IL-18 and infections: Is there a role for targeted therapies?

Podoplanin expressing macrophages and their involvement in tertiary lymphoid structures in mouse models of Sjögren's disease

Tertiary lymphoid structures (TLSs) are formed in tissues targeted by chronic inflammation processes, such as infection and autoimmunity. In Sjögren's disease, the organization of immune cells into TLS is an important part of disease progression. Here, we investigated the dynamics of tissue resident macrophages in the induction and expansion of salivary gland TLS. We induced Sjögren's disease by cannulation of the submandibular glands of C57BL/6J mice with LucAdV5. In salivary gland tissues from these mice, we analyzed the different macrophage populations prior to cannulation on day 0 and on day 2, 5, 8, 16 and 23 post-infection using multicolored flow cytometry, mRNA gene analysis, and histological evaluation of tissue specific macrophages. The histological localization of macrophages in the LucAdV5 induced inflamed salivary glands was compared to salivary glands of NZBW/F1 lupus prone mice, a spontaneous mouse model of Sjögren's disease. The evaluation of the dynamics and changes in macrophage phenotype revealed that the podoplanin (PDPN) expressing CX3CR1+ macrophage population was increased in the salivary gland tissue during LucAdV5 induced inflammation. This PDPN+ CX3CR1+ macrophage population was, together with PDPN+CD206+ macrophages, observed to be localized in the parenchyma during the acute inflammation phase as well as surrounding the TLS structure in the later stages of inflammation. This suggests a dual role of tissue resident macrophages, contributing to both proinflammatory and anti-inflammatory processes, as well as their possible interactions with other immune cells within the inflamed tissue. These macrophages may be involved with lymphoid neogenesis, which is associated with disease severity and progression. In conclusion, our study substantiates the involvement of proinflammatory and regulatory macrophages in autoimmune pathology and underlines the possible multifaceted functions of macrophages in lymphoid cell organization.

Tangzu granule alleviate neuroinflammation in diabetic peripheral neuropathy by suppressing pyroptosis through P2X7R /NLRP3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus, mainly manifested as paresthesia. Tangzu granule (TZG) is derived from famous traditional Chinese medicine decoctions and optimized by long-term temporary practice. TZG has good efficacy in improving numbness, pain and pruritus of the lower extremities of DPN patients. However, the overall regulatory mechanisms underlying its effects on DPN remain unclear.

AIM OF THE STUDY

This study aims to explore the potential mechanism of TZG for treating DPN.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were used to establish an in vivo model of DPN with streptozotocin (STZ) injection and high-fat diet (HFD) feeding. Additionally, sciatic glial RSC96 cells were induced with high glucose in vitro. SD rats in intervention group received TZG treatment for 12 weeks. After 12 weeks of treatment, sciatic nerve function was evaluated by intelligent hot plate meter and neuro electrophysiology detector. The morphological changes of sciatic nerve cells were observed by hematoxylin-eosin staining and transmission electron microscope. IL-1β, IL-18 inflammatory cytokines, pyroptosis and P2X7R/NLRP3 signaling pathway were observed by Western blotting, immunofluorescence staining and ELISA.

RESULTS

TZG improved nerve conduction velocity and sciatic neuropathy rational structural changes in DPN rats. It also inhibited RSC96 inflammatory response and cell death that induced by high glucose. This may be related to TZG inhibiting P2X7R, decreasing the activation of NLRP3 inflammasomes, down-regulating the levels of pyroptosis proteins such as caspase-1, cleaved caspase-1, gasdermin D (GSDMD), and GSDMD-N, and inhibiting the release of interleuki (IL)-18 and IL-1β inflammatory cytokines.

CONCLUSIONS

TZG inhibited pyroptosis through P2X7R/NLRP3 signaling pathway, alleviated neuroinflammation, and showed protective effect in the treatment of DPN.

Exploring the causal relationship between the immune cell-inflammatory factor axis and lung cancer: a Mendelian randomization study

Background

Lung cancer is a major health burden globally and smoking is a well-known risk factor. It has been observed that chronic inflammation contributes to lung cancer progression, with immune cells and inflammatory cytokines implicated in tumor development. Clarifying the causal links between these immune components and lung cancer could enhance prevention and therapy.

Methods

We performed Mendelian randomization (MR) to explore causal connections between immune cells, inflammatory markers, and lung cancer risk, using genetic variants as instruments. Data from GWAS on these variables underpinned our MR analyses.

Results

Our findings indicated an inverse association between some immune cells and lung cancer risk, implying that more immune cells might be protective. NK T cells (CD16-CD56) and myeloid cells (HLA DR+ on CD33dim HLA DR+ CD11b+) had an inverse correlation with lung cancer risk. Furthermore, a direct relationship was observed between inflammatory cytokines and these immune cells. In contrast, IL-18 was inversely associated with lung cancer, while IL-13 showed a direct correlation.

Conclusion

The study underscores the role of immune and inflammatory factors in lung cancer. These insights could lead to new therapeutic strategies for combating lung cancer.

Primary immunodeficiency-related genes and varicella-zoster virus reactivation syndrome: a Mendelian randomization study

Background

Currently, evidence regarding the causal relationship between primary immunodeficiency-related genes and varicella-zoster virus reactivation syndrome is limited and inconsistent. Therefore, this study employs Mendelian randomization (MR) methodology to investigate the causal relationship between the two.

Methods

This study selected 110 single-nucleotide polymorphisms (SNPs) of primary immunodeficiency-related genes as instrumental variables (IVs). Genetic associations of primary immunodeficiency-related genes were derived from recent genome-wide association studies (GWAS) data on human plasma protein levels and circulating immune cells. Data on genes associated with varicella-zoster virus reactivation syndrome were obtained from the GWAS Catalog and FINNGEN database, primarily analyzed using inverse variance weighting (IVW) and sensitivity analysis.

Results

Through MR analysis, we identified 9 primary immunodeficiency-related genes causally associated with herpes zoster and its subsequent neuralgia; determined causal associations of 20 primary immunodeficiency-related genes with three vascular lesions (stroke, cerebral aneurysm, giant cell arteritis); revealed causal associations of 10 primary immunodeficiency-related genes with two ocular diseases (retinopathy, keratitis); additionally, three primary immunodeficiency-related genes each were associated with encephalitis, cranial nerve palsy, and gastrointestinal infections.

Conclusions

This study discovers a certain association between primary immunodeficiency-related genes and varicella-zoster virus reactivation syndrome, yet further investigations are warranted to explore the specific mechanisms underlying these connections.

Mitochondria: a breakthrough in combating rheumatoid arthritis

As a chronic autoimmune disease with complex aetiology, rheumatoid arthritis (RA) has been demonstrated to be associated with mitochondrial dysfunction since mitochondrial dysfunction can affect the survival, activation, and differentiation of immune and non-immune cells involved in the pathogenesis of RA. Nevertheless, the mechanism behind mitochondrial dysfunction in RA remains uncertain. Accordingly, this review addresses the possible role and mechanisms of mitochondrial dysfunction in RA and discusses the potential and challenges of mitochondria as a potential therapeutic strategy for RA, thereby providing a breakthrough point in the prevention and treatment of RA.

Early symptom-associated inflammatory responses shift to type 2 responses in controlled human schistosome infection

Schistosomiasis is an infection caused by contact with Schistosoma-contaminated water and affects more than 230 million people worldwide with varying morbidity. The roles of T helper 2 (TH2) cells and regulatory immune responses in chronic infection are well documented, but less is known about human immune responses during acute infection. Here, we comprehensively map immune responses during controlled human Schistosoma mansoni infection using male or female cercariae. Immune responses to male or female parasite single-sex infection were comparable. An early TH1-biased inflammatory response was observed at week 4 after infection, which was particularly apparent in individuals experiencing symptoms of acute schistosomiasis. By week 8 after infection, inflammatory responses were followed by an expansion of TH2 and regulatory cell subsets. This study demonstrates the shift from TH1 to both TH2 and regulatory responses, typical of chronic schistosomiasis, in the absence of egg production and provides immunological insight into the clinical manifestations of acute schistosomiasis.

An antibody to IL-1 receptor 7 protects mice from LPS-induced tissue and systemic inflammation

Introduction

Interleukin-18 (IL-18), a pro-inflammatory cytokine belonging to the IL-1 Family, is a key mediator ofautoinflammatory diseases associated with the development of macrophage activation syndrome (MAS).High levels of IL-18 correlate with MAS and COVID-19 severity and mortality, particularly in COVID-19patients with MAS. As an inflammation inducer, IL-18 binds its receptor IL-1 Receptor 5 (IL-1R5), leadingto the recruitment of the co-receptor, IL-1 Receptor 7 (IL-1R7). This heterotrimeric complex subsequentlyinitiates downstream signaling, resulting in local and systemic inflammation.

Methods

We reported earlier the development of a novel humanized monoclonal anti-human IL-1R7 antibody whichspecifically blocks the activity of human IL-18 and its inflammatory signaling in human cell and wholeblood cultures. In the current study, we further explored the strategy of blocking IL-1R7 inhyperinflammation in vivo using animal models.

Results

We first identified an anti-mouse IL-1R7 antibody that significantly suppressed mouse IL-18 andlipopolysaccharide (LPS)-induced IFNg production in mouse splenocyte and peritoneal cell cultures. Whenapplied in vivo, the antibody reduced Propionibacterium acnes and LPS-induced liver injury and protectedmice from tissue and systemic hyperinflammation. Importantly, anti-IL-1R7 significantly inhibited plasma,liver cell and spleen cell IFNg production. Also, anti-IL-1R7 downregulated plasma TNFa, IL-6, IL-1b,MIP-2 production and the production of the liver enzyme ALT. In parallel, anti-IL-1R7 suppressed LPSinducedinflammatory cell infiltration in lungs and inhibited the subsequent IFNg production andinflammation in mice when assessed using an acute lung injury model.

Discussion

Altogether, our data suggest that blocking IL-1R7 represents a potential therapeutic strategy to specificallymodulate IL-18-mediated hyperinflammation, warranting further investigation of its clinical application intreating IL-18-mediated diseases, including MAS and COVID-19.

Innate and adaptive immunity in acute myocarditis

Acute myocarditis is an acute inflammatory cardiomyopathy associated with cardiac damage triggered by a virus or a pathological immune activation. It may present with a wide range of clinical presentations, ranging from mild symptoms to severe forms like fulminant myocarditis, characterized by hemodynamic compromise and cardiogenic shock. The immune system plays a central role in the pathogenesis of myocarditis. In fact, while its function is primarily protective, aberrant responses can be detrimental. In this context, both innate and adaptive immunity play pivotal roles; notably, the innate system offers a non-specific and immediate defense, while the adaptive provides specialized protection with immunological memory. However, dysregulation in these systems can misidentify cardiac tissue, triggering autoimmune reactions and possibly leading to significant cardiac tissue damage. This review highlights the importance of innate and adaptive immune responses in the progression and treatment of acute myocarditis.

Integrated mRNA-miRNA transcriptome profiling of blood immune responses potentially related to pulmonary fibrosis in forest musk deer

Background

Forest musk deer (FMD, Moschus Berezovskii) is a critically endangered species world-widely, the death of which can be caused by pulmonary disease in the farm. Pulmonary fibrosis (PF) was a huge threat to the health and survival of captive FMD. MicroRNAs (miRNAs) and messenger RNAs (mRNAs) have been involved in the regulation of immune genes and disease development. However, the regulatory profiles of mRNAs and miRNAs involved in immune regulation of FMD are unclear.

Methods

In this study, mRNA-seq and miRNA-seq in blood were performed to constructed coexpression regulatory networks between PF and healthy groups of FMD. The hub immune- and apoptosis-related genes in the PF blood of FMD were explored through Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Further, protein-protein interaction (PPI) network of immune-associated and apoptosis-associated key signaling pathways were constructed based on mRNA-miRNA in the PF blood of the FMD. Immune hub DEGs and immune hub DEmiRNAs were selected for experimental verification using RT-qPCR.

Results

A total of 2744 differentially expressed genes (DEGs) and 356 differentially expressed miRNAs (DEmiRNAs) were identified in the PF blood group compared to the healthy blood group. Among them, 42 DEmiRNAs were negatively correlated with 20 immune DEGs from a total of 57 correlations. The DEGs were significantly associated with pathways related to CD molecules, immune disease, immune system, cytokine receptors, T cell receptor signaling pathway, Th1 and Th2 cell differentiation, cytokine-cytokine receptor interaction, intestinal immune network for IgA production, and NOD-like receptor signaling pathway. There were 240 immune-related DEGs, in which 186 immune-related DEGs were up-regulated and 54 immune-related DEGs were down-regulated. In the protein-protein interaction (PPI) analysis of immune-related signaling pathway, TYK2, TLR2, TLR4, IL18, CSF1, CXCL13, LCK, ITGB2, PIK3CB, HCK, CD40, CD86, CCL3, CCR7, IL2RA, TLR3, and IL4R were identified as the hub immune genes. The mRNA-miRNA coregulation analysis showed that let-7d, miR-324-3p, miR-760, miR-185, miR-149, miR-149-5p, and miR-1842-5p are key miRNAs that target DEGs involved in immune disease, immune system and immunoregulation.

Conclusion

The development and occurrence of PF were significantly influenced by the immune-related and apoptosis-related genes present in PF blood. mRNAs and miRNAs associated with the development and occurrence of PF in the FMD.

Genome Mining Leads to Diverse Sesquiterpenes with Anti-inflammatory Activity from an Arctic-Derived Fungus

With the advancement of bioinformatics, the integration of genome mining with efficient separation technology enables the discovery of a greater number of novel bioactive compounds. The deletion of the key gene responsible for triterpene cyclase biosynthesis in the polar strain Eutypella sp. D-1 instigated metabolic shunting, resulting in the activation of dormant genes and the subsequent production of detectable, new compounds. Fifteen sesquiterpenes were isolated from the mutant strain, with eight being new compounds. The structural elucidation of these compounds was obtained through a combination of HRESIMS, NMR spectroscopy, and ECD calculations, revealing six distinct skeleton types. Compound 7 possessed a unique skeleton of 5/10 macrocyclic ether structure. Based on the gene functions and newly acquired secondary metabolites, the metabolic shunting pathway in the mutant strain was inferred. Compounds 6, 8, 11, 14, and 15 exhibited anti-inflammatory effects without cytotoxicity through the release of nitric oxide from lipopolysaccharide-stimulated RAW264.7 cells. Notably, acorane-type sesquiterpene 8 inhibited nitric oxide production and modulated the MAPK and NLRP3/caspase-1 signaling pathways. Compound 8 also alleviated the CuSO4-induced systemic neurological inflammation symptoms in a transgenic fluorescent zebrafish model.

Age-associated declined function of endothelial progenitor cells and its correlation with plasma IL-18 or IL-23 concentrations in patients with ST-segment elevation myocardial infarction

Background

ST-segment elevation myocardial infarction (STEMI) persists to be prevalent in the elderly with a dismal prognosis. The capacity of endothelial progenitor cells (EPCs) is reduced with aging. Nevertheless, the influence of aging on the functionality of EPCs in STEMI is not fully understood.

Method

This study enrolled 20 younger STEMI patients and 21 older STEMI patients. We assessed the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events Risk (GRACE) scores in two groups. Then, we detected EPC migration, proliferation, adhesion, and plasma interleukin (IL)-18 and IL-23 concentrations in two groups. In addition, we analyzed the interconnection between age, EPC function, plasma IL-18 and IL-23 concentrations, and GRACE or TIMI scores in STEMI patients.

Result

GRACE and TIMI scores in older STEMI patients were higher than in younger STEMI patients, whereas EPC function declined. GRACE and TIMI scores were found to have an inverse relationship with the EPC function. In older STEMI patients, plasma concentrations of IL-18 and IL-23 increased. Plasma IL-18 and IL-23 concentrations were adversely connected to EPC capacity and positively related to GRACE and TIMI scores. Moreover, age was positively correlated with plasma IL-18 or IL-23 concentrations, as well as GRACE or TIMI scores. However, age was adversely correlated with EPC function.

Conclusion

In patients with STEMI, aging results in declined EPC function, which may be associated with inflammatory cytokines. The current investigation may offer new perception about mechanism and therapeutic targets of aging STEMI.

Opposing roles of resident and infiltrating immune cells in the defense against Legionella longbeachae via IL-18R/IFN-γ/ROS axis in mice

The immune response against Legionella longbeachae, a causative agent of the often-fatal Legionnaires' pneumonia, is poorly understood. Here, we investigated the specific roles of tissue-resident alveolar macrophages (AMs) and infiltrating phagocytes during infection with this pathogen. AMs were the predominant cell type that internalized bacteria 1 day after infection. A total of 3 and 5 days after infection, AM numbers were greatly reduced, whereas there was an influx of neutrophils and, later, monocyte-derived cells (MCs) into lung tissue. AMs carried greater numbers of viable L. longbeachae than neutrophils and MCs, which correlated with a higher capacity of L. longbeachae to translocate bacterial effector proteins required for bacterial replication into the AM cytosol. Cell ablation experiments demonstrated that AM promoted infection, whereas neutrophils and MC were required for efficient bacterial clearance. Interleukin (IL)-18 was important for interferon-γ production by IL-18R+ natural killer cells and T cells, which, in turn, stimulated reactive oxygen species-mediated bactericidal activity in neutrophils, resulting in the restriction of L. longbeachae infection. Ciliated bronchiolar epithelial cells also expressed IL-18R but did not play a role in IL-18-mediated L. longbeachae clearance. Our results have identified opposing innate functions of tissue-resident and infiltrating immune cells during L. longbeachae infection that may be manipulated to improve protective responses.

Potential of Neuroinflammation-Modulating Strategies in Tuberculous Meningitis: Targeting Microglia

Tuberculous meningitis (TBM) is the most severe complication of tuberculosis (TB) and is associated with high rates of disability and mortality. Mycobacterium tuberculosis (M. tb), the infectious agent of TB, disseminates from the respiratory epithelium, breaks through the blood-brain barrier, and establishes a primary infection in the meninges. Microglia are the core of the immune network in the central nervous system (CNS) and interact with glial cells and neurons to fight against harmful pathogens and maintain homeostasis in the brain through pleiotropic functions. However, M. tb directly infects microglia and resides in them as the primary host for bacillus infections. Largely, microglial activation slows disease progression. The non-productive inflammatory response that initiates the secretion of pro-inflammatory cytokines and chemokines may be neurotoxic and aggravate tissue injuries based on damages caused by M. tb. Host-directed therapy (HDT) is an emerging strategy for modulating host immune responses against diverse diseases. Recent studies have shown that HDT can control neuroinflammation in TBM and act as an adjunct therapy to antibiotic treatment. In this review, we discuss the diverse roles of microglia in TBM and potential host-directed TB therapies that target microglia to treat TBM. We also discuss the limitations of applying each HDT and suggest a course of action for the near future.

The antagonism mechanism of astilbin against cadmium-induced injury in chicken lungs via Treg/Th1 balance signaling pathway

The purpose of this study was to investigate the effect of Treg/Th1 imbalance in cadmium-induced lung injury and the potential protective effect of astilbin against cadmium-induced lung injury in chicken. Cadmium exposure significantly decreased T-AOC and GSH-Px levels and SOD activity in the chicken lung tissues. In contrast, it significantly increased the MDA and NO levels. These results indicate that cadmium triggers oxidative stress in lungs. Histopathological analysis revealed that cadmium exposure further induced infiltration of lymphocytes in the chicken lungs, indicating that cadmium causes pulmonary damage. Further analysis revealed that cadmium decreased the expression of IL-4 and IL-10 but increased those of IL-17, Foxp3, TNF-α, and TGF-β, indicating that the exposure of cadmium induced the imbalance of Treg/Th1. Moreover, cadmium adversely affected chicken lung function by activating the NF-kB pathway and inducing expression of genes downstream to these pathways (COX-2, iNOS), associated with inflammatory injury in the lung tissue. Astilbin reduced cadmium-induced oxidative stress and inflammation in the lungs by increasing antioxidant enzyme activities and restoring Treg/Th1 balance. In conclusion, our results suggest that astilbin treatment alleviated the effects of cadmium-mediated lung injury in chickens by restoring the Treg/Th1 balance.

Inflammatory liver diseases and susceptibility to sepsis

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.

Lactococcus lactis as an Interleukin Delivery System for Prophylaxis and Treatment of Inflammatory and Autoimmune Diseases

Target delivery of therapeutic agents with anti-inflammatory properties using probiotics as delivery and recombinant protein expression vehicles is a promising approach for the prevention and treatment of many diseases, such as cancer and intestinal immune disorders. Lactococcus lactis, a Lactic Acid Bacteria (LAB) widely used in the dairy industry, is one of the most important microorganisms with GRAS status for human consumption, for which biotechnological tools have already been developed to express and deliver recombinant biomolecules with anti-inflammatory properties. Cytokines, for  example, are immune system communication molecules present at virtually all levels of the immune response. They are essential in cellular and humoral processes, such as hampering inflammation or adjuvating in the adaptive immune response, making them good candidates for therapeutic approaches. This review discusses the advances in the development of new therapies and prophylactic approaches using LAB to deliver/express cytokines for the treatment of inflammatory and autoimmune diseases in the future.

Gasdermin D promotes influenza virus-induced mortality through neutrophil amplification of inflammation

Influenza virus activates cellular inflammasome pathways, which can be both beneficial and detrimental to infection outcomes. Here, we investigate the function of the inflammasome-activated, pore-forming protein gasdermin D (GSDMD) during infection. Ablation of GSDMD in knockout (KO) mice (Gsdmd-/-) significantly attenuates influenza virus-induced weight loss, lung dysfunction, lung histopathology, and mortality compared with wild type (WT) mice, despite similar viral loads. Infected Gsdmd-/- mice exhibit decreased inflammatory gene signatures shown by lung transcriptomics. Among these, diminished neutrophil gene activation signatures are corroborated by decreased detection of neutrophil elastase and myeloperoxidase in KO mouse lungs. Indeed, directly infected neutrophils are observed in vivo and infection of neutrophils in vitro induces release of DNA and tissue-damaging enzymes that is largely dependent on GSDMD. Neutrophil depletion in infected WT mice recapitulates the reductions in mortality, lung inflammation, and lung dysfunction observed in Gsdmd-/- animals, while depletion does not have additive protective effects in Gsdmd-/- mice. These findings implicate a function for GSDMD in promoting lung neutrophil responses that amplify influenza virus-induced inflammation and pathogenesis. Targeting the GSDMD/neutrophil axis may provide a therapeutic avenue for treating severe influenza.

Basella alba L. (Malabar Spinach) as an Abundant Source of Betacyanins: Identification, Stability, and Bioactivity Studies on Natural and Processed Fruit Pigments

The antioxidant and anti-inflammatory activities of acylated and decarboxylated gomphrenins, as well as Basella alba L. fruit extract, were investigated in relation to gomphrenin, known for its high biological potential. The most abundant natural acylated gomphrenins, namely, 6'-O-E-caffeoyl-gomphrenin (malabarin) and 6'-O-E-4-coumaroyl-gomphrenin (globosin), were isolated from B. alba extract for the studies. In addition, controlled thermal decarboxylation of gomphrenin in the purified B. alba extract at 65-75 °C resulted in the formation of the most prevalent decarboxylated products, including 17-decarboxy-gomphrenin and 2,17-bidecarboxy-gomphrenin, along with their isoforms. The structures of the decarboxylated pigments were confirmed by NMR analyses. Exploring the matrix effect on pigment reactivity revealed a tremendous increase in the stability of all betacyanins after the initial stage of extract purification using a cation exchanger under various conditions. This indicates the removal of a substantial portion of the unfavorable matrix from the extract, which presumably contains reactive species that could otherwise degrade the pigments. Furthermore, the high concentration of citrates played a significant role in favoring the formation of 2-decarboxy-gomphrenin to a considerable extent. In vitro screening experiments revealed that the tested compounds demonstrated strong anti-inflammatory properties in lipopolysaccharide (LPS)-activated human macrophages. This effect encompassed the selective inhibition of cytokine and chemokine release from activated macrophages, modulation of the chemotactic activity of immune cells, and the regulation of tissue remodeling mediators' release.

Protective effects of IL18-105G > A and IL18-137C > Ggenetic variants on severity of COVID-19

OBJECTIVE AND DESIGN

A cross-sectional study evaluated the IL18-105G > A (rs360717) and IL18-137C > G (rs187238) variants on Coronavírus Disease 2019 (COVID-19) severity.

SUBJECTS AND METHODS

528 patients with COVID-19 classifed with mild (n = 157), moderate (n = 63) and critical (n = 308) disease were genotpyed for the IL18-105G > A and IL18-137C > G variants.

RESULTS

We observed associations between severe + critical COVID-19 groups (reference group was mild COVID-19) and the IL18-105G > A (p = 0.008) and IL18-137C > G (p = 0.01) variants, which remained significant after adjusting for sex, ethnicity and age. Consequently, we have examined the associations between moderate + critical COVID-19 and the genotypes of both variants using different genetic models. The IL18-105G > A was associated with severe disease (moderate + critical), with effects of the GA genotype in the codominant [Odds ratio (OR), (95 % confidence interval) 0.55, 0.34-0.89, p = 0.015], overdominant (0.56, 0.35-0.89, p = 0.014) and dominant (0.60, 0.38-0.96, p = 0.031) models. IL18-105 GA coupled with age, chest computed tomograhy scan anormalities, body mass index, heart diseases, type 2 diabetes mellitus, hypertension, and inflammation may be used to predict the patients who develop severe disease with an accuracy of 84.3 % (sensitivity: 83.3 % and specificity: 86.5 %). Therefore, the presence of the IL18-105 A allele in homozygosis or heterozygosis conferred about 44.0 % of protection in the development of moderate and severe COVID-19. The IL18-137C > G variant was also associated with protective effects in the codominant (0.55, 0.34-0.89, p = 0.015), overdominant (0.57, 0.36-0.91, p = 0.018), and dominant models (0.59, 0.37-0.93, p = 0.025). Therefore, the IL18-137 G allele showed a protective effect against COVID-19 severity.

CONCLUSION

The IL18-105G > A and IL18-137C > Gvariants may contribute with protective effects for COVID-19 severity and the effects of IL18-137C > G may be modulating IL-18 production and Th1-mediated immune responses.

Ratios between the Levels of IL-18, Free IL-18, and IL-1β-Binding Protein Depending on the Severity and Outcome of COVID-19

In 89 patients with COVID-19, the ratios between IL-18, free IL-18, and IL-18-binding protein (IL-18BP) were analyzed depending on severity and outcome of the disease. At admission to the hospital, the levels of IL-18 and free IL-18 were significantly higher than 3 months after discharge from the hospital, the levels IL-18BP of being almost the same. In patients with more severe lung injury (computed tomography data), the levels of IL-18 and free IL-18 were higher and IL-18BP levels were lower than in patients with mild and moderate COVID-19. Three months after discharge from the hospital, no differences between these parameters were found. In 9 patients who died in the hospital, free IL-18 levels were significantly higher and IL-18BP levels were lower than in survivors. Thus, high levels of bioactive free IL-18 in combination with low levels of IL-18BP can be indicative of severe inflammatory phase of COVID-19 and the risk of worse clinical outcomes.

The cellular microenvironment regulates CX3CR1 expression on CD8+ T cells and the maintenance of CX3CR1+ CD8+ T cells

Expression levels of the chemokine receptor CX3CR1 serve as high-resolution marker delineating functionally distinct antigen-experienced T-cell states. The factors that influence CX3CR1 expression in T cells are, however, incompletely understood. Here, we show that in vitro priming of naïve CD8+ T cells failed to robustly induce CX3CR1, which highlights the shortcomings of in vitro priming settings in recapitulating in vivo T-cell differentiation. Nevertheless, in vivo generated memory CD8+ T cells maintained CX3CR1 expression during culture. This allowed us to investigate whether T-cell receptor ligation, cell death, and CX3CL1 binding influence CX3CR1 expression. T-cell receptor stimulation led to downregulation of CX3CR1. Without stimulation, CX3CR1+ CD8+ T cells had a selective survival disadvantage, which was enhanced by factors released from necrotic but not apoptotic cells. Exposure to CX3CL1 did not rescue their survival and resulted in a dose-dependent loss of CX3CR1 surface expression. At physiological concentrations of CX3CL1, CX3CR1 surface expression was only minimally reduced, which did not hamper the interpretability of T-cell differentiation states delineated by CX3CR1. Our data further support the broad utility of CX3CR1 surface levels as T-cell differentiation marker and identify factors that influence CX3CR1 expression and the maintenance of CX3CR1 expressing CD8+ T cells.

Suppressed transcript diversity and immune response in COVID-19 ICU patients: a longitudinal study

Understanding the dynamic changes in gene expression during Acute Respiratory Distress Syndrome (ARDS) progression in post-acute infection patients is crucial for unraveling the underlying mechanisms. Study investigates the longitudinal changes in gene/transcript expression patterns in hospital-admitted severe COVID-19 patients with ARDS post-acute SARS-CoV-2 infection. Blood samples were collected at three time points and patients were stratified into severe and mild ARDS, based on their oxygenation saturation (SpO2/FiO2) kinetics over 7 d. Decline in transcript diversity was observed over time, particularly in patients with higher severity, indicating dysregulated transcriptional landscape. Comparing gene/transcript-level analyses highlighted a rather limited overlap. With disease progression, a transition towards an inflammatory state was evident. Strong association was found between antibody response and disease severity, characterized by decreased antibody response and activated B cell population in severe cases. Bayesian network analysis identified various factors associated with disease progression and severity, viz. humoral response, TLR signaling, inflammatory response, interferon response, and effector T cell abundance. The findings highlight dynamic gene/transcript expression changes during ARDS progression, impact on tissue oxygenation and elucidate disease pathogenesis.

Pyroptosis-related gene signature elicits immune response in rosacea

Rosacea is a complex chronic inflammatory skin disorder with high morbidity. Pyroptosis is known as a regulated inflammatory cell death. While its association with immune response to various inflammatory disorders is well established, little is known about its functional relevance of rosacea. So, we aimed to explore and enrich the pathogenesis involved in pyroptosis-related rosacea aggravations. In this study, we evaluated the pyroptosis-related patterns of rosacea by consensus clustering analysis of 45 ferroptosis-related genes (FRGs), with multiple immune cell infiltration analysis to identify the pyroptosis-mediated immune response in rosacea using GSE65914 dataset. The co-co-work between PRGs and WGCNA-revealed hub genes has established using PPI network. FRG signature was highlighted in rosacea using multi-transcriptomic and experiment analysis. Based on this, three distinct pyroptosis-related rosacea patterns (non/moderate/high) were identified, and the notably enriched pathways have revealed through GO, KEGG and GSEA analysis, especially immune-related pathways. Also, the XCell/MCPcount/ssGSEA/Cibersort underlined the immune-related signalling (NK cells, Monocyte, Neutrophil, Th2 cells, Macrophage), whose hub genes were identified through WGCNA (NOD2, MYD88, STAT1, HSPA4, CXCL8). Finally, we established a pyroptosis-immune co-work during the rosacea aggravations. FRGs may affect the progression of rosacea by regulating the immune cell infiltrations. In all, pyroptosis with its mediated immune cell infiltration is a critical factor during the development of rosacea.

SARS-CoV-2 infection threatening intestinal health: A review of potential mechanisms and treatment strategies

The outbreak of the COVID-19 pandemic has brought great problems to mankind, including economic recession and poor health. COVID-19 patients are frequently reported with gastrointestinal symptoms such as diarrhea and vomiting in clinical diagnosis. Maintaining intestinal health is the key guarantee to maintain the normal function of multiple organs, otherwise it will be a disaster. Therefore, the purpose of this review was deeply understanded the potential mechanism of SARS-CoV-2 infection threatening intestinal health and put forward reasonable treatment strategies. Combined with the existing researches, we summarized the mechanism of SARS-CoV-2 infection threatening intestinal health, including intestinal microbiome disruption, intestinal barrier dysfunction, intestinal oxidative stress and intestinal cytokine storm. These adverse intestinal events may affect other organs through the circulatory system or aggravate the course of the disease. Typically, intestinal disadvantage may promote the progression of SARS-CoV-2 through the gut-lung axis and increase the disease degree of COVID-19 patients. In view of the lack of specific drugs to inhibit SARS-CoV-2 replication, the current review described new strategies of probiotics, prebiotics, postbiotics and nutrients to combat SARS-CoV-2 infection and maintain intestinal health. To provide new insights for the prevention and treatment of gastrointestinal symptoms and pneumonia in patients with COVID-19.

Efficacy and safety of MAS825 (anti-IL-1β/IL-18) in COVID-19 patients with pneumonia and impaired respiratory function

MAS825, a bispecific IL-1β/IL-18 monoclonal antibody, could improve clinical outcomes in COVID-19 pneumonia by reducing inflammasome-mediated inflammation. Hospitalized non-ventilated patients with COVID-19 pneumonia (n = 138) were randomized (1:1) to receive MAS825 (10 mg/kg single i.v.) or placebo in addition to standard of care (SoC). The primary endpoint was the composite Acute Physiology and Chronic Health Evaluation II (APACHE II) score on Day 15 or on the day of discharge (whichever was earlier) with worst-case imputation for death. Other study endpoints included safety, C-reactive protein (CRP), SARS-CoV-2 presence, and inflammatory markers. On Day 15, the APACHE II score was 14.5 ± 1.87 and 13.5 ± 1.8 in the MAS825 and placebo groups, respectively (P = 0.33). MAS825 + SoC led to 33% relative reduction in intensive care unit (ICU) admissions, ~1 day reduction in ICU stay, reduction in mean duration of oxygen support (13.5 versus 14.3 days), and earlier clearance of virus on Day 15 versus placebo + SoC group. On Day 15, compared with placebo group, patients treated with MAS825 + SoC showed a 51% decrease in CRP levels, 42% lower IL-6 levels, 19% decrease in neutrophil levels, and 16% lower interferon-γ levels, indicative of IL-1β and IL-18 pathway engagement. MAS825 + SoC did not improve APACHE II score in hospitalized patients with severe COVID-19 pneumonia; however, it inhibited relevant clinical and inflammatory pathway biomarkers and resulted in faster virus clearance versus placebo + SoC. MAS825 used in conjunction with SoC was well tolerated. None of the adverse events (AEs) or serious AEs were treatment-related.

The Cytokine Profile in Different Stages of Schistosomiasis Japonica

To explore and profile the level of cytokines in the sera of patients infected with Schistosoma japonicum to explore the helper T-cell response of patients either at the chronic or advanced stage of the disease. We randomly selected 58 subjects from several areas endemic for schistosomiasis japonica in China and collected serum samples to be tested for 18 different cytokines secreted by (1) Th1/Th2 cells (GM-CSF, IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-12p70, IL-10, IL-13, IL-18 and TNF-α) and (2) Th9/Th17/Th22/Treg cells (IL-9, IL-17A, IL-21, IL-22, IL-23 and IL-27). The Th1/Th2 cytokines in chronic patients were not significantly different from those in healthy people, while patients with advanced schistosomiasis had higher levels of IL-2, IL-23 and IL-27 and lower levels of IL-18 and IFN-γ. With respect to the Th9/Th17/Th22/Treg cell cytokines, there were higher levels of IL-23. Thus, a limited variation of the cytokine response between the three patient groups was evident, but only in those with advanced infection, while there was no difference between chronic schistosomiasis infection and healthy subjects in this respect. The cytokine expression should be followed in patients with advanced schistosomiasis who show a cytokine pattern of a weakened Th1 cell response and an increased Th17 response.

NETosis: an emerging therapeutic target in renal diseases

Introduction

Neutrophil extracellular traps (NETs) are web-like structures composed of nuclear and granular components. The primary role of NETS is to prevent the dissemination of microbes and facilitate their elimination. However, this process is accompanied by collateral proinflammatory adverse effects when the NET release becomes uncontrollable, or clearance is impaired. Although NET-induced organ damage is conducted primarily and indirectly via immune complexes and the subsequent release of cytokines, their direct effects on cells are also remarkable. NETosis plays a critical pathogenic role in several renal disorders, such as the early phase of acute tubular necrosis, anti-neutrophil cytoplasmic antibody-mediated renal vasculitis, lupus nephritis, thrombotic microangiopathies, anti-glomerular basement membrane disease, and diabetic nephropathy. Their substantial contribution in the course of these disorders makes them a desirable target in the therapeutic armamentarium. This article gives an in-depth review of the heterogeneous pathogenesis and physiological regulations of NETosis and its pivotal role in renal diseases. Based on the pathogenesis, the article also outlines the current therapeutic options and possible molecular targets in the treatment of NET-related renal disorders.

Methods

We carried out thorough literature research published in PubMed and Google Scholar, including a comprehensive review and analysis of the classification, pathomechanisms, and a broad spectrum of NET-related kidney disorders.

Conclusions

NETosis plays a pivotal role in certain renal diseases. It initiates and maintains inflammatory and autoimmune disorders, thus making it a desirable target for improving patient and renal outcomes. Better understanding and clinical translation of the pathogenesis are crucial aspects to treatment, for improving patient, and renal outcomes.

Interleukin 18 and IL-18 BP response to Sars-CoV-2 virus infection

The immune response to the SARS-CoV-2 infection is crucial to the patient outcome. IL-18 is involved in the lymphocyte response to the disease and it is well established its important role in the complex developing of the host response to viral infection. This study aims at the analysis of the concentrations of IL-18, IL-18BP, INF-γ at the onset of the SARS-CoV-2 infection. The serum levels of measured interleukins were obtained through enzyme-linked immunosorbent assay. Furthermore, the free fraction of IL-18 was numerically evaluated. The enrolled patients were divided in two severity groups according to a threshold value of 300 for the ratio of arterial partial pressure of oxygen and fraction of inspired oxygen fraction and according to the parenchymal involvement as evaluated by computerized tomography at the admittance. In the group of patients with a more severe disease, a significant increase of the IL-18, INF-γ and IL-18BP levels have been observed, whereas the free IL-18 component values were almost constant. The results confirm that, at the onset of the disease, the host response keep the inflammatory cytokines in an equilibrium and support the hypothesis to adopt the IL-18BP modulation as a possible and effective therapeutic approach.

IL-18 Signaling in the Rat Central Amygdala Is Disrupted in a Comorbid Model of Post-Traumatic Stress and Alcohol Use Disorder

Alcohol use disorder (AUD) and anxiety disorders are frequently comorbid and share dysregulated neuroimmune-related pathways. Here, we used our established rat model of comorbid post-traumatic stress disorder (PTSD)/AUD to characterize the interleukin 18 (IL-18) system in the central amygdala (CeA). Male and female rats underwent novel (NOV) and familiar (FAM) shock stress, or no stress (unstressed controls; CTL) followed by voluntary alcohol drinking and PTSD-related behaviors, then all received renewed alcohol access prior to the experiments. In situ hybridization revealed that the number of CeA positive cells for Il18 mRNA increased, while for Il18bp decreased in both male and female FAM stressed rats versus CTL. No changes were observed in Il18r1 expression across groups. Ex vivo electrophysiology showed that IL-18 reduced GABAA-mediated miniature inhibitory postsynaptic currents (mIPSCs) frequencies in CTL, suggesting reduced CeA GABA release, regardless of sex. Notably, this presynaptic effect of IL-18 was lost in both NOV and FAM males, while it persisted in NOV and FAM females. IL-18 decreased mIPSC amplitude in CTL female rats, suggesting postsynaptic effects. Overall, our results suggest that stress in rats with alcohol access impacts CeA IL-18-system expression and, in sex-related fashion, IL-18's modulatory function at GABA synapses.

The central role of the NLRP3 inflammasome pathway in the pathogenesis of age-related diseases in the eye and the brain

With increasing age, structural changes occur in the eye and brain. Neuronal death, inflammation, vascular disruption, and microglial activation are among many of the pathological changes that can occur during ageing. Furthermore, ageing individuals are at increased risk of developing neurodegenerative diseases in these organs, including Alzheimer's disease (AD), Parkinson's disease (PD), glaucoma and age-related macular degeneration (AMD). Although these diseases pose a significant global public health burden, current treatment options focus on slowing disease progression and symptomatic control rather than targeting underlying causes. Interestingly, recent investigations have proposed an analogous aetiology between age-related diseases in the eye and brain, where a process of chronic low-grade inflammation is implicated. Studies have suggested that patients with AD or PD are also associated with an increased risk of AMD, glaucoma, and cataracts. Moreover, pathognomonic amyloid-β and α-synuclein aggregates, which accumulate in AD and PD, respectively, can be found in ocular parenchyma. In terms of a common molecular pathway that underpins these diseases, the nucleotide-binding domain, leucine-rich-containing family, and pyrin domain-containing-3 (NLRP3) inflammasome is thought to play a vital role in the manifestation of all these diseases. This review summarises the current evidence regarding cellular and molecular changes in the brain and eye with age, similarities between ocular and cerebral age-related diseases, and the role of the NLRP3 inflammasome as a critical mediator of disease propagation in the eye and the brain during ageing.

Role of interleukins in acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematological malignancy with strong heterogeneity. Immune disorders are a feature of various malignancies, including AML. Interleukins (ILs) and other cytokines participate in a series of biological processes of immune disorders in the microenvironment, and serve as a bridge for communication between various cellular components in the immune system. The role of ILs in AML is complex and pleiotropic. It can not only play an anti-AML role by enhancing anti-leukemia immunity and directly inducing AML cell apoptosis, but also promote the growth, proliferation and drug resistance of AML. These properties of ILs can be used to explore their potential efficacy in disease monitoring, prognosis assessment, and development of new treatment strategies for AML. This review aims to clarify some of the complex roles of ILs in AML and their clinical applications.

An overview of programmed cell death: Apoptosis and pyroptosis-Mechanisms, differences, and significance in organism physiology and pathophysiology

Regulated cell death is an essential and heterogeneous process occurring in the life cycle of organisms, from embryonic development and aging to the regulation of homeostasis and organ maintenance. Under this term, we can distinguish many distinct pathways, including apoptosis and pyroptosis. Recently, there has been an increasing comprehension of the mechanisms governing these phenomena and their characteristic features. The coexistence of different types of cell death and the differences and similarities between them has been the subject of many studies. This review aims to present the latest literature in the field of pyroptosis and apoptosis and compare their molecular pathway's elements and significance in the physiology and pathophysiology of the organism.

Epithelial responses and Candida albicans pathogenicity are enhanced in the presence of oral streptococci

Experimental models that consider host-pathogen interactions are relevant for improving knowledge about oral candidiasis. The aim of this study was to assess the epithelial immune responses, Candida penetration of cell monolayers, and virulence during mixed species culture infections. Single species cultures of Candida albicans and mixed cultures (C. albicans, Streptococcus mutans, and Streptococcus sanguinis) were used to infect monolayers of HaCaT and FaDu ATCC HTB-43 cells for 12 h. After infection, IL-18 and IL-34 gene expression was measured to assess epithelial cell immune responses, and lactate dehydrogenase (LDH) activity was measured as an indicator of cell damage. Microscopy determined C. albicans morphology and penetration of fungal cells through the keratinocyte monolayer. Monolayers devoid of infection served as controls. Data were analyzed by an ANOVA one-way test followed by Tukey's post-hoc test (α = 0.05). The results found that IL-18 and IL-34 gene expression and LDH activity were significantly (p < 0.05) upregulated for both cell lines exposed to mixed species cultures compared with C. albicans alone. Candida albicans yeast and hyphae were evident in C. albicans only infections. In contrast, monolayers infected by C. albicans, S. mutans, and S. sanguinis exhibited higher microbial invasion with several hyphal aggregates detected. The presence of streptococci in C. albicans infection enhances the virulence and pathogenicity of the fungus with associated increased immune responses and tissue damage. Extrapolation of these findings to oral infection would indicate the added potential benefit of managing bacterial components of biofilms during treatment.

KRT13-expressing epithelial cell population predicts better response to chemotherapy and immunotherapy in bladder cancer: Comprehensive evidences based on BCa database

Neoadjuvant chemotherapy (NAC) prior to surgery and immune checkpoint therapy (ICT) has revolutionized bladder cancer (BCa) treatment. Patients likely to benefit from these therapies need to be accurately stratified; however, this remains a major clinical challenge. In the present study, single-cell RNA sequencing was used to evaluate the predictive ability of an epithelial cell population highly expressing keratin 13 (KRT13) to assess therapeutic response in BCa. The presence of KRT13-enriched tumors indicated favorable outcomes after NAC and superior response to ICT in patients with BCa. Furthermore, KRT13 population characteristics appeared to be closely related to changes in the immune microenvironment in the vicinity of this cell population. We constructed a prognostic model using an artificial neural network based on the gene signatures in the KRT13 population; the model demonstrated strong robustness and superiority. Additionally, a user-friendly and open-access web application named BCa database was developed for researchers to study BCa by mining the connective map database.

The Anti-Atopic Dermatitis Effects of Mentha arvensis Essential Oil Are Involved in the Inhibition of the NLRP3 Inflammasome in DNCB-Challenged Atopic Dermatitis BALB/c Mice

The NLRP3 inflammasome is upregulated by various agents, such as nuclear factor-kappa B (NF-κB), lipopolysaccharide (LPS), and adenosine triphosphate (ATP). The NLRP3 inflammasome facilitations the maturation of interleukin (IL)-1β, a proinflammatory cytokine that is critically involved in the pathogenesis of atopic dermatitis (AD). Although the NLRP3 inflammasome clearly exacerbates AD symptoms such as erythema and pruritus, drugs for AD patients targeting the NLRP3 inflammasome are still lacking. Based on the previous findings that Mentha arvensis essential oil (MAEO) possesses strong anti-inflammatory and anti-AD properties through its inhibition of the ERK/NF-κB signaling pathway, we postulated that MAEO might be capable of modulating the NLRP3 inflammasome in AD. The aim of this research was to investigate whether MAEO affects the inhibition of NLRP3 inflammasome activation in murine bone marrow-derived macrophages (BMDMs) stimulated with LPS + ATP in vitro and in a murine model displaying AD-like symptoms induced by 2,4-dinitrochlorobenzene (DNCB) in vivo. We found that MAEO inhibited the expression of NLRP3 and caspase-1, leading to the suppression of NLRP3 inflammasome activation and IL-1β production in BMDMs stimulated with LPS + ATP. In addition, MAEO exhibited efficacy in ameliorating AD symptoms in a murine model induced by DNCB, as indicated by the reduction in dermatitis score, ear thickness, transepidermal water loss (TEWL), epidermal thickness, and immunoglobulin E (IgE) levels. Furthermore, MAEO attenuated the recruitment of NLRP3-expressing macrophages and NLRP3 inflammasome activation in murine dorsal skin lesions induced by DNCB. Overall, we provide evidence for the anti-AD effects of MAEO via inhibition of NLRP3 inflammasome activation.

Gasdermin D promotes influenza virus-induced mortality through neutrophil amplification of inflammation

Influenza virus activates cellular inflammasome pathways, which can be either beneficial or detrimental to infection outcomes. Here, we investigated the role of the inflammasome-activated pore-forming protein gasdermin D (GSDMD) during infection. Ablation of GSDMD in knockout (KO) mice significantly attenuated virus-induced weight loss, lung dysfunction, lung histopathology, and mortality compared with wild type (WT) mice, despite similar viral loads. Infected GSDMD KO mice exhibited decreased inflammatory gene signatures revealed by lung transcriptomics, which also implicated a diminished neutrophil response. Importantly, neutrophil depletion in infected WT mice recapitulated the reduced mortality and lung inflammation observed in GSDMD KO animals, while having no additional protective effects in GSDMD KOs. These findings reveal a new function for GSDMD in promoting lung neutrophil responses that amplify influenza virus-induced inflammation and pathogenesis. Targeting the GSDMD/neutrophil axis may provide a new therapeutic avenue for treating severe influenza.

The roles of critical pro-inflammatory cytokines in the drive of cytokine storm during SARS-CoV-2 infection

In patients with severe COVID-19, acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), and even mortality can result from cytokine storm, which is a hyperinflammatory medical condition caused by the excessive and uncontrolled release of pro-inflammatory cytokines. High levels of numerous crucial pro-inflammatory cytokines, such as interleukin-1 (IL-1), IL-2, IL-6, tumor necrosis factor-α, interferon (IFN)-γ, IFN-induced protein 10 kDa, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein-1, and IL-10 and so on, have been found in severe COVID-19. They participate in cascade amplification pathways of pro-inflammatory responses through complex inflammatory networks. Here, we review the involvements of these critical inflammatory cytokines in SARS-CoV-2 infection and discuss their potential roles in triggering or regulating cytokine storm, which can help to understand the pathogenesis of severe COVID-19. So far, there is rarely effective therapeutic strategy for patients with cytokine storm besides using glucocorticoids, which is proved to result in fatal side effects. Clarifying the roles of key involved cytokines in the complex inflammatory network of cytokine storm will help to develop an ideal therapeutic intervention, such as neutralizing antibody of certain cytokine or inhibitor of some inflammatory signal pathways.

SARS-CoV-2 spike protein induces IL-18-mediated cardiopulmonary inflammation via reduced mitophagy

Cardiopulmonary complications are major drivers of mortality caused by the SARS-CoV-2 virus. Interleukin-18, an inflammasome-induced cytokine, has emerged as a novel mediator of cardiopulmonary pathologies but its regulation via SARS-CoV-2 signaling remains unknown. Based on a screening panel, IL-18 was identified amongst 19 cytokines to stratify mortality and hospitalization burden in patients hospitalized with COVID-19. Supporting clinical data, administration of SARS-CoV-2 Spike 1 (S1) glycoprotein or receptor-binding domain (RBD) proteins into human angiotensin-converting enzyme 2 (hACE2) transgenic mice induced cardiac fibrosis and dysfunction associated with higher NF-κB phosphorylation (pNF-κB) and cardiopulmonary-derived IL-18 and NLRP3 expression. IL-18 inhibition via IL-18BP resulted in decreased cardiac pNF-κB and improved cardiac fibrosis and dysfunction in S1- or RBD-exposed hACE2 mice. Through in vivo and in vitro work, both S1 and RBD proteins induced NLRP3 inflammasome and IL-18 expression by inhibiting mitophagy and increasing mitochondrial reactive oxygenation species. Enhancing mitophagy prevented Spike protein-mediated IL-18 expression. Moreover, IL-18 inhibition reduced Spike protein-mediated pNF-κB and EC permeability. Overall, the link between reduced mitophagy and inflammasome activation represents a novel mechanism during COVID-19 pathogenesis and suggests IL-18 and mitophagy as potential therapeutic targets.

Pyroptosis and degenerative diseases of the elderly

Pyroptosis is a recently described mechanism of programmed cell death mediated by proteins of the gasdermin family. Widely recognized signaling cascades include the classical, non-classical, caspase-3-dependent gasdermin E and caspase-8-dependent gasdermin D pathways. Additional pyroptotic pathways have been subsequently reported. With the rising prevalence of advanced age, the role of pyroptosis in the degenerative diseases of the elderly has attracted increased research attention. This article reviews the primary mechanisms of pyroptosis and summarizes progress in the research of degenerative diseases of the elderly such as presbycusis, age-related macular degeneration, Alzheimer's disease, intervertebral disc degeneration, and osteoarthritis.

Efficacy and safety of plasma diafiltration: Review of case reports and case series

Plasma diafiltration (PDF), a blood purification procedure that combines dialysis with plasma filtration by a selective membrane, has been used to treat acute liver failure, sepsis, and other acute conditions. We reviewed 14 eligible case reports and case series that examined PDF in 357 patients to assess its efficacy and safety. Fourteen diseases may be indications for PDF. The primary indication in the included studies was acute liver failure without obvious inducement or cause not mentioned. Eighty-three patients reached the primary endpoint (31 deaths, 52 recoveries) and the efficacy was 62.7%. There were large changes in 16 toxins or clinical markers after PDF, including total bilirubin, IL-18, IL-6. In conclusion, PDF appears to be an effective treatment for clearance of bilirubin and other inflammatory mediators in patients with acute liver injury or a disease characterized by a systemic inflammatory state. Randomized controlled trials are needed to compare PDF with other blood purification methods, such as plasma exchange and the Molecular Adsorbent Recirculating System™.

Interleukin-18-primed human umbilical cord-mesenchymal stem cells achieve superior therapeutic efficacy for severe viral pneumonia via enhancing T-cell immunosuppression

Coronavirus disease 2019 (COVID-19) treatments are still urgently needed for critically and severely ill patients. Human umbilical cord-mesenchymal stem cells (hUC-MSCs) infusion has therapeutic benefits in COVID-19 patients; however, uncertain therapeutic efficacy has been reported in severe patients. In this study, we selected an appropriate cytokine, IL-18, based on the special cytokine expression profile in severe pneumonia of mice induced by H1N1virus to prime hUC-MSCs in vitro and improve the therapeutic effect of hUC-MSCs in vivo. In vitro, we demonstrated that IL-18-primed hUC-MSCs (IL18-hUCMSC) have higher proliferative ability than non-primed hUC-MSCs (hUCMSCcon). In addition, VCAM-1, MMP-1, TGF-β1, and some chemokines (CCL2 and CXCL12 cytokines) are more highly expressed in IL18-hUCMSCs. We found that IL18-hUCMSC significantly enhanced the immunosuppressive effect on CD3⁺ T-cells. In vivo, we demonstrated that IL18-hUCMSC infusion could reduce the body weight loss caused by a viral infection and significantly improve the survival rate. Of note, IL18-hUCMSC can also significantly attenuate certain clinical symptoms, including reduced activity, ruffled fur, hunched backs, and lung injuries. Pathologically, IL18-hUCMSC transplantation significantly enhanced the inhibition of inflammation, viral load, fibrosis, and cell apoptosis in acute lung injuries. Notably, IL18-hUCMSC treatment has a superior inhibitory effect on T-cell exudation and proinflammatory cytokine secretion in bronchoalveolar lavage fluid (BALF). Altogether, IL-18 is a promising cytokine that can prime hUC-MSCs to improve the efficacy of precision therapy against viral-induced pneumonia, such as COVID-19.

Infection of Pro- and Anti-Inflammatory Macrophages by Wild Type and Vaccine Strains of Measles Virus: NLRP3 Inflammasome Activation Independent of Virus Production

In humans and non-human primates, wild type (WT) measles virus (MeV) replicates extensively in lymphoid tissue and induces an innate response characteristic of NF-κB and inflammasome activation without type I interferon. In contrast, the live attenuated MeV vaccine (LAMV) replicates poorly in lymphoid tissue with little detectable in vivo cytokine production. To characterize the innate responses of macrophages to WT MeV and LAMV infection, we analyzed primary human monocyte-derived macrophages and phorbol myristic acid-matured monocytic THP-1 cells (M0) polarized to inflammatory (M1) and anti-inflammatory (M2) phenotypes 24 h after MeV infection. LAMV infected macrophages more efficiently than WT MeV but produced less virus than WT MeV-infected macrophages. Both strains induced production of NF-κB-responsive cytokines IL-6 and TNFα and inflammasome products IL-1β and IL-18 without evidence of pyroptosis. Analysis of THP-1 cells deficient in inflammasome sensors NOD-like receptor pyrin (NLRP)3, IFN-γ-inducible protein 16 (IFI16) or absent in melanoma (AIM)2; adaptor apoptosis-associated speck-like protein containing a CARD (ASC) or effector caspase 1 showed that IL-18 production was dependent on NLRP3, ASC, and caspase 1. However, M1 cells produced IL-1β in the absence of ASC or caspase 1 indicating alternate pathways for MeV-induced pro-IL-1β processing. Therefore, the innate response to in vitro infection of macrophages with both LAMV and WT MeV includes production of IL-6 and TNFα and activation of the NLRP3 inflammasome to release IL-1β and IL-18. LAMV attenuation impairs production of infectious virus but does not reduce ability to infect macrophages or innate responses to infection.

Multi-Omic Factors Associated with Frequency of Upper Respiratory Infections in Developing Infants

Susceptibility to upper respiratory infections (URIs) may be influenced by host, microbial, and environmental factors. We hypothesized that multi-omic analyses of molecular factors in infant saliva would identify complex host-environment interactions associated with URI frequency. A cohort study involving 146 infants was used to assess URI frequency in the first year of life. Saliva was collected at 6 months for high-throughput multi-omic measurement of cytokines, microRNAs, transcripts, and microbial RNA. Regression analysis identified environmental (daycare attendance, atmospheric pollution, breastfeeding duration), microbial (Verrucomicrobia, Streptococcus phage), and host factors (miR-22-5p) associated with URI frequency (p < 0.05). These results provide pathophysiologic clues about molecular factors that influence URI susceptibility. Validation of these findings in a larger cohort could one day yield novel approaches to detecting and managing URI susceptibility in infants.

Clinical Value of Serum Interleukin-18 in Neonatal Sepsis Diagnosis and Mortality Prediction

Purpose

Previous studies have demonstrated that interleukin-18 (IL-18) levels were elevated in adult patients with sepsis. However, its role in neonatal sepsis remains unknown. The current research was conducted to assess the clinical value of serum IL-18 level as a candidate biomarker in neonatal sepsis diagnosis and prediction of mortality.

Patients and Methods

From July 2022 to September 2022, we prospectively enrolled 91 septic neonates and 31 non-sepsis neonates in the intensive care unit of neonates at Henan Children's Hospital in Zhengzhou, China. Neonatal peripheral blood serum was collected at admission and levels of serum IL-18 were assessed. Employing multivariate logistic regression analysis, the evaluation of the potential of IL-18 as an independent biomarker for sepsis was executed. Furthermore, employing the receiver operating characteristic (ROC) curve analysis, the diagnostic value of IL-18 in sepsis and the ability of IL-18 in predicting the mortality of neonatal sepsis was measured. The statistical package SPSS 24.0 was employed to conduct all statistical analyses.

Results

Serum IL-18 levels in neonates in the sepsis group were elevated compared to the control group, reaching the highest levels in the non-survival sepsis group (P < 0.001). Correlation analysis exhibited a positive relationship between IL-18 levels and age, body temperature, respiratory rate, and C-reactive protein levels. IL-18 was identified as an independent biomarker in identifying sepsis (OR = 4.747, 95% CI 1.493-15.092, P = 0.008) by multiple logistic regression. ROC curve analysis exhibited that IL-18 was good in identifying neonatal sepsis (area under curve (AUC) = 0.77, 95% CI = 0.68-0.85, P < 0.001) and predicting neonatal mortality (AUC = 0.80, 95% CI = 0.63-0.96, P = 0.003).

Conclusion

IL-18 was a potential biomarker for identifying neonatal sepsis and neonatal mortality prediction.

IL-18BP Improves Early Graft Function and Survival in Lewis-Brown Norway Rat Orthotopic Liver Transplantation Model

Interleukin-18 (IL-18) can effectively activate natural killer (NK) cells and induce large concentrations of interferon-γ (IFN-γ). In healthy humans, IL-18 binding protein (IL-18BP) can inhibit the binding of IL-18 to IL-18R and counteract the biological action of IL-18 due to its high concentration and high affinity, thus preventing the production of IFN-γ and inhibiting NK-cell activation. Through previous studies and the phenomena observed by our group in pig-non-human primates (NHPs) liver transplantation experiments, we proposed that the imbalance in IL-18/IL-18BP expression upon transplantation encourages the activation, proliferation, and cytotoxic effects of NK cells, ultimately causing acute vascular rejection of the graft. In this research, we used Lewis-Brown Norway rat orthotopic liver transplantation (OLTx) as a model of acute vascular rejection. AAV8-Il18bp viral vectors as gene delivery vehicles were constructed for gene therapy to overexpress IL-18BP and alleviate NK-cell rejection of the graft after transplantation. The results showed that livers overexpressing IL-18BP had reduced damage and could function longer after transplantation, effectively improving the survival time of the recipients.

Predictive value of specific cytokines for lethal COVID-19 outcome

In our study, we aimed to evaluate the significance of specific cytokines in blood plasma as predictive markers of COVID-associated mortality. Materials and methods. In plasma samples of 29 patients with PCR-confirmed COVID-19 we measured the concentrations of 47 molecules. These molecules included: interleukins and selected pro-inflammatory cytokines (IL-1, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-9, IL-12 (p40), IL-12 (p70), IL 13, IL-15, IL-17A/CTLA8, IL-17-E/IL-25, IL-17F, IL-18, IL-22, IL-27, IFN2, IFN, TNF, TNF/Lymphotoxin-(LTA)); chemokines (CCL2/MCP-1, CCL3/MIP-1, CCL4/MIP-1, CCL7/MCP-3, CCL11/Eotaxin, CCL22/MDC, CXCL1/GRO, CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10, CX3CL1/Fractalkine); anti-inflammatory cytokines (IL-1Ra, IL-10); growth factors (EGF, FGF-2/FGF-basic, Flt-3 Ligand, G-CSF, M-CSF, GM-CSF, PDGF-AA, PDGFAB/BB, TGF, VEGF-A); and sCD40L. We used multiplex analysis based on xMAP technology (Luminex, USA) using Luminex MagPix. As controls, we used plasma samples of 20 healthy individuals. Based on the results, we applied Receiver Operating Characteristic (ROC) analysis and Area Under Curve (AUC) values to compare two different predictive tests and to choose the optimal division point for disease outcome (survivors/non-survivors). To find optimal biomarker combinations, we as used cytokines concentrations as dependent variables to grow a regression tree using JMP 16 Software.Results. Out of 47 studied cytokines/chemokines/growth factors, we picked four pro-inflammatory cytokines as having high significance in evaluation of COVID-19 outcome: IL-6, IL-8, IL-15, and IL-18. Based on the results received, we assume that the highest significance in terms of predicting the outcome of acute COVID-19 belongs to IL-6 and IL-18. Conclusion. Analyzing concentrations of IL-6 and IL-18 before administering treatment may prove valuable in terms of outcome prognosis.

The intercorrelations between blood levels of ferritin, sCD163, and IL-18 in COVID-19 patients and their association to prognosis

Coronavirus disease 2019 (COVID-19) is associated with immune dysregulation, severe respiratory failure, and multiple organ dysfunction caused by a cytokine storm involving high blood levels of ferritin and IL-18. Furthermore, there is a resemblance between COVID-19 and macrophage activation syndrome (MAS) characterized by high concentrations of soluble CD163 (sCD163) receptor and IL-18. High levels of ferritin, IL-18, and sCD163 receptor are associated with “hyperferritinemic syndrome”, a family of diseases that appears to include COVID-19. In this retrospective cohort study, we tested the association and intercorrelations in the serum levels of ferritin, sCD163, and IL-18 and their impact on the prognosis of COVID-19. We analyzed data of 70 hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The levels of sCD163, ferritin, and IL-18 were measured and the correlation of these parameters with the respiratory deterioration and overall 30-day survival was assessed. Among the 70 patients, 60 survived 30 days from hospitalization. There were substantial differences between the subjects who were alive following 30 days compared to those who expired. The differences were referring to lymphocyte and leukocyte count, CRP, D-dimer, ferritin, sCD163, and IL-18. Results showed high levels of IL-18 (median, 444 pg/mL in the survival group compared with 916 pg/mL in the mortality group, p-value 8.54 × 10–2), a statistically significant rise in levels of ferritin (median, 484 ng/mL in the survival group compared with 1004 ng/mL in the mortality group p-value, 7.94 × 10–3), and an elevated value of in sCD163 (mean, 559 ng/mL in the survival group compared with 840 ng/mL in the mortality group, p-value 1.68 × 10–2). There was no significant correlation between the rise of ferritin and the levels sCD163 or IL-18. Taken together, sCD163, ferritin, and IL-18 were found to correlate with the severity of COVID-19 infection. Although these markers are associated with COVID-19 and might contribute to the cytokine storm, no intercorrelation was found among them. It cannot be excluded though that the results depend on the timing of sampling, assuming that they play distinct roles in different stages of the disease course. The data represented herein may provide clinical benefit in improving our understanding of the pathological course of the disease. Furthermore, measuring these biomarkers during the disease progression may help target them at the right time and refine the decision-making regarding the requirement for hospitalization.

Interleukin-1 and the NLRP3 inflammasome in COVID-19: Pathogenetic and therapeutic implications

A hyperinflammatory response during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection crucially worsens clinical evolution of coronavirus disease 2019 (COVID-19). The interaction between SARS-CoV-2 and angiotensin-converting enzyme 2 (ACE2) triggers the activation of the NACHT, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome. Enhanced inflammasome activity has been associated with increased disease severity and poor prognosis. Evidence suggests that inflammasome activation and interleukin-1β (IL-1β) release aggravate pulmonary injury and induce hypercoagulability, favoring progression to respiratory failure and widespread thrombosis eventually leading to multiorgan failure and death. Observational studies with the IL-1 blockers anakinra and canakinumab provided promising results. In the SAVE-MORE trial, early treatment with anakinra significantly shortened hospital stay and improved survival in patients with moderate-to-severe COVID-19. In this review, we summarize current evidence supporting the pathogenetic role of the NLRP3 inflammasome and IL-1β in COVID-19, and discuss clinical trials testing IL-1 inhibition in COVID-19.

Identification of Monocytes Associated with Severe COVID-19 in the PBMCs of Severely Infected Patients Through Single-Cell Transcriptome Sequencing

Understanding the immunological characteristics of monocytes-including the characteristics associated with fibrosis-in severe coronavirus disease 2019 (COVID-19) is crucial for understanding the pathogenic mechanism of the disease and preventing disease severity. In this study, we performed single-cell transcriptomic sequencing of peripheral blood samples collected from six healthy controls and 14 COVID-19 samples including severe, moderate, and convalescent samples from three severely/critically ill and four moderately ill patients. We found that the monocytes were strongly remodeled in the severely/critically ill patients with COVID-19, with an increased proportion of monocytes and seriously reduced diversity. In addition, we discovered two novel severe-disease-specific monocyte subsets: Mono 0 and Mono 5. These subsets expressed amphiregulin (AREG), epiregulin (EREG), and cytokine interleukin-18 (IL-18) gene, exhibited an enriched erythroblastic leukemia viral oncogene homolog (ErbB) signaling pathway, and appeared to exhibit pro-fibrogenic and pro-inflammation characteristics. We also found metabolic changes in Mono 0 and Mono 5, including increased glycolysis/gluconeogenesis and an increased hypoxia inducible factor-1 (HIF-1) signaling pathway. Notably, one pre-severe sample displayed a monocyte atlas similar to that of the severe/critical samples. In conclusion, our study discovered two novel severe-disease-specific monocyte subsets as potential predictors and therapeutic targets for severe COVID-19. Overall, this study provides potential predictors for severe disease and therapeutic targets for COVID-19 and thus provides a resource for further studies on COVID-19.

Elevated IL-18 predicts poor prognosis in critically ill COVID-19 patients at a Brazilian hospital in 2020–21

Background: A dysregulated inflammatory response contributes to decline in patients with COVID-19. This cross-sectional study evaluated biomarkers of unvaccinated patients admitted to the intensive care unit of a hospital in Fortaleza, Brazil. Methods: Twenty cytokines were quantified upon hospital admission; clinical and laboratory data were analyzed, as well as sociodemographic data, to search for an association with clinical outcomes, including fatal (n = 40) or recovered cases (n = 38). Results: Fatal cases exhibited significantly higher levels of IL-18 (p = 0.009); deceased patients were older (p = 0.0001), had a lower number of platelets (p = 0.0063) and higher neutrophil–lymphocyte ratio (p = 0.0230) than those who recovered. Conclusion: These findings indicate that IL-18 is a possible marker to predict poor prognosis in critically ill patients with COVID-19.