAIT cells as potential therapeutic targets and sensitive predictors for clinical outcome in individuals experiencing liver failure and post liver transplantation.

Objective: This study aims to investigate the potential prognostic value of albumin-bilirubin (ALBI) score in breast cancer patients with liver metastasis after surgery.Methods: This was a retrospective study of 178 breast cancer patients with liver metastasis after surgery. ALBI score was calculated by the following formula: (log10 bilirubin x 0.66) - (albumin x 0.085). The optimal cutoff value of ALBI score was assessed by X-tile. The clinical influence of ALBI score on survival outcomes using Kaplan-Meier method, Log-rank test, Cox proportional hazards regression model. The calibration curves, decision curve analysis and time-dependent ROC curve were used to assess the predictive performance of the nomogram's models.Results: The classifications of 178 breast cancer patients with liver metastasis after surgery were as follows: low ALBI score group (<- 3.36) vs. high ALBI score group (>=-3.36). The Cox proportional hazards regression model indicated that ALBI score was a potential predictor. Kaplan-Meier survival curve performed that the median disease free survival (p = 0.0029) and overall survival (p<0.0001) in low ALBI score group were longer than in high ALBI score group. The ALBI-based nomograms had good predictive performance.Conclusions: The ALBI score has high prognostic ability for survival time in breast cancer with liver metastasis after surgery. These models will be valuable in discriminating patients at high risks of liver metastasis.

Extracellular regulated protein kinases (ERK) signaling is a master regulator of cell behavior, life, and fate. Although ERK pathway is shown to be involved in T-cell activation, little is known about its role in the development of allograft rejection. Here, it is reported that ERK signaling pathway is activated in allograft-infiltrating T cells. On the basis of surface plasmon resonance technology, lycorine is identified as an ERK-specific inhibitor. ERK inhibition by lycorine significantly prolongs allograft survival in a stringent mouse cardiac allotransplant model. As compared to untreated mice, lycorine-treated mice show a decrease in the number and activation of allograft-infiltrated T cells. It is further confirmed that lycorine-treated mouse and human T cells are less responsive to stimulation in vitro, as indicated by their low proliferative rates and decreased cytokine production. Mechanistic studies reveal that T cells treated with lycorine exhibit mitochondrial dysfunction, resulting in metabolic reprogramming upon stimulation. Transcriptome analysis of lycorine-treated T cells reveals an enrichment in a series of downregulated terms related to immune response, the mitogen-activated protein kinase cascade, and metabolic processes. These findings offer new insights into the development of immunosuppressive agents by targeting the ERK pathway involved in T-cell activation and allograft rejection.

Concanavalin A (Con A) is known to be a T-cell mitogen and has been shown to induce hepatitis in mice through the triggering of conventional T cells and NKT cells. However, it remains unknown whether Con A itself can directly induce rapid hepatocyte death in the absence of a functional immune system. Here, by using an immunodeficient mouse model, we found Con A rapidly induced liver injury in vivo despite a lack of immunocyte involvement. We further observed in vitro that hepatocytes underwent a dose-dependent but caspase-independent apoptosis in response to Con A stimulation in vitro. Moreover, transcriptome RNA-sequencing analysis revealed that apoptosis pathways were activated in both our in vivo and in vitro models. We conclude that Con A can directly induce rapid but non-classical apoptosis in hepatocytes without the participation of immunocytes. These findings provide new insights into the mechanism of Con A-induced hepatitis.

Aims: To investigate the potential of imDCs with high expression of HO-1 in preventing or delaying the onset of Type 1 diabetes mellitus (T1DM) in non-obese diabetic (NOD) mice.Materials and methods: The phenotypic features of DCs in each group were assessed using flow cytometry. Western blot analysis was used to confirm the high expression of HO-1 in imDCs induced with CoPP. Addi-tionally, flow cytometry was used to evaluate the suppressive capacity of CoPP-induced imDCs on splenic lymphocyte proliferation. Finally, the preventive effect of CoPP-induced imDCs was tested in NOD mice.Key findings: Compared to imDCs, CoPP-induced imDCs exhibited a reduced mean fluorescence intensity (MFI) of the co-stimulatory molecule CD80 on their surface (P < 0.05) and significantly increased HO-1 protein expression (P < 0.05). Following LPS stimulation, the MFI of co-stimulatory molecules CD80 and CD86 on the surface of CoPP-induced imDCs remained at a lower level (P < 0.05). Furthermore, there was a reduced pro-liferation rate of lymphocytes stimulated with anti-CD3/28 antibodies. The adoptive transfer of CoPP-imDCs significantly reduced the incidence of T1DM (16.66 % vs. control group: 66.67 %, P = 0.004). Furthermore, at 15 weeks of age, the insulitis score was also decreased in the CoPP-induced imDC treatment group (P < 0.05). There were no significant differences in serum insulin levels among all groups.Significance: ImDCs induced with CoPP and exhibiting high expression of HO-1 demonstrate a robust ability to inhibit immune responses and effectively reduce the onset of diabetes in NOD mice. This finding suggests that CoPP-induced imDCs could potentially serve as a promising treatment strategy for T1DM.