Bat ASC2 suppresses inflammasomes and ameliorates inflammatory diseases.

Bats are special in their ability to live long and host many emerging viruses. Our previous studies showed that bats have altered inflammasomes, which are central players in aging and infection. However, the role of inflammasome signaling in combating inflammatory diseases remains poorly understood. Here, we report bat ASC2 as a potent negative regulator of inflammasomes. Bat ASC2 is highly expressed at both the mRNA and protein levels and is highly potent in inhibiting human and mouse inflammasomes. Transgenic expression of bat ASC2 in mice reduced the severity of peritonitis induced by gout crystals and ASC particles. Bat ASC2 also dampened inflammation induced by multiple viruses and reduced mortality of influenza A virus infection. Importantly, it also suppressed SARS-CoV-2-immune-complex-induced inflammasome activation. Four key residues were identified for the gain of function of bat ASC2. Our results demonstrate that bat ASC2 is an important negative regulator of inflammasomes with therapeutic potential in inflammatory diseases.

Chimeric efferocytic receptors improve apoptotic cell clearance and alleviate inflammation.

Our bodies turn over billions of cells daily via apoptosis and are in turn cleared by phagocytes via the process of "efferocytosis." Defects in efferocytosis are now linked to various inflammatory diseases. Here, we designed a strategy to boost efferocytosis, denoted "chimeric receptor for efferocytosis" (CHEF). We fused a specific signaling domain within the cytoplasmic adapter protein ELMO1 to the extracellular phosphatidylserine recognition domains of the efferocytic receptors BAI1 or TIM4, generating BELMO and TELMO, respectively. CHEF-expressing phagocytes display a striking increase in efferocytosis. In mouse models of inflammation, BELMO expression attenuates colitis, hepatotoxicity, and nephrotoxicity. In mechanistic studies, BELMO increases ER-resident enzymes and chaperones to overcome protein-folding-associated toxicity, which was further validated in a model of ER-stress-induced renal ischemia-reperfusion injury. Finally, TELMO introduction after onset of kidney injury significantly reduced fibrosis. Collectively, these data advance a concept of chimeric efferocytic receptors to boost efferocytosis and dampen inflammation.

Cross-tissue single-cell landscape of human monocytes and macrophages in health and disease.

Mononuclear phagocytes (MNPs) encompass dendritic cells, monocytes, and macrophages (MoMac), which exhibit antimicrobial, homeostatic, and immunoregulatory functions. We integrated 178,651 MNPs from 13 tissues across 41 datasets to generate a MNP single-cell RNA compendium (MNP-VERSE), a publicly available tool to map MNPs and define conserved gene signatures of MNP populations. Next, we generated a MoMac-focused compendium that revealed an array of specialized cell subsets widely distributed across multiple tissues. Specific pathological forms were expanded in cancer and inflammation. All neoplastic tissues contained conserved tumor-associated macrophage populations. In particular, we focused on IL4I1+CD274(PD-L1)+IDO1+ macrophages, which accumulated in the tumor periphery in a T cell-dependent manner via interferon-γ (IFN-γ) and CD40/CD40L-induced maturation from IFN-primed monocytes. IL4I1_Macs exhibited immunosuppressive characteristics through tryptophan degradation and promoted the entry of regulatory T cell into tumors. This integrated analysis provides a robust online-available platform for uniform annotation and dissection of specific macrophage functions in healthy and pathological states.

Response to anti-IL17 therapy in inflammatory disease is not strongly impacted by genetic background.

Response to the anti-IL17 monoclonal antibody secukinumab is heterogeneous, and not all participants respond to treatment. Understanding whether this heterogeneity is driven by genetic variation is a key aim of pharmacogenetics and could influence precision medicine approaches in inflammatory diseases. Using changes in disease activity scores across 5,218 genotyped individuals from 19 clinical trials across four indications (psoriatic arthritis, psoriasis, ankylosing spondylitis, and rheumatoid arthritis), we tested whether genetics predicted response to secukinumab. We did not find any evidence of association between treatment response and common variants, imputed HLA alleles, polygenic risk scores of disease susceptibility, or cross-disease components of shared genetic risk. This suggests that anti-IL17 therapy is equally effective regardless of an individual's genetic background, a finding that has important implications for future genetic studies of biological therapy response in inflammatory diseases.

Interleukin 23 receptor: Expression and regulation in immune cells.

The importance of IL-23 and its specific receptor, IL-23R, in the pathogenesis of several chronic inflammatory diseases has been established, but the underlying pathological mechanisms are not fully understood. This review focuses on IL-23R expression and regulation in immune cells.

Next-Generation Vaccine Development with Nanomaterials: Recent Advances, Possibilities, and Challenges.

Nanomaterials are becoming important tools for vaccine development owing to their tunable and adaptable nature. Unique properties of nanomaterials afford opportunities to modulate trafficking through various tissues, complement or augment adjuvant activities, and specify antigen valency and display. This versatility has enabled recent work designing nanomaterial vaccines for a broad range of diseases, including cancer, inflammatory diseases, and various infectious diseases. Recent successes of nanoparticle vaccines during the coronavirus disease 2019 (COVID-19) pandemic have fueled enthusiasm further. In this review, the most recent developments in nanovaccines for infectious disease, cancer, inflammatory diseases, allergic diseases, and nanoadjuvants are summarized. Additionally, challenges and opportunities for clinical translation of this unique class of materials are discussed.

Structure-guided engineering of tick evasins for targeting chemokines in inflammatory diseases.

As natural chemokine inhibitors, evasin proteins produced in tick saliva are potential therapeutic agents for numerous inflammatory diseases. Engineering evasins to block the desired chemokines and avoid off-target side effects requires structural understanding of their target selectivity. Structures of the class A evasin EVA-P974 bound to human CC chemokine ligands 7 and 17 (CCL7 and CCL17) and to a CCL8-CCL7 chimera reveal that the specificity of class A evasins for chemokines of the CC subfamily is defined by conserved, rigid backbone-backbone interactions, whereas the preference for a subset of CC chemokines is controlled by side-chain interactions at four hotspots in flexible structural elements. Hotspot mutations alter target preference, enabling inhibition of selected chemokines. The structure of an engineered EVA-P974 bound to CCL2 reveals an underlying molecular mechanism of EVA-P974 target preference. These results provide a structure-based framework for engineering evasins as targeted antiinflammatory therapeutics.

Faecal microbial transfer and complex carbohydrates mediate protection against COPD.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a major cause of global illness and death, most commonly caused by cigarette smoke. The mechanisms of pathogenesis remain poorly understood, limiting the development of effective therapies. The gastrointestinal microbiome has been implicated in chronic lung diseases via the gut-lung axis, but its role is unclear. DESIGN: Using an in vivo mouse model of cigarette smoke (CS)-induced COPD and faecal microbial transfer (FMT), we characterised the faecal microbiota using metagenomics, proteomics and metabolomics. Findings were correlated with airway and systemic inflammation, lung and gut histopathology and lung function. Complex carbohydrates were assessed in mice using a high resistant starch diet, and in 16 patients with COPD using a randomised, double-blind, placebo-controlled pilot study of inulin supplementation. RESULTS: FMT alleviated hallmark features of COPD (inflammation, alveolar destruction, impaired lung function), gastrointestinal pathology and systemic immune changes. Protective effects were additive to smoking cessation, and transfer of CS-associated microbiota after antibiotic-induced microbiome depletion was sufficient to increase lung inflammation while suppressing colonic immunity in the absence of CS exposure. Disease features correlated with the relative abundance of Muribaculaceae, Desulfovibrionaceae and Lachnospiraceae family members. Proteomics and metabolomics identified downregulation of glucose and starch metabolism in CS-associated microbiota, and supplementation of mice or human patients with complex carbohydrates improved disease outcomes. CONCLUSION: The gut microbiome contributes to COPD pathogenesis and can be targeted therapeutically.

Dupilumab demonstrated efficacy and was well tolerated regardless of prior use of swallowed topical corticosteroids in adolescent and adult patients with eosinophilic oesophagitis: a subgroup analysis of the phase 3 LIBERTY EoE TREET study.

OBJECTIVE: To assess the effect of long-term dupilumab on histological, symptomatic and endoscopic aspects of eosinophilic oesophagitis (EoE) in adolescent and adult patients with and without prior use of swallowed topical corticosteroids (STC) or prior inadequate response, intolerance or contraindication to STC. DESIGN: Pre-specified analysis of data from the phase 3 LIBERTY EoE TREET study on patients who received dupilumab 300 mg once a week or placebo for 24 weeks (W24) in parts A and B, and an additional 28 weeks (W52) in part C. Patients were categorised as with/without prior STC use and with/without inadequate/intolerance/contraindication to STC. The proportion of patients achieving ≤6 eosinophils per high-power field (eos/hpf), absolute change in Dysphagia Symptom Questionnaire (DSQ) score, mean change in Endoscopic Reference Score and Histologic Scoring System grade/stage scores were assessed for each subgroup. RESULTS: Regardless of prior STC use, dupilumab increased the proportion of patients achieving ≤6 eos/hpf and improved DSQ score versus placebo at W24, with improvements maintained or improved at W52. The DSQ score and the proportion of patients achieving ≤6 eos/hpf after switching from placebo to dupilumab at W24 were similar to those observed in the dupilumab group at W24, regardless of prior STC use or inadequate/intolerance/contraindication to STC. Improvements in other outcomes with dupilumab were similar in patients with/without prior STC use or inadequate/intolerance/contraindication to STC. CONCLUSION: Dupilumab 300 mg once a week demonstrated efficacy and was well tolerated in patients with EoE regardless of prior STC use or inadequate response, intolerance and/or contraindication to STC. TRIAL REGISTRATION NUMBER: NCT03633617.

Inhibition of cleavage of human complement component C5 and the R885H C5 variant by two distinct high affinity anti-C5 nanobodies.

The human complement system plays a crucial role in immune defense. However, its erroneous activation contributes to many serious inflammatory diseases. Since most unwanted complement effector functions result from C5 cleavage into C5a and C5b, development of C5 inhibitors, such as clinically approved monoclonal antibody eculizumab, are of great interest. Here, we developed and characterized two anti-C5 nanobodies, UNbC5-1 and UNbC5-2. Using surface plasmon resonance, we determined a binding affinity of 119.9 pM for UNbC5-1 and 7.7 pM for UNbC5-2. Competition experiments determined that the two nanobodies recognize distinct epitopes on C5. Both nanobodies efficiently interfered with C5 cleavage in a human serum environment, as they prevented red blood cell lysis via membrane attack complexes (C5b-9) and the formation of chemoattractant C5a. The cryo-EM structure of UNbC5-1 and UNbC5-2 in complex with C5 (3.6 Å resolution) revealed that the binding interfaces of UNbC5-1 and UNbC5-2 overlap with known complement inhibitors eculizumab and RaCI3, respectively. UNbC5-1 binds to the MG7 domain of C5, facilitated by a hydrophobic core and polar interactions, and UNbC5-2 interacts with the C5d domain mostly by salt bridges and hydrogen bonds. Interestingly, UNbC5-1 potently binds and inhibits C5 R885H, a genetic variant of C5 that is not recognized by eculizumab. Altogether, we identified and characterized two different, high affinity nanobodies against human C5. Both nanobodies could serve as diagnostic and/or research tools to detect C5 or inhibit C5 cleavage. Furthermore, the residues targeted by UNbC5-1 hold important information for therapeutic inhibition of different polymorphic variants of C5.

Pathophysiological Roles of the cGAS-STING Inflammatory Pathway.

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) inflammatory pathway is a component of the innate immune system that recognizes cytosolic nucleic acids. The pathway has been implicated in several processes including aging, autoinflammatory conditions, cancer, and metabolic diseases. The cGAS-STING pathway represents a promising therapeutic target in a variety of chronic inflammatory diseases.

Homotherapy for heteropathy: Interleukin-41 and its biological functions.

Interleukin-41 (IL-41) is a newly discovered cytokine, named Cometin, Subfatin, meteorin-like transcription (Metrnl), and so forth. It is widely expressed in animals and can exert its biological roles through autocrine and paracrine forms. It has functions such as anti-inflammatory, improving body metabolism, regulating immunity, regulating fat metabolism and participates in the process of autoimmune disease or inflammatory injury. It plays an important role in psoriasis, diabetes, Crohn's disease (CD), osteoarthritis, Kawasaki disease (KD), Graves' disease, autoimmune hepatitis, infertility, obesity, sepsis, cardiovascular diseases and respiratory diseases. This paper reviews the biological functions of IL-41, the relationship between IL-41 and diseases, the effects of IL-41 in the cytokine network and the possible signalling pathways. In order to explore the same target or the same drug for the treatment of different diseases from the perspective of homotherapy for heteropathy, cytokine strategies based on IL-41 have been put forward for the precise treatment of immune diseases and inflammatory diseases. It is worth noting that IL-41 related preparations for lung protection and smoking cessation are interesting research fields.

Flavonoid extracted from Epimedium attenuate cGAS-STING-mediated diseases by targeting the formation of functional STING signalosome.

Hyperactivation of the cyclic-GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signalling pathway has been shown to be associated with the development of a variety of inflammatory diseases, and the discovery of an inhibitor of the cGAS-STING signalling pathway holds great promise in the therapeutic interventions. Epimedium flavonoid (EF), a major active ingredient isolated from the medicinal plant Epimedium, has been reported to have good anti-inflammatory activity, but its exact mechanism of action remains unclear. In the present study, we found that EF in mouse bone marrow-derived macrophages (BMDMs), THP-1 (Tohoku Hospital Pediatrics-1) as well as in human peripheral blood mononuclear cells (hPBMC) inhibited the activation of the cGAS-STING signalling pathway, which subsequently led to a decrease in the expression of type I interferon (IFN-ß, CXCL10 and ISG15) and pro-inflammatory cytokines (IL-6 and TNF-α). Mechanistically, EF does not affect STING oligomerization, but inhibits the formation of functional STING signalosome by attenuating the interaction of interferon regulatory factor 3 (IRF3) with STING and TANK-binding kinase 1 (TBK1). Importantly, in vivo experiments, EF has shown promising therapeutic effects on inflammatory diseases mediated by the cGAS-STING pathway, which include the agonist model induced by DMXAA stimulation, the autoimmune inflammatory disease model induced by three prime repair exonuclease 1 (Trex1) deficiency, and the non-alcoholic steatohepatitis (NASH) model induced by a pathogenic amino acid and choline deficiency diet (MCD). To summarize, our study suggests that EF is a potent potential inhibitor component of the cGAS-STING signalling pathway for the treatment of inflammatory diseases mediated by the cGAS-STING signalling pathway.

Molecular Foundations of Inflammatory Diseases: Insights into Inflammation and Inflammasomes.

Inflammatory diseases are a global health problem affecting millions of people with a wide range of conditions. These diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), osteoarthritis (OA), gout, and diabetes, impose a significant burden on patients and healthcare systems. A complicated interaction between genetic variables, environmental stimuli, and dysregulated immune responses shows the complex biological foundation of various diseases. This review focuses on the molecular mechanisms underlying inflammatory diseases, including the function of inflammasomes and inflammation. We investigate the impact of environmental and genetic factors on the progression of inflammatory diseases, explore the connection between inflammation and inflammasome activation, and examine the incidence of various inflammatory diseases in relation to inflammasomes.

Immune-mediated inflammatory diseases and periodontal disease: a bidirectional two-sample mendelian randomization study.

BACKGROUND: Previous observational studies have shown a bidirectional association between immune-mediated inflammatory disorders (IMID) and periodontal disease. However, evidence regarding the causal role of IMID and periodontal disease is still lacking. Therefore, we conducted a bidirectional two-sample Mendelian randomization (MR) study to uncover the potential genetic causal effects between IMID and periodontal disease. METHODS: Bidirectional two-sample MR analysis was employed. Data for ten IMIDs were sourced from genome-wide association studies (GWAS) conducted by the FinnGen Consortium (range from 1023 to 36321 cases) and UK Biobank (UKB) (range from 150 to 17574 cases). Furthermore, GWAS data for periodontal disease were obtained from the FinnGen Consortium (87497 cases), UKB (458 cases), and Gene Lifestyle Interactions in Dental Endpoints (GLIDE) consortium (17,353 periodontitis cases). Subsequently, the causal relationships were analyzed by random effects inverse variance weighting, weighted median, and MR-Egger. Sensitivity analyses were performed using the Cochrane Q test, funnel plot, and Mr-Egger intercept test to ensure robustness. Eventually, replication analysis and meta-analysis across different databases were carried out. RESULTS: Systemic lupus erythematosus (SLE) [IVW: OR = 1.079 (95% CI: 1.032-1.128) and P < 0.001], Sjogren syndrome [IVW: OR = 1.082 (95% CI: 1.012-1.157) and P = 0.022] and hypothyroidism [IVW: OR = 1.52 (95% CI: 1.13-2.04) and P = 0.005] may increase the risk of periodontal disease. In addition, periodontal disease may reduce the risk of SLE [IVW: OR = 0.8079 (95% CI: 0.6764-0.9650) and P = 0.019] and hyperthyroidism [IVW: OR = 5.59*10-9 (95% CI: 1.43*10-15-2.18*10-2) and P = 0.014]. Meta-analysis indicated a causal correlation between SLE and an increased risk of periodontal disease: [OR = 1.08 (95% CI: 1.03-1.13), P = 0.0009]. No significant evidence suggests bilateral causal relationships between other IMIDs and periodontal disease. No significant estimation of heterogeneity or pleiotropy is detected. CONCLUSIONS: Our study has confirmed a genetic causal relationship between IMIDs and periodontal disease, thereby unveiling novel potential mechanisms underlying IMIDs and periodontal disease. This discovery is promising in fostering interdisciplinary collaboration between clinicians and stomatologists to facilitate appropriate and precise screening, prevention, and early treatment of IMIDs and periodontal disease.

Fibroblasts in immune-mediated inflammatory diseases: The soil of inflammation.

As one of the most abundant stromal cells, fibroblasts are primarily responsible for the production and remodeling of the extracellular matrix. Traditionally, fibroblasts have been viewed as quiescent cells. However, recent advances in multi-omics technologies have demonstrated that fibroblasts exhibit remarkable functional diversity at the single-cell level. Additionally, fibroblasts are heterogeneous in their origins, tissue locations, and transitions with stromal cells. The dynamic nature of fibroblasts is further underscored by the fact that disease stages can impact their heterogeneity and behavior, particularly in immune-mediated inflammatory diseases such as psoriasis, inflammatory bowel diseases, and rheumatoid arthritis, etc. Fibroblasts can actively contribute to the disease initiation, progression, and relapse by responding to local microenvironmental signals, secreting downstream inflammatory factors, and interacting with immune cells during the pathological process. Here we focus on the development, plasticity, and heterogeneity of fibroblasts in inflammation, emphasizing the need for a developmental and dynamic perspective on fibroblasts.

High incidence of immune-mediated inflammatory diseases in sepsis survivors: A nationwide exposed-nonexposed epidemiological study.

OBJECTIVE: Sepsis is characterized by an excessive release of inflammatory cytokines. Cytokine dysregulation is pivotal to the pathophysiology of immune-mediated inflammatory diseases (IMIDs). We aimed to analyze the incidence of IMIDs in patients who survived sepsis. METHODS: We performed a matched-cohort study using the National Medico-Administrative Hospital database in order to analyze the association between sepsis and incident IMIDs in 2020 in France. Sepsis was defined by the combination of at least one infection diagnosis code and one organ failure code. Patients with a first sepsis diagnosed in 2020 were randomly matched with patients admitted during the same period for acute myocardial infarction (AMI) with an exact matching procedure using age, gender, and comorbidities as matching variables. The main outcome was an IMID diagnosis in a 9-month follow-up period starting the first day of hospitalization for sepsis or AMI. RESULTS: In France, the incidence rate of IMIDs after a sepsis in 2020-analyzed in 62,257 patients-was of 7956 (95% confidence interval [95% CI] 7392-8520) per 100,000 patient-years. As compared to the AMI population, we observed an increased risk for IMIDs of 2.80 (hazard ratio [HR]; 95% CI [2.22-3.54]) starting from day 16 after admission in the sepsis population. The risk of IMIDs onset in sepsis survivors depended on the type of IMIDs and was higher for immune thrombocytopenia (5.51 [1.97-15.4]), autoimmune hemolytic anemia (HR 4.83 [1.45-16.1]), and antineutrophil cytoplasmic antibody-associated vasculitis (4.66 [2.05-10.6]). Association between sepsis and IMIDs onset appeared well balanced across pathogen categories. CONCLUSION: Our study shows a high incidence of IMIDs among sepsis survivors.

Recent Advances of Engineered Cell Membrane-Based Nanotherapeutics to Combat Inflammatory Diseases.

An immune reaction known as inflammation serves as a shield from external danger signals, but an overactive immune system may additionally lead to tissue damage and even a variety of inflammatory disorders. By inheriting biological functionalities and serving as both a therapeutic medication and a drug carrier, cell membrane-based nanotherapeutics offer the potential to treat inflammatory disorders. To further strengthen the anti-inflammatory benefits of natural cell membranes, researchers alter and optimize the membranes using engineering methods. This review focuses on engineered cell membrane-based nanotherapeutics (ECMNs) and their application in treating inflammation-related diseases. Specifically, this article discusses the methods of engineering cell membranes for inflammatory diseases and examines the progress of ECMNs in inflammation-targeted therapy, inflammation-neutralizing therapy, and inflammation-immunomodulatory therapy. Additionally, the article looks into the perspectives and challenges of ECMNs in inflammatory treatment and offers suggestions as well as guidance to encourage further investigations and implementations in this area.

The role of mitochondrial fusion and fission in immune-mediated inflammatory diseases.

Mitochondria are highly dynamic organelles that maintain their homeostasis through mitochondrial dynamics. Mitochondrial fusion and fission are two important processes of mitochondrial dynamics. There is accumulating evidence that mitochondrial fusion and fission play an important role in the development of immune-mediated inflammatory diseases. This article provides a brief review of the essential role of mitochondrial fusion and fission in immune-mediated inflammatory diseases. It will provide a novel perspective and direction for the elucidation of the pathogenesis and treatment of immune-mediated inflammatory diseases.

The research progression of direct NLRP3 inhibitors to treat inflammatory disorders.

The NLRP3 inflammasome represents a cytoplasmic multiprotein complex with the capability to recognize a wide range of pathogen-derived, environmental, and endogenous stress-related factors. Dysregulated activation of the NLRP3 inflammasome has been implicated in the development of various inflammasome-associated disorders, highlighting its significance as a pivotal target for the treatment of inflammatory diseases. Nonetheless, despite its clinical importance, there is currently a lack of specific drugs available for directly targeting the NLRP3 inflammasome. Several strategies have been explored to target different facets of the NLRP3 inflammasome, with interventions aimed at directly inhibiting NLRP3 demonstrating the most promising efficacy and safety profiles. In this review, we provide a summary of direct inhibitors targeting NLRP3, elucidating their inhibitory mechanisms, clinical trial phases, and potential applications. Through this discussion, we aim to shed light on the implications of NLRP3 inhibition for the treatment of inflammatory diseases.