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BackgroundAt present,hepatic ischemia-reperfusion injury (IRI) is an important complication of partial hepatectomy and liver transplantation,and it is an important cause of poor prognosis. Spleen tyrosine kinase(SYK) plays an important role in a variety of signaling pathways in the liver,but its role in hepatic IRI is still unclear. This study aims to investigate the role and mechanism of SYK in hepatic IRI and tumor recurrence.MethodsWe first observed the activation of SYK in the liver of mice in response to hepatic IRI. Subsequently,Pharmacological inhibitions of SYK were used to evaluated the effect of SYK on neutrophil recruitment and NETosis,and further explored the effect of SYK on IRI and tumor recurrence.ResultsOur study shows that SYK is activated in response to hepatic IRI and aggravates liver injury. On the one hand,neutrophils SYK during the early stage of liver reperfusion increases neutrophil extracellular traps (NETs) production by promoting Pyruvate kinase M2(PKM2) nuclear translocation leading to upregulation of phosphorylated STAT3,thereby exacerbating liver inflammation and tumor recurrence. On the other hand,macrophages SYK can promote the recruitment of neutrophils and increase the activation of NLRP3 inflammasome and IL1β,which further promotes the formation of NETs.ConclusionsOur study demonstrates that neutrophil and macrophage SYK synergistically promote hepatic IRI and tumor recurrence,and SYK may be a potential target to improve postoperative hepatic IRI and tumor recurrence.Supplementary InformationThe online version contains supplementary material available at 10.1186/s10020-024-00907-7. View Publication

SummaryAntibodies represent a primary mediator of protection against respiratory viruses. Serum neutralizing antibodies (NAbs) are often considered a primary correlate of protection. However,detailed antibody profiles including characterization of antibody functions in different anatomic compartments are poorly understood. Here we show that antibody correlates of protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) challenge are different in systemic versus mucosal compartments in rhesus macaques. In serum,NAbs were the strongest correlate of protection and linked to spike-specific binding antibodies and other extra-NAb functions that create a larger protective network. In bronchiolar lavage (BAL),antibody-dependent cellular phagocytosis (ADCP) proved the strongest correlate of protection rather than NAbs. Within BAL,ADCP was linked to mucosal spike-specific immunoglobulin (Ig)G,IgA/secretory IgA,and Fcγ-receptor binding antibodies. Our results support a model in which antibodies with different functions mediate protection at different anatomic sites. Graphical abstract Highlights•Correlates of protection to SARS-CoV-2 Omicron are highly compartment specific•Antibody effector functions are primary correlates of protection at infection site•Mucosal boosting enhances IgA and functionally levered IgG in lower respiratory tract Health sciences; Biological sciences View Publication

Pain and inflammation contribute immeasurably to reduced quality of life,yet modern analgesic and anti-inflammatory therapeutics can cause dependence and side effects. Here,we screened 1444 plant extracts,prepared primarily from native species in California and the United States Virgin Islands,against two voltage-gated K+ channels - T-cell expressed Kv1.3 and nociceptive-neuron expressed Kv7.2/7.3. A subset of extracts both inhibits Kv1.3 and activates Kv7.2/7.3 at hyperpolarized potentials,effects predicted to be anti-inflammatory and analgesic,respectively. Among the top dual hits are witch hazel and fireweed; polymodal modulation of multiple K+ channel types by hydrolysable tannins contributes to their dual anti-inflammatory,analgesic actions. In silico docking and mutagenesis data suggest pore-proximal extracellular linker sequence divergence underlies opposite effects of hydrolysable tannins on different Kv1 isoforms. The findings provide molecular insights into the enduring,widespread medicinal use of witch hazel and fireweed and demonstrate a screening strategy for discovering dual anti-inflammatory,analgesic small molecules. A dual potassium channel functional screen of 1444 plant extracts uncovers unexpected molecular mechanisms underlying the traditional use of witch hazel and fireweed as analgesic,anti-inflammatory medicines. View Publication

A shift of arginine metabolism from polyamine synthesis to nitric oxide synthesis induces reprogramming of macrophages from pro-tumor M2 to anti-tumor M1 types. HER2+ breast tumors have abundant immune-suppressive cells,including M2-type tumor-associated macrophages (TAMs). Although TAMs consist of the immune-stimulatory M1 type and immune-suppressive M2 type,the M1/M2-TAM ratio is reduced in immune-suppressive tumors,contributing to their immunotherapy refractoriness. M1- versus M2-TAM formation depends on differential arginine metabolism,where M1-TAMs convert arginine to nitric oxide (NO) and M2-TAMs convert arginine to polyamines (PAs). We hypothesize that such distinct arginine metabolism in M1- versus M2-TAMs is attributed to different availability of BH4 (NO synthase cofactor) and that its replenishment would reprogram M2-TAMs to M1-TAMs. Recently,we reported that sepiapterin (SEP),the endogenous BH4 precursor,elevates the expression of M1-TAM markers within HER2+ tumors. Here,we show that SEP restores BH4 levels in M2-like macrophages,which then redirects arginine metabolism to NO synthesis and converts M2 type to M1 type. The reprogrammed macrophages exhibit full-fledged capabilities of antigen presentation and induction of effector T cells to trigger immunogenic cell death of HER2+ cancer cells. This study substantiates the utility of SEP in the metabolic shift of the HER2+ breast tumor microenvironment as a novel immunotherapeutic strategy. View Publication

SummaryA tissue resident-like phenotype in tumor infiltrating T cells can limit systemic anti-tumor immunity. Enhanced systemic anti-tumor immunity is observed in head and neck cancer patients after neoadjuvant PD-L1 immune checkpoint blockade (ICB) and transforming growth factor β (TGF-β) neutralization. Using T cell receptor (TCR) sequencing and functional immunity assays in a syngeneic model of oral cancer,we dissect the relative contribution of these treatments to enhanced systemic immunity. The addition of TGF-β neutralization to ICB resulted in the egress of expanded and exhausted CD8+ tumor infiltrating lymphocytes (TILs) into circulation and greater systemic anti-tumor immunity. This enhanced egress associated with reduced expression of Itgae (CD103) and its upstream regulator Znf683. Circulating CD8+ T cells expressed higher Cxcr3 after treatment,an observation also made in samples from patients treated with dual TGF-β neutralization and ICB. These findings provide the scientific rationale for the use of PD-L1 ICB and TGF-β neutralization in newly diagnosed patients with carcinomas prior to definitive treatment of locoregional disease. Graphical abstract Highlights•TGF-β blockade reduces Znf683 and CD103 in αPDL1-activated TILs•Reduced TIL CD103 expression associates with egress into circulation•The addition of TGF-β blockade to αPDL1 enhances systemic anti-tumor immunity•Circulating CD8+ T cells express greater CXCR3 after dual TGF-β and PDL1 blockade Natural sciences; Biological sciences; Immunology ; Immune response; Systems biology; Cancer systems biology; Cancer View Publication

Epstein-Barr Virus (EBV) is associated with numerous cancers including B cell lymphomas. In vitro,EBV transforms primary B cells into immortalized Lymphoblastoid Cell Lines (LCLs) which serves as a model to study the role of viral proteins in EBV malignancies. EBV induced cellular transformation is driven by viral proteins including EBV-Nuclear Antigens (EBNAs). EBNA-LP is important for the transformation of naïve but not memory B cells. While EBNA-LP was thought to promote gene activation by EBNA2,EBNA-LP Knockout (LPKO) virus-infected cells express EBNA2-activated cellular genes efficiently. Therefore,a gap in knowledge exists as to what roles EBNA-LP plays in naïve B cell transformation. We developed a trans-complementation assay wherein transfection with wild-type EBNA-LP rescues the transformation of peripheral blood- and cord blood-derived naïve B cells by LPKO virus. Despite EBNA-LP phosphorylation sites being important in EBNA2 co-activation; neither phospho-mutant nor phospho-mimetic EBNA-LP was defective in rescuing naïve B cell outgrowth. However,we identified conserved leucine-rich motifs in EBNA-LP that were required for transformation of adult naïve and cord blood B cells. Because cellular PPAR-g coactivator (PGC) proteins use leucine-rich motifs to engage transcription factors including YY1,a key regulator of DNA looping and metabolism,we examined the role of EBNA-LP in engaging transcription factors. We found a significant overlap between EBNA-LP and YY1 in ChIP-Seq data. By Cut&Run,YY1 peaks unique to WT compared to LPKO LCLs occur at more highly expressed genes. Moreover,Cas9 knockout of YY1 in primary B cells prior to EBV infection indicated YY1 to be important for EBV-mediated transformation. We confirmed EBNA-LP and YY1 biochemical association in LCLs by endogenous co-immunoprecipitation and found that the EBNA-LP leucine-rich motifs were required for YY1 interaction in LCLs. We propose that EBNA-LP engages YY1 through conserved leucine-rich motifs to promote EBV transformation of naïve B cells. Author summaryEpstein-Barr Virus (EBV) is associated with various B cell lymphomas,particularly in immunosuppressed individuals. In the absence of a functional immune system,viral latency proteins,including EBV Nuclear Antigens (EBNAs) act as oncoproteins to promote tumorigenesis. EBNA-LP is one of the first viral proteins produced after infection and is important for the transformation of naïve B cells. However,the roles of EBNA-LP during infection are largely undefined. In this study,developed an assay in which the role of wild type and mutant EBNA-LP could be investigated in the context of primary naïve B cells infected with an EBNA-LP Knockout virus. Using this assay,we identified highly conserved leucine-rich motifs within EBNA-LP that are important for transformation of EBV-infected naïve B cells. These conserved motifs associate with the cellular transcription factor YY1,an important transcriptional regulator in B cell development and in many cancers,that we now show is essential for outgrowth of EBV infected B cells. Our study provides further insights into the mechanisms by which EBV transforms naïve B cells. View Publication

SummaryTumor-infiltrating regulatory T cells (TI-Tregs) elicit immunosuppressive effects in the tumor microenvironment (TME) leading to accelerated tumor growth and resistance to immunotherapies against solid tumors. Here,we demonstrate that poly-(ADP-ribose)-polymerase-11 (PARP11) is an essential regulator of immunosuppressive activities of TI-Tregs. Expression of PARP11 correlates with TI-Treg cell numbers and poor responses to immune checkpoint blockade (ICB) in human patients with cancer. Tumor-derived factors including adenosine and prostaglandin E2 induce PARP11 in TI-Tregs. Knockout of PARP11 in the cells of the TME or treatment of tumor-bearing mice with selective PARP11 inhibitor ITK7 inactivates TI-Tregs and reinvigorates anti-tumor immune responses. Accordingly,ITK7 decelerates tumor growth and significantly increases the efficacy of anti-tumor immunotherapies including ICB and adoptive transfer of chimeric antigen receptor (CAR) T cells. These results characterize PARP11 as a key driver of TI-Treg activities and a major regulator of immunosuppressive TME and argue for targeting PARP11 to augment anti-cancer immunotherapies. Graphical abstract Highlights•Tumor-derived factors upregulate PARP11 in the tumor-infiltrating Treg cells•PARP11 supports the immunosuppressive properties of Treg cells•Pharmacologic inhibition of PARP11 inactivates intratumoral Treg cells•PARP11 inhibitor augments the efficacy of immunotherapies Basavaraja et al. demonstrate that induction of PARP11 in the intratumoral regulatory T (Treg) cells is required for their regulatory functions and contributes to the immunosuppressive tumor microenvironment. The selective inhibitor of PARP11 ITK7 inactivates tumor Treg cells and improves the efficacy of immunotherapies against tumors. View Publication

IntroductionInnate lymphoid cells (ILCs) are enriched at mucosal surfaces where they respond rapidly to environmental stimuli and contribute to both tissue inflammation and healing. MethodsTo gain insight into the role of ILCs in the pathology and recovery from COVID-19 infection,we employed a multi-omics approach consisting of Abseq and targeted mRNA sequencing to respectively probe the surface marker expression,transcriptional profile and heterogeneity of ILCs in peripheral blood of patients with COVID-19 compared with healthy controls. ResultsWe found that the frequency of ILC1 and ILC2 cells was significantly increased in COVID-19 patients. Moreover,all ILC subsets displayed a significantly higher frequency of CD69-expressing cells,indicating a heightened state of activation. ILC2s from COVID-19 patients had the highest number of significantly differentially expressed (DE) genes. The most notable genes DE in COVID-19 vs healthy participants included a) genes associated with responses to virus infections and b) genes that support ILC self-proliferation,activation and homeostasis. In addition,differential gene regulatory network analysis revealed ILC-specific regulons and their interactions driving the differential gene expression in each ILC. DiscussionOverall,this study provides mechanistic insights into the characteristics of ILC subsets activated during COVID-19 infection. View Publication

Migrasomes are organelles that are generated by migrating cells. Here we report the key role of neutrophil-derived migrasomes in haemostasis. We found that a large number of neutrophil-derived migrasomes exist in the blood of mice and humans. Compared with neutrophil cell bodies and platelets,these migrasomes adsorb and enrich coagulation factors on the surface. Moreover,they are highly enriched with adhesion molecules,which enable them to preferentially accumulate at sites of injury,where they trigger platelet activation and clot formation. Depletion of neutrophils,or genetic reduction of the number of these migrasomes,significantly decreases platelet plug formation and impairs coagulation. These defects can be rescued by intravenous injection of purified neutrophil-derived migrasomes. Our study reveals neutrophil-derived migrasomes as a previously unrecognized essential component of the haemostasis system,which may shed light on the cause of various coagulation disorders and open therapeutic possibilities. Jiang et al. document an abundance of neutrophil-derived migrasomes in the blood of mice and humans and show that migrasomes are enriched in coagulation factors,accumulate at sites of injury and trigger platelet activation and clot formation. View Publication

The progressive decline of CD8 T cell effector function—also known as terminal exhaustion—is a major contributor to immune evasion in cancer. Yet,the molecular mechanisms that drive CD8 T cell dysfunction remain poorly understood. Here,we report that the Kelch-like ECH-associated protein 1 (KEAP1)-Nuclear factor erythroid 2-related factor 2 (NRF2) signaling axis,which mediates cellular adaptations to oxidative stress,directly regulates CD8 T cell exhaustion. Transcriptional profiling of dysfunctional CD8 T cells from chronic infection and cancer reveals enrichment of NRF2 activity in terminally exhausted (Texterm) CD8 T cells. Increasing NRF2 activity in CD8 T cells (via conditional deletion of KEAP1) promotes increased glutathione production and antioxidant defense yet accelerates the development of terminally exhausted (PD-1+TIM-3+) CD8 T cells in response to chronic infection or tumor challenge. Mechanistically,we identify PTGIR,a receptor for the circulating eicosanoid prostacyclin,as an NRF2-regulated protein that promotes CD8 T cell dysfunction. Silencing PTGIR expression restores the anti-tumor function of KEAP1-deficient T cells. Moreover,lowering PTGIR expression in CD8 T cells both reduces terminal exhaustion and enhances T cell effector responses (i.e. IFN-γ and granzyme production) to chronic infection and cancer. Together,these results establish the KEAP1-NRF2 axis as a metabolic sensor linking oxidative stress to CD8 T cell dysfunction and identify the prostacyclin receptor PTGIR as an NRF2-regulated immune checkpoint that regulates CD8 T cell fate decisions between effector and exhausted states. One Sentence Summary:The KEAP1-NRF2 pathway is hyperactivated in terminally exhausted CD8 T cells and drives T cell dysfunction via transcriptional regulation of the prostacyclin receptor,Ptgir. View Publication

SummaryEnvironmental lipids are essential for fueling tumor energetics,but whether these exogenous lipids transported into cancer cells facilitate immune escape remains unclear. Here,we find that CD36,a transporter for exogenous lipids,promotes acute myeloid leukemia (AML) immune evasion. We show that,separately from its established role in lipid oxidation,CD36 on AML cells senses oxidized low-density lipoprotein (OxLDL) to prime the TLR4-LYN-MYD88-nuclear factor κB (NF-κB) pathway,and exogenous palmitate transfer via CD36 further potentiates this innate immune pathway by supporting ZDHHC6-mediated MYD88 palmitoylation. Subsequently,NF-κB drives the expression of immunosuppressive genes that inhibit anti-tumor T cell responses. Notably,high-fat-diet or hypomethylating agent decitabine treatment boosts the immunosuppressive potential of AML cells by hijacking CD36-dependent innate immune signaling,leading to a dampened therapeutic effect. This work is of translational interest because lipid restriction by US Food and Drug Administration (FDA)-approved lipid-lowering statin drugs improves the efficacy of decitabine therapy by weakening leukemic CD36-mediated immunosuppression. Graphical abstract Highlights•CD36 on AML cells suppresses T cell proliferation independently of lipid oxidation•OxLDL and palmitate synergize to inhibit T cell activity via CD36 signaling in AML cells•Targeting CD36 signaling with statins improves the efficacy of decitabine therapy in AML Guo et al. find that OxLDL and palmitate uptake by AML cells synergistically upregulates CD36-mediated innate immune signaling to suppress T cell activity. High-fat-diet or decitabine treatment dampened the therapeutic effect by hijacking CD36 signaling. Targeting the CD36 immunosuppressive pathway with statins improves the efficacy of decitabine therapy in AML. View Publication

BackgroundInterleukin-17 (IL-17) family cytokines promote protective inflammation for pathogen resistance,but also facilitate autoimmunity and tumor development. A direct signal of IL-17 to regulatory T cells (Tregs) has not been reported and may help explain these dichotomous responses.MethodsWe generated a conditional knockout of Il17ra in Tregs by crossing Foxp3-YFP-Cre mice to Il17ra-flox mice (Il17ra ΔTreg mice). Subsequently,we adoptively transferred bone marrow cells from Il17ra ΔTreg mice to a mouse model of sporadic colorectal cancer (Cdx2-Cre +/Apc F/+),to selectively ablate IL-17 direct signaling on Tregs in colorectal cancer. Single cell RNA sequencing and bulk RNA sequencing were performed on purified Tregs from mouse colorectal tumors,and compared to those of human tumor infiltrating Treg cells.ResultsIL-17 Receptor A (IL-17RA) is expressed in Tregs that reside in mouse mesenteric lymph nodes and colon tumors. Ablation of IL-17RA,specifically in Tregs,resulted in increased Th17 cells,and exacerbated tumor development. Mechanistically,tumor-infiltrating Tregs exhibit a unique gene signature that is linked to their activation,maturation,and suppression function,and this signature is in part supported by the direct signaling of IL-17 to Tregs. To study pathways of Treg programming,we found that loss of IL-17RA in tumor Tregs resulted in reduced RNA splicing,and downregulation of several RNA binding proteins that are known to regulate alternative splicing and promote Treg function.ConclusionIL-17 directly signals to Tregs and promotes their maturation and function. This signaling pathway constitutes a negative feedback loop that controls cancer-promoting inflammation in CRC. View Publication