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Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis and current therapies show limited efficacy. Ligands and receptors of the TIGIT axis were analyzed using multicolor flow cytometry of tumor and blood samples, immunohistochemistry from primary tumors, and single-cell RNA sequencing from primary tumors and liver metastasis from patients with various stages of PDAC. The effect of soluble and plate-bound Nectin-4 on T cell function was tested in vitro. Further, patient-derived PDAC organoids were treated with the standard of care therapies FOLFIRINOX, gemcitabine plus paclitaxel, or the antibody-drug conjugate enfortumab vedotin. TIGIT expression was increased on tumor-infiltrating conventional and regulatory T cells compared with T cells from matched blood. Nectin-4, but not CD155 expression was associated with poor outcome. Nectin-4 was exclusively expressed by tumor cells and correlated with low immune infiltration. Notably, Nectin-4 inhibited T cell effector cytokine production in vitro. Targeting Nectin-4 with the antibody-drug conjugate enfortumab vedotin inhibited tumor growth in multiple patient-derived PDAC organoids. Collectively, our data underscores Nectin-4 as a novel therapeutic target and provides the rationale to test this agent in PDAC patients.

Infection leads to durable cell-autonomous changes in hematopoietic stem and progenitor cells (HSPCs), resulting in production of innate immune cells with heightened immunity. The mechanisms underlying this phenomenon, termed central trained immunity, remain poorly understood. We hypothesized that infection induces histone modifications leading to changes in chromatin accessibility that are conserved during differentiation from HSPCs to myeloid progenitors and monocytes. We conducted genome-wide surveillance of histone marks H3K27ac and H3K4me3 and chromatin accessibility in hematopoietic stem cells, multipotent progenitor 3, granulocyte-monocyte progenitors, monocytes and macrophages of naïve and Mycobacterium avium infected mice. Interferon signaling pathways and related transcription factor binding motifs including IRFs, NF-κB, and CEBP showed increased activating histone marks and chromatin accessibility across cell types. However, histone marks and increased chromatin accessibility were conserved at only a few loci, notably Irf1 and Gbp6. Knock out of IRF1 disrupted enhanced mitochondrial respiration and bacterial killing in human monocyte cell lines, while GBP6 KO monocyte cell lines showed dysregulated mitochondrial respiration. In summary, this study identifies IRF1 and GBP6 as two key loci at which infection-induced systemic inflammation leads to epigenetic changes that are conserved from HSPCs to downstream monocytes, providing a mechanistic avenue for central trained immunity.

Vaso-occlusive episodes (VOEs) in the setting of hyperhemolysis can rapidly evolve into multiorgan failure in sickle cell disease (SCD). Although the mechanisms for rapid progression to multiorgan failure are unclear, a systemic vasculopathy with thrombotic microangiopathy-type features has been described. Reduced thrombomodulin (TM) function is implicated in some thrombotic microangiopathy syndromes. We observed a greater decline in platelet count and hemoglobin concentration and increase in vascular injury biomarkers within 24-hours of admission for a VOE in 12 SCD patients with versus 12 without multiorgan failure. We observed decreased TM expression on the lung and kidney vasculature of three additional SCD patients with multiorgan failure and an autopsy performed compared to a non-SCD control. Transgenic SCD mice challenged with cell-free hemoglobin had reduced TM function, increased vascular injury biomarkers, and reduced renal cortical blood flow. Infusion of recombinant TM 2- or 24-hours after the challenge restored cortical blood flow, mitigated increases in vascular injury, complement activation, and tubular injury biomarkers, and protected against acute kidney and lung injury. We demonstrated that impaired TM function may be involved in the systemic vasculopathy of SCD-related multiorgan failure and infusion of recombinant TM may restore vascular function and protect against acute organ damage.

Epigenetic macromolecular enzyme complexes tightly regulate gene expression at the chromatin level and have recently been found to colocalize with RNA splicing machinery during active transcription; however, the precise functional consequences of these interactions are uncertain. Here, we identify unique interactions of the CoREST repressor complex (LSD1-HDAC1-CoREST) with components of the RNA splicing machinery and their functional consequences in tumorigenesis. Using mass spectrometry, in vivo binding assays, and cryo-EM we find that CoREST complex-splicing factor interactions are direct and perturbed by the CoREST complex selective inhibitor, corin, leading to extensive changes in RNA splicing in melanoma and other malignancies. Moreover, these corin-induced splicing changes are shown to promote global effects on oncogenic and survival-associated splice variants leading to a tumor-suppressive phenotype. Using machine learning models, MHC IP-MS, and ELISpot assays we identify thousands of neopeptides derived from unannotated splice sites which generate corin-induced splice-neoantigens that are demonstrated to be immunogenic in vitro. Corin is further shown to reactivate the response to immune checkpoint blockade, effectively sensitizing tumors to anti-PD1 immunotherapy. These data position CoREST complex inhibition as a unique therapeutic opportunity which perturbs oncogenic splicing programs while also creating tumor-associated neoantigens that enhance the immunogenicity of current therapeutics.

The biological age of organs may better quantify risk for health deterioration compared with chronological age. We investigated organ-specific aging patterns in a community-based cohort and assessed the associations with adverse health outcomes. Biological ages of 11 organs were estimated for 11,757 participants of the Atherosclerosis Risk in Communities (ARIC) study (55.6% women, mean age, 57.1 years) using a circulating protein-based model. Older organ ages were significantly associated with related adverse outcomes, even after accounting for chronological age; for example, older arteries and hearts were associated with an increased risk for coronary heart disease (CHD; hazard ratio [HR] per 5-year-higher age gap, 1.22; 95% CI [1.13-1.31] and 1.16 [1.07-1.26], respectively, and older lungs with lung cancer (HR 1.12 [1.09-1.16]). Hierarchical agglomerative clustering based on organ ages revealed 3 patient phenotypes: those with older organs, normal/slightly older organs, and younger organs. The patients with older organs were at higher risk for cancer (HR 1.19; 95% CI [1.08-1.31]), death (HR 1.75 [1.64-1.86]), end-stage kidney disease (HR 6.12 [4.65-8.06]), CHD (HR 1.21 [1.06-1.38]), heart failure (HR 1.92 [1.73-2.13]), infection (HR 1.56 [1.44-1.68]), and stroke (HR 1.36 [1.16-1.61]). Proteomic organ aging signatures demonstrated significant associations with multiple adverse health outcomes and may be useful for health risk identification.

Glycolysis fuels cytotoxic allogeneic T cells in acute graft-versus-host disease (aGvHD), but the downstream role of glucose metabolism in modulating aGvHD remains unclear. Targeting glycolysis or glucose receptors is toxic. Therefore, we explored alternative glucose-dependent pathways, focusing on the pentose phosphate pathway (PPP). Single-cell RNA sequencing revealed PPP upregulation in allogeneic T cells during allogeneic hematopoietic cell transplantation (allo-HCT). We showed that donor T cell deficiency in 6-phosphogluconate dehydrogenase (6PGD), the second rate-limiting enzyme in the PPP, significantly reduced aGvHD severity and mortality in murine models. Functional assays demonstrated that PPP blockade led to proliferation arrest without inducing apoptosis. PPP blockade shifted T cell metabolism away from T cell dependency on glycolysis for rapid T cell proliferation. Pharmacological inhibition of the PPP through 6PGD blockade with 6-aminonicotinamide (6AN) effectively reduced aGvHD severity, like donor 6PGD-deficient T cells in an allogeneic aGvHD model. Similarly, 6AN reduced xenogeneic GvHD lethality. 6PGD inhibition preserved the graft-versus-tumor (GvT) effect, with the generation of a small subset of granzyme Bhi effector T cells with potent antitumor activity. These findings highlight the PPP as a key regulator of allogeneic T cell proliferation and differentiation and identify 6PGD as a promising therapeutic target to mitigate aGvHD severity while preserving beneficial GvT effects.

BACKGROUNDSuboptimal fetal growth (SFG), being born small for gestational age (SGA), and catch-up (CU) growth are, individually and together, linked to cardiometabolic risks. However, not all develop adverse outcomes. This study aimed to validate a transcriptomic signature to identify individuals at greatest cardiometabolic risk.METHODSUsing National Heart, Lung and Blood Institute (NHLBI) criteria to define cardiometabolic risk, healthy and prehypertensive 17-year-olds were identified in the Avon Longitudinal Study of Parents and Children (ALSPAC) (UK) childhood cohort. Epigenomic and transcriptomic differences were analyzed. A hypergraph identified functionally related genes, which were used in random forest classification to predict prehypertensive phenotypes. The BabyGRO (UK) cohort included 80 children aged 3-7 years, born at term following pregnancies with SFG risks. Anthropometric and cardiometabolic markers and transcriptomic profiles were collected, fetal and childhood weight trajectories and their relationship to cardiometabolic markers were assessed, and transcriptome was used for prediction.RESULTSIndividuals with CU-SGA in ALSPAC were 1.6 times more likely than all others to be prehypertensive at 17 years (P < 1 × 10-5). A 42-gene hypergraph cluster was highly predictive of prehypertension (AUC 0.984, error rate 5.4%). In BabyGRO, 20 of these genes accurately predicted higher systolic blood pressure (AUC 0.971, error rate 3.6%). This transcriptomic signature could help identify children with adverse pre- and postnatal growth who may develop prehypertension.CONCLUSIONA blood transcriptomic signature exists in childhood which distinguishes those at risk of adult cardiometabolic disease among children with adverse pre- and postnatal growth.TRIAL REGISTRATIONRegional ethics committee reference 17/NW/0153, IRAS project ID 187679.FUNDINGCentre grant to the Maternal and Fetal Health Research Centre by Tommy's The Pregnancy and Baby Charity, Child Growth Foundation, European Research Council funding as part of the Health and Environment-wide Associations based on Large Population Surveys (HEALS) study.

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. During early sepsis, kinins are released and bind to B1 (BDKRB1) and B2 (BDKRB2) bradykinin receptors, but the involvement of these receptors in sepsis remains incompletely understood. This study demonstrated that the genetic deletion of Bdkrb2 had no significant impact on sepsis induced by cecal ligation and puncture (CLP) compared to wild-type (WT) mice. In contrast, Bdkrb1-/- mice subjected to CLP exhibited decreased lethality and bacterial load, associated with an increased influx of neutrophils into the peritoneal cavity, compared with WT mice. Neutrophils from CLP-Bdkrb1-/- mice partially restored CXCR2 expression and reduced the upregulation of P110γ observed in WT CLP neutrophils. Pharmacologic inhibition of BDKRB1 combined with imipenem treatment substantially improved survival compared with antibiotic therapy alone. In human neutrophils, stimulation with LPS led to the upregulation of BDKRB1 expression, and antagonism of BDKRB1 restored neutrophil migration in response to CXCL8. These findings identify BDKRB1 as an important modulator of neutrophil dysfunction in sepsis and a promising therapeutic target whose inhibition improves bacterial clearance, restores neutrophil migration, and increases the efficacy of antibiotic treatment.

Mitochondrial dysfunction is a major mechanism of acute kidney injury (AKI), and increased circulating interleukin 6 (IL-6) is associated with systemic inflammation and death due to sepsis. We tested whether kidney mitochondrial DNA (mtDNA) contributes to IL-6 release in sepsis-associated AKI via Toll-like receptor 9 (TLR9). In a murine model of sepsis via cecal ligation and puncture (CLP), we used next-generation sequencing of plasma mtDNA to inform the design of optimal target sequences for quantification by droplet digital PCR, and to identify single-nucleotide polymorphisms (SNPs) to infer tissue origin. We found significantly higher concentrations of plasma mtDNA after CLP versus shams and that plasma mtDNA SNPs matched kidney SNPs more than other organs. Kidney mtDNA contributed directly to IL-6 and mtDNA release from dendritic cells in vitro and kidney mitochondria solution led to higher IL-6 concentrations in vivo. IL-6 release was mitigated by a TLR9 inhibitor. Finally, plasma mtDNA was significantly higher in septic patients with AKI compared with those without AKI and correlated significantly with plasma IL-6. We conclude that AKI contributes to increased circulating IL-6 in sepsis via mtDNA release. Targeting kidney mitochondria and mtDNA release are potential translational avenues to decrease mortality from sepsis-associated AKI.

Recombinant hepatitis B surface antigen (rHBsAg) vaccine with various adjuvants fails to break T and B cell tolerance in hosts with chronic hepatitis B (CHB). This study aims to explore the mechanisms to break immune tolerance that allows the host to respond to rHBsAg, achieving a cure for CHB. We engineered an anti-PD-L1-IFN-α (aPD-L1-IFN-α) heterodimeric fusion protein to allow rHBsAg to rejuvenate T and B cell responses in hepatitis B virus-tolerant (HBV-tolerant) mice. S.c. coimmunization with aPD-L1-IFN-α and rHBsAg significantly enhanced antigen uptake and maturation of both macrophage and dendritic cell (DC) subsets in draining lymph nodes. Macrophages drove early B cell activation, while cDC1s primed CD8+ T cells, breaking tolerance and leading to both B cell and cytotoxic T lymphocyte (CTL) differentiation. This strategy elicited not only anti-HBsAg neutralizing antibodies but also HBsAg-specific CD8+ T cell responses, achieving a functional cure without systemic toxicity. The efficacy of the aPD-L1-IFN-α adjuvant depended on both PD-L1 cis-targeting and IFN-α receptor signaling in antigen-presenting cells. These findings establish aPD-L1-IFN-α as a translatable adjuvant to break the strong tolerance induced by CHB, providing a dual-pathway strategy to induce HBV-specific T and B cell responses.