技术资料

The immune system has a critical role in orchestrating tissue healing. As a result,regenerative strategies that control immune components have proved effective1,2. This is particularly relevant when immune dysregulation that results from conditions such as diabetes or advanced age impairs tissue healing following injury2,3. Nociceptive sensory neurons have a crucial role as immunoregulators and exert both protective and harmful effects depending on the context4–12. However,how neuro–immune interactions affect tissue repair and regeneration following acute injury is unclear. Here we show that ablation of the NaV1.8 nociceptor impairs skin wound repair and muscle regeneration after acute tissue injury. Nociceptor endings grow into injured skin and muscle tissues and signal to immune cells through the neuropeptide calcitonin gene-related peptide (CGRP) during the healing process. CGRP acts via receptor activity-modifying protein 1 (RAMP1) on neutrophils,monocytes and macrophages to inhibit recruitment,accelerate death,enhance efferocytosis and polarize macrophages towards a pro-repair phenotype. The effects of CGRP on neutrophils and macrophages are mediated via thrombospondin-1 release and its subsequent autocrine and/or paracrine effects. In mice without nociceptors and diabetic mice with peripheral neuropathies,delivery of an engineered version of CGRP accelerated wound healing and promoted muscle regeneration. Harnessing neuro–immune interactions has potential to treat non-healing tissues in which dysregulated neuro–immune interactions impair tissue healing. Experiments in mouse models show that NaV1.8+ nociceptors innervate sites of injury and provide wound repair signals to immune cells by releasing calcitonin gene-related peptide (CGRP). View Publication

Prime editing enables the precise modification of genomes through reverse transcription of template sequences appended to the 3′ ends of CRISPR–Cas guide RNAs1. To identify cellular determinants of prime editing,we developed scalable prime editing reporters and performed genome-scale CRISPR-interference screens. From these screens,a single factor emerged as the strongest mediator of prime editing: the small RNA-binding exonuclease protection factor La. Further investigation revealed that La promotes prime editing across approaches (PE2,PE3,PE4 and PE5),edit types (substitutions,insertions and deletions),endogenous loci and cell types but has no consistent effect on genome-editing approaches that rely on standard,unextended guide RNAs. Previous work has shown that La binds polyuridine tracts at the 3′ ends of RNA polymerase III transcripts2. We found that La functionally interacts with the 3′ ends of polyuridylated prime editing guide RNAs (pegRNAs). Guided by these results,we developed a prime editor protein (PE7) fused to the RNA-binding,N-terminal domain of La. This editor improved prime editing with expressed pegRNAs and engineered pegRNAs (epegRNAs),as well as with synthetic pegRNAs optimized for La binding. Together,our results provide key insights into how prime editing components interact with the cellular environment and suggest general strategies for stabilizing exogenous small RNAs therein. Genome-scale genetic screens identify the small RNA-binding protein La as a strong mediator of prime editing. View Publication

Midnolin is an essential gene with previously unknown effects in vivo. This paper shows that midnolin stimulates proteasome activity necessary for lymphopoiesis and B cell cancer growth in mice. In a genetic screen,we identified two viable missense alleles of the essential gene Midnolin (Midn) that were associated with reductions in peripheral B cells. Causation was confirmed in mice with targeted deletion of four of six MIDN protein isoforms. MIDN was expressed predominantly in lymphocytes where it augmented proteasome activity. We showed that purified MIDN directly stimulated 26S proteasome activity in vitro in a manner dependent on the ubiquitin-like domain and a C-terminal region. MIDN-deficient B cells displayed aberrant activation of the IRE-1/XBP-1 pathway of the unfolded protein response. Partial or complete MIDN deficiency strongly suppressed Eμ-Myc–driven B cell leukemia and the antiapoptotic effects of Eμ-BCL2 on B cells in vivo and induced death of Sp2/0 hybridoma cells in vitro,but only partially impaired normal lymphocyte development. Thus,MIDN is required for proteasome activity in support of normal lymphopoiesis and is essential for malignant B cell proliferation over a broad range of differentiation states. View Publication

SUMMARY Tumor-associated macrophages (TAMs) shape tumor immunity and therapeutic efficacy. However,it is poorly understood whether and how post-translational modifications (PTMs) intrinsically affect the phenotype and function of TAMs. Here,we reveal that peptidylarginine deiminase 4 (PAD4) exhibits the highest expression among common PTM enzymes in TAMs and negatively correlates with the clinical response to immune checkpoint blockade. Genetic and pharmacological inhibition of PAD4 in macrophages prevents tumor progression in tumor-bearing mouse models,accompanied by an increase in macrophage major histocompatibility complex (MHC) class II expression and T cell effector function. Mechanistically,PAD4 citrullinates STAT1 at arginine 121,thereby promoting the interaction between STAT1 and protein inhibitor of activated STAT1 (PIAS1),and the loss of PAD4 abolishes this interaction,ablating the inhibitory role of PIAS1 in the expression of MHC class II machinery in macrophages and enhancing T cell activation. Thus,the PAD4-STAT1-PIAS1 axis is an immune restriction mechanism in macrophages and may serve as a cancer immunotherapy target. Graphical Abstract In brief Pitter et al. demonstrate that the PAD4-mediated citrullination of STAT1 in macrophages enforces the STAT1-PIAS1 interaction restraining STAT1 transcriptional activity and MHC class II machinery expression and,consequently,limits T cell-mediated anti-tumor immunity. View Publication

BACKGROUND:Venous thromboembolism is a major health problem. After thrombus formation,its resolution is essential to re-establish blood flow,which is crucially mediated by infiltrating neutrophils and monocytes in concert with activated platelets and endothelial cells. Thus,we aimed to modulate leukocyte function during thrombus resolution post-thrombus formation by blocking P-selectin/CD62P-mediated cell interactions.METHODS:Thrombosis was induced by inferior vena cava stenosis through ligation in mice. After 1 day,a P-selectin-blocking antibody or isotype control was administered and thrombus composition and resolution were analyzed.RESULTS:Localizing neutrophils and macrophages in thrombotic lesions of wild-type mice revealed that these cells enter the thrombus and vessel wall from the caudal end. Neutrophils were predominantly present 1 day and monocytes/macrophages 3 days after vessel ligation. Blocking P-selectin reduced circulating platelet-neutrophil and platelet-Ly6Chigh monocyte aggregates near the thrombus,and diminished neutrophils and Ly6Chigh macrophages in the cranial thrombus part compared with isotype-treated controls. Depletion of neutrophils 1 day after thrombus initiation did not phenocopy P-selectin inhibition but led to larger thrombi compared with untreated controls. In vitro,P-selectin enhanced human leukocyte function as P-selectin-coated beads increased reactive oxygen species production by neutrophils and tissue factor expression of classical monocytes. Accordingly,P-selectin inhibition reduced oxidative burst in the thrombus and tissue factor expression in the adjacent vessel wall. Moreover,blocking P-selectin reduced thrombus density determined by scanning electron microscopy and increased urokinase-type plasminogen activator levels in the thrombus,which accelerated caudal fibrin degradation from day 3 to day 14. This accelerated thrombus resolution as thrombus volume declined more rapidly after blocking P-selectin.CONCLUSIONS:Inhibition of P-selectin-dependent activation of monocytes and neutrophils accelerates venous thrombosis resolution due to reduced infiltration and activation of innate immune cells at the site of thrombus formation,which prevents early thrombus stabilization and facilitates fibrinolysis. View Publication

SUMMARYRegulatory T cells (Tregs) are promising cellular therapies to induce immune tolerance in organ transplantation and autoimmune disease. The success of chimeric antigen receptor (CAR) T-cell therapy for cancer has sparked interest in using CARs to generate antigen-specific Tregs. Here,we compared CAR with endogenous T cell receptor (TCR)/CD28 activation in human Tregs. Strikingly,CAR Tregs displayed increased cytotoxicity and diminished suppression of antigen-presenting cells and effector T (Teff) cells compared with TCR/CD28 activated Tregs. RNA sequencing revealed that CAR Tregs activate Teff cell gene programs. Indeed,CAR Tregs secreted high levels of inflammatory cytokines,with a subset of FOXP3+ CAR Tregs uniquely acquiring CD40L surface expression and producing IFNγ. Interestingly,decreasing CAR antigen affinity reduced Teff cell gene expression and inflammatory cytokine production by CAR Tregs. Our findings showcase the impact of engineered receptor activation on Treg biology and support tailoring CAR constructs to Tregs for maximal therapeutic efficacy. Graphical Abstract View Publication

More than 80% of patients with myasthenia gravis (MG) are positive for anti-acetylcholine receptor (AChR) antibodies. Regulatory T cells (Tregs) suppress overproduction of these antibodies,and patients with AChR antibody-positive MG (AChR MG) exhibit impaired Treg function and reduced Treg numbers. The gut microbiota and their metabolites play a crucial role in maintaining Treg differentiation and function. However,whether impaired Tregs correlate with gut microbiota activity in patients with AChR MG remains unknown. Here,we demonstrate that butyric acid-producing gut bacteria and serum butyric acid level are reduced in patients with AChR MG. Butyrate supplementation effectively enhanced Treg differentiation and their suppressive function of AChR MG. Mechanistically,butyrate activates autophagy of Treg cells by inhibiting the mammalian target of rapamycin. Activation of autophagy increased oxidative phosphorylation and surface expression of cytotoxic T-lymphocyte-associated protein 4 on Treg cells,thereby promoting Treg differentiation and their suppressive function in AChR MG. This observed effect of butyrate was blocked using chloroquine,an autophagy inhibitor,suggesting the vital role of butyrate-activated autophagy in Tregs of patients with AChR MG. We propose that gut bacteria derived butyrate has potential therapeutic efficacy against AChR MG by restoring impaired Tregs.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12964-024-01588-9. View Publication

Allogeneic CAR T–cell therapies are being developed for hematologic malignancies. The authors implement a Cas12a chRDNA platform to generate allogeneic immune-cloaked BCMA-specific CAR T cells with resistance to host response–mediated rejection for evaluation in multiple myeloma. AbstractAllogeneic chimeric antigen receptor (CAR) T cell therapies hold the potential to overcome many of the challenges associated with patient-derived (autologous) CAR T cells. Key considerations in the development of allogeneic CAR T cell therapies include prevention of graft-vs-host disease (GvHD) and suppression of allograft rejection. Here,we describe preclinical data supporting the ongoing first-in-human clinical study,the CaMMouflage trial (NCT05722418),evaluating CB-011 in patients with relapsed/refractory multiple myeloma. CB-011 is a hypoimmunogenic,allogeneic anti–B-cell maturation antigen (BCMA) CAR T cell therapy candidate. CB-011 cells feature 4 genomic alterations and were engineered from healthy donor–derived T cells using a Cas12a CRISPR hybrid RNA–DNA (chRDNA) genome-editing technology platform. To address allograft rejection,CAR T cells were engineered to prevent endogenous HLA class I complex expression and overexpress a single-chain polyprotein complex composed of beta-2 microglobulin (B2M) tethered to HLA-E. In addition,T-cell receptor (TCR) expression was disrupted at the TCR alpha constant locus in combination with the site-specific insertion of a humanized BCMA-specific CAR. CB-011 cells exhibited robust plasmablast cytotoxicity in vitro in a mixed lymphocyte reaction in cell cocultures derived from patients with multiple myeloma. In addition,CB-011 cells demonstrated suppressed recognition by and cytotoxicity from HLA-mismatched T cells. CB-011 cells were protected from natural killer cell–mediated cytotoxicity in vitro and in vivo due to endogenous promoter-driven expression of B2M–HLA-E. Potent antitumor efficacy,when combined with an immune-cloaking armoring strategy to dampen allograft rejection,offers optimized therapeutic potential in multiple myeloma. See related Spotlight by Caimi and Melenhorst,p. 385 View Publication

Macrophage activation syndrome (MAS) is a life-threatening complication of systemic juvenile arthritis,accompanied by cytokine storm and hemophagocytosis. In addition,COVID-19–related hyperinflammation shares clinical features of MAS. Mechanisms that activate macrophages in MAS remain unclear. Here,we identify the role of miRNA in increased phagocytosis and interleukin-12 (IL-12) production by macrophages in a murine model of MAS. MAS significantly increased F4/80+ macrophages and phagocytosis in the mouse liver. Gene expression profile revealed the induction of Fcγ receptor–mediated phagocytosis (FGRP) and IL-12 production in the liver. Phagocytosis pathways such as High-affinity IgE receptor is known as Fc epsilon RI -signaling and pattern recognition receptors involved in the recognition of bacteria and viruses and phagosome formation were also significantly upregulated. In MAS,miR-136-5p and miR-501-3p targeted and caused increased expression of Fcgr3,Fcgr4,and Fcgr1 genes in FGRP pathway and consequent increase in phagocytosis by macrophages,whereas miR-129-1-3p and miR-150-3p targeted and induced Il-12. Transcriptome analysis of patients with MAS revealed the upregulation of FGRP and FCGR gene expression. A target analysis of gene expression data from a patient with MAS discovered that miR-136-5p targets FCGR2A and FCGR3A/3B,the human orthologs of mouse Fcgr3 and Fcgr4,and miR-501-3p targets FCGR1A,the human ortholog of mouse Fcgr1. Together,we demonstrate the novel role of miRNAs during MAS pathogenesis,thereby suggesting miRNA mimic–based therapy to control the hyperactivation of macrophages in patients with MAS as well as use overexpression of FCGR genes as a marker for MAS classification. View Publication

The corneal epithelium acts as a barrier to pathogens entering the eye; corneal epithelial cells are continuously renewed by uni-potent,quiescent limbal stem cells (LSCs) located at the limbus,where the cornea transitions to conjunctiva. There has yet to be a consensus on LSC markers and their transcriptome profile is not fully understood,which may be due to using cadaveric tissue without an intact stem cell niche for transcriptomics. In this study,we addressed this problem by using single nuclei RNA sequencing (snRNAseq) on healthy human limbal tissue that was immediately snap-frozen after excision from patients undergoing cataract surgery. We identified the quiescent LSCs as a sub-population of corneal epithelial cells with a low level of total transcript counts. Moreover,TP63,KRT15,CXCL14,and ITGβ4 were found to be highly expressed in LSCs and transiently amplifying cells (TACs),which constitute the corneal epithelial progenitor populations at the limbus. The surface markers SLC6A6 and ITGβ4 could be used to enrich human corneal epithelial cell progenitors,which were also found to specifically express the putative limbal progenitor cell markers MMP10 and AC093496.1. View Publication

BackgroundSystemic sclerosis (SSc) is an autoimmune connective tissue disease characterized by vasculopathy and progressive fibrosis of skin and several internal organs,including lungs. Macrophages are the main cells involved in the immune-inflammatory damage of skin and lungs,and alternatively activated (M2) macrophages seem to have a profibrotic role through the release of profibrotic cytokines (IL10) and growth factors (TGFβ1). Nintedanib is a tyrosine kinase inhibitor targeting several fibrotic mediators and it is approved for the treatment of SSc-related interstitial lung disease (ILD). The study aimed to evaluate the effect of nintedanib in downregulating the profibrotic M2 phenotype in cultured monocyte-derived macrophages (MDMs) obtained from SSc-ILD patients.MethodsFourteen SSc patients,fulfilling the 2013 ACR/EULAR criteria for SSc,10 SSc patients affected by ILD (SSc-ILD pts),4 SSc patients non affected by ILD (SSc pts no-ILD),and 5 voluntary healthy subjects (HSs),were recruited at the Division of Clinical Rheumatology-University of Genova,after obtaining Ethical Committee approval and patients’ informed consent. Monocytes were isolated from peripheral blood,differentiated into MDMs,and then maintained in growth medium without any treatment (untreated cells),or treated with nintedanib (0.1 and 1µM) for 3,16,and 24 h. Gene expression of macrophage scavenger receptors (CD204,CD163),mannose receptor-1 (CD206),Mer tyrosine kinase (MerTK),identifying M2 macrophages,together with TGFβ1 and IL10,were evaluated by quantitative real-time polymerase chain reaction. Protein synthesis was investigated by Western blotting and the level of active TGFβ1 was evaluated by ELISA. Statistical analysis was carried out using non-parametric Wilcoxon test.ResultsCultured untreated SSc-ILD MDMs showed a significant increased protein synthesis of CD206 (p < 0.05),CD204,and MerTK (p < 0.01),together with a significant upregulation of the gene expression of MerTK and TGFβ1 (p < 0.05; p < 0.01) compared to HS-MDMs. Moreover,the protein synthesis of CD206 and MerTK and the gene expression of TGFβ1 were significantly higher in cultured untreated MDMs from SSc-ILD pts compared to MDMs without ILD (p < 0.05; p < 0.01). In cultured SSc-ILD MDMs,nintedanib 0.1 and 1µM significantly downregulated the gene expression and protein synthesis of CD204,CD206,CD163 (p < 0.05),and MerTK (p < 0.01) compared to untreated cells after 24 h of treatment. Limited to MerTK and IL10,both nintedanib concentrations significantly downregulated their gene expression already after 16 h of treatment (p < 0.05). In cultured SSc-ILD MDMs,nintedanib 0.1 and 1µM significantly reduced the release of active TGFβ1 after 24 h of treatment (p < 0.05 vs. untreated cells).ConclusionsIn cultured MDMs from SSc-ILD pts,nintedanib seems to downregulate the profibrotic M2 phenotype through the significant reduction of gene expression and protein synthesis of M2 cell surface markers,together with the significant reduction of TGFβ1 release,and notably MerTK,a tyrosine kinase receptor involved in lung fibrosis.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13075-024-03308-7. View Publication

AbstractAcute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common life‐threatening syndrome with no effective pharmacotherapy. Sepsis‐related ARDS is the main type of ARDS and is more fatal than other types. Extracellular vesicles (EVs) are considered novel mediators in the development of inflammatory diseases. Our previous research suggested that endothelial cell‐derived EVs (EC‐EVs) play a crucial role in ALI/ARDS development,but the mechanism remains largely unknown. Here,we demonstrated that the number of circulating EC‐EVs was increased in sepsis,exacerbating lung injury by targeting monocytes and reprogramming them towards proinflammatory macrophages. Bioinformatics analysis and further mechanistic studies revealed that vascular cell adhesion molecule 1 (VCAM1),overexpressed on EC‐EVs during sepsis,activated the NF‐κB pathway by interacting with integrin subunit alpha 4 (ITGA4) on the monocyte surface,rather than the tissue resident macrophage surface,thereby regulating monocyte differentiation. This effect could be attenuated by decreasing VCAM1 levels in EC‐EVs or blocking ITGA4 on monocytes. Furthermore,the number of VCAM1+ EC‐EVs was significantly increased in patients with sepsis‐related ARDS. These findings not only shed light on a previously unidentified mechanism underling sepsis‐related ALI/ARDS,but also provide potential novel targets and strategies for its precise treatment. During extra‐pulmonary sepsis,more endothelial cell‐derived extracellular vesicles (EC‐EVs) are released,which play a critical role in the development of ALI/ARDS by specifically targeting and reprogramming monocytes. VCAM1,highly expressed on these EVs,activates the NF‐κB pathway by acting on ITGA4,thus promoting the differentiation of monocytes into M1‐type macrophages. View Publication