Hydrogel activation of Mincle receptors for tumor cell processing: A novel approach in cancer immunotherapy.

An obstacle in current tumor immunotherapies lies in the challenge of achieving sustained and tumor-targeting T cell immunity, impeded by the limited antigen processing and cross-presentation of tumor antigens. Here, we propose a hydrogel-based multicellular immune factory within the body that autonomously converts tumor cells into an antitumor vaccine. Within the body, the scaffold, formed by a calcium-containing chitosan hydrogel complex (ChitoCa) entraps tumor cells and attracts immune cells to establish a durable and multicellular microenvironment. Within this context, tumor cells are completely eliminated by antigen-presenting cells (APCs) and processed for cross-antigen presentation. The regulatory mechanism relies on the Mincle receptor, a cell-phagocytosis-inducing C-type lectin receptor specifically activated on ChitoCa-recruited APCs, which serves as a recognition synapse, facilitating a tenfold increase in tumor cell engulfment and subsequent elimination. The ChitoCa-induced tumor cell processing further promotes the cross-presentation of tumor antigens to prime protective CD8+ T cell responses. Therefore, the ChitoCa treatment establishes an immune niche within the tumor microenvironment, resulting in effective tumor regression either used alone or in combination with other immunotherapies. This hydrogel-induced immune factory establishes a functional organ-like multicellular colony for tumor-specific immunotherapy, paving the way for innovative strategies in cancer treatment.

The evolution of the TIPS placement technique and its applications over four decades.

Transjugular intrahepatic portosystemic shunt (TIPS), a highly effective procedure reducing portal hypertension, has been in use for over seven decades and is now a cornerstone in managing portal hypertension-related complications such as variceal bleeding and ascites. Historically, TIPS has dealt with two main challenges: ensuring stent patency and preventing post-TIPS hepatic encephalopathy. The introduction of PTFE-coated stents markedly reduced the risk of TIPS dysfunction and stent patency is no longer a major concern. However, despite improved patient selection criteria, hepatic encephalopathy continues to be a significant and persistent issue. In addition, the broader application of TIPS in recent decades has brought to light additional, albeit less common, complications, such as post-TIPS heart failure. This review offers a comprehensive overview of TIPS historical evolution, advancements in technique, and its application in the treatment of portal hypertension.

Small Transjugular Intrahepatic Portosystemic Shunt Plus Variceal Embolization for Gastric Varices: A Multicenter Cohort Study.

BACKGROUND & AIMS: The effect of transjugular intrahepatic portosystemic shunt (TIPS) plus variceal embolization for treating gastric varices (GVs) remains controversial. This nationwide multicenter cohort study aimed to evaluate whether adding variceal embolization to a small diameter (8-mm) TIPS could reduce the rebleeding incidence in patients with different types of GVs. METHODS: This retrospective cohort study involved 629 patients who underwent 8-mm TIPS for gastric varices at 7 medical centers. The primary endpoint was all-cause rebleeding, and the secondary endpoints included overt hepatic encephalopathy (OHE) and all-cause mortality. RESULTS: A total of 629 patients were included. Among them, 429 (68.2%) had gastroesophageal varices type 1 (GOV1), 145 (23.1%) had gastroesophageal varices type 2 (GOV2), and 55 (8.7%) had isolated gastric varices type 1 (IGV1). In the entire cohort, adjunctive embolization reduced rebleeding (6.2% vs 13.6%; P = .005) and OHE (31.0% vs 39.4%; P = .02) compared with TIPS alone. However, no significant differences were found in mortality (12.0% vs 9.7%; P = .42). In patients with GOV2 and IGV1, TIPS plus variceal embolization reduced both rebleeding (GOV2: 7.8% vs 25.1%; P = .01; IGV1: 5.6% vs 30.8%; P = .03) and OHE (GOV2: 31.8% vs 51.5%; P = .008; IGV1: 11.6% vs 38.5%; P = .04). However, in patients with GOV1, adjunctive embolization did not reduce rebleeding (5.9% vs 8.7%; P = .37) or OHE (33.1% vs 35.3%; P = .60). CONCLUSIONS: Compared with TIPS alone, 8-mm TIPS plus variceal embolization reduced rebleeding and OHE in patients with GOV2 and IGV1. These findings suggest that patients with GOV2 and IGV1, rather than GOV1, could benefit from embolization with TIPS.

Efficacy of TIPS plus extrahepatic collateral embolisation in real-world data: a validation study.

OBJECTIVES: The efficacy of transjugular intrahepatic portosystemic shunt (TIPS) plus extrahepatic collateral embolisation (TIPS+E) in reducing rebleeding and hepatic encephalopathy (HE) post-TIPS was recently reported in a meta-analysis, but further validation is essential. This study aims to confirm the effectiveness of TIPS+E using real-world data. METHODS: The multicentre retrospective cohort included 2077 patients with cirrhosis who underwent TIPS±E (TIPS: 631, TIPS+E: 1446) between January 2010 and December 2022. Regression and propensity score matching (PSM) were used to adjust for baseline characteristic differences. After PSM, clinical outcomes, including rebleeding, HE, survival and further decompensation (FDC), were analysed. Baseline data from all patients contributed to the construction of prognostic models. RESULTS: After PSM, 1136 matched patients (TIPS+E: TIPS=568:568) were included. TIPS+E demonstrated a significant reduction in rebleeding (HR 0.77; 95% CI 0.59 to 0.99; p=0.04), HE (HR 0.82; 95% CI 0.68 to 0.99; p=0.04) and FDC (HR 0.85; 95% CI 0.73 to 0.99; p=0.04), comparing to TIPS. Significantly, TIPS+E also reduced rebleeding, HE and FDC in subgroup of using 8 mm diameter stents and embolising of gastric varices+spontaneous portosystemic shunts (GV+SPSS). However, there were no differences in overall or subgroup survival analysis. Additionally, the random forest models showed higher accuracy and AUROC comparing to other models. Controlling post-TIPS portal pressure gradient (pPPG) within 7 mm Hg

Shaping immune landscape of colorectal cancer by cholesterol metabolites.

Cancer immunotherapies have achieved unprecedented success in clinic, but they remain largely ineffective in some major types of cancer, such as colorectal cancer with microsatellite stability (MSS CRC). It is therefore important to study tumor microenvironment of resistant cancers for developing new intervention strategies. In this study, we identify a metabolic cue that determines the unique immune landscape of MSS CRC. Through secretion of distal cholesterol precursors, which directly activate RORγt, MSS CRC cells can polarize T cells toward Th17 cells that have well-characterized pro-tumor functions in colorectal cancer. Analysis of large human cancer cohorts revealed an asynchronous pattern of the cholesterol biosynthesis in MSS CRC, which is responsible for the abnormal accumulation of distal cholesterol precursors. Inhibiting the cholesterol biosynthesis enzyme Cyp51, by pharmacological or genetic interventions, reduced the levels of intratumoral distal cholesterol precursors and suppressed tumor progression through a Th17-modulation mechanism in preclinical MSS CRC models. Our study therefore reveals a novel mechanism of cancer-immune interaction and an intervention strategy for the difficult-to-treat MSS CRC.

Upregulation of ATG9b by propranolol promotes autophagic cell death of hepatic stellate cells to improve liver fibrosis.

Proranolol has long been recommended to prevent variceal bleeding in patients with cirrhosis. However, the mechanisms of propranolol in liver fibrosis have not yet been thoroughly elucidated. Autophagic cell death (ACD) of activated hepatic stellate cells (HSCs) is important in the alleviation of liver fibrosis. Our study aims to assess the mechanisms of propranolol regulating HSC ACD and liver fibrosis. ACD of HSCs was investigated using lentivirus transfection. The molecular mechanism was determined using a PCR profiler array. The role of autophagy-related protein 9b (ATG9b) in HSC ACD was detected using co-immunoprecipitation and co-localization of immunofluorescence. Changes in the signalling pathway were detected by the Phospho Explorer antibody microarray. Propranolol induces ACD and apoptosis in HSCs. ATG9b upregulation was detected in propranolol-treated HSCs. ATG9b upregulation promoted ACD of HSCs and alleviated liver fibrosis in vivo. ATG9b enhanced the P62 recruitment to ATG5-ATG12-LC3 compartments and increased the co-localization of P62 with ubiquitinated proteins. The PI3K/AKT/mTOR pathway is responsible for ATG9b-induced ACD in activated HSCs, whereas the p38/JNK pathway is involved in apoptosis. This study provides evidence for ATG9b as a new target gene and propranolol as an agent to alleviate liver fibrosis by regulating ACD of activated HSCs.

Gasdermin D-mediated pyroptosis is regulated by AMPK-mediated phosphorylation in tumor cells.

Gasdermin D (GSDMD) is a critical mediator of pyroptosis, which consists of a N-terminal pore-forming domain and a C-terminal autoinhibitory domain. Its cytolytic activity is sequestered by the intramolecular autoinhibitory mechanism. Upon caspase-1/11 mediated cleavage of GSDMD, the N-terminal pore-forming domain (GD-NT) is released to mediate pyroptosis. However, it remains unclear how GD-NT is regulated once it is generated. In the current study, we developed a TetOn system in which GD-NT was selectively induced in tumor cells to explore how the cytolytic activity of GD-NT is regulated. We found that the cytolytic activity of GD-NT was negatively regulated by the AMP-activated protein kinase (AMPK) and AMPK activation rendered tumor cells resistant to GD-NT-mediated pyroptosis. Mechanistically, AMPK phosphorylated GD-NT at the serine 46 (pS46-GD), which altered GD-NT oligomerization and subsequently eliminated its pore-forming ability. In our in vivo tumor model, AMPK-mediated phosphorylation abolished GD-NT-induced anti-tumor activity and resulted in an aggressive tumor growth. Thus, our data demonstrate the critical role of AMPK in negatively regulating the cytolytic activity of GD-NT. Our data also highlight an unexpected link between GSDMD-mediated pyroptosis and the AMPK signaling pathway in certain tumor cells.

The unique expression pattern of human leukocyte antigen in trophoblasts potentially explains the key mechanism of maternal-fetal tolerance and successful pregnancy.

The success of pregnancy mainly depends on immune tolerance of the mother for the semi-allogeneic fetus. The placenta carrying paternal antigens develops in the maternal uterus without suffering immune attack, making the underlying mechanism of maternal tolerance an enduring mystery. As we all know, human leukocyte antigen (HLA) plays an important role in antigen processing and presentation, thus inducing specific immune responses. Therefore, it is reasonable to speculate that the absence of classical HLA class-I（HLA-I) and HLA class-II (HLA-II) molecules in trophoblasts may account for the maternal-fetal tolerance. Here, we review the HLA-involved interactions between trophoblast cells and decidual immune cells, which contribute to the immunotolerance in the development of normal pregnancy. We also compare the similarity between the maternal-fetal interface and tumor-immune microenvironment because the important role of HLA molecules in tumor immune invasion can provide some references to studies of maternal-fetal immune tolerance. Besides, the abnormal HLA expression is likely to be associated with unexplained miscarriage, making HLA molecules potential therapeutic targets. The advances reported by these studies may exert profound influences on other research areas, including tumor immunity, organ transplantation and autoimmune disease in the future.

Clinical outcomes of clip-assisted endoscopic cyanoacrylate injection versus conventional endoscopic cyanoacrylate injection in treating gastric varices with a gastrorenal shunt.

BACKGROUND AND STUDY AIMS: The optimal treatment for gastric varices (GVs) is a topic that remains definite for this study. This study compared the clinical outcomes of clip-assisted endoscopic cyanoacrylate injection (clip-ECI) to conventional endoscopic cyanoacrylate injection (con-ECI) for the treatment of GVs with a gastrorenal shunt. PATIENTS AND METHODS: Data were collected retrospectively in five medical centers from 2015 to 2020. The patients were treated with con-ECI (n = 126) or clip-ECI (n = 148). Clinical characteristics and procedural outcomes were compared. Patients were followed until death, liver transplantation or 6 months after the treatment. The primary outcome was rebleeding, and the secondary outcome was survival. RESULTS: There were no significant differences in age, sex, etiology, shunt diameter and Child-Pugh classification between the two groups. Fewer GVs obliteration sessions were required in the clip-ECI group than in the con-ECI group (p = 0.015). The cumulative 6-month rebleeding-free rates were 88.6% in the clip-ECI group and 73.7% in the con-ECI group (p = 0.002). The cumulative 6-month survival rates were 97.1% in the clip-ECI group and 94.8% in the con-ECI group (p = 0.378). CONCLUSIONS: Compared with con-ECI, clip-ECI appears more effective for the treatment of GVs with a gastrorenal shunt, which required less sessions and achieved a higher 6-month rebleeding-free rate.

Exhaustion-associated cholesterol deficiency dampens the cytotoxic arm of antitumor immunity.

The concept of targeting cholesterol metabolism to treat cancer has been widely tested in clinics, but the benefits are modest, calling for a complete understanding of cholesterol metabolism in intratumoral cells. We analyze the cholesterol atlas in the tumor microenvironment and find that intratumoral T cells have cholesterol deficiency, while immunosuppressive myeloid cells and tumor cells display cholesterol abundance. Low cholesterol levels inhibit T cell proliferation and cause autophagy-mediated apoptosis, particularly for cytotoxic T cells. In the tumor microenvironment, oxysterols mediate reciprocal alterations in the LXR and SREBP2 pathways to cause cholesterol deficiency of T cells, subsequently leading to aberrant metabolic and signaling pathways that drive T cell exhaustion/dysfunction. LXRß depletion in chimeric antigen receptor T (CAR-T) cells leads to improved antitumor function against solid tumors. Since T cell cholesterol metabolism and oxysterols are generally linked to other diseases, the new mechanism and cholesterol-normalization strategy might have potential applications elsewhere.

Immunogenetic Metabolomics Reveals Key Enzymes That Modulate CAR T-cell Metabolism and Function.

Immune evasion is a critical step of cancer progression that remains a major obstacle for current T cell-based immunotherapies. Hence, we investigated whether it is possible to genetically reprogram T cells to exploit a common tumor-intrinsic evasion mechanism whereby cancer cells suppress T-cell function by generating a metabolically unfavorable tumor microenvironment (TME). In an in silico screen, we identified ADA and PDK1 as metabolic regulators. We then showed that overexpression (OE) of these genes enhanced the cytolysis of CD19-specific chimeric antigen receptor (CAR) T cells against cognate leukemia cells, and conversely, ADA or PDK1 deficiency dampened this effect. ADA-OE in CAR T cells improved cancer cytolysis under high concentrations of adenosine, the ADA substrate, and an immunosuppressive metabolite in the TME. High-throughput transcriptomics and metabolomics analysis of these CAR T cells revealed alterations of global gene expression and metabolic signatures in both ADA- and PDK1-engineered CAR T cells. Functional and immunologic analyses demonstrated that ADA-OE increased proliferation and decreased exhaustion in CD19-specific and HER2-specific CAR T cells. ADA-OE improved tumor infiltration and clearance by HER2-specific CAR T cells in an in vivo colorectal cancer model. Collectively, these data unveil systematic knowledge of metabolic reprogramming directly in CAR T cells and reveal potential targets for improving CAR T-cell therapy.

Hepatic Venous Occlusion Type of Budd-Chiari Syndrome versus Pyrrolizidine Alkaloid-Induced Hepatic Sinusoidal Obstructive Syndrome: A Multi-Center Retrospective Study.

(1) Background: Hepatic venous occlusion type of Budd-Chiari syndrome (BCS-HV) and pyrrolizidine alkaloid-induced hepatic sinusoidal obstructive syndrome (PA-HSOS), share similar clinical features, and imaging findings, leading to misdiagnoses; (2) Methods: We retrospectively analyzed 139 patients with BCS-HV and 257 with PA-HSOS admitted to six university-affiliated hospitals. We contrasted the two groups by clinical manifestations, laboratory tests, and imaging features for the most valuable distinguishing indicators.; (3) Results: The mean patient age in BCS-HV is younger than that in PA-HSOS (p < 0.05). In BCS-HV, the prevalence of hepatic vein collateral circulation of hepatic veins, enlarged caudate lobe of the liver, and early liver enhancement nodules were 73.90%, 47.70%, and 8.46%, respectively; none of the PA-HSOS patients exhibited these features (p < 0.05). DUS showed that 86.29% (107/124) of patients with BCS-HV showed occlusion of the hepatic vein, while CT or MRI showed that only 4.55%(5/110) patients had this manifestation (p < 0.001). Collateral circulation of hepatic veins was visible in 70.97% (88/124) of BCS-HV patients on DUS, while only 4.55% (5/110) were visible on CT or MRI (p < 0.001); (4) Conclusions: In addition to an established history of PA-containing plant exposure, local hepatic vein stenosis and the presence of collateral circulation of hepatic veins are the most important differential imaging features of these two diseases. However, these important imaging features may be missed by enhanced CT or MRI, leading to an incorrect diagnosis.

Immunogenetic metabolomics revealed key enzymes that modulate CAR-T metabolism and function.

Immune evasion is a critical step of cancer progression that remains a major obstacle for current T cell-based immunotherapies. Hence, we seek to genetically reprogram T cells to exploit a common tumor-intrinsic evasion mechanism, whereby cancer cells suppress T cell function by generating a metabolically unfavorable tumor microenvironment (TME). Specifically, we use an in silico screen to identify ADA and PDK1 as metabolic regulators, in which gene overexpression (OE) enhances the cytolysis of CD19-specific CD8 CAR-T cells against cognate leukemia cells, and conversely, ADA or PDK1 deficiency dampens such effect. ADA -OE in CAR-T cells improves cancer cytolysis under high concentrations of adenosine, the ADA substrate and an immunosuppressive metabolite in the TME. High-throughput transcriptomics and metabolomics in these CAR-Ts reveal alterations of global gene expression and metabolic signatures in both ADA- and PDK1- engineered CAR-T cells. Functional and immunological analyses demonstrate that ADA -OE increases proliferation and decreases exhaustion in α-CD19 and α-HER2 CAR-T cells. ADA-OE improves tumor infiltration and clearance by α-HER2 CAR-T cells in an in vivo colorectal cancer model. Collectively, these data unveil systematic knowledge of metabolic reprogramming directly in CAR-T cells, and reveal potential targets for improving CAR-T based cell therapy. Synopsis: The authors identify the adenosine deaminase gene (ADA) as a regulatory gene that reprograms T cell metabolism. ADA-overexpression (OE) in α-CD19 and α-HER2 CAR-T cells increases proliferation, cytotoxicity, memory, and decreases exhaustion, and ADA-OE α-HER2 CAR-T cells have enhanced clearance of HT29 human colorectal cancer tumors in vivo .

Percutaneous transhepatic intraportal biopsy using gastroscope biopsy forceps for diagnosis of a pancreatic neuroendocrine neoplasm: A case report.

BACKGROUND: Pancreatic neuroendocrine neoplasms (PNENs) are a rare group of neoplasms originating from the islets of the Langerhans. Portal vein tumor thrombosis has been reported in 33% of patients with PNENs. While the histopathological diagnosis of PNENs is usually based on percutaneous biopsy or endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), these approaches may be impeded by gastric varices, poor access windows, or anatomically contiguous critical structures. Obtaining a pathological diagnosis using a gastroscope biopsy forceps via percutaneous transhepatic intravascular pathway is an innovative method that has rarely been reported. CASE SUMMARY: A 72-year-old man was referred to our hospital for abdominal pain and melena. Abdominal contrast-enhanced magnetic resonance imaging revealed a well-enhanced tumor (size: 2.4 cm × 1.2 cm × 1.2 cm) in the pancreatic tail with portal vein invasion. Traditional pathological diagnosis via EUS-FNA was not possible because of diffuse gastric varices. We performed a percutaneous transportal biopsy of the portal vein tumor thrombus using a gastroscope biopsy forceps. Histopathologic examination revealed a pancreatic neuroendocrine neoplasm (G2) with somatostatin receptors 2 (+), allowing systemic treatment. CONCLUSION: Intravascular biopsy using gastroscope biopsy forceps appears to be a safe and effective method for obtaining a histopathological diagnosis. Although well-designed clinic trials are required to obtain more definitive evidence, this procedure may help improve the diagnosis of portal vein thrombosis and related diseases.

Individualized portal pressure gradient threshold based on liver function categories in preventing rebleeding after TIPS.

BACKGROUND: The evidence in Portal pressure gradient (PPG) < 12 mmHg after transjugular intrahepatic portosystemic shunt (TIPS) for preventing rebleeding mostly comes from observations in uncovered stents era. Moreover, association between Child-Pugh classes and post-TIPS hepatic encephalopathy (HE) has indicated that tolerance of PPG reduction depends on liver function. This study aimed to investigate the optimal PPG for covered TIPS and explore the optimal threshold tailored to the Child-Pugh classes to find individualized PPG to balance rebleeding and overt HE. METHODS: This multicenter retrospective study analyzed rebleeding, OHE, and mortality of patients associated with post-TIPS PPGs (8, 10, 12, and 14 mmHg) in the entire cohort and among different Child-Pugh classes. Propensity score matching (PSM) and competing risk analyses were performed for sensitivity analyses. RESULTS: We included 2100 consecutively screened patients undergoing TIPS. In all patients, PPG < 12 mmHg reduced rebleeding after TIPS (p = 0.022). In Child-Pugh class A, none of the PPG thresholds were discriminative of clinical outcomes. In Child-Pugh class B, 12 mmHg (p = 0.022) and 14 mmHg (p = 0.037) discriminated rebleeding, but 12 mmHg showed a higher net benefit. In Child-Pugh class C, PPG < 14 mmHg had a lower rebleeding incidence (p = 0.017), and exhibited more net benefit than 12 mmHg. CONCLUSION: Different PPG standards may be required for patients with different liver function categories. A PPG threshold < 12 mmHg might be suitable for patients in Child-Pugh class B, while < 14 mmHg might be optimal for patients in Child-Pugh class C.

Hepatocyte-derived exosomes deliver H2AFJ to hepatic stellate cells and promote liver fibrosis via the MAPK/STMN1 axis activation.

Hepatic stellate cells (HSCs) activate and acquire proliferative features in response to liver injury. However, mechanisms involved in the activation of fibrotic HSCs remain uncharacterized. This study aims at elaborating the mechanistic basis by which exosomal H2AFJ derived from hepatocytes might affect the activation of HSCs and liver fibrosis. Bioinformatics analysis based on transcriptomic RNA-seq data was used to screen out the downstream regulatory genes and pathways of H2AFJ. Mouse hepatocytes AML-12 cells were stimulated with CCl4 to mimic an in vitro microenvironment of liver fibrosis, from which exosomes were isolated. Next, HSCs were co-cultured with hepatocyte-derived exosomes followed by detection of HSC migration and invasion in the presence of manipulated H2AFJ and STMN1 expression and MAPK pathway inhibitor. It was found that H2AFJ was highly expressed in hepatocyte-derived exosomes after CCl4 stimulation. Hepatocyte-derived exosomal H2AFJ promoted HSC migration and invasion. H2AFJ upregulated c-jun-mediated STMN1 by activating the MAPK signaling pathway. Furthermore, in vivo experiments verified that silencing of H2AFJ attenuated liver fibrosis in mice, while restoration of STMN1 negated its effect. Collectively, hepatocyte-derived exosomal H2AFJ aggravated liver fibrosis by activating the MAPK/STMN1 signaling pathway. This study provides a potential therapeutic target for alleviating liver fibrosis.

Ox40-Cre-mediated deletion of BRD4 reveals an unexpected phenotype of hair follicle stem cells in alopecia.

BRD4 is a bromodomain extraterminal domain family member and functions primarily as a chromatin reader regulating genes involved in cell-fate decisions. Here, we bred Brd4fl/fl Ox40-Cre mice in which Brd4 was conditionally deleted in OX40-expressing cells to examine the role of BRD4 in regulating immune responses. We found that the Brd4fl/fl Ox40-Cre mice developed profound alopecia and dermatitis, while other organs and tissues were not affected. Surprisingly, lineage-tracing experiments using the Rosa26fl/fl-Yfp mice identified a subset of hair follicle stem cells (HFSCs) that constitutively express OX40, and deletion of Brd4 specifically in such HFSCs resulted in cell death and a complete loss of skin hair growth. We also found that death of HFSCs triggered massive activation of the intradermal γδ T cells, which induced epidermal hyperplasia and dermatitis by producing the inflammatory cytokine IL-17. Interestingly, deletion of Brd4 in Foxp3+ Tregs, which also constitutively express OX40, compromised their suppressive functions, and this, in turn, contributed to the enhanced activation of γδ T cells, as well as the severity of dermatitis and hair follicle destruction. Thus, our data demonstrate an unexpected role of BRD4 in regulating skin follicle stem cells and skin inflammation.