Optimization of the Irf8 +32-kb enhancer disrupts dendritic cell lineage segregation.

Autoactivation of lineage-determining transcription factors mediates bistable expression, generating distinct cell phenotypes essential for complex body plans. Classical type 1 dendritic cell (cDC1) and type 2 dendritic cell (cDC2) subsets provide nonredundant functions for defense against distinct immune challenges. Interferon regulatory factor 8 (IRF8), the cDC1 lineage-determining transcription factor, undergoes autoactivation in cDC1 progenitors to establish cDC1 identity, yet its expression is downregulated during cDC2 differentiation by an unknown mechanism. This study reveals that the Irf8 +32-kb enhancer, responsible for IRF8 autoactivation, is naturally suboptimized with low-affinity IRF8 binding sites. Introducing multiple high-affinity IRF8 sites into the Irf8 +32-kb enhancer causes a gain-of-function effect, leading to erroneous IRF8 autoactivation in specified cDC2 progenitors, redirecting them toward cDC1 and a novel hybrid DC subset with mixed-lineage phenotypes. Further, this also causes a loss-of-function effect, reducing Irf8 expression in cDC1s. These developmental alterations critically impair both cDC1-dependent and cDC2-dependent arms of immunity. Collectively, our findings underscore the significance of enhancer suboptimization in the developmental segregation of cDCs required for normal immune function.

Complete genome sequences of two Pantoea stewartii strains ATCC 8199 from maize and PSCN1 from sugarcane.

OBJECTIVES: The pathogen of Pantoea stewartii (Ps) is the causal agent of bacterial disease in corn and various graminaceous plants. Ps has two subspecies, Pantoea stewartii subsp. stewartia (Pss) and Pantoea stewartii subsp. indologenes (Psi). This study presents two complete genomes of Ps strains including ATCC 8199 isolated from maize and PSCN1 causing bacterial wilt in sugarcane. The two bacterial genomes information will be helpful for taxonomy analysis in this genus Pantoea at whole-genome levels and accurately discriminated the two subspecies of Pss and Psi. DATA DESCRIPTION: The reference strain ATCC 8199 isolated from maize was purchased from Beijing Biobw Biotechnology Co., Ltd. (China) and the strain of PSCN1 was isolated from sugarcane cultivar YZ08-1095 in Zhanjiang, Guangdong province of China. Two complete genomes were sequenced using Illumina Hiseq (second-generation) and Oxford Nanopore (third-generation) platforms. The genome of the strain ATCC 8199 comprised of 4.78 Mb with an average GC content of 54.03%, along with five plasmids, encoding a total of 4,846 gene with an average gene length of 827 bp. The genome of PSCN1 comprised of 5.03 Mb with an average GC content of 53.78%, along with two plasmids, encoding a total of 4,725 gene with an average gene length of 913 bp. The bacterial pan-genome analysis highlighted the strain ATCC 8199 was clustered into a subgroup with a Pss strain CCUG 26,359 from USA, while the strain PSCN1 was clustered into another subgroup with a Ps strain NRRLB-133 from USA. These findings will serve as a useful resource for further analyses of the evolution of Ps strains and corresponding disease epidemiology worldwide.

Anatomy of a superenhancer.

Interferon regulatory factor-8 (IRF8) is the lineage determining transcription factor for the type one classical dendritic cell (cDC1) subset, a terminal selector for plasmacytoid dendritic cells and important for the function of monocytes. Studies of Irf8 gene regulation have identified several enhancers controlling its activity during development of progenitors in the bone marrow that precisely regulate expression at distinct developmental stages. Each enhancer responds to distinct transcription factors that are expressed at each stage. IRF8 is first expressed in early progenitors that form the monocyte dendritic cell progenitor (MDP) in response to induction of the transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) acting at the Irf8 +56 kb enhancer. IRF8 levels increase further as the MDP transits into the common dendritic cell progenitor (CDP) in response to E protein activity at the Irf8 +41 kb enhancer. Upon Nfil3-induction in CDPs leading to specification of the cDC1 progenitor, abrupt induction of BATF3 forms the JUN/BATF3/IRF8 heterotrimer that activates the Irf8 +32 kb enhancer that sustains Irf8 autoactivation throughout the cDC1 lifetime. Deletions of each of these enhancers has revealed their stage dependent activation. Surprisingly, studies of compound heterozygotes for each combination of enhancer deletions revealed that activation of each subsequent enhancer requires the successful activation of the previous enhancer in strictly cis-dependent mechanism. Successful progression of enhancer activation is finely tuned to alter the functional accessibility of subsequent enhancers to factors active in the next stage of development. The molecular basis for these phenomenon is still obscure but could have implications for genomic regulation in a broader developmental context.

Neoantigen-specific cytotoxic Tr1 CD4 T cells suppress cancer immunotherapy.

CD4+ T cells can either enhance or inhibit tumour immunity. Although regulatory T cells have long been known to impede antitumour responses1-5, other CD4+ T cells have recently been implicated in inhibiting this response6,7. Yet, the nature and function of the latter remain unclear. Here, using vaccines containing MHC class I (MHC-I) neoantigens (neoAgs) and different doses of tumour-derived MHC-II neoAgs, we discovered that whereas the inclusion of vaccines with low doses of MHC-II-restricted peptides (LDVax) promoted tumour rejection, vaccines containing high doses of the same MHC-II neoAgs (HDVax) inhibited rejection. Characterization of the inhibitory cells induced by HDVax identified them as type 1 regulatory T (Tr1) cells expressing IL-10, granzyme B, perforin, CCL5 and LILRB4. Tumour-specific Tr1 cells suppressed tumour rejection induced by anti-PD1, LDVax or adoptively transferred tumour-specific effector T cells. Mechanistically, HDVax-induced Tr1 cells selectively killed MHC-II tumour antigen-presenting type 1 conventional dendritic cells (cDC1s), leading to low numbers of cDC1s in tumours. We then documented modalities to overcome this inhibition, specifically via anti-LILRB4 blockade, using a CD8-directed IL-2 mutein, or targeted loss of cDC2/monocytes. Collectively, these data show that cytotoxic Tr1 cells, which maintain peripheral tolerance, also inhibit antitumour responses and thereby function to impede immune control of cancer.

Transcription factor C/EBPα is required for the development of Ly6Chi monocytes but not Ly6Clo monocytes.

Monocytes comprise two major subsets, Ly6Chi classical monocytes and Ly6Clo nonclassical monocytes. Notch2 signaling in Ly6Chi monocytes triggers transition to Ly6Clo monocytes, which require Nr4a1, Bcl6, Irf2, and Cebpb. By comparison, less is known about transcriptional requirements for Ly6Chi monocytes. We find transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) is highly expressed in Ly6Chi monocytes, but down-regulated in Ly6Clo monocytes. A few previous studies described the requirement of C/EBPα in the development of neutrophils and eosinophils. However, the role of C/EBPα for in vivo monocyte development has not been understood. We deleted the Cebpa +37 kb enhancer in mice, eliminating hematopoietic expression of C/EBPα, reproducing the expected neutrophil defect. Surprisingly, we also found a severe and selective loss of Ly6Chi monocytes, while preserving Ly6Clo monocytes. We find that BM progenitors from Cebpa +37-/- mice rapidly progress through the monocyte progenitor stage to develop directly into Ly6Clo monocytes even in the absence of Notch2 signaling. These results identify a previously unrecognized role for C/EBPα in maintaining Ly6Chi monocyte identity.

A single center retrospective study: Comparison between centrifugal separation plasma exchange with ACD-A and membrane separation plasma exchange with heparin on acute liver failure and acute on chronic liver failure.

The purpose of this retrospective study is to compare the efficacy and safety of the centrifugal separation therapeutic plasma exchange (TPE) using citrate anticoagulant (cTPEc) with membrane separation TPE using heparin anticoagulant (mTPEh) in liver failure patients. The patients treated by cTPEc were defined as cTPEc group and those treated by mTPEh were defined as mTPEh group, respectively. Clinical characteristics were compared between the two groups. Survival analyses of two groups and subgroups classified by the model for end-stage liver disease (MELD) score were performed by Kaplan-Meier method and were compared by the log-rank test. In this study, there were 51 patients in cTPEc group and 18 patients in mTPEh group, respectively. The overall 28-day survival rate was 76% (39/51) in cTPEc group and 61% (11/18) in mTPEh group (P > .05). The 90-day survival rate was 69% (35/51) in cTPEc group and 50% (9/18) in mTPEh group (P > .05). MELD score = 30 was the best cut-off value to predict the prognosis of patients with liver failure treated with TPE, in mTPEh group as well as cTPEc group. The median of total calcium/ionized calcium ratio (2.84, range from 2.20 to 3.71) after cTPEc was significantly higher than the ratio (1.97, range from 1.73 to 3.19) before cTPEc (P < .001). However, there was no significant difference between the mean concentrations of total calcium before cTPEc and at 48 h after cTPEc. Our study concludes that there was no statistically significant difference in survival rate and complications between cTPEc and mTPEh groups. The liver failure patients tolerated cTPEc treatment via peripheral vascular access with the prognosis similar to mTPEh. The prognosis in patients with MELD score < 30 was better than in patients with MELD score ≥ 30 in both groups. In this study, the patients with acute liver failure (ALF) and acute on chronic liver failure (ACLF) treated with cTPEc tolerated the TPE frequency of every other day without significant clinical adverse event of hypocalcemia with similar outcomes to the mTPEh treatment. For liver failure patients treated with cTPEc, close clinical observation and monitoring ionized calcium are necessary to ensure the patients' safety.

Insights into the volatile flavor and quality profiles of loquat (Eriobotrya japonica Lindl.) during shelf-life via HS-GC-IMS, E-nose, and E-tongue.

Loquat fruits are among the most popular Chinese fruits because of their unique taste and aroma. The quality profiles of these fruits during 18 days of shelf-life at 20 °C were elucidated by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), E-nose, and E-tongue. During shelf-life period, the properties and variations of 43 (20 aldehydes, 7 esters, 6 ketones, 1 alcohol, and 1 furan) volatile flavored compounds were determined by GC-IMS, which showed that the contents of methyl 3-methyl butanoate, ethyl acetate, and dimethyl ketone gradually decrease with prolonged shelf-life time, while (E)-2-heptenal, heptanal, (E)-2-pentenal, 1-penten-3-one 3-pentanone and 2-pentylfuran increase. The PCA based on the signal intensity of GC-IMS and E-nose, revealed that loquat fruits are well distinguished at different shelf-life times. The taste profile alternates as the storage time increases, along with higher pH, and lower amounts of total soluble solids, vitamin C, and total phenolics. The visual plots of GC-IMS, E-nose, and E-tongue had good consistency, and they characterized the aroma characteristics of loquat fruits well during different shelf-life periods. The findings of this research provide a useful understanding of the flavors of loquat fruits during their prolonged shelf-life, and a potential research basis for advancements in the loquat industry.

Ethyl acetate extract of Terminalia chebula alleviates DSS-induced ulcerative colitis in C57BL/6 mice.

Background: The Chinese pharmacopeia records Terminalia chebula as effective in treating prolonged diarrhea and dysentery, blood in the stool, and prolapse. Modern pharmacological research proves it has multiple pharmacological benefits, including antioxidant, anti-inflammatory, analgesic, hepatoprotective, neuroprotective, and other properties. Objectives: This study aims to clarify the role of Terminalia chebula's ethyl acetate extract (TCEA) on ulcerative colitis (UC) induced by dextran sodium sulfate (DSS) in mice, as well as explore the potential mechanism of action. Materials and methods: The variation of different extracts of T. chebula was detected using the HPLC technique, and the main components in TCEA were identified. DSS was used to establish a mouse model to mimic the physiological state of UC in humans; the alleviating effect of TCEA and positive control 5-ASA on UC mice were evaluated by gavage treatment. Disease progression was assessed by monitoring the mouse's weight change and disease activity index (DAI). The changes in colon tissue were estimated by measuring colon length, HE, and AB-PAS staining and detecting oxidative stress parameters. The results draw from Western blot and real-time PCR showed the TLR4/MyD88/NF-κB pathway may involve in the anti-inflammatory activity of TCEA. Furthermore, the gut flora sequencing technique was employed to monitor the differentiation of intestinal microbiota of mice induced by DSS and TCEA treatment. Results: TCEA significantly lowered DAI scores and inhibited the weight loss and colonic shortening induced by DSS. The colon histomorphology and oxidative stress levels were enhanced after TCEA treatment compared with DSS induced UC group. TCEA attenuated the inflammatory response by regulating TLR4/MyD88/NF-κB pathway activation. Intestinal flora sequencing showed that DSS and TCEA greatly impacted mice's composition and diversity of intestinal microorganisms. But TCEA increased the abundance of Bacteroidetes and decreased the abundance of Firmicutes and Proteobacteria compared with the DSS group, which contributed a lot to returning the intestinal flora to a balanced state. Conclusion: This study confirms the alleviating effect of TCEA on UC and provides new ideas for developing TCEA into a new drug to treat UC.

Changes in Bone Mineral Density and Related Influencing Factors Assessed by Quantitative Computed Tomography in Maintenance Dialysis Patients.

OBJECTIVE: To investigate the changes in volumetric bone mineral density (vBMD) assessed by quantitative computed tomography (QCT) in chronic kidney disease (CKD) patients on maintenance dialysis. STUDY DESIGN: Descriptive study. Place and Duration of the Study: Department of Radiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China, from March to July 2022. METHODOLOGY: Maintenance dialysis patients were selected for this study, and parameters related to renal function and bone metabolism markers were recorded. Patients undergoing routine physical examination were age-matched with maintenance dialysis patients to serve as the control group. vBMD scans of the lumbar spine (L1-3) were obtained by QCT for all participants. RESULTS: Among the 141 maintenance dialysis patients, there were 67 patients with secondary hyperparathyroidism (SHPT) and 74 patients with non-secondary hyperparathyroidism (non-SHPT) with mean vBMDs of 145.99±55.13 mg/cm3 and 129.10±44.20 mg/cm3, respectively. The 159 individuals in the control group had mean age of 52.77±11.66 years and mean vBMD of 129.62±36.36 mg/cm3. The vBMD of the SHPT group was greater than that of both the non-SHPT group and the control group (all p<0.05). For dialysis patients, vBMD was positively correlated with calcium-phosphorus product and intact parathyroid hormone (iPTH) levels (r = 0.181, 0.214, respectively, p<0.05); vBMD was inversely correlated with age (r = -0.555, p<0.05). After adjusting for the covariates, vBMD remained positively correlated with iPTH (r = 0.184, p<0.05). CONCLUSION: Increased lumbar vertebral vBMD in maintenance dialysis patients may be associated with high iPTH, providing clinicians with a new understanding of the changes in bone mineral density in maintenance dialysis patients. KEY WORDS: Bone mineral density, Quantitative computed tomography, Chronic kidney disease, Maintenance dialysis.

Safety of sodium-glucose transporter 2 (SGLT-2) inhibitors in patients with type 2 diabetes: a meta-analysis of cohort studies.

Aims: This study aimed to investigate the association between the use of sodium-glucose transporter 2 inhibitors (SGLT-2i) and the risk of diabetic ketoacidosis (DKA), lower limb amputation (LLA), urinary tract infections (UTI), genital tract infections (GTI), bone fracture, and hypoglycemia in cohort studies. Methods: A systematic search was conducted in the PubMed and Embase databases to identify cohort studies comparing the safety of SGLT-2i versus other glucose-lowering drugs (oGLD) in patients with type 2 diabetes mellitus (T2DM). The quality of the studies was assessed using the Newcastle-Ottawa Scale. Primary endpoints were DKA and LLA, while secondary endpoints included UTI, GTI, bone fracture, and hypoglycemia. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated. Results: A total of 9,911,454 patients from 40 cohort studies were included in the analysis. SGLT-2i use was associated with a higher risk of DKA (HR: 1.21, 95% CI: 1.07-1.38, p = 0.003) and GTI (HR: 2.72, 95% CI: 2.48-2.98, p < 0.01). However, it was not associated with an increased risk of LLA (HR: 1.06, 95% CI: 0.92-1.23, p = 0.42), UTI (HR: 0.99, 95% CI: 0.89-1.10, p = 0.83), or bone fracture (HR: 0.99, 95% CI: 0.94-1.04, p = 0.66). Furthermore, SGLT-2i was associated with a reduced risk of hypoglycemia. Furthermore, compared to dipeptidyl peptidase 4 inhibitors, SGLT-2i as a class and individually was associated with an increased risk of DKA. Canagliflozin specifically increased the risk of LLA (HR: 1.19, 95% CI: 1.04-1.36, p = 0.01). The subgroup analysis suggested that SGLT-2i increased the risk of LLA among patients with a history of cardiovascular disease. Conclusion: SGLT-2i versus oGLD was associated with a similar occurrence of LLA, UTI, and bone fracture. However, SGLT-2i was associated with a higher risk of DKA and GTI than oGLD. These findings provide valuable information on the safety profile of SGLT-2i in patients with T2DM and can help inform clinical decision-making.

Terminalia bellirica Fruit Extract Alleviates DSS-Induced Ulcerative Colitis by Regulating Gut Microbiota, Inflammatory Mediators, and Cytokines.

Ulcerative colitis (UC) is a chronic inflammatory disease significantly impacting patients' lives. This study aimed to elucidate the alleviating effect of ethyl acetate extract (TBEA) from Terminalia bellirica fruit on UC and to explore its mechanism. TBEA was the fraction with the best anti-inflammatory activity screened using in vitro anti-inflammatory assays, and HPLC initially characterized its composition. The mice model of ulcerative colitis was established after free drinking of 2.5% dextran sulfate sodium for six days, and the experimental group was treated with 50 mg/kg and 100 mg/kg TBEA for seven days. We found that TBEA significantly alleviated symptoms in UC mice, including a physiologically significant reduction in disease activity index and pathological damage to colonic tissue. TBEA dramatically slowed down oxidative stress and inflammatory process in UC mice, as evidenced by decreasing myeloperoxidase and malondialdehyde activities and increasing glutathione and catalase levels by reducing the concentrations of IL-6, IL-1ß, TNF-α, and NO in UC mice, as well as by regulating key proteins in the IL-6/JAK2/STAT3 pathway. Meanwhile, TBEA maintained intestinal homeostasis by regulating intestinal flora structure. Our study provides new ideas for developing TBEA into a new drug to treat UC.

IL-6 selectively suppresses cDC1 specification via C/EBPß.

Cytokines produced in association with tumors can impair antitumor immune responses by reducing the abundance of type 1 conventional dendritic cells (cDC1), but the mechanism remains unclear. Here, we show that tumor-derived IL-6 generally reduces cDC development but selectively impairs cDC1 development in both murine and human systems through the induction of C/EBPß in the common dendritic cell progenitor (CDP). C/EBPß and NFIL3 compete for binding to sites in the Zeb2 -165 kb enhancer and support or repress Zeb2 expression, respectively. At homeostasis, pre-cDC1 specification occurs upon Nfil3 induction and consequent Zeb2 suppression. However, IL-6 strongly induces C/EBPß expression in CDPs. Importantly, the ability of IL-6 to impair cDC development is dependent on the presence of C/EBPß binding sites in the Zeb2 -165 kb enhancer, as this effect is lost in Δ1+2+3 mutant mice in which these binding sites are mutated. These results explain how tumor-associated IL-6 suppresses cDC1 development and suggest therapeutic approaches preventing abnormal C/EBPß induction in CDPs may help reestablish cDC1 development to enhance antitumor immunity.

Downregulated calmodulin expression contributes to endothelial cell impairment in diabetes.

Endothelial dysfunction, a central hallmark of cardiovascular pathogenesis in diabetes mellitus, is characterized by impaired endothelial nitric oxide synthase (eNOS) and NO bioavailability. However, the underlying mechanisms remain unclear. Here in this study, we aimed to identify the role of calmodulin (CaM) in diabetic eNOS dysfunction. Human umbilical vein endothelial cells and murine endothelial progenitor cells (EPCs) treated with high glucose (HG) exhibited downregulated CaM mRNA/protein and vascular endothelial growth factor (VEGF) expression with impeded eNOS phosphorylation and cell migration/tube formation. These perturbations were reduplicated in CALM1-knockdown cells but prevented in CALM1-overexpressing cells. EPCs from type 2 diabetes animals behaved similarly to HG-treated normal EPCs, which could be rescued by CALM1-gene transduction. Consistently, diabetic animals displayed impaired eNOS phosphorylation, endothelium-dependent dilation, and CaM expression in the aorta, as well as deficient physical interaction of CaM and eNOS in the gastrocnemius. Local CALM1 gene delivery into a diabetic mouse ischemic hindlimb improved the blunted limb blood perfusion and gastrocnemius angiogenesis, and foot injuries. Diabetic patients showed insufficient foot microvascular autoregulation, eNOS phosphorylation, and NO production with downregulated CaM expression in the arterial endothelium, and abnormal CALM1 transcription in genome-wide sequencing analysis. Therefore, our findings demonstrated that downregulated CaM expression is responsible for endothelium dysfunction and angiogenesis impairment in diabetes, and provided a novel mechanism and target to protect against diabetic endothelial injury.

Enhanced in vitro type 1 conventional dendritic cell generation via the recruitment of hematopoietic stem cells and early progenitors by Kit ligand.

In vitro culture of bone marrow (BM) with Fms-like tyrosine kinase 3 ligand (Flt3L) is widely used to study development and function of type 1 conventional dendritic cells (cDC1). Hematopoietic stem cells (HSCs) and many progenitor populations that possess cDC1 potential in vivo do not express Flt3 and thus may not contribute to Flt3L-mediated cDC1 production in vitro. Here, we present a KitL/Flt3L protocol that recruits such HSCs and progenitors into the production of cDC1. Kit ligand (KitL) is used to expand HSCs and early progenitors lacking Flt3 expression into later stage where Flt3 is expressed. Following this initial KitL phase, a second Flt3L phase is used to support the final production of DCs. With this two-stage culture, we achieved approximately tenfold increased production of both cDC1 and cDC2 compared to Flt3L culture. cDC1 derived from this culture are similar to in vivo cDC1 in their dependence on IRF8, ability to produce IL-12, and induction of tumor regression in cDC1-deficient tumor-bearing mice. This KitL/Flt3L system for cDC1 production will be useful in further analysis of cDC1 that rely on in vitro generation from BM.

Natamycin Has an Inhibitory Effect on Neofusicoccum parvum, the Pathogen of Chestnuts.

This research aimed to investigate natamycin's antifungal effect and its mechanism against the chestnut pathogen Neofusicoccum parvum. Natamycin's inhibitory effects on N. parvum were investigated using a drug-containing plate culture method and an in vivo assay in chestnuts and shell buckets. The antifungal mechanism of action of natamycin on N. parvum was investigated by conducting staining experiments of the fungal cell wall and cell membrane. Natamycin had a minimum inhibitory concentration (MIC) of 100 µg/mL and a minimum fungicidal concentration (MFC) of 200 µg/mL against N. parvum. At five times the MFC, natamycin had a strong antifungal effect on chestnuts in vivo, and it effectively reduced morbidity and extended the storage period. The cell membrane was the primary target of natamycin action against N. parvum. Natamycin inhibits ergosterol synthesis, disrupts cell membranes, and causes intracellular protein, nucleic acid, and other macromolecule leakages. Furthermore, natamycin can cause oxidative damage to the fungus, as evidenced by decreased superoxide dismutase and catalase enzyme activity. Natamycin exerts a strong antifungal effect on the pathogenic fungus N. parvum from chestnuts, mainly through the disruption of fungal cell membranes.

Cis interactions in the Irf8 locus regulate stage-dependent enhancer activation.

Individual elements within a superenhancer can act in a cooperative or temporal manner, but the underlying mechanisms remain obscure. We recently identified an Irf8 superenhancer, within which different elements act at distinct stages of type 1 classical dendritic cell (cDC1) development. The +41-kb Irf8 enhancer is required for pre-cDC1 specification, while the +32-kb Irf8 enhancer acts to support subsequent cDC1 maturation. Here, we found that compound heterozygous Δ32/Δ41 mice, lacking the +32- and +41-kb enhancers on different chromosomes, show normal pre-cDC1 specification but, surprisingly, completely lack mature cDC1 development, suggesting cis dependence of the +32-kb enhancer on the +41-kb enhancer. Transcription of the +32-kb Irf8 enhancer-associated long noncoding RNA (lncRNA) Gm39266 is also dependent on the +41-kb enhancer. However, cDC1 development in mice remained intact when Gm39266 transcripts were eliminated by CRISPR/Cas9-mediated deletion of lncRNA promoters and when transcription across the +32-kb enhancer was blocked by premature polyadenylation. We showed that chromatin accessibility and BATF3 binding at the +32-kb enhancer were dependent on a functional +41-kb enhancer located in cis Thus, the +41-kb Irf8 enhancer controls the subsequent activation of the +32-kb Irf8 enhancer in a manner that is independent of associated lncRNA transcription.

Zinc-Catalyzed Enantioselective [3 + 3] Annulation for Synthesis of Chiral Spiro[indoline-3,4'-thiopyrano[2,3-b]indole] Derivatives.

With a dinuclear zinc-ProPhenol complex as a catalyst, an efficient and novel [3 + 3] annulation of indoline-2-thiones and isatylidene malononitriles has been successfully developed via the Brønsted base and Lewis acid cooperative activation model. This practical methodology gives access to a broad range of chiral spiro[indoline-3,4'-thiopyrano[2,3-b]indole] derivatives in good yields with excellent levels of enantioselectivities (up to 88% yield and 99% ee).

Effects of L-arginine on Nitric Oxide Synthesis and Larval Metamorphosis of Mytilus coruscus.

To investigate the regulatory functions of L-arginine and nitric oxide (NO) on Mytilus coruscus metamorphosis, M. coruscus larvae were exposed to an inhibitor of nitric oxide synthase (NOS), aminoguanidine hemisulfate (AGH), and a substrate for NO synthesis, L-arginine. We observed that NO levels showed a significant increase, and this trend continued with L-arginine treatment. When NOS activity was inhibited, the larvae could not synthesize NO, and metamorphosis was not inhibited even in the presence of L-arginine. On transfecting pediveliger larvae with NOS siRNA followed by L-arginine exposure, we found that the larvae did not produce NO and that the larval metamorphosis rate was significantly increased, suggesting that L-arginine regulates M. coruscus larval metamorphosis by promoting NO synthesis. Our findings improve our understanding of the effects of marine environmental factors on larval metamorphosis of mollusks.

Mechanisms of CD40-dependent cDC1 licensing beyond costimulation.

CD40 signaling in classical type 1 dendritic cells (cDC1s) is required for CD8 T cell-mediated tumor rejection, but the underlying mechanisms are incompletely understood. Here, we identified CD40-induced genes in cDC1s, including Cd70, Tnfsf9, Ptgs2 and Bcl2l1, and examined their contributions to anti-tumor immunity. cDC1-specific inactivation of CD70 and COX-2, and global CD27 inactivation, only partially impaired tumor rejection or tumor-specific CD8 T cell expansion. Loss of 4-1BB, alone or in Cd27-/- mice, did not further impair anti-tumor immunity. However, cDC1-specific CD40 inactivation reduced cDC1 mitochondrial transmembrane potential and increased caspase activation in tumor-draining lymph nodes, reducing migratory cDC1 numbers in vivo. Similar impairments occurred during in vitro antigen presentation by Cd40-/- cDC1s to CD8+ T cells, which were reversed by re-expression of Bcl2l1. Thus, CD40 signaling in cDC1s not only induces costimulatory ligands for CD8+ T cells but also induces Bcl2l1 that sustains cDC1 survival during priming of anti-tumor responses.

cDC1 Vaccines Drive Tumor Rejection by Direct Presentation Independently of Host cDC1.

As a cell-based cancer vaccine, dendritic cells (DC), derived from peripheral blood monocytes or bone marrow (BM) treated with GM-CSF (GMDC), were initially thought to induce antitumor immunity by presenting tumor antigens directly to host T cells. Subsequent work revealed that GMDCs do not directly prime tumor-specific T cells, but must transfer their antigens to host DCs. This reduces their advantage over strictly antigen-based strategies proposed as cancer vaccines. Type 1 conventional DCs (cDC1) have been reported to be superior to GMDCs as a cancer vaccine, but whether they act by transferring antigens to host DCs is unknown. To test this, we compared antitumor responses induced by GMDCs and cDC1 in Irf8 +32-/- mice, which lack endogenous cDC1 and cannot reject immunogenic fibrosarcomas. Both GMDCs and cDC1 could cross-present cell-associated antigens to CD8+ T cells in vitro. However, injection of GMDCs into tumors in Irf8 +32-/- mice did not induce antitumor immunity, consistent with their reported dependence on host cDC1. In contrast, injection of cDC1s into tumors in Irf8 +32-/- mice resulted in their migration to tumor-draining lymph nodes, activation of tumor-specific CD8+ T cells, and rejection of the tumors. Tumor rejection did not require the in vitro loading of cDC1 with antigens, indicating that acquisition of antigens in vivo is sufficient to induce antitumor responses. Finally, cDC1 vaccination showed abscopal effects, with rejection of untreated tumors growing concurrently on the opposite flank. These results suggest that cDC1 may be a useful future avenue to explore for antitumor therapy. See related Spotlight by Hubert et al., p. 918.