Pathogen recognition and inflammatory signaling in innate immune defenses. Clin Microbiol Rev. 2009;22:240-273, Table of Contents. [PMID: 19366914 DOI: 10.1128/cmr.00046-08]

Protective effect of N-(E)-p-coumaroyltyrosine on LPS-induced acute inflammatory injury and signaling pathway analysis

N-trans-p-coumaroyltyrosine (N-(E)-p-coumaroyltyrosine, NPCT), extracted and purified from Abri Mollis Herba, is an amino acid amide. The defense mechanism of NPCT against inflammatory response is still unknown. In this study, lipopolysaccharide (LPS)-induced zebrafish acute inflammatory injury model was established to observe the inhibitory effect of NPCT on the aggregation of inflammatory cells in the yolk sac of zebrafish, as well as the inhibitory effect of NPCT on inflammatory and gas signaling factors. Results show that NPCT could inhibit inflammatory cell infiltration in zebrafish yolk sac, the migration and aggregation of macrophages and neutrophils to the site of inflammation, and the release of Nitric Oxide (NO) and Reactive Oxygen Species (ROS) in zebrafish, indicating that NPCT could substantially significantly prevent the development of LPS-induced acute systemic inflammation. In addition, the analysis results of RNA-seq showed that in the model group versus the administered group, the differentially expressed genes were mainly enriched to inflammatory signaling pathways, such as the NOD-like receptor signaling pathway and Toll-like receptor signaling pathway, which were down-regulated in the administered group. The TLR4, MyD88, IRAK4, NF-κB, IκB, NLRP3, Caspase-1, ASC, IL-1β, and IL-6 genes were significantly different in the transcripts, and the overall trend of the qPCR results was consistent with the transcriptome sequencing results. Therefore, NPCT had a significant inhibitory effect on LPS-induced acute inflammatory injury in zebrafish, and its anti-inflammatory mechanism may be through the regulation of key genes on the NOD-like receptor signaling pathway and Toll-like receptor signaling pathway, thereby affecting the release of relevant inflammatory cytokines.

Emerging perspectives on RNA virus-mediated infections: from pathogenesis to therapeutic interventions

RNA viruses continue to pose significant threats to global public health, necessitating a profound understanding of their pathogenic mechanisms and the development of effective therapeutic interventions. This manuscript provides a comprehensive overview of emerging perspectives on RNA virus-mediated infections, spanning from the intricate intricacies of viral pathogenesis to the forefront of innovative therapeutic strategies. A critical exploration of antiviral drugs sets the stage, highlighting the diverse classes of compounds that target various stages of the viral life cycle, underscoring the ongoing efforts to combat viral infections. Central to this discussion is the exploration of RNA-based therapeutics, with a spotlight on messenger RNA (mRNA)-based approaches that have revolutionized the landscape of antiviral interventions. Furthermore, the manuscript delves into the intricate world of delivery systems, exploring inno-vative technologies designed to enhance the efficiency and safety of mRNA vaccines. By analyzing the challenges and advancements in delivery mechanisms, this review offers a roadmap for future research and development in this critical area. Beyond conventional infectious diseases, the document explores the expanding applications of mRNA vaccines, including their promising roles in cancer immunotherapy and personalized medicine approaches. This manuscript serves as a valuable resource for researchers, clinicians, and policymakers alike, offering a nuanced perspective on RNA virus pathogenesis and the cutting-edge therapeutic interventions. By synthesizing the latest advancements and challenges, this review contributes significantly to the ongoing discourse in the field, driving the development of novel strategies to combat RNA virus-mediated infections effectively.

TLR agonists as vaccine adjuvants in the prevention of viral infections: an overview

Tol-like receptor (TLR) agonists, as potent adjuvants, have gained attention in vaccine research for their ability to enhance immune responses. This study focuses on their application in improving vaccine efficacy against key viral infections, including hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), SARS-CoV-2, influenza virus, and flaviviruses, including West Nile virus, dengue virus, and chikungunya virus. Vaccines are crucial in preventing microbial infections, including viruses, and adjuvants play a vital role in modulating immune responses. However, there are still many diseases for which effective vaccines are lacking or have limited immune response, posing significant threats to human health. The use of TLR agonists as adjuvants in viral vaccine formulations holds promise in improving vaccine effectiveness. By tailoring adjuvants to specific pathogens, such as HBV, HCV, HIV, SARS-CoV-2, influenza virus, and flavivirus, protective immunity against chronic and emerging infectious disease can be elicited.

Activation of sperm Toll-like receptor 2 induces hyperactivation to enhance the penetration to mucus and uterine glands: a trigger for the uterine inflammatory cascade in cattle

It is known that sperm and seminal plasma (SP) affect uterine immunity. In cattle, artificial insemination enables breeding by depositing frozen and largely diluted sperm with a negligible amount of SP into the uterus. Thus, the present study focused on the impact of frozen-thawed sperm on bovine uterine immunity. We have previously shown that in the bovine uterus, sperm swim smoothly over the luminal epithelium and some sperm interact with uterine glands to induce a weak inflammatory response mainly via the endometrial Toll-like receptor 2 (TLR2) signaling. However, the process by which sperm is encountered in the uterine glands is not completely clear. The present study intended to evaluate the role of sperm-TLR2 in sperm-uterine mucus penetration for reaching the glandular epithelium to induce the uterine immune response. To activate and block sperm-TLR2, they were treated with TLR2 agonist and antagonist, respectively. TLR2 activation enhanced sperm hyperactivation and improved its capacity to penetrate the artificial viscoelastic fluid and estrous-uterine-mucus. In contrast, TLR2-blocked sperm showed completely opposite effects. It is noteworthy, that the TLR2-activated sperm that penetrated the uterine mucus exhibited increased motile activity with hyperactivation. In the sperm-endometrial ex-vivo model, a greater amount of TLR2-activated sperm entered the uterine glands with an immune response, which was seen as the upregulation of mRNA expression for TNFA, IL1B, IL8, PGES, and TLR2 similar to those in control sperm. On the other hand, a lesser amount of TLR2-blocked sperm entered the uterine glands and weakened the sperm-induced increase only in PGES, suggesting that penetration of a certain number of sperm in the uterine gland is necessary enough to trigger the inflammatory response. Altogether, the present findings indicate that activation of sperm-TLR2 promotes their hyperactivation and mucus penetration with greater motility, allowing them to enter into the uterine glands more. This further suggests that the hyperactivated sperm contributes to triggering the pro-inflammatory cascade partly via TLR2 in the uterus.

How Can Imbalance in Oral Microbiota and Immune Response Lead to Dental Implant Problems?

Dental implantology is one of the most dynamically developing fields of dentistry, which, despite developing clinical knowledge and new technologies, is still associated with many complications that may lead to the loss of the implant or the development of the disease, including peri-implantitis. One of the reasons for this condition may be the fact that dental implants cannot yield a proper osseointegration process due to the development of oral microbiota dysbiosis and the accompanying inflammation caused by immunological imbalance. This study aims to present current knowledge as to the impact of oral microflora dysbiosis and deregulation of the immune system on the course of failures observed in dental implantology. Evidence points to a strong correlation between these biological disturbances and implant complications, often stemming from improper osseointegration, pathogenic biofilms on implants, as well as an exacerbated inflammatory response. Technological enhancements in implant design may mitigate pathogen colonization and inflammation, underscoring implant success rates.

Transcription factors in the development and treatment of immune disorders

Immune function is highly controlled at the transcriptional level by the binding of transcription factors (TFs) to promoter and enhancer elements. Several TF families play major roles in immune gene expression, including NF-κB, STAT, IRF, AP-1, NRs, and NFAT, which trigger anti-pathogen responses, promote cell differentiation, and maintain immune system homeostasis. Aberrant expression, activation, or sequence of isoforms and variants of these TFs can result in autoimmune and inflammatory diseases as well as hematological and solid tumor cancers. For this reason, TFs have become attractive drug targets, even though most were previously deemed "undruggable" due to their lack of small molecule binding pockets and the presence of intrinsically disordered regions. However, several aspects of TF structure and function can be targeted for therapeutic intervention, such as ligand-binding domains, protein-protein interactions between TFs and with cofactors, TF-DNA binding, TF stability, upstream signaling pathways, and TF expression. In this review, we provide an overview of each of the important TF families, how they function in immunity, and some related diseases they are involved in. Additionally, we discuss the ways of targeting TFs with drugs along with recent research developments in these areas and their clinical applications, followed by the advantages and disadvantages of targeting TFs for the treatment of immune disorders.

Regulatory TR3-56 Cells in the Complex Panorama of Immune Activation and Regulation

The interplay between immune activation and immune regulation is a fundamental aspect of the functional harmony of the immune system. This delicate balance is essential to triggering correct and effective immune responses against pathogens while preventing excessive inflammation and the immunopathogenic mechanisms of autoimmunity. The knowledge of all the mechanisms involved in immune regulation is not yet definitive, and, probably, the overall picture is much broader than what has been described in the scientific literature so far. Given the plasticity of the immune system and the diversity of organisms, it is highly probable that numerous other cells and molecules are still to be ascribed to the immune regulation process. Here, we report a general overview of how immune activation and regulation interact, based on the involvement of molecules and cells specifically dedicated to these processes. In addition, we discuss the role of TR3-56 lymphocytes as a new cellular candidate in the immune regulation landscape.

The Immune Response to the Myxozoan Parasite Myxobolus cerebralis in Salmonids: A Review on Whirling Disease

Salmonids are affected by the economically significant whirling disease (WD) caused by the myxozoan parasite Myxobolus cerebralis. In the past, it was endemic to Eurasia, but it has now spread to different regions of North America, Europe, New Zealand, and South Africa. Among salmonids, rainbow trout is considered the most highly susceptible host. Upon entering to the host's body, the parasite invades the spine and cranium, resulting in whirling behaviour, a blackened tail, and destruction of cartilage. The disease is characterized by the infiltration of numerous inflammatory cells, primarily lymphocytes and macrophages, with the onset of fibrous tissue infiltration. Several efforts have been undertaken to investigate the role of various immune modulatory molecules and immune regulatory genes using advanced molecular methods including flow cytometry and transcriptional techniques. Investigation of the molecular and cellular responses, the role of STAT3 in Th17 cell differentiation, and the inhibitory actions of suppressors of cytokine signaling (SOCS) on interferons and interleukins, as well as the role of natural resistance-associated macrophage proteins (Nramp) in WD have significantly contributed to our understanding of the immune regulation mechanism in salmonids against M. cerebralis. This review thoroughly highlights previous research and discusses potential future directions for understanding the molecular immune response of salmonids and the possible development of prophylactic approaches against WD.

Microglial Senescence and Activation in Healthy Aging and Alzheimer's Disease: Systematic Review and Neuropathological Scoring

The greatest risk factor for neurodegeneration is the aging of the multiple cell types of human CNS, among which microglia are important because they are the "sentinels" of internal and external perturbations and have long lifespans. We aim to emphasize microglial signatures in physiologic brain aging and Alzheimer's disease (AD). A systematic literature search of all published articles about microglial senescence in human healthy aging and AD was performed, searching for PubMed and Scopus online databases. Among 1947 articles screened, a total of 289 articles were assessed for full-text eligibility. Microglial transcriptomic, phenotypic, and neuropathological profiles were analyzed comprising healthy aging and AD. Our review highlights that studies on animal models only partially clarify what happens in humans. Human and mice microglia are hugely heterogeneous. Like a two-sided coin, microglia can be protective or harmful, depending on the context. Brain health depends upon a balance between the actions and reactions of microglia maintaining brain homeostasis in cooperation with other cell types (especially astrocytes and oligodendrocytes). During aging, accumulating oxidative stress and mitochondrial dysfunction weaken microglia leading to dystrophic/senescent, otherwise over-reactive, phenotype-enhancing neurodegenerative phenomena. Microglia are crucial for managing Aβ, pTAU, and damaged synapses, being pivotal in AD pathogenesis.

Medicinal Herbs: Promising Immunomodulators for the Treatment of Infectious Diseases

Humans are constantly at high risk of emerging pandemics caused by viral and bacterial infections. The emergence of new pandemics is mainly caused by evolved viruses and bacteria that are highly resistant to existing medications. The rapid evolution of infectious agents demands the urgent investigation of new therapeutic strategies to prevent and treat these infections at an early stage. One of these therapeutic strategies includes the use of medicinal herbs for their antibacterial and antiviral properties. The use of herbal medicines as remedies is very ancient and has been employed for centuries. Many studies have confirmed the antimicrobial activities of herbs against various pathogens in vitro and in vivo. The therapeutic effect of medicinal herbs is mainly attributed to the natural bioactive molecules present in these plants such as alkaloids, flavonoids, and terpenoids. Different mechanisms have been proposed for how medicinal herbs enhance the immune system and combat pathogens. Such mechanisms include the disruption of bacterial cell membranes, suppression of protein synthesis, and limitation of pathogen replication through the inhibition of nucleic acid synthesis. Medicinal herbs have been shown to treat a number of infectious diseases by modulating the immune system's components. For instance, many medicinal herbs alleviate inflammation by reducing pro-inflammatory cytokines (e.g., tumor necrosis factor-alpha (TNF-α), interleukin-1, IL-6) while promoting the production of anti-inflammatory cytokines (e.g., IL-10). Medicinal herbs also play a role in defense against viral and intracellular infections by enhancing the proliferation and functions of natural killer cells, T-helper-1 cells, and macrophages. In this review, we will explore the use of the most common herbs in preventing and treating infectious and non-infectious diseases. Using current and recently published studies, we focus on the immunomodulatory and therapeutic effects induced by medicinal herbs to enhance immune responses during diseases.

Cranberry Proanthocyanidins Mitigate Reflux-Induced Transporter Dysregulation in an Esophageal Adenocarcinoma Model

We recently reported that cranberry proanthocyanidins (C-PACs) inhibit esophageal adenocarcinoma (EAC) by 83% through reversing reflux-induced bacterial, inflammatory and immune-implicated proteins and genes as well as reducing esophageal bile acids, which drive EAC progression. This study investigated whether C-PACs' mitigation of bile reflux-induced transporter dysregulation mechanistically contributes to EAC prevention. RNA was isolated from water-, C-PAC- and reflux-exposed rat esophagi with and without C-PAC treatment. Differential gene expression was determined by means of RNA sequencing and RT-PCR, followed by protein assessments. The literature, coupled with the publicly available Gene Expression Omnibus dataset GSE26886, was used to assess transporter expression levels in normal and EAC patient biopsies for translational relevance. Significant changes in ATP-binding cassette (ABC) transporters implicated in therapeutic resistance in humans (i.e., Abcb1, Abcb4, Abcc1, Abcc3, Abcc4, Abcc6 and Abcc10) and the transport of drugs, xenobiotics, lipids, and bile were altered in the reflux model with C-PACs' mitigating changes. Additionally, C-PACs restored reflux-induced changes in solute carrier (SLC), aquaporin, proton and cation transporters (i.e., Slc2a1, Slc7a11, Slc9a1, Slco2a1 and Atp6v0c). This research supports the suggestion that transporters merit investigation not only for their roles in metabolism and therapeutic resistance, but as targets for cancer prevention and targeting preventive agents in combination with chemotherapeutics.

Interactions between Leishmania parasite and sandfly: a review

Leishmaniasis transmission cycles are maintained and sustained in nature by the complex crosstalk of the Leishmania parasite, sandfly vector, and the mammalian hosts (human, as well as zoonotic reservoirs). Regardless of the vast research on human host-parasite interaction, there persists a substantial knowledge gap on the parasite's development and modulation in the vector component. This review focuses on some of the intriguing aspects of the Leishmania-sandfly interface, beginning with the uptake of the intracellular amastigotes from an infected host to the development of the parasite within the sandfly's alimentary canal, followed by the transmission of infective metacyclic stages to another potential host. Upon ingestion of the parasite, the sandfly hosts an intricate repertoire of immune barriers, either to evade the parasite or to ensure its homeostatic coexistence with the vector gut microbiome. Sandfly salivary polypeptides and Leishmania exosomes are co-egested with the parasite inoculum during the infected vector bite. This has been attributed to the modulation of the parasite infection and subsequent clinical manifestation in the host. While human host-based studies strive to develop effective therapeutics, a greater understanding of the vector-parasite-microbiome and human host interactions could help us to identify the targets and to develop strategies for effectively preventing the transmission of leishmaniasis.

Extracellular vesicles in bacterial and fungal diseases - Pathogenesis to diagnostic biomarkers

Intercellular communication among microbes plays an important role in disease exacerbation. Recent advances have described small vesicles, termed as "extracellular vesicles" (EVs), previously disregarded as "cellular dust" to be vital in the intracellular and intercellular communication in host-microbe interactions. These signals have been known to initiate host damage and transfer of a variety of cargo including proteins, lipid particles, DNA, mRNA, and miRNAs. Microbial EVs, referred to generally as "membrane vesicles" (MVs), play a key role in disease exacerbation suggesting their importance in pathogenicity. Host EVs help coordinate antimicrobial responses and prime the immune cells for pathogen attack. Hence EVs with their central role in microbe-host communication, may serve as important diagnostic biomarkers of microbial pathogenesis. In this review, we summarize current research regarding the roles of EVs as markers of microbial pathogenesis with specific focus on their interaction with host immune defence and their potential as diagnostic biomarkers in disease conditions.

To target or not to target? The role of DNA and histone methylation in bacterial infections

Epigenetics describes chemical modifications of the genome that do not alter DNA sequence but participate in the regulation of gene expression and cellular processes such as proliferation, division, and differentiation of eukaryotic cell. Disruption of the epigenome pattern in a human cell is associated with different diseases, including infectious diseases. During infection pathogens induce epigenetic modifications in the host cell. This can occur by controlling expression of genes involved in immune response. That enables bacterial survival and replication within the host and evasion of the immune response. Methylation is an example of epigenetic modification that occurs on DNA and histones. Reasoning that DNA and histone methylation of human host cells plays a crucial role during pathogenesis, these modifications are promising targets for the development of alternative treatment strategies in infectious diseases. Here, we discuss the role of DNA and histone methyltransferases in human host cell upon bacterial infections. We further hypothesize that compounds targeting methyltransferases are tools to study epigenetics in the context of host-pathogen interactions and can open new avenues for the treatment of bacterial infections.

A bacterial effector protein promotes nuclear translocation of Stat3 to induce IL-10

The multifunctional Yersinia effector YopM inhibits effector triggered immunity and increases production of the anti-inflammatory cytokine Interleukin-10 (IL-10) to suppress the host immune response. Previously it was shown that YopM induces IL-10 gene expression by elevating phosphorylation of the serine-threonine kinase RSK1 in the nucleus of human macrophages. Using transcriptomics, we found that YopM strongly affects expression of genes belonging to the JAK-STAT signaling pathway. Further analysis revealed that YopM mediates nuclear translocation of the transcription factor Stat3 in Y. enterocolitica infected macrophages and that knockdown of Stat3 inhibited YopM-induced IL-10 gene expression. YopM-induced Stat3 translocation did not depend on autocrine IL-10, activation of RSK1 or tyrosine phosphorylation of Stat3. Thus, besides activation of RSK1, stimulation of nuclear translocation of Stat3 is another mechanism by which YopM increases IL-10 gene expression in macrophages.

A Membrane-Targeted Photosensitizer Prevents Drug Resistance and Induces Immune Response in Treating Candidiasis

Candida albicans (C. albicans), a ubiquitous polymorphic fungus in humans, causes different types of candidiasis, including oral candidiasis (OC) and vulvovaginal candidiasis (VVC), which are physically and mentally concerning and financially costly. Thus, developing alternative antifungals that prevent drug resistance and induce immunity to eliminate Candida biofilms is crucial. Herein, a novel membrane-targeted aggregation-induced emission (AIE) photosensitizer (PS), TBTCP-QY, is developed for highly efficient photodynamic therapy (PDT) of candidiasis. TBTCP-QY has a high molar absorption coefficient and an excellent ability to generate 1 O2 and •OH, entering the interior of biofilms due to its high permeability. Furthermore, TBTCP-QY can efficiently inhibit biofilm formation by suppressing the expression of genes related to the adhesion (ALS3, EAP1, and HWP1), invasion (SAP1 and SAP2), and drug resistance (MDR1) of C. albicans, which is also advantageous for eliminating potential fungal resistance to treat clinical infectious diseases. TBTCP-QY-mediated PDT efficiently targets OC and VVC in vivo in a mouse model, induces immune response, relieves inflammation, and accelerates the healing of mucosal defects to combat infections caused by clinically isolated fluconazole-resistant strains. Moreover, TBTCP-QY demonstrates excellent biocompatibility, suggesting its potential applications in the clinical treatment of OC and VVC.

Intratumoral adoptive transfer of inflammatory macrophages engineered by co-activating TLR and STING signaling pathways exhibits robust antitumor activity

Despite the success of chimeric antigen receptor (CAR) T cells in hematologic malignancies, adoptive cell therapy (ACT) has not been effective in treating solid tumors. Here, we developed an inflammatory macrophage-based ACT to effectively treat solid tumors. We engineered inflammatory macrophages to enhance their antitumor activities, including proinflammatory cytokine secretion and co-stimulatory molecule expression by co-activating toll-like receptor and stimulator of interferon genes signaling pathways. Engineered macrophages maintain an inflammatory phenotype after their adoptive transfer into the anti-inflammatory tumor microenvironment (TME), whereas conventional inflammatory macrophages prepared using interferon-γ treatment are repolarized to an anti-inflammatory phenotype. In a mouse melanoma model, intratumoral adoptive transfer of engineered macrophages showed robust tumor growth inhibition by increasing CD8+ T cells in the TME and tumor antigen-specific CD8+ T cells in the blood. This study demonstrated that engineered inflammatory macrophages have potential as an effective ACT for treating solid tumors.

The microbiology and pathogenesis of nonfermenting Gram-negative infections

PURPOSE OF REVIEW

This review provides an overview of most recent evidence about pathogenesis traits and virulence factors contributing to successful colonization or infection by P. aeruginosa , A. baumannii , S. maltophilia and B. cepacia complex, among the most clinically relevant nonfermenting Gram-negative bacteria (NFGNB).

RECENT FINDINGS

The growing clinical importance of NFGNB as important opportunistic pathogens causing difficult-to-treat infections in a fragile patients' population in stressed by numerous studies. Identification of novel virulence factors and deciphering of their mechanisms of action have greatly furthered our understanding of NFGNB pathogenesis, revealing that each pathogen-specific armamentarium of virulence factors (adhesins, motility, capsule, biofilm, lipopolysaccharide, exotoxins, exoenzymes, secretion systems, siderophores) can be likely responsible for the difference in the pathophysiology even in the context of a similar infection site. Emerging evidence of the immunomodulatory effect of some virulence factors is also acknowledged.

SUMMARY

NFGNB continue to be a serious global problem as cause of life-threatening opportunistic infections, owing to a highly heterogeneous content of virulence factors and their extensive number of intrinsic resistance mechanisms. Further efforts in development of novel effective antimicrobials and of alternative strategies targeting key virulence factors are warranted.

Peptide derived from SLAMF1 prevents TLR4-mediated inflammation in vitro and in vivo

Inflammation plays a crucial role in the development and progression of many diseases, and is often caused by dysregulation of signalling from pattern recognition receptors, such as TLRs. Inhibition of key protein-protein interactions is an attractive target for treating inflammation. Recently, we demonstrated that the signalling lymphocyte activation molecule family 1 (SLAMF1) positively regulates signalling downstream of TLR4 and identified the interaction interface between SLAMF1 and the TLR4 adaptor protein TRIF-related adapter molecule (TRAM). Based on these findings, we developed a SLAMF1-derived peptide, P7, which is linked to a cell-penetrating peptide for intracellular delivery. We found that P7 peptide inhibits the expression and secretion of IFNβ and pro-inflammatory cytokines (TNF, IL-1β, IL-6) induced by TLR4, and prevents death in mice subjected to LPS shock. The mechanism of action of P7 peptide is based on interference with several intracellular protein-protein interactions, including TRAM-SLAMF1, TRAM-Rab11FIP2, and TIRAP-MyD88 interactions. Overall, P7 peptide has a unique mode of action and demonstrates high efficacy in inhibiting TLR4-mediated signalling in vitro and in vivo.

QX-type infectious bronchitis virus infection in roosters can seriously injure the reproductive system and cause sex hormone secretion disorder

Since its discovery, QX-type avian infectious bronchitis virus (IBV) has rapidly spread worldwide and become the most prevalent dominant genotype in Asia and Europe. Currently, although the pathogenicity of QX-type IBV in the reproductive system of hens is widely and deeply understood, its pathogenicity in the reproductive system of roosters remains largely unknown. In this study, 30-week-old specific pathogen-free (SPF) roosters were used to investigate the pathogenicity of QX-type IBV in the reproductive system after infection. The results showed that QX-type IBV infection caused abnormal testicular morphology, moderate atrophy and obvious dilatation of seminiferous tubules, and produced intense inflammation and obvious pathological injuries in the ductus deferens of infected chickens. Immunohistochemistry results showed that QX-type IBV can replicate in spermatogenic cells at various stages and in the mucous layer of the ductus deferens. Further studies showed that QX-type IBV infection affects plasma levels of testosterone, luteinizing hormone, and follicle-stimulating hormone as well as causes changes in transcription levels of their receptors in the testis. Furthermore, the transcription levels of StAR, P450scc, 3βHSD and 17βHSD4 also changed during testosterone synthesis after QX-type IBV infection, indicating that the virus can directly affect steroidogenesis. Finally, we found that QX-type IBV infection leads to extensive germ cell apoptosis in the testis. Collectively, our results suggest that QX-type IBV replicates in the testis and ductus deferens, causing severe tissue damage and disruption of reproductive hormone secretion. These adverse events eventually lead to mass germ cell apoptosis in the testis, affecting the reproductive function of roosters.

Exploring the impact of oral bacteria remnants on stem cells from the Apical papilla: mineralization potential and inflammatory response

Introduction

Bacterial persistence is considered one of the main causal factors for regenerative endodontic treatment (RET) failure in immature permanent teeth. This interference is claimed to be caused by the interaction of bacteria that reside in the root canal with the stem cells that are one of the essentials for RET. The aim of the study was to investigate whether prolonged exposure of stem cells from the apical papilla (SCAP) to bacterial remnants of Fusobacterium nucleatum, Actinomyces gerensceriae, Slackia exigua, Enterococcus faecalis, Peptostreptococcaceae yurii, commonly found in infected traumatized root canals, and the probiotic bacteria Lactobacillus gasseri and Limosilactobacillus reuteri, can alter SCAP's inflammatory response and mineralization potential.

Methods

To assess the effect of bacterial remnants on SCAP, we used UV-C-inactivated bacteria (as cell wall-associated virulence factors) and bacterial DNA. Histochemical staining using Osteoimage Mineralization Assay and Alizarin Red analysis was performed to study SCAP mineralization, while inflammatory and osteo/odontogenic-related responses of SCAPs were assessed with Multiplex ELISA.

Results

We showed that mineralization promotion was greater with UV C-inactivated bacteria compared to bacterial DNA. Immunofluorescence analysis detected that the early mineralization marker alkaline phosphatase (ALP) was increased by the level of E. coli lipopolysaccharide (LPS) positive control in the case of UV-C-inactivated bacteria; meanwhile, DNA treatment decreased the level of ALP compared to the positive control. SCAP's secretome assessed with Multiplex ELISA showed the upregulation of pro-inflammatory factors IL-6, IL-8, GM-CSF, IL-1b, neurotrophic factor BDNF, and angiogenic factor VEGF, induced by UV-C-killed bacteria.

Discussion

The results suggest that long term stimulation (for 21 days) of SCAP with UV-C-inactivated bacteria stimulate their mineralization and inflammatory response, while DNA influence has no such effect, which opens up new ideas about the nature of RET failure.

Shedding light on the molecular and regulatory mechanisms of TLR4 signaling in endothelial cells under physiological and inflamed conditions

Toll-like receptor 4 (TLR4) are part of the innate immune system. They are capable of recognizing pathogen-associated molecular patterns (PAMPS) of microbes, and damage-associated molecular patterns (DAMPs) of damaged tissues. Activation of TLR4 initiates downstream signaling pathways that trigger the secretion of cytokines, type I interferons, and other pro-inflammatory mediators that are necessary for an immediate immune response. However, the systemic release of pro-inflammatory proteins is a powerful driver of acute and chronic inflammatory responses. Over the past decades, immense progress has been made in clarifying the molecular and regulatory mechanisms of TLR4 signaling in inflammation. However, the most common strategies used to study TLR4 signaling rely on genetic manipulation of the TLR4 or the treatment with agonists such as lipopolysaccharide (LPS) derived from the outer membrane of Gram-negative bacteria, which are often associated with the generation of irreversible phenotypes in the target cells or unintended cytotoxicity and signaling crosstalk due to off-target or pleiotropic effects. Here, optogenetics offers an alternative strategy to control and monitor cellular signaling in an unprecedented spatiotemporally precise, dose-dependent, and non-invasive manner. This review provides an overview of the structure, function and signaling pathways of the TLR4 and its fundamental role in endothelial cells under physiological and inflammatory conditions, as well as the advances in TLR4 modulation strategies.

The relationship between atrial fibrillation and NLRP3 inflammasome: a gut microbiota perspective

Atrial fibrillation (AF) is a common clinical arrhythmia whose pathogenesis has not been fully elucidated, and the inflammatory response plays an important role in the development of AF. The inflammasome is an important component of innate immunity and is involved in a variety of pathophysiologic processes. The NLRP3 inflammasome is by far the best studied and validated inflammasome that recognizes multiple pathogens through pattern recognition receptors of innate immunity and mediates inflammatory responses through activation of Caspase-1. Several studies have shown that NLRP3 inflammasome activation contributes to the onset and development of AF. Ecological dysregulation of the gut microbiota has been associated with the development of AF, and some evidence suggests that gut microbiota components, functional byproducts, or metabolites may induce or exacerbate the development of AF by directly or indirectly modulating the NLRP3 inflammasome. In this review, we report on the interconnection of NLRP3 inflammasomes and gut microbiota and whether this association is related to the onset and persistence of AF. We discuss the potential value of pharmacological and dietary induction in the management of AF in the context of the association between the NLRP3 inflammasome and gut microbiota. It is hoped that this review will lead to new therapeutic targets for the future management of AF.

Advancements in Vaccine Adjuvants: The Journey from Alum to Nano Formulations

Vaccination is a groundbreaking approach in preventing and controlling infectious diseases. However, the effectiveness of vaccines can be greatly enhanced by the inclusion of adjuvants, which are substances that potentiate and modulate the immune response. This review is based on extensive searches in reputable databases such as Web of Science, PubMed, EMBASE, Scopus, and Google Scholar. The goal of this review is to provide a thorough analysis of the advances in the field of adjuvant research, to trace the evolution, and to understand the effects of the various adjuvants. Historically, alum was the pioneer in the field of adjuvants because it was the first to be approved for use in humans. It served as the foundation for subsequent research and innovation in the field. As science progressed, research shifted to identifying and exploiting the potential of newer adjuvants. One important area of interest is nano formulations. These advanced adjuvants have special properties that can be tailored to enhance the immune response to vaccines. The transition from traditional alum-based adjuvants to nano formulations is indicative of the dynamism and potential of vaccine research. Innovations in adjuvant research, particularly the development of nano formulations, are a promising step toward improving vaccine efficacy and safety. These advances have the potential to redefine the boundaries of vaccination and potentially expand the range of diseases that can be addressed with this approach. There is an optimistic view of the future in which improved vaccine formulations will contribute significantly to improving global health outcomes.

Role of Cherry Valley duck IRF1 mediated signal pathway in host anti-duck Tembusu virus

China is the country with the largest amount of duck breeding as well as duck meat and egg production. In recent years, the emergence and spread of duck Tembusu virus (DTMUV) has become one of the important factors in reducing the amount of duck slaughter, which seriously endangers the duck breeding industry in our country. In-depth research on the mechanism of duck innate immunity facilitates the exploration of new models for the treatment of DTMUV infection. IRF1 can induce the expression of many antiviral immune factors in the animal organism and play an important role in the innate immune response. In this study, we used interfering RNA to knock down the IRF1 gene in DEF cells and then the cells were infected with DTMUV. We found that knockdown of IRF1 promoted DTMUV replication at an early stage and caused downregulation of the expression of several major pattern recognition receptors (PRRs), interleukins (IL), interferons (IFN), antiviral proteins, and MHC molecules by assay, showing that the duIRF1-mediated signaling pathway plays an extremely important role in DTMUV-induced host innate immunity. In addition, we constructed the recombinant expression plasmid pET32a(+)-duIRF1-His, and finally prepared the polyclonal antibody of duIRF1 with good specificity, hoping to provide a detection means for research on the mechanism of IRF1 in innate immunity in our laboratory and in this field.

Immune escape of bovine parvovirus by VP1 inhibiting IFN-β production through the RIG-I-like receptor pathway

OBJECTIVE

The present study aimed to explore if bovine parvovirus (BPV) impacts beta interferon (IFN-β) production and to reveal further molecular mechanism of BPV immune escape.

METHOD

The pCMV-Myc-BPV-VP1 recombinant plasmid was verified with both double-enzyme digestion and sequence. HEK 293 T cells were transfected with this recombinant protein and then infected with the vesicular stomatitis virus (VSV). Expression levels of IFN-β mRNA were detected using qPCR.

RESULTS

The expression level of BPV VP1 mRNA in the pCMV-Myc-BPV-VP1 group was significantly higher than those of the untreated group (UT) and pCMV-Myc vector group. BPV virus copies in bovine turbinate (BT) cells of the BPV-VP1 group were raised (P < 0.05) with an increment of 5.8 × 104. Expression levels of IFN-β mRNA of the BPV VP1 group in HEK 293 T cells were decreased (P < 0.01). Following treatment of TBK1 and IRF3(5D), IFN-β expression levels in HEK 293 T cells were depressed. Additionally, expression levels of TBK1, IRF3(5D), MDA5, and MAVS were less than those of the flag empty vector, respectively.

CONCLUSION

pCMV-Myc-BPV-VP1 could heighten transcription levels of VP1 protein in BT cells, promote BPV proliferation, and ascend the production of IFN-β. Overexpression of pCMV-Myc-BPV-VP decreased IFN-β mRNA expression in HEK 293 T cells and inhibited IFN-β production induced by TBK1 and IRF3(5D). Furthermore, BPV VP1 obviously declined expression levels of TBK1, IRF3(5D), MDA5, and MAVS in the RIG-I-like receptor (RLR) pathway. Our findings revealed a novel mechanism evolved by BPV VP1 to inhibit type I IFN production and provided a solid scientific basis into the immunosuppression of BPV.

The pentraxin family in autoimmune disease

The pentraxins represent a family of multifunctional proteins composed of long and short pentamers. The latter includes serum amyloid P component (SAP) and C-reactive protein (CRP) whereas the former includes neuronal PTX1 and PTX2 (NPTX1 and NPTX2, respectively), PTX3 and PTX4. These serve as a bridge between adaptive immunity and innate immunity and a link between inflammation and immunity. Similarities and differences between long and short pentamers are examined and their roles in autoimmune disease are discussed. Increased CRP and PTX3 could indicate the activity of rheumatoid arthritis, systemic lupus erythematosus or other autoimmune diseases. Mechanistically, CRP and PTX3 may predict target organ injury, regulate bone metabolic immunity and maintain homeostasis as well as participate in vascular endothelial remodeling. Interestingly, PTX3 is pleiotropic, being involved in inflammation and tissue repair. Given the therapeutic potential of PTX3 and CRP, targeting these factors to exert a beneficial effect is the focus of research efforts. Unfortunately, studies on NPTX1, NPTX2, PTX4 and SAP are scarce and more research is clearly needed to elaborate their potential roles in autoimmune disease.

Curcumin as an antiviral agent and immune-inflammatory modulator in COVID-19: A scientometric analysis

Background

Reports regarding the antiviral activity of curcumin have surfaced. However, to date there has been no scientometric analysis of the relationship between curcumin and Coronavirus Disease 2019 (COVID-19). To comprehensively understand the studies involving curcumin in the context of COVID-19, we conducted a scientometric analysis to provide an exhaustive review of these studies.

Methods

We systematically searched the Web of Science core collection database for bibliographic data indexed from January 1, 2020, to December 31, 2022, using keywords such as 'curcumin', 'COVID-19', and their synonyms. To clarify the research content and trends related to curcumin in COVID-19, we utilized VOSviewer, Origin 2023, and Charticulator for analysis, supplemented by external data.

Results

The final count of publications included in this study was 252. These publications originated from 63 countries or territories, with India contributing the highest number of publications. They were published across 170 journals. Notably, the Egyptian Knowledge Bank (EKB) emerged as the most important institution that carried out this study. The most cited publication had been referenced 166 times. The main elements involved in the keyword analysis were reflected in the antiviral activity of curcumin and the immuno-inflammatory modulation of the inflammatory cytokine storm. Furthermore, the pharmacological mechanisms of curcumin for treating COVID-19 emerged as a prominent area of research. Simultaneously, there exists direct evidence of clinical usage of curcumin to enhance COVID-19 outcomes.

Conclusions

The scientometric analysis underscores the burgeoning professional domain of curcumin-based treatment for COVID-19. Ongoing studies have focused on the antiviral activity of curcumin and its immunomodulatory effects on inflammatory cytokine storms. On the other hand, the pharmacological mechanism of curcumin in the treatment of COVID-19 is a hot spot in the research field at present, which may become the main research trend in this field in the future. While maintaining a focus on foundational research, the clinical application of curcumin in COVID-19 infection is developing in parallel, highlighting its obvious guiding value in clinical practice. These insights offer researchers a snapshot of the present state of curcumin treatment for COVID-19 and guide further mechanistic validation efforts in the future.

Evolving immunometabolic response to the early Leishmania infantum infection in the spleen of BALB/c mice described by gene expression profiling

Transcriptional analysis is a useful approximation towards the identification of global changes in host-pathogen interaction, in order to elucidate tissue-specific immune responses that drive the immunopathology of the disease. For this purpose, expression of 223 genes involved in innate and adaptive immune response, lipid metabolism, prostaglandin synthesis, C-type lectin receptors and MAPK signaling pathway, among other processes, were analyzed during the early infection in spleens of BALB/c mice infected by Leishmania infantum. Our results highlight the activation of immune responses in spleen tissue as early as 1 day p.i., but a mixed pro-inflammatory and regulatory response at day 10 p.i., failing to induce an effective response towards control of Leishmania infection in the spleen. This ineffective response is coupled to downregulation of metabolic markers relevant for pathways related to icosanoid biosynthesis, adipocytokine signaling or HIF-1 signaling, among others. Interestingly, the over-representation of processes related to immune response, revealed Il21 as a potential early biomarker of L. infantum infection in the spleen. These results provide insights into the relationships between immune and metabolic responses at transcriptional level during the first days of infection in the L. infantum-BALB/c experimental model, revealing the deregulation of many important pathways and processes crucial for parasitic control in infected tissues.

The role and application of three IFN-related reactions in psoriasis

The pathophysiology of psoriasis is a highly complicated one. Due to the disease's specificity, it not only affects the patient's skin negatively but also manifests systemic pathological changes. These clinical symptoms seriously harm the patient's physical and mental health. IFN, a common immunomodulatory factor, has been increasingly demonstrated to have a significant role in the development of psoriatic skin disease. Psoriasis is connected with a variety of immunological responses. New targets for the therapy of autoimmune skin diseases may emerge from further research on the mechanics of the associated IFN upstream and downstream pathways. Different forms of IFNs do not behave in the same manner in psoriasis, and understanding how different types of IFNs are involved in psoriasis may provide a better notion for future research. This review focuses on the involvement of three types of IFNs in psoriasis and related therapeutic investigations, briefly describing the three IFNs' production and signaling, as well as the dual effects of IFNs on the skin. It is intended that it would serve as a model for future research.

Abomasal RNA-seq reveals a strong local cellular response in suckling lambs with resistance against Haemonchus contortus

Santa Ines (SI) and Ile de France (IF) sheep are known to be resistant and susceptible to Haemonchus contortus infection, respectively. Several studies have shown some genes as potential biological markers for sheep resistance against gastrointestinal nematodes using molecular tools, including transcriptomic analysis. In this study, we sequenced the polyadenylated RNA of the abomasal tissue of SI and IF suckling lambs to identify mucosa-specific transcript alterations between breeds artificially infected with H. contortus. Naïve SI (n = 4) and IF (n = 4) lambs were artificially infected every other day, over a period of 52 days, from 14 to 66 days old, with a total of 5,400 H. contortus infective larvae. Fundic abomasal tissue samples were collected at 68 days old, and submitted to high-throughput RNA sequencing (RNA-seq). Differential expression analysis (P value < 0.001 and False Discovery Rate (FDR) < 0.05) between SI and IF samples identified 292 genes, most of which showed greater expression in SI lambs. To help annotate and assign possible function to differentially expressed genes (DEGs), we used previously available single-cell RNA-seq (scRNA-seq) data from ovine abomasal mucosa to putatively identify cell types and possible mechanisms involved in resistance to H. contortus. In particular, genes associated with endothelial and tuft cells showed the greatest increases in expression in SI relative to IF lambs. SI lambs had higher percentages of tuft cells than IF lambs in the fundic abomasal mucosa. Although we found innate immunity (cell-mediated in mucosa) acting as a protagonist in impairing H. contortus infection, a stronger acquired immune response was being modulated at an earlier stage by SI lambs. We suggest that the complex connection between innate and adaptive immunity is via cellular antigen processing and presentation (APP). Based on comparison with scRNA-seq data, SI lambs showed a robust APP mechanism characterized mainly by greater T cell APP, macrophage differentiation, and cytokine signalling. We identified potential mechanisms and markers to advance knowledge for selection of H. contortus resistance at a very early age, in SI as well as in other commercial sheep breeds.

Nanoscale coordination polymer synergizes photodynamic therapy and toll-like receptor activation for enhanced antigen presentation and antitumor immunity

While activating antitumor immunity with toll-like receptor (TLR) agonists provides a promising approach toward cancer immunotherapy, existing TLR agonists, including resiquimod (R848), have shown poor tumor selectivity and ineffective TLR activation in tumors for optimal antitumor effects. We hypothesized that improved delivery of TLR agonists to tumors and their effective combination with tumor antigens could significantly enhance their antitumor efficacy. Here, we report a novel nanoscale coordination polymer, Ce6/R848, for the co-delivery of Ce6 photosensitizer to elicit immunogenic cell death via photodynamic therapy (PDT) and cholesterol-conjugated R848 (Chol-R848) for tumor-selective TLR7/8 activation. Upon light irradiation, Ce6-mediated PDT released tumor antigens while selectively delivered R848 activated TLR7/8 in the tumors to synergistically activate antigen-presenting cells and prime T cells for enhanced innate and adaptive antitumor immune responses. Ce6/R848 achieved a 50% cure rate and 99.4% inhibition of tumor growth in subcutaneous MC38 colorectal tumors with minimal systemic toxicity.

From reactive species to disease development: Effect of oxidants and antioxidants on the cellular biomarkers

The influence of modern lifestyle, diet, exposure to chemicals such as phytosanitary substances, together with sedentary lifestyles and lack of exercise play an important role in inducing reactive stress (RS) and disease. The imbalance in the production and scavenging of free radicals and the induction of RS (oxidative, nitrosative, and halogenative) plays an essential role in the etiology of various chronic pathologies, such as cardiovascular diseases, diabetes, neurodegenerative diseases, and cancer. The implication of free radicals and reactive species injury in metabolic disturbances and the onset of many diseases have been accumulating for several decades, and are now accepted as a major cause of many chronic diseases. Exposure to elevated levels of free radicals can cause molecular structural impact on proteins, lipids, and DNA, as well as functional alteration of enzyme homeostasis, leading to aberrations in gene expression. Endogenous depletion of antioxidant enzymes can be mitigated using exogenous antioxidants. The current interest in the use of exogenous antioxidants as adjunctive agents for the treatment of human diseases allows a better understanding of these diseases, facilitating the development of new therapeutic agents with antioxidant activity to improve the treatment of various diseases. Here we examine the role that RS play in the initiation of disease and in the reactivity of free radicals and RS in organic and inorganic cellular components.

Clinical Characteristics and Immune Responses in Children with Primary Ciliary Dyskinesia during Pneumonia Episodes: A Case-Control Study

OBJECTIVE

This study explored the clinical features and immune responses of children with primary ciliary dyskinesia (PCD) during pneumonia episodes.

METHODS

The 61 children with PCD who were admitted to hospital because of pneumonia were retrospectively enrolled into this study between April 2017 and August 2022. A total of 61 children with pneumonia but without chronic diseases were enrolled as the control group. The clinical characteristics, levels of inflammatory indicators, pathogens, and imaging features of the lungs were compared between the two groups.

RESULTS

The PCD group had higher levels of lymphocytes (42.80% versus 36.00%, p = 0.029) and eosinophils (2.40% versus 1.25%, p = 0.020), but lower neutrophil counts (3.99 versus 5.75 × 109/L, p = 0.011), percentages of neutrophils (46.39% versus 54.24%, p = 0.014), CRP (0.40 versus 4.20 mg/L, p < 0.001) and fibrinogen (257.50 versus 338.00 mg/dL, p = 0.010) levels. Children with PCD and children without chronic diseases were both most commonly infected with Mycoplasma pneumoniae (24.6% versus 51.9%). Children with PCD had significantly more common imaging features, including mucous plugging (p = 0.042), emphysema (p = 0.007), bronchiectasis (p < 0.001), mosaic attenuation (p = 0.012), interstitial inflammation (p = 0.015), and sinusitis (p < 0.001).

CONCLUSION

PCD is linked to immune system impairment, which significantly contributes to our understanding of the pathophysiology of this entity.

Effect of titanium implants along with silver ions and tetracycline on type I interferon-beta expression during implant-related infections in co-culture and mouse model

Type I interferon-beta (IFN-β) is a crucial component of innate and adaptive immune systems inside the host. The formation of bacterial biofilms on medical implants can lead to inflammatory diseases and implant failure. Biofilms elicit IFN-β production inside the host that, in turn, restrict bacterial growth. Biofilms pose strong antibiotic resistance, whereas surface modification of medical implants with antibacterial agents may demonstrate strong antimicrobial effects. Most of the previous investigations were focused on determining the antibacterial activities of implant surfaces modified with antibacterial agents. The present study, for the first time, measured antibacterial activities and IFN-β expression of titanium surfaces along with silver or tetracycline inside co-culture and mouse models. A periodontal pathogen: Aggregatibacter actinomycetemcomitans reported to induce strong inflammation, was used for infection. Silver and tetracycline were added to the titanium surface using the heat evaporation method. Macrophages showed reduced compatibility on titanium surfaces with silver, and IFN-β expression inside cultured cells significantly decreased. Macrophages showed compatibility on implant surfaces with tetracycline, but IFN-β production significantly decreased inside seeded cells. The decrease in IFN-β production inside macrophages cultured on implant surfaces with silver and tetracycline was not related to the downregulation of Ifn-β gene. Bacterial infection significantly upregulated mRNA expression levels of Isg15, Mx1, Mx2, Irf-3, Irf-7, Tlr-2, Tnf-α, Cxcl-1, and Il-6 genes. Notably, mRNA expression levels of Mx1, Irf7, Tlr2, Tnf-α, Cxcl1, and Il-6 genes inside macrophages significantly downregulated on implant surfaces with silver or tetracycline. Titanium with tetracycline showed higher antibacterial activities than silver. The in vivo evaluation of IFN-β expression around implants was measured inside transgenic mice constitutive for IFN-β expression. Of note, the non-invasive in vivo imaging revealed a significant decrease in IFN-β expression around subcutaneous implants with silver compared to titanium and titanium with tetracycline in sterile or infected situations. The histology of peri-implant tissue interfaces around infected implants with silver showed a thick interface with a significantly higher accumulation of inflammatory cells. Titanium implants with silver and tetracycline remained antibacterial in mice. Findings from this study unequivocally indicate that implant surfaces with silver decrease IFN-β expression, a crucial component of host immunity.

The NLRP3 Inflammasome in Neurodegenerative Disorders: Insights from Epileptic Models

Neuroinflammation represents a dynamic process of defense and protection against the harmful action of infectious agents or other detrimental stimuli in the central nervous system (CNS). However, the uncontrolled regulation of this physiological process is strongly associated with serious dysfunctional neuronal issues linked to the progression of CNS disorders. Moreover, it has been widely demonstrated that neuroinflammation is linked to epilepsy, one of the most prevalent and serious brain disorders worldwide. Indeed, NLRP3, one of the most well-studied inflammasomes, is involved in the generation of epileptic seizures, events that characterize this pathological condition. In this context, several pieces of evidence have shown that the NLRP3 inflammasome plays a central role in the pathophysiology of mesial temporal lobe epilepsy (mTLE). Based on an extensive review of the literature on the role of NLRP3-dependent inflammation in epilepsy, in this review we discuss our current understanding of the connection between NLRP3 inflammasome activation and progressive neurodegeneration in epilepsy. The goal of the review is to cover as many of the various known epilepsy models as possible, providing a broad overview of the current literature. Lastly, we also propose some of the present therapeutic strategies targeting NLRP3, aiming to provide potential insights for future studies.

An immune-competent human gut microphysiological system enables inflammation-modulation of Faecalibacterium prausnitzii

Crosstalk of microbes with human gut epithelia and immune cells is crucial for gut health. However, there is no existing system for a long-term co-culture of human innate immune cells with epithelium and oxygen-intolerant commensal microbes, hindering the understanding of microbe-immune interactions in a controlled manner. Here, we establish a gut epithelium-microbe-immune microphysiological system to maintain the long-term continuous co-culture of Faecalibacterium prausnitzii/Faecalibacterium duncaniae with colonic epithelium, antigen-presenting cells (APCs, herein dendritic cells and macrophages), with CD4+ naïve T cells circulating underneath the colonic epithelium. Multiplex cytokine assays suggested that APCs contribute to the elevated level of cytokines and chemokines being secreted into both apical and basolateral compartments. In contrast, the absence of APCs does not allow reliable detection of these cytokines. In the presence of APCs, F. prausnitzii increased the transcription of pro-inflammatory genes such as toll-like receptor 1 (TLR1) and interferon alpha 1 (IFNA1) in the colonic epithelium, but no significant change on the secreted cytokines. In contrast, integration of CD4+ naïve T cells reverses this effect by decreasing the transcription of TLR1, IFNA1, and indoleamine 2,3-dioxygenase, and increasing the F. prausnitzii-induced secretion of pro-inflammatory cytokines such as IL-8, MCP-1/CCL2, and IL1A. These results highlight the contribution of individual innate immune cells in the regulation of the immune response triggered by the gut commensal F. prausnitzii. The successful integration of defined populations of immune cells in this gut microphysiological system demonstrated the usefulness of the GuMI physiomimetic platform to study microbe-epithelial-immune interactions in health and disease.

Mapping the epigenomic landscape of human monocytes following innate immune activation reveals context-specific mechanisms driving endotoxin tolerance

BACKGROUND

Monocytes are key mediators of innate immunity to infection, undergoing profound and dynamic changes in epigenetic state and immune function which are broadly protective but may be dysregulated in disease. Here, we aimed to advance understanding of epigenetic regulation following innate immune activation, acutely and in endotoxin tolerant states.

METHODS

We exposed human primary monocytes from healthy donors (n = 6) to interferon-γ or differing combinations of endotoxin (lipopolysaccharide), including acute response (2 h) and two models of endotoxin tolerance: repeated stimulations (6 + 6 h) and prolonged exposure to endotoxin (24 h). Another subset of monocytes was left untreated (naïve). We identified context-specific regulatory elements based on epigenetic signatures for chromatin accessibility (ATAC-seq) and regulatory non-coding RNAs from total RNA sequencing.

RESULTS

We present an atlas of differential gene expression for endotoxin and interferon response, identifying widespread context specific changes. Across assayed states, only 24-29% of genes showing differential exon usage are also differential at the gene level. Overall, 19.9% (6,884 of 34,616) of repeatedly observed ATAC peaks were differential in at least one condition, the majority upregulated on stimulation and located in distal regions (64.1% vs 45.9% of non-differential peaks) within which sequences were less conserved than non-differential peaks. We identified enhancer-derived RNA signatures specific to different monocyte states that correlated with chromatin accessibility changes. The endotoxin tolerance models showed distinct chromatin accessibility and transcriptomic signatures, with integrated analysis identifying genes and pathways involved in the inflammatory response, detoxification, metabolism and wound healing. We leveraged eQTL mapping for the same monocyte activation states to link potential enhancers with specific genes, identifying 1,946 unique differential ATAC peaks with 1,340 expression associated genes. We further use this to inform understanding of reported GWAS, for example involving FCHO1 and coronary artery disease.

CONCLUSION

This study reports context-specific regulatory elements based on transcriptomic profiling and epigenetic signatures for enhancer-derived RNAs and chromatin accessibility in immune tolerant monocyte states, and demonstrates the informativeness of linking such elements and eQTL to inform future mechanistic studies aimed at defining therapeutic targets of immunosuppression and diseases.

Impact of Microbiome-Brain Communication on Neuroinflammation and Neurodegeneration

The gut microbiome plays a pivotal role in maintaining human health, with numerous studies demonstrating that alterations in microbial compositions can significantly affect the development and progression of various immune-mediated diseases affecting both the digestive tract and the central nervous system (CNS). This complex interplay between the microbiota, the gut, and the CNS is referred to as the gut-brain axis. The role of the gut microbiota in the pathogenesis of neurodegenerative diseases has gained increasing attention in recent years, and evidence suggests that gut dysbiosis may contribute to disease development and progression. Clinical studies have shown alterations in the composition of the gut microbiota in multiple sclerosis patients, with a decrease in beneficial bacteria and an increase in pro-inflammatory bacteria. Furthermore, changes within the microbial community have been linked to the pathogenesis of Parkinson's disease and Alzheimer's disease. Microbiota-gut-brain communication can impact neurodegenerative diseases through various mechanisms, including the regulation of immune function, the production of microbial metabolites, as well as modulation of host-derived soluble factors. This review describes the current literature on the gut-brain axis and highlights novel communication systems that allow cross-talk between the gut microbiota and the host that might influence the pathogenesis of neuroinflammation and neurodegeneration.

Exploring exercise-driven inhibition of pyroptosis: novel insights into treating diabetes mellitus and its complications

Diabetes mellitus (DM) and its complications are important, worldwide public health issues, exerting detrimental effects on human health and diminishing both quality of life and lifespan. Pyroptosis, as a new form of programmed cell death, plays a critical role in DM and its complications. Exercise has been shown to be an effective treatment for improving insulin sensitivity or preventing DM. However, the molecular mechanisms underlying the effects of exercise on pyroptosis-related diseases remain elusive. In this review, we provided a comprehensive elucidation of the molecular mechanisms underlying pyroptosis and the potential mechanism of exercise in the treatment of DM and its complications through the modulation of anti-pyroptosis-associated inflammasome pathways. Based on the existing evidence, further investigation into the mechanisms by which exercise inhibits pyroptosis through the regulation of inflammasome pathways holds promising potential for expanding preventive and therapeutic strategies for DM and facilitating the development of novel therapeutic interventions.

Identification and characterization of mitogen-activated protein kinase kinase 4 (MKK4) from the mud crab Scylla paramamosain in response to Vibrio alginolyticus and White Spot Syndrome Virus (WSSV)

Mitogen-activated protein kinase kinase 4 (MKK4), serves as a critical component of the mitogen-activated protein kinase signaling pathway, facilitating the direct phosphorylation and activation of the c-Jun N-terminal kinase (JNK) and p38 families of MAP kinases in response to environmental stresses. In the current research, we identified two MKK4 subtypes, namely SpMKK4-1 and SpMKK4-2, from Scylla paramamosain, followed by the analysis of their molecular characteristics and tissue distributions. The expression of SpMKK4s was induced upon WSSV and Vibrio alginolyticus challenges, and the bacteria clearance capacity and antimicrobial peptide (AMP) genes' expression upon bacterial infection were significantly decreased after knocking down SpMKK4s. Additionally, the overexpression of both SpMKK4s remarkably activated NF-κB reporter plasmid in HEK293T cells, suggesting the activation of the NF-κB signaling pathway. These results indicated the participation of SpMKK4s in the innate immunity of crabs, which shed light on a better understanding of the mechanisms through which MKK4s regulate innate immunity.

Influence of androgens on the innate immune system

BACKGROUND

Sexual dimorphism is observed in the occurrence, course, and severity of human disease. The difference in immune response between males and females can in part be attributed to sexual genotype. However, immunological differences can also be explained by endocrine-immune interactions. Specifically, androgens possess the ability of directly modulating the development and function of immune cells. Although androgens generally contribute to immunosuppressive effects, this is not necessarily always the case.

AIM

The aim of the review is to uncover the role of androgens in shaping the innate immune response.

MATERIAL & METHODS

Authors included papers in this review which discussed the impact of androgens on specific innate immune cells.

RESULTS

Androgens modulate the innate immune response through various mechanisms. However, there is conflicting evidence in the literature regarding the interplay betwen androgens and the innate immune system.

DISCUSSION

Conflicting evidence presented in this review could in part be explained by the limitations present in interpreting results.

CONCLUSION

This review is of great importance for our understanding of occurence and mechanism of human inflammatory disease.

Interferon-Free Regimens and Direct-Acting Antiviral Agents for Delta Hepatitis: Are We There Yet?

Chronic delta hepatitis is a global health problem. Although a smaller percentage of chronic HBV-infected patients are coinfected with the hepatitis delta virus, these patients have a higher risk of an accelerated progression to fulminant "delta hepatitis", cirrhosis, hepatic decompensation, and hepatocellular carcinoma, putting a financial strain on the healthcare system and increasing the need for a liver transplant. Since its discovery, tremendous efforts have been directed toward understanding the intricate pathogenic mechanisms, discovering the complex viral replication process, the essential replicative intermediates, and cell division-mediated viral spread, which enables virion viability. The consideration of the interaction between HBV and HDV is crucial in the process of developing novel pharmaceuticals. Until just recently, interferon-based therapy was the only treatment available worldwide. This review aims to present the recent advancements in understanding the life cycle of HDV, which have consequently facilitated the development of innovative drug classes. Additionally, we will examine the antiviral strategies currently in phases II and III of development, including bulevirtide (an entry inhibitor), lonafarnib (a prenylation inhibitor), and REP 2139 (an HBsAg release inhibitor).

RNA Editing-Dependent and -Independent Roles of Adenosine Deaminases Acting on RNA Proteins in Herpesvirus Infection-Hints on Another Layer of Complexity

The Adenosine Deaminases Acting on RNA (ADAR) catalyze the posttranscriptional deamination of adenosine residues to inosine in double-stranded RNAs (dsRNAs, A-to-I editing), preventing the overactivation of dsRNA sensor molecules and interferons. RNA editing is the cornerstone of innate immunity that distinguishes between self and non-self (virus), and it is essential for normal regulation of cellular homeostasis. Although much is already known about the role of ADAR proteins in RNA virus infection, the role of ADAR proteins in herpesvirus infection remains largely unexplored. In this review, we provide several lines of evidence from studies of different herpesviruses for another level of complexity in regulating the already intricate biphasic life cycle of herpesviruses.

Host Responses to Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) infections are a constant public health problem, especially in infants and older adults. Virtually all children will have been infected with RSV by the age of two, and reinfections are common throughout life. Since antigenic variation, which is frequently observed among other respiratory viruses such as SARS-CoV-2 or influenza viruses, can only be observed for RSV to a limited extent, reinfections may result from short-term or incomplete immunity. After decades of research, two RSV vaccines were approved to prevent lower respiratory tract infections in older adults. Recently, the FDA approved a vaccine for active vaccination of pregnant women to prevent severe RSV disease in infants during their first RSV season. This review focuses on the host response to RSV infections mediated by epithelial cells as the first physical barrier, followed by responses of the innate and adaptive immune systems. We address possible RSV-mediated immunomodulatory and pathogenic mechanisms during infections and discuss the current vaccine candidates and alternative treatment options.

Revealing the Salmo salar NLRP3 Inflammasome: Insights from Structural Modeling and Transcriptome Analysis

The NLRP3, one of the most heavily studied inflammasome-related proteins in mammals, remains inadequately characterized in Atlantic salmon (Salmo salar), despite the significant commercial importance of this salmonid. The NLRP3 inflammasome is composed of the NLRP3 protein, which is associated with procaspase-1 via an adapter molecule known as ASC. This work aims to characterize the Salmo salar NLRP3 inflammasome through in silico structural modeling, functional transcript expression determination in the SHK-1 cell line in vitro, and a transcriptome analysis on Atlantic salmon. The molecular docking results suggested a similar arrangement of the ternary complex between NLRP3, ASC, and caspase-1 in both the Atlantic salmon and the mammalian NLRP3 inflammasomes. Moreover, the expression results confirmed the functionality of the SsNLRP3 inflammasome in the SHK-1 cells, as evidenced by the lipopolysaccharide-induced increase in the transcription of genes involved in inflammasome activation, including ASC and NLRP3. Additionally, the transcriptome results revealed that most of the inflammasome-related genes, including ASC, NLRP3, and caspase-1, were down-regulated in the Atlantic salmon following its adaptation to seawater (also known as parr-smolt transformation). This is correlated with a temporary detrimental effected on the immune system. Collectively, these findings offer novel insights into the evolutionarily conserved role of NLRP3.

A-to-I RNA editing by ADAR and its therapeutic applications: From viral infections to cancer immunotherapy

ADAR deaminases catalyze adenosine-to-inosine (A-to-I) editing on double-stranded RNA (dsRNA) substrates that regulate an umbrella of biological processes. One of the two catalytically active ADAR enzymes, ADAR1, plays a major role in innate immune responses by suppression of RNA sensing pathways which are orchestrated through the ADAR1-dsRNA-MDA5 axis. Unedited immunogenic dsRNA substrates are potent ligands for the cellular sensor MDA5. Upon activation, MDA5 leads to the induction of interferons and expression of hundreds of interferon-stimulated genes with potent antiviral activity. In this way, ADAR1 acts as a gatekeeper of the RNA sensing pathway by striking a fine balance between innate antiviral responses and prevention of autoimmunity. Reduced editing of immunogenic dsRNA by ADAR1 is strongly linked to the development of common autoimmune and inflammatory diseases. In viral infections, ADAR1 exhibits both antiviral and proviral effects. This is modulated by both editing-dependent and editing-independent functions, such as PKR antagonism. Several A-to-I RNA editing events have been identified in viruses, including in the insidious viral pathogen, SARS-CoV-2 which regulates viral fitness and infectivity, and could play a role in shaping viral evolution. Furthermore, ADAR1 is an attractive target for immuno-oncology therapy. Overexpression of ADAR1 and increased dsRNA editing have been observed in several human cancers. Silencing ADAR1, especially in cancers that are refractory to immune checkpoint inhibitors, is a promising therapeutic strategy for cancer immunotherapy in conjunction with epigenetic therapy. The mechanistic understanding of dsRNA editing by ADAR1 and dsRNA sensing by MDA5 and PKR holds great potential for therapeutic applications. This article is categorized under: RNA Processing > RNA Editing and Modification RNA in Disease and Development > RNA in Disease.

A clash on the Toll pathway: competitive action between pesticides and zymosan A on components of innate immunity in Apis mellifera

Background

The immune system of honeybees includes multiple pathways that may be affected by pesticide exposure decreasing the immune competencies of bees and increasing their susceptibility to diseases like the fungal Nosema spp. infection, which is detected in collapsed colonies.

Methods

To better understand the effect of the co-presence of multiple pesticides that interact with bees like imidacloprid and amitraz, we evaluated the expression of immune-related genes in honeybee hemocytes.

Results

Imidacloprid, amitraz, and the immune activator, zymosan A, mainly affect the gene expression in the Toll pathway.

Discussion

Imidacloprid, amitraz, and zymosan A have a synergistic or an antagonistic relationship on gene expression depending on the level of immune signaling. The presence of multiple risk factors like pesticides and pathogens requires the assessment of their complex interaction, which has differential effects on the innate immunity of honeybees as seen in this study.

Host and HBV Interactions and Their Potential Impact on Clinical Outcomes

Hepatitis B virus (HBV) is a challenge for global health services, affecting millions and leading thousands to end-stage liver disease each year. This comprehensive review explores the interactions between HBV and the host, examining their impact on clinical outcomes. HBV infection encompasses a spectrum of severity, ranging from acute hepatitis B to chronic hepatitis B, which can potentially progress to cirrhosis and hepatocellular carcinoma (HCC). Occult hepatitis B infection (OBI), characterized by low HBV DNA levels in hepatitis B surface antigen-negative individuals, can reactivate and cause acute hepatitis B. HBV genotyping has revealed unique geographical patterns and relationships with clinical outcomes. Moreover, single nucleotide polymorphisms (SNPs) within the human host genome have been linked to several clinical outcomes, including cirrhosis, HCC, OBI, hepatitis B reactivation, and spontaneous clearance. The immune response plays a key role in controlling HBV infection by eliminating infected cells and neutralizing HBV in the bloodstream. Furthermore, HBV can modulate host metabolic pathways involved in glucose and lipid metabolism and bile acid absorption, influencing disease progression. HBV clinical outcomes correlate with three levels of viral adaptation. In conclusion, the clinical outcomes of HBV infection could result from complex immune and metabolic interactions between the host and HBV. These outcomes can vary among populations and are influenced by HBV genotypes, host genetics, environmental factors, and lifestyle. Understanding the degrees of HBV adaptation is essential for developing region-specific control and prevention measures.

NLRP3 inflammasome and interleukin-1 contributions to COVID-19-associated coagulopathy and immunothrombosis

Immunothrombosis-immune-mediated activation of coagulation-is protective against pathogens, but excessive immunothrombosis can result in pathological thrombosis and multiorgan damage, as in severe coronavirus disease 2019 (COVID-19). The NACHT-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome produces major proinflammatory cytokines of the interleukin (IL)-1 family, IL-1β and IL-18, and induces pyroptotic cell death. Activation of the NLRP3 inflammasome pathway also promotes immunothrombotic programs including release of neutrophil extracellular traps and tissue factor by leukocytes, and prothrombotic responses by platelets and the vascular endothelium. NLRP3 inflammasome activation occurs in patients with COVID-19 pneumonia. In preclinical models, NLRP3 inflammasome pathway blockade restrains COVID-19-like hyperinflammation and pathology. Anakinra, recombinant human IL-1 receptor antagonist, showed safety and efficacy and is approved for the treatment of hypoxaemic COVID-19 patients with early signs of hyperinflammation. The non-selective NLRP3 inhibitor colchicine reduced hospitalization and death in a subgroup of COVID-19 outpatients but is not approved for the treatment of COVID-19. Additional COVID-19 trials testing NLRP3 inflammasome pathway blockers are inconclusive or ongoing. We herein outline the contribution of immunothrombosis to COVID-19-associated coagulopathy, and review preclinical and clinical evidence suggesting an engagement of the NLRP3 inflammasome pathway in the immunothrombotic pathogenesis of COVID-19. We also summarize current efforts to target the NLRP3 inflammasome pathway in COVID-19, and discuss challenges, unmet gaps, and the therapeutic potential that inflammasome-targeted strategies may provide for inflammation-driven thrombotic disorders including COVID-19.