Bismuth-Cyclized Cell-Penetrating Peptides.

Intracellular delivery of biological cargos, which would yield new research tools and novel therapeutics, remains an active area of research. A convenient and potentially general approach involves the conjugation of a cell-penetrating peptide to a cargo of interest. However, linear CPPs lack sufficient cytosolic entry efficiency and metabolic stability, while previous backbone cyclized CPPs have several drawbacks including the necessity for chemical synthesis and posttranslational conjugation to peptide/protein cargos and epimerization during cyclization. We report here a new class of bismuth cyclized CPPs with excellent cytosolic entry efficiencies, proteolytic stability, and potential compatibility with genetic encoding and recombinant production.

Cu Nanowires Trigger Efficient Cuproptosis via Special Intracellular Distribution and Excessive Cu Ion Release.

Cuproptosis, dependent on Cu overload, presents novel opportunities for cancer therapy. Cu-based nanomaterials have shown excellent advantages for the intracellular delivery of Cu. However, the biological process of Cu nanomaterials transporting Cu ions into cancer cells remains unclear. In this study, we tracked the Cu ion release process of copper nanowires (CuNWs) and copper nanoparticles (CuNPs) at the single-cell level. CuNWs with 5-µm length and CuNPs were found to be completely internalized by cancer cells. Interestingly, CuNWs escaped from the endolysosomal system, whereas CuNPs were mainly trapped in the lysosomes. This specific intracellular distribution of CuNWs led to cytoplasmic Cu ion overload, directly damaging mitochondria and inducing dihydrolipoamide S-acetyltransferase (DLAT) protein aggregation. Through these excessive Cu ions, CuNWs triggered more efficient cuproptosis than CuNPs to further increase cell death. Thus, CuNWs are more effective in delivering Cu ions than CuNPs, providing a novel perspective for designing cuproptosis-based functional nanomaterials for cancer therapy.

Efficient delivery of curcumin by functional solid lipid nanoparticles with promoting endosomal escape and liver targeting properties.

In the realm of intracellular drug delivery, overcoming the barrier of endosomal entrapment stands as a critical factor influencing the effectiveness of nanodrug delivery systems. This study focuses on the synthesis of an acid-sensitive fatty acid derivative called imidazole-stearic acid (IM-SA). Leveraging the proton sponge effect attributed to imidazole groups, IM-SA was anticipated to play a pivotal role in facilitating endosomal escape. Integrated into the lipid core of solid lipid nanoparticles (SLNs), IM-SA was paired with hyaluronic acid (HA) coating on the surface of SLNs loading with curcumin (CUR). The presence of IM-SA and HA endowed HA-IM-SLNs@CUR with dual functionalities, enabling the promotion of endosomal escape, and specifical targeting of liver cancer. HA-IM-SLNs@CUR exhibited a particle size of ∼228 nm, with impressive encapsulation efficiencies (EE) of 87.5 % ± 2.3 % for CUR. Drugs exhibit significant pH sensitive release behavior. Cellular experiments showed that HA-IM-SLN@CUR exhibits enhanced drug delivery capability. The incorporation of IM-SA significantly improved the endosomal escape of HA-IM-SLN@CUR, facilitating accelerated intracellular drug release and increasing intracellular drug concentration, exhibiting excellent growth inhibitory effects on HepG2 cells. Animal experiments revealed a 3.4-fold increase in CUR uptake at the tumor site with HA-IM-SLNs@CUR over the free CUR, demonstrating remarkable tumor homing potential with the tumor growth inhibition rate of 97.2 %. These findings indicated the significant promise of HA-IM-SLNs@CUR in the realm of cancer drug delivery.

Hypomethylation-associated ELF3 helps nasopharyngeal carcinoma to escape immune surveillance via MUC16-mediated glycolytic metabolic reprogramming.

Immune escape and metabolic reprogramming are two essential hallmarks of cancer. Mucin-16 (MUC16) has been linked to glycolysis and immune response in different cancers. However, its involvement in nasopharyngeal carcinoma (NPC) has not been well described. We seek to dissect the functions and detailed mechanisms of MUC16 in NPC. Bioinformatics prediction was performed to identify NPC-related molecules. MUC16 was significantly enhanced in NPC tissues, which was correlated with the advanced tumor stage of patients. Lentiviral plasmids-mediated MUC16 deletion inhibited the malignant behavior of NPC cells, and glycolysis inhibition by MUC16 deletion blocked immune escape in NPC cells. E74-like factor 3 (ELF3) bound to the MUC16 promoter to promote transcription of MUC16. MUC16 overexpression reversed the repressive effect of ELF3 silencing on glycolysis and immune escape in NPC and accelerated tumor growth in vivo. Overexpression of ELF3 in NPC was associated with reduced DNA methylation in its promoter. Our findings revealed the role of the ELF3/MUC16 axis in the immune escape and metabolic reprogramming of NPC, providing potential therapeutic targets for NPC.

CCL22 as an independent prognostic factor in endometrial cancer patients.

OBJECTIVES: The chemokine CCL22 is recognized for recruiting immunosuppressive regulatory T-cells (Treg) that contribute to disease progression in various tumor entities helping them to evade the host immune response. Our study aims to identify the expressing cell types and to evaluate the prognostic significance of CCL22 secretion and its association with Treg invasion in endometrial cancer (EC), an immunogenic cancer. METHODS: Specimens from 275 patients with EC and 28 healthy controls were screened immunohistochemically for CCL22. Immunofluorescence double-staining for CCL22 and different immune cell markers was performed. In vitro regulation of CCL22-expression was examined in EC cell lines (Ishikawa+, RL95-2) and human PBMCs in coculture settings via qPCR and ELISA. RESULTS: Elevated CCL22 staining in tumor cells and CCL22-positive M1-macrophages in tumordistant areas were significantly associated with increased overall survival (OS). Conversely, high, secretory-appearing staining in the peritumoral and intratumoral stroma correlated with reduced OS. Although the analysis of the in vitro coculture model of epithelial tumor- and immune cells revealed PBMCs as the primary source of CCL22, we could confirm expression of the chemokine also in the EC epithelial cells. CONCLUSION: Our study suggests that CCL22 in EC is associated with OS, dependent on its location and the cell type producing it. Intracellular upregulation and extracellular secretion must be considered separately when investigating CCL22 expressing cell types in EC. These results may provide evidence for CCL22-mediated Treg recruitment in EC as a potential future therapeutic target.

Enhancing peptide and PMO delivery to mouse airway epithelia by chemical conjugation with the amphiphilic peptide S10.

Delivery of antisense oligonucleotides (ASOs) to airway epithelial cells is arduous due to the physiological barriers that protect the lungs and the endosomal entrapment phenomenon, which prevents ASOs from reaching their intracellular targets. Various delivery strategies involving peptide-, lipid-, and polymer-based carriers are being investigated, yet the challenge remains. S10 is a peptide-based delivery agent that enables the intracellular delivery of biomolecules such as GFP, CRISPR-associated nuclease ribonucleoprotein (RNP), base editor RNP, and a fluorescent peptide into lung cells after intranasal or intratracheal administrations to mice, ferrets, and rhesus monkeys. Herein, we demonstrate that covalently attaching S10 to a fluorescently labeled peptide or a functional splice-switching phosphorodiamidate morpholino oligomer improves their intracellular delivery to airway epithelia in mice after a single intranasal instillation. Data reveal a homogeneous delivery from the trachea to the distal region of the lungs, specifically into the cells lining the airway. Quantitative measurements further highlight that conjugation via a disulfide bond through a pegylated (PEG) linker was the most beneficial strategy compared with direct conjugation (without the PEG linker) or conjugation via a permanent thiol-maleimide bond. We believe that S10-based conjugation provides a great strategy to achieve intracellular delivery of peptides and ASOs with therapeutic properties in lungs.

Genetically engineered CD276-anchoring biomimetic nanovesicles target senescent escaped tumor cells to overcome chemoresistant and immunosuppressive breast cancer.

Chemotherapy-induced cellular senescence leads to an increased proportion of cancer stem cells (CSCs) in breast cancer (BC), contributing to recurrence and metastasis, while effective means to clear them are currently lacking. Herein, we aim to develop new approaches for selectively killing senescent-escape CSCs. High CD276 (95.60%) expression in multidrug-resistant BC cells, facilitates immune evasion by low-immunogenic senescent escape CSCs. CALD1, upregulated in ADR-resistant BC, promoting senescent-escape of CSCs with an anti-apoptosis state and upregulating CD276, PD-L1 to promote chemoresistance and immune escape. We have developed a controlled-released thermosensitive hydrogel containing pH- responsive anti-CD276 scFV engineered biomimetic nanovesicles to overcome BC in primary, recurrent, metastatic and abscopal humanized mice models. Nanovesicles coated anti-CD276 scFV selectively fuses with cell membrane of senescent-escape CSCs, then sequentially delivers siCALD1 and ADR due to pH-responsive MnP shell. siCALD1 together with ADR effectively induce apoptosis of CSCs, decrease expression of CD276 and PD-L1, and upregulate MHC I combined with Mn2+ to overcome chemoresistance and promote CD8+T cells infiltration. This combined therapeutic approach reveals insights into immune surveillance evasion by senescent-escape CSCs, offering a promising strategy to immunotherapy effectiveness in cancer therapy.

NDR1 mediates PD-L1 deubiquitination to promote prostate cancer immune escape via USP10.

Prostate cancer (PCa) is one of the most common male genitourinary system malignancies. Despite the significant benefits of anti-PD-L1 immune checkpoint inhibitor therapy in other cancers, the reasons for its poor therapeutic efficacy in prostate cancer (PCa) remain unclear.NDR1 plays an important role in innate immunity, but its role in tumor immunity and immunotherapy has not been investigated. The role of NDR1 in the immune microenvironment of PCa and the related mechanisms are unknown. Here, we found a positive correlation between NDR1 and PD-L1 expression in PCa. NDR1 significantly inhibits CD8 + T cell infiltration and function, thereby promoting immune escape in prostate cancer.More importantly, NDR1 inhibition significantly enhanced CD8 + T cell activation, which enhanced the therapeutic effect of anti-PD-L1. Mechanistic studies revealed that NDR1 inhibits ubiquitination-mediated PD-L1 degradation via the deubiquitinase USP10, upregulates PD-L1, and promotes PCa immune escape. Thus, our study suggests a unique PD-L1 regulatory mechanism underlying PCa immunotherapy failure. The significance of NDR1 in PCa immune escape and its mechanism of action were clarified, and combined NDR1/PD-L1 inhibition was suggested as an approach to boost PCa immunotherapy effectiveness.

The roles and mechanisms of endoplasmic reticulum stress-mediated autophagy in animal viral infections.

The endoplasmic reticulum (ER) is a unique organelle responsible for protein synthesis and processing, lipid synthesis in eukaryotic cells, and the replication of many animal viruses is closely related to ER. A considerable number of viral proteins are synthesised during viral infection, resulting in the accumulation of unfolded and misfolded proteins in ER, which in turn induces endoplasmic reticulum stress (ERS). ERS further drives three signalling pathways (PERK, IRE1, and ATF6) of the cellular unfolded protein response (UPR) to respond to the ERS. In numerous studies, ERS has been shown to mediate autophagy, a highly conserved cellular degradation mechanism to maintain cellular homeostasis in eukaryotic cells, through the UPR to restore ER homeostasis. ERS-mediated autophagy is closely linked to the occurrence and development of numerous viral diseases in animals. Host cells can inhibit viral replication by regulating ERS-mediated autophagy, restoring the ER's normal physiological process. Conversely, many viruses have evolved strategies to exploit ERS-mediated autophagy to achieve immune escape. These strategies include the regulation of PERK-eIF2α-Beclin1, PERK-eIF2α-ATF4-ATG12, IRE1α-JNK-Beclin1, and other signalling pathways, which provide favourable conditions for the replication of animal viruses in host cells. The ERS-mediated autophagy pathway has become a hot topic in animal virological research. This article reviews the most recent research regarding the regulatory functions of ERS-mediated autophagy pathways in animal viral infections, emphasising the underlying mechanisms in the context of different viral infections. Furthermore, it considers the future direction and challenges in the development of ERS-mediated autophagy targeting strategies for combating animal viral diseases, which will contribute to unveiling their pathogenic mechanism from a new perspective and provide a scientific reference for the discovery and development of new antiviral drugs and preventive strategies.

CD24 affects the immunosuppressive effect of tumor-infiltrating cells and tumor resistance in a variety of cancers.

BACKGROUND: Cluster of differentiation 24 (CD24) is a highly glycosylated glycosylphosphatidylinositol (GPI)-anchored surface protein, expressed in various tumor cells, as a "don't eat me" signaling molecule in tumor immune. This study aimed to investigate the potential features of CD24 in pan-cancer. METHODS: The correlations between 22 immune cells and CD24 expression were using TIMER analysis. R package "ESTIMATE" was used to predict the proportion of immune and stromal cells in pan-cancer. Spearman's correlation analysis was performed to evaluate the relationships between CD24 expression and immune checkpoints, chemokines, mismatch repair, tumor mutation burden and microsatellite instability, and qPCR and western blot were conducted to assess CD24 expression levels in liver hepatocellular carcinoma (LIHC). In addition, loss of function was performed for the biological evaluation of CD24 in LIHC. RESULTS: CD24 expression was positively correlated with myeloid cells, including neutrophils and myeloid-derived suppressor cells, in various tumors, such as BLCA, HNSC-HPV, HNSC, KICH, KIRC, KIRP, TGCT, THCA, THYM, and UCEC. In contrast, anti-tumor NK cells and NKT cells showed a negative association with CD24 expression in BRCA-Her2, ESCA, HNSC-HPV, KIRC, THCA, and THYM. The top three tumors with the highest correlation between CD24 and ImmuneScore were TGCT, THCA, and SKCM. Functional enrichment analysis revealed CD24 expression was negatively associated with various immune-related pathways. Immune checkpoints and chemokines also exhibited inverse correlations with CD24 in CESC, CHOL, COAD, ESCA, READ, TGCT, and THCA. Additionally, CD24 was overexpressed in most tumors, with high CD24 expression in BRCA, LIHC, and CESC correlating with poor prognosis. The TIDE database indicated tumors with high CD24 expression, particularly melanoma, were less responsive to PD1/PD-L1 immunotherapy. Finally, CD24 knockdown resulted in impaired proliferation and cell cycle progression in LIHC. CONCLUSION: CD24 participates in regulation of immune infiltration, influences patient prognosis and serves as a potential tumor marker.

Enhancing the cytotoxicity of immunotoxins by facilitating their dissociation from target receptors under the reducing conditions of the endocytic pathway.

Immunotoxins (ITs) are recombinant chimeric proteins that combine a protein toxin with a targeting moiety to facilitate the selective delivery of the toxin to cancer cells. Here, we present a novel strategy to enhance the cytosolic access of ITs by promoting their dissociation from target receptors under the reducing conditions of the endocytic pathway. We engineered monobodySS, a human fibronectin type III domain-based monobody with disulfide bond (SS)-containing paratopes, targeting receptors such as EGFR, EpCAM, Her2, and FAP. MonobodySS exhibited SS-dependent target receptor binding with a significant reduction in binding under reducing conditions. We then created monobodySS-based ITs carrying a 25 kDa fragment of Pseudomonas exotoxin A (PE25), termed monobodySS-PE25. These ITs showed dose-dependent cytotoxicity against target receptor-expressing cancer cells and a wider therapeutic window due to higher efficacy at lower doses compared to controls with SS reduction inhibited. ERSS/28-PE25, with a KD of 28 nM for EGFR, demonstrated superior tumor-killing potency compared to ER/21-PE25, which lacks an SS bond, at equivalent and lower doses. In vivo, ERSS/28-PE25 outperformed ER/21-PE25 in suppressing tumor growth in EGFR-overexpressing xenograft mouse models. This study presents a strategy for developing solid tumor-targeting ITs using SS-containing paratopes to enhance cytosolic delivery and antitumor efficacy.

Exosomes: a significant medium for regulating drug resistance through cargo delivery.

Exosomes are small lipid nanovesicles with a diameter of 30-150 nm. They are present in all body fluids and are actively secreted by the majority of cells through the process of exocytosis. Exosomes play an essential role in intercellular communication and act as significant molecular carriers in regulating various physiological and pathological processes, such as the emergence of drug resistance in tumors. Tumor-associated exosomes transfer drug resistance to other tumor cells by releasing substances such as multidrug resistance proteins and miRNAs through exosomes. These substances change the cell phenotype, making it resistant to drugs. Tumor-associated exosomes also play a role in impacting drug resistance in other cells, like immune cells and stromal cells. Exosomes alter the behavior and function of these cells to help tumor cells evade immune surveillance and form a tumor niche. In addition, exosomes also export substances such as tumoricidal drugs and neutralizing antibody drugs to help tumor cells resist drug therapy. In this review, we summarize the mechanisms of exosomes in promoting drug resistance by delivering cargo in the context of the tumor microenvironment (TME).

Haematopoietic regeneration by HLA-A*0206-deficient clones in severe aplastic anaemia without definitive immunosuppressive treatment.

We describe the case of a 74-year-old man with severe aplastic anaemia who experienced persistent remission attributed to proliferation of HLA allele-deficient clones. Despite an initial worsening of pancytopenia with eltrombopag and ciclosporin treatment, gradual trilineage haematopoietic recovery occurred, with blood counts normalizing over 3 years. Flow cytometry and deep nucleotide sequencing revealed that haematopoiesis was primarily supported by several clones with somatic mutations that inactivated antigen presentation via HLA-A*0206. This suggests that monitoring haematopoietic regeneration by immune escape clones could be an alternative approach for immune aplastic anaemia patients who possess HLA allele-deficient clones and cannot tolerate standard therapy.

Scrolling for fun or to cope? Associations between social media motives and social media disorder symptoms in adolescents and young adults.

Introduction: Although not yet recognized as an official disorder, Social Media Disorder (SMD) has recently received considerable interest in the research. However, relatively little is known about underlying motives for social media use and to what extent motives show differential associations with SMD symptom severity and SMD diagnosis. The overall aim of the present study was therefore to examine motives for social media use in relation to (1) which motives are most common, (2) associations between motives and both SMD symptom severity and SMD diagnosis, and (3) the effects of sex and age. Methods: Data were collected through a digital survey (n = 1820) and included both high school students (n = 924) and university students (n = 896). Six different motives were assessed, and SMD was measured in relation to both Heavy Involvement and Negative Consequences of social media use. Results: The results showed that the most common social media use motives were Entertainment, Social Maintenance, and Information and Skills. However, it was the three least common motives - Social Compensation, Self-status, and Escape - that were most strongly associated with SMD symptom severity and SMD diagnosis. These three motives explained as much as 42% of the variance in negative consequences of social media use. Only a few small effects of sex or age were found. Discussion: Some social media use motives are much more strongly associated with SMD than others are. This could indicate that prevention and intervention programs should target these motives specifically, rather than focusing on social media use in general.

Involvement of tumor immune microenvironment metabolic reprogramming in colorectal cancer progression, immune escape, and response to immunotherapy.

Metabolic reprogramming is a k`ey hallmark of tumors, developed in response to hypoxia and nutrient deficiency during tumor progression. In both cancer and immune cells, there is a metabolic shift from oxidative phosphorylation (OXPHOS) to aerobic glycolysis, also known as the Warburg effect, which then leads to lactate acidification, increased lipid synthesis, and glutaminolysis. This reprogramming facilitates tumor immune evasion and, within the tumor microenvironment (TME), cancer and immune cells collaborate to create a suppressive tumor immune microenvironment (TIME). The growing interest in the metabolic reprogramming of the TME, particularly its significance in colorectal cancer (CRC)-one of the most prevalent cancers-has prompted us to explore this topic. CRC exhibits abnormal glycolysis, glutaminolysis, and increased lipid synthesis. Acidosis in CRC cells hampers the activity of anti-tumor immune cells and inhibits the phagocytosis of tumor-associated macrophages (TAMs), while nutrient deficiency promotes the development of regulatory T cells (Tregs) and M2-like macrophages. In CRC cells, activation of G-protein coupled receptor 81 (GPR81) signaling leads to overexpression of programmed death-ligand 1 (PD-L1) and reduces the antigen presentation capability of dendritic cells. Moreover, the genetic and epigenetic cell phenotype, along with the microbiota, significantly influence CRC metabolic reprogramming. Activating RAS mutations and overexpression of epidermal growth factor receptor (EGFR) occur in approximately 50% and 80% of patients, respectively, stimulating glycolysis and increasing levels of hypoxia-inducible factor 1 alpha (HIF-1α) and MYC proteins. Certain bacteria produce short-chain fatty acids (SCFAs), which activate CD8+ cells and genes involved in antigen processing and presentation, while other mechanisms support pro-tumor activities. The use of immune checkpoint inhibitors (ICIs) in selected CRC patients has shown promise, and the combination of these with drugs that inhibit aerobic glycolysis is currently being intensively researched to enhance the efficacy of immunotherapy.

Obovatol inhibits proliferation, invasion and immune escape of hepatocellular carcinoma cells through modulating the JAK/STST3/PD-L1 pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common cancer that is fatal and has a dismal prognosis. Obovatol (Ob), a novel lignan derived from the leaf and stem bark of Magnolia obovata Thunb, has exhibited anti-tumor effect on diverse tumors. However, its effect and mechanisms on HCC remain to be further explored. METHODS: Huh7 and Hep3B cells, as well as BALB/c nude mice were used to determine the function and mechanisms of Ob on growth, invasion and immune escape by cell counting kit-8, transwell, enzyme-linked immunosorbent assay (ELISA) and western blot experiments. RESULTS: Ob reduced the cell viability of Huh7 and Hep3B cells, with a IC50 value of 57.41 µM and 62.86 µM, respectively. Ob declined the invasion ability, the protein expression of N-cadherin and the concentrations of IL-10 and TGF-ß, whereas increased the E-cadherin expression and the contents of IFN-γ and IL-2 in Hep3B and Huh7 cells. Mechanically, Ob decreased the protein level of p-JAK/JAK, p-STAT3/STAT3 and PD-L1, which was partly restored with the treatment of RO8191, an activator of JAK/STAT3 axis. The effect of Ob on the cell viability, the invasion ability, the protein level of N-cadherin and E-cadherin, and the concentrations of IL-10, TGF-ß, IFN-γ and IL-2 in both Hep3B and Huh7 cells was reversed with the management of RO8191. In vivo, Ob reduced tumor volume and weight, the level of N-cadherin, PD-L1, p-JAK/JAK, and p-STAT3/STAT3, with an elevated expression of E-cadherin and IFN-γ. CONCLUSION: Ob downregulated the JAK/STST3/PD-L1 pathway to attenuate the growth, invasion and immune escape of HCC.

Asiaticoside enhances the effect of propofol on the invasion, ferroptosis and immune escape of bladder cancer.

Bladder cancer is a highly prevalent malignancy. Asiaticoside (AC), a triterpenoid derivative, exhibits antitumor effect on different tumors. This study aimed to explore the role and mechanism of AC on bladder cancer. J82 and T24 cells were treated with AC and/or propofol, and nude mice were subcutaneously administrated with T24 cells. The effect and mechanism of AC and/or propofol were explored by cell counting kit-8, transwell, flow cytometry, enzyme-linked immunosorbent assay, immunohistochemistry and western blot assays both in vitro and in vivo. Cell viability of J82 and T24 cells was inhibited by AC with a IC50 value of 2.43 µM and 2.16 µM, and by propofol with a IC50 value of 42.51 µM and 48.37 µM, respectively. AC or propofol alone decreased cell proliferation, invasion, and immune escape with the increased ferroptosis, as well as downregulating the level of the PI3K/AKT pathway in both animal and cell experiments. The effect of propofol on the above-mentioned indicators was further enhanced with the co-treatment of AC in vitro and in vivo. Taken together, AC promoted the ameliorative effect of propofol on bladder cancer involved in PI3K/AKT pathway.

The CALR mutations enhance the expression of the immunosuppressive proteins GARP and LAP on peripheral blood lymphocytes through increased binding of activated platelets.

Recently, an antibody which inhibits the glycoprotein A repetitions predominant (GARP)-mediated release of active transforming growth factor beta (TGFß) from the TGFß propeptide latency-associated peptide (LAP) showed preclinical activity in a murine model of the chronic myeloproliferative neoplasms (MPN). Consequently, we investigated the expression of the immunosuppressive molecules LAP and GARP on peripheral blood lymphocytes from 56 MPN patients and 11 healthy donors (HD). We found that lymphocytes from patients with MPN express higher levels of LAP and GARP with no strong differences found between the different MPN diagnoses. The impact of clinical parameters on the expression of LAP and GARP by lymphocytes showed that patients with calreticulin (CALR)mut MPN have increased expression compared with HD and patients with the Januskinase2 (JAK2) mutation. The fraction of lymphocytes bound to activated platelets (aPLT) strongly correlate to LAP and GARP expression suggesting that it is not the lymphocytes themselves but aPLT, which confer the increased expression of GARP and LAP on MPN patient lymphocytes. Notably, no differences in neither platelet counts nor anti-thrombotic therapy was identified between patients with JAK2- and CALRmut patients. Analysis of platelet gene expression failed to identify differences in expression of relevant genes between JAK2- and CALRmut patients.

PTBP3 Mediates IL-18 Exon Skipping to Promote Immune Escape in Gallbladder Cancer.

Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system, with poor response to current treatments. Abnormal alternative splicing has been associated with the development of a variety of tumors. Combining the GEO database and GBC mRNA-seq analysis, it is found high expression of the splicing factor polypyrimidine region- binding protein 3 (PTBP3) in GBC. Multi-omics analysis revealed that PTBP3 promoted exon skipping of interleukin-18 (IL-18), resulting in the expression of ΔIL-18, an isoform specifically expressed in tumors. That ΔIL-18 promotes GBC immune escape by down-regulating FBXO38 transcription levels in CD8+T cells to reduce PD-1 ubiquitin-mediated degradation is revealed. Using a HuPBMC mouse model, the role of PTBP3 and ΔIL-18 in promoting GBC growth is confirmed, and showed that an antisense oligonucleotide that blocked ΔIL-18 production displayed anti-tumor activity. Furthermore, that the H3K36me3 promotes exon skipping of IL-18 by recruiting PTBP3 via MRG15 is demonstrated, thereby coupling the processes of IL-18 transcription and alternative splicing. Interestingly, it is also found that the H3K36 methyltransferase SETD2 binds to hnRNPL, thereby interfering with PTBP3 binding to IL-18 pre-mRNA. Overall, this study provides new insights into how aberrant alternative splicing mechanisms affect immune escape, and provides potential new perspectives for improving GBC immunotherapy.