Toll-like receptors and their crosstalk with other innate receptors in infection and immunity

Modic changes: From potential molecular mechanisms to future research directions (Review)

Low back pain (LBP) is a leading cause of disability worldwide. Although not all patients with Modic changes (MCs) experience LBP, MC is often closely associated with LBP and disc degeneration. In clinical practice, the focus is usually on symptoms related to MC, which are hypothesized to be associated with LBP; however, the link between MC and nerve compression remains unclear. In cases of intervertebral disc herniation, nerve compression is often the definitive cause of symptoms. Recent advances have shed light on the pathophysiology of MC, partially elucidating its underlying mechanisms. The pathogenesis of MC involves complex bone marrow‑disc interactions, resulting in bone marrow inflammation and edema. Over time, hematopoietic cells are gradually replaced by adipocytes, ultimately resulting in localized bone marrow sclerosis. This process creates a barrier between the intervertebral disc and the bone marrow, thereby enhancing the stability of the vertebral body. The latest understanding of the pathophysiology of MC suggests that chronic inflammation plays a significant role in its development and hypothesizes that the complement system may contribute to its pathological progression. However, this hypothesis requires further research to be confirmed. The present review we proposed a pathological model based on current research, encompassing the transition from Modic type 1 changes (MC1) to Modic type 2 changes (MC2). It discussed key cellular functions and their alterations in the pathogenesis of MC and outlined potential future research directions to further elucidate its mechanisms. Additionally, it reviewed the current clinical staging and pathogenesis of MC, recommended the development of an updated staging system and explored the prospects of integrating emerging artificial intelligence technologies.

A derivative of tanshinone IIA and salviadione, 15a, inhibits inflammation and alleviates DSS-induced colitis in mice by direct binding and inhibition of RIPK2

Inflammatory bowel diseases (IBDs) are chronic inflammatory conditions primarily affecting the gastrointestinal tract. Previous studies established the role of the NF-κB signaling pathway in the development of IBDs, suggesting that anti-inflammatory therapies might offer a viable treatment strategy. Tanshinone IIA and salviadione, both derived from Salviae Miltiorrhizae Radix et Rhizoma, possess anti-inflammatory and anti-oxidative activities. A series of new compounds were synthesized by hybridizing salviadione with tanshinone. Among these compounds, 15a showed beneficial effects in LPS-induced acute lung injury and diabetes-induced renal injury mouse models. The current study explored the therapeutic efficacy of 15a using both acute and chronic colitis models and elucidated the underlying mechanisms. DSS-induced colitis models were established in mice, where acute colitis was treated with compound 15a (5 or 10 mg·kg-1·d-1) for 8 days, while chronic colitis mice received compound 15a (5 or 10 mg·kg-1·d-1, i.g.) during 2.5% DSS administration. The 15a treatment significantly alleviated DSS-induced pathological and inflammatory damages in both acute and chronic colitis mouse models. In mouse intestinal epithelial cell line MODE-K, pretreatment with compound 15a (5 or 10 μM) significantly suppressed LPS + L18-MDP-induced inflammatory responses. The receptor-interacting serine/threonine kinase 2 (RIPK2) was identified as a direct binding target of compound 15a using microarrays and recombinant human proteins. Moreover, 15a could directly bind to and inhibit the phosphorylation of RIPK2, leading to the suppression of the NF-κB and MAPK signaling pathways. Furthermore, LEU153 and VAL32 were identified within the KD domain of RIPK2 as critical amino residues for the binding of 15a. Briefly, the current findings demonstrate that compound 15a holds promise as a therapeutic agent for managing acute and chronic colitis.

E3 ligase SYVN1-mediated polyubiquitination of CPSF6 promotes alternative polyadenylation and antivirus effects of macrophages

Transcriptome-wide alternative polyadenylation (APA) is involved in both innate and adaptive immune responses of immune cells. Downregulation of the CPSF6 protein, one of the 3' end-processing factors, mediates APA in macrophages with responses to virus infection and plays an important role in its anti-virus effect. However, the signaling pathway and molecular mechanism underlying the downregulation of the CPSF6 protein remain elusive. Here, we found that MAVS triggers the nuclear import of the E3 ligase SYVN1 mediated by NUP153 in response to vesicular stomatitis virus infection. Then, SYVN1 catalyzes K48-linked polyubiquitination of CPSF6, resulting in degradation of CPSF6 via the proteasome and then transcriptome-wide APA and anti-virus effects. Our results identify an antiviral mechanism via APA regulation based on ubiquitination modification of the CPSF6 protein, which may serve as a target for developing immune interventions.

OpenMMDL - Simplifying the Complex: Building, Simulating, and Analyzing Protein-Ligand Systems in OpenMM

Molecular dynamics (MD) simulations have become an essential tool for studying the dynamics of biological systems and exploring protein-ligand interactions. OpenMM is a modern, open-source software toolkit designed for MD simulations. Until now, it has lacked a module dedicated to building receptor-ligand systems, which is highly useful for investigating protein-ligand interactions for drug discovery. We therefore introduce OpenMMDL, an open-source toolkit that enables the preparation and simulation of protein-ligand complexes in OpenMM, along with the subsequent analysis of protein-ligand interactions. OpenMMDL consists of three main components: OpenMMDL Setup, a graphical user interface based on Python Flask to prepare protein and simulation settings, OpenMMDL Simulation to perform MD simulations with consecutive trajectory postprocessing, and finally OpenMMDL Analysis to analyze simulation results with respect to ligand binding. OpenMMDL is not only a versatile tool for analyzing protein-ligand interactions and generating ligand binding modes throughout simulations; it also tracks and clusters water molecules, particularly those exhibiting minimal displacement from their previous coordinates, providing insights into solvent dynamics. We applied OpenMMDL to study ligand-receptor interactions across diverse biological systems, including LDN-193189 and LDN-212854 with ALK2 (kinases), nifedipine and amlodipine in Cav1.1 (ion channels), LSD in 5-HT2B (G-protein coupled receptors), letrozole in CYP19A1 (cytochrome P450 oxygenases), flavin mononucleotide binding the FMN-riboswitch (RNAs), ligand C08 bound to TLR8 (toll-like receptor), and PZM21 bound to MOR (opioid receptor), highlighting distinct functionalities of OpenMMDL. OpenMMDL is publicly available at https://github.com/wolberlab/OpenMMDL.

Functional studies and synchrotron FTIR biochemical signatures reveal the potential of protein nanoparticles as a VHS virus vaccine

As an innovative strategy towards new biomaterials for fish vaccine development, we have generated the C-terminal half of the viral haemorrhagic septicaemia virus (VHSV) G protein as nanostructured bacterial inclusion bodies (IBs). IBs offer a slow release of biologically active, native and native-like proteins from a protective scaffold based on a nontoxic amyloid network. These nanoscale materials are an attractive type of vaccine design for aquaculture, being cheap, scalable and stable in vivo without the need for encapsulation, unlike soluble proteins. The bacterial remnants carried in IBs, such as lipopolysaccharide, are safe for fish and act as immunostimulants. Here we tested VHSV-G fragment-based protein nanoparticles in a range of scenarios to ascertain cellular uptake, metabolic changes and immunogenicity. Trout (Oncorhynchus mykiss) macrophages, in the first line of defence against infections, uptake the particles, resulting in impacts on global cell biochemical signatures measured by synchrotron FTIR. These changes were similar to those observed using inactivated VHSV virus. In a trout VHSV infection model, fish immunized with the developed nanoparticles raised specific anti-VHSV IgM antibodies, detected by ELISA. Among these, neutralizing antibodies were present, shown by a viral neutralization assay in Epithelioma Papulosum Cyprini (EPC) carp cell line. Further, the anti-VHSV IgM antibody titre increased significantly in the vaccinated group post VHSV infection, compared to sham-vaccinated fish. We therefore show that viral proteins, nanostructured as IBs, can elicit specific, functional anti-viral antibodies in fish and also can mimic in vitro the metabolic signatures associated to viral stimuli. All together, these data demonstrate the potential of this strategy for vaccine development.

Innate immune sensors and regulators at the blood brain barrier: focus on toll-like receptors and inflammasomes as mediators of neuro-immune crosstalk and inflammation

Cerebral endothelial cells (CEC) that form the brain capillaries are the principal constituents of the blood brain barrier (BBB), the main active interface between the blood and the brain which plays a protective role by restricting the infiltration of pathogens, harmful substances and immune cells into the brain while allowing the entry of essential nutrients. Aberrant CEC function often leads to increased permeability of the BBB altering the bidirectional communication between the brain and the bloodstream and facilitating the extravasation of immune cells into the brain. In addition to their role as essential gatekeepers of the BBB, CEC exhibit immune cell properties as they can receive and transmit signals between the blood and the brain partly via release of inflammatory effectors in pathological conditions. Cerebral endothelial cells express innate immune receptors, including toll like receptors (TLRs) and inflammasomes which are the first sensors of exogenous or endogenous dangers and initiators of immune and inflammatory responses which drive neural dysfunction and degeneration. Accumulating evidence indicates that activation of TLRs and inflammasomes in CEC compromises BBB integrity, promotes aberrant neuroimmune interactions and modulates both systemic and neuroinflammation, common pathological features of neurodegenerative and psychiatric diseases and central nervous system (CNS) infections and injuries. The goal of the present review is to provide an overview of the pivotal roles played by TLRs and inflammasomes in CEC function and discuss the molecular and cellular mechanisms by which they contribute to BBB disruption and neuroinflammation especially in the context of traumatic and ischemic brain injuries and brain infections. We will especially focus on the most recent advances and literature reports in the field to highlight the knowledge gaps. We will discuss future research directions that can advance our understanding of the central contribution of innate immune receptors to CEC and BBB dysfunction and the potential of innate immune receptors at the BBB as promising therapeutic targets in a wide variety of pathological conditions of the brain.

Eucommia ulmoides Oliv. Bark Extracts Alleviate MCAO/Reperfusion-Induced Neurological Dysfunction by Suppressing Microglial Inflammation in the Gray Matter

Ischemic stroke ranks as the second leading cause of global mortality. The limited time for effective thrombolytic treatment has prompted the exploration of alternative prevention approaches. Eucommia ulmoides (E. ulmoides) Oliv. bark has shown multiple pharmacological effects, including neuroprotection, anti-inflammation and autophagy modulation. This study aims to elucidate the neuroprotective effects of water extract of E. ulmoides (WEU) supplementation in a middle cerebral artery occlusion (MCAO) mouse model and to further explore the underlying molecular mechanisms. Seven bioactive compounds in WEU-aucubin, chlorogenic acid, geniposidic acid, quercetin, protocatechuic acid, betulin and pinoresinol diglucoside-were identified using HPLC-MS. Our results showed that WEU supplementation significantly decreased infarct volume and ameliorated neurological dysfunction in mice following MCAO/reperfusion (MCAO/R) injury. Furthermore, the administration of WEU significantly attenuated microglia activation induced by cortical ischemia in mice and inhibited the production of pro-inflammatory mediators, including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Importantly, in contrast with the vehicle group, the protein expression levels of Toll-like receptor 4 (TLR4), phospho-p38 (p-p38) and nuclear factor kappa B (NF-κB) were reduced in the WEU group. Therefore, this present study provides evidence that E. ulmoides improves neurological behaviors by suppressing neuroinflammation and inhibiting the activation of the TLR4/ p38 MAPK and NF-κB pathways in mice after ischemia, which indicates that E.ulmoides is a promising candidate for alleviating gray matter ischemic change.

Platycodin D facilitates antiviral immunity through inhibiting cytokine storm via targeting K63-linked TRAF6 ubiquitination

Influenza virus infection is a worldwide challenge that causes heavy burdens on public health. The mortality rate of severe influenza patients is often associated with hyperactive immunological abnormalities characterized by hypercytokinemia. Due to the continuous mutations and the occurrence of drug-resistant influenza virus strains, the development of host-directed immunoregulatory drugs is urgently required. Platycodon grandiflorum is among the top 10 herbs of traditional Chinese medicine used to treat pulmonary diseases. As one of the major terpenoid saponins extracted from P. grandiflorum, Platycodin D (PD) has been reported to play several roles, including anti-inflammation, analgesia, anticancer, hepatoprotection, and immunoregulation. However, the therapeutic roles of PD to treat influenza virus infection remain unknown. Here, we show that PD can protect the body weight loss in severely infected influenza mice, alleviate lung damage, and thus improve the survival rate. More specifically, PD protects flu mice via decreasing the immune cell infiltration into lungs and downregulating the overactivated inflammatory response. Western blot and immunofluorescence assays exhibited that PD could inhibit the activation of TAK1/IKK/NF-κB and MAPK pathways. Besides that, cellular thermal shift assay, surface plasmon resonance, and immunoprecipitation assays indicated that PD binds with TRAF6 to decrease its K63 ubiquitination after R837 stimulation. Additionally, small interfering RNA interference experiments exhibited that PD could inhibit the secretion of interleukin-1β and tumor necrosis factor α in TRAF6-dependent manner. Altogether, our results suggested that PD is a promising drug candidate for treating influenza. Our study also offered a scientific explanation for the commonly used P. grandiflorum in many antiepidemic classic formulas. Due to its host-directed regulatory role, PD may serve as an adjuvant therapeutic drug in conjunction with other antiviral drugs to treat the flu.

Loss of STIM1 and STIM2 in Salivary Glands Disrupts ANO1 Function but Does Not Induce Sjogren's Disease

Ca2+ signaling via the store-operated Ca2+ entry (SOCE) mediated by STIM1 and STIM2 proteins and the ORAI1 Ca2+ channel is important in saliva fluid secretion and has been associated with Sjogren's disease (SjD). However, there are no studies addressing STIM1/2 dysfunction in salivary glands or SjD in animal models. We report that mice lacking Stim1 and Stim2 [Stim1/2K14Cre(+)] in salivary glands exhibited reduced Ca2+ levels and hyposalivate. SOCE was functionally required for the activation of the Ca2+ activated Cl- channel ANO1. Ageing Stim1/2K14Cre(+) mice showed no evidence of lymphocytic infiltration or increased levels of autoantibodies characteristic of SjD, possibly associated with a downregulation of toll-like receptor 8 (Tlr8) expression. Salivary gland biopsies of SjD patients showed increased expression of STIM1 and TLR7/8. Our study shows that SOCE activates ANO1 function and fluid secretion in salivary glands and highlights a potential link between SOCE and TLR signaling in SjD.

Dihydromyricetin/montmorillonite intercalation compounds ameliorates DSS-induced colitis: Role of intestinal epithelial barrier, NLRP3 inflammasome pathway and gut microbiota

Dihydromyricetin (DHM), the primary active compound in vine tea possesses various pharmacological effects such as anti-inflammatory and antioxidant properties, along with high biosafety. However, its oral delivery remains a significant challenge. Montmorillonite (MMT), the primary component of bentonite, is a commonly used drug in the clinical treatment of gastrointestinal diseases and serves as an excellent drug carrier due to its intercalation capability. In this study, we intercalated DHM into the interlayer spaces of MMT via solution intercalation method combined with rotary evaporation and used it to treat ulcerative colitis in mice. SEM, XRD, and FTIR analyses confirmed the successful synthesis of the DHM/MMT intercalation compound. In vitro studies shown that DHM/MMT eliminated intracellular ROS and suppressed inflammatory genes IL-1β, IL-6, and TNF-α. Moreover, DHM/MMT demonstrated notable therapeutic effects in ulcerative colitis (UC) mice, significantly restoring the intestinal mucosa. Importantly, the therapeutic mechanism of DHM/MMT is closely linked to the inhibition of the NLRP3 signaling pathway. Additionally, this strategy modulated gut microbiota by increasing probiotics and suppressing harmful bacteria, thereby maintaining intestinal homeostasis. In conclusion, DHM/MMT presents a promising strategy for UC treatment.

A small-molecule enhancer of STAT1 affects herpes simplex keratitis prognosis by mediating plasmacytoid dendritic cells migration through CXCR3/CXCL10

Herpes simplex keratitis (HSK) is a prevalent infectious corneal disorder. This study aims to explore the role of plasmacytoid dendritic cells (pDCs) in HSK, an area that remains underexplored. The investigation centers on the effects of a STAT1 transcription enhancer, 2-NP, on pDCs and its underlying mechanisms. Our findings revealed that 2-NP treatment significantly reduced corneal opacity and neovascularization in a mouse HSK model. This intervention increased CXCR3 expression on the cell membrane, promoting pDC migration to the cornea via the CXCR3/CXCL10 axis. Additionally, it triggered STAT1 phosphorylation, enhancing IFN-α production, which in turn activated the JAK1/STAT1 signaling pathway. These results uncover a novel molecular mechanism by which the STAT1 transcriptional enhancer drives pDC migration to inflamed corneas, presenting a new therapeutic strategy for HSK.

Exploring precision treatments in immune-mediated inflammatory diseases: Harnessing the infinite potential of nucleic acid delivery

Immune-mediated inflammatory diseases (IMIDs) impose an immeasurable burden on individuals and society. While the conventional use of immunosuppressants and disease-modifying drugs has provided partial relief and control, their inevitable side effects and limited efficacy cast a shadow over finding a cure. Promising nucleic acid drugs have shown the potential to exert precise effects at the molecular level, with different classes of nucleic acids having regulatory functions through varying mechanisms. For the better delivery of nucleic acids, safe and effective viral vectors and non-viral delivery systems (including liposomes, polymers, etc.) have been intensively explored. Herein, after describing a range of nucleic acid categories and vectors, we focus on the application of therapeutic nucleic acid delivery in various IMIDs, including rheumatoid arthritis, inflammatory bowel disease, psoriasis, multiple sclerosis, asthma, ankylosing spondylitis, systemic lupus erythematosus, and uveitis. Molecules implicated in inflammation and immune dysregulation are abnormally expressed in a series of IMIDs, and their meticulous modulation through nucleic acid therapy results in varying degrees of remission and improvement of these diseases. By synthesizing findings centered on specific molecular targets, this review delivers a systematic elucidation and perspective towards advancing and utilization of nucleic acid therapeutics for managing IMIDs.

Interleukin-1 Receptor-Associated Kinase 4 (IRAK4) Degraders for Treating Inflammatory Diseases: Advances and Prospects

Interleukin-1 receptor-associated kinase 4 (IRAK4) is involved in various inflammation-related diseases. Both the kinase and scaffolding functions of IRAK4 initiate pro-inflammatory factor transcription and expression. The scaffolding function of IRAK4 is essential for Myddosome assembly and NF-κB activation. Conventional small-molecule inhibitors effectively inhibit the kinase function of IRAK4 but do not block its scaffolding function. Recently, various IRAK4 degraders have shown promising therapeutic potential in inflammatory diseases. The most advanced IRAK4-selective degrader, KT-474 (SAR444656), significantly reduced inflammatory biomarker levels in patients and demonstrated high safety and tolerability. This perspective introduces and discusses the physiological biology of IRAK4, its associated diseases, and the current development of IRAK4 degraders, thereby offering insights into future research directions.

Investigation of Clostridium butyricum on atopic dermatitis based on gut microbiota and TLR4/MyD88/ NF-κB signaling pathway

BACKGROUND

Probiotics, as common regulators of the gut microbiota, have been used in research to alleviate clinical symptoms of atopic dermatitis (AD).

OBJECTIVE

Our research team has previously identified a potential relieving effect of Clostridium butyricum on the treatment of AD, but the specific mechanism of how Clostridium butyricum alleviates AD has not yet been confirmed.

METHODS

In this study, we explored the relieving effect of Clostridium butyricum on AD through in vivo and in vitro experiments. AD mice induced by 2,4-dinitrofluorobenzene (DNFB) were orally administered with 1 × 108 CFU of Clostridium butyricum for three consecutive weeks.

RESULTS

Oral administration of Clostridium butyricum reduced ear swelling, alleviated back skin lesions, decreased mast cell and inflammatory cell infiltration, and regulated the levels of inflammation-related cytokines. Clostridium butyricum activated the intestinal immune system through the TLR4/MyD88/NF-κB signaling pathway, suppressed the expression of inflammatory factors IL-10 and IL-13, and protected the damaged intestinal mucosa.

CONCLUSION

Clostridium butyricum administration improved the diversity and abundance of the gut microbiota, enhanced the functionality of the immune system, and protected the epidermal barrier.

New perspectives on microbiome-dependent gut-brain pathways for the treatment of depression with gastrointestinal symptoms: from bench to bedside

Patients with depression are more likely to have chronic gastrointestinal (GI) symptoms than the general population, but such symptoms are considered only somatic symptoms of depression and lack special attention. There is a chronic lack of appropriate diagnosis and effective treatment for patients with depression accompanied by GI symptoms, and studying the association between depression and GI disorders (GIDs) is extremely important for clinical management. There is growing evidence that depression is closely related to the microbiota present in the GI tract, and the microbiota-gut-brain axis (MGBA) is creating a new perspective on the association between depression and GIDs. Identifying and treating GIDs would provide a key opportunity to prevent episodes of depression and may also improve the outcome of refractory depression. Current studies on depression and the microbially related gut-brain axis (GBA) lack a focus on GI function. In this review, we combine preclinical and clinical evidence to summarize the roles of the microbially regulated GBA in emotions and GI function, and summarize potential therapeutic strategies to provide a reference for the study of the pathomechanism and treatment of depression in combination with GI symptoms.

Bacillus pumilus SMU5927 protect mice from damage caused by Salmonella Enteritidis colonization

BACKGROUND

Salmonella Enteritidis is one of the main pathogens of foodborne diseases and an important pathogen causing diarrhea in yaks. Antibiotics are the mainstay of treatment for salmonellosis, but the widespread use of antibiotics has increased Salmonella resistance. Probiotics have been shown to antagonize Salmonella and reduce Salmonella infection. Bacillus pumilus is one of the microbial feed additives approved by the Chinese Ministry of Agriculture for use in animal breeding, which has the effect of improving animal growth performance and immunity, among others. Therefore, this paper explored the anti-infective effect of Bacillus pumilus against Salmonella.

RESULTS

Bacillus pumilus SMU5927 significantly enhances the intestinal mechanical barrier and reduces the number of Salmonella transferred to the organs. Bacillus pumilus SMU5927 ameliorated intestinal tissue damage and attenuated intestinal inflammatory responses in mice. In addition, Bacillus pumilus increased the ratio of the Firmicutes/Bacteroidetes in the intestinal flora, increased the abundance of beneficial bacteria such as Lactobacillus, and decreased the abundance of harmful bacteria.

CONCLUSION

This study confirmed the role of Bacillus pumilus SMU5927 in preventing and attenuating Salmonella damage and provided ideas for the development of novel antimicrobial drugs.

Pyrimidine synthesis enzyme CTP synthetase 1 suppresses antiviral interferon induction by deamidating IRF3

Metabolism is typically contextualized in conjunction with proliferation and growth. The roles of metabolic enzymes beyond metabolism-such as in innate immune responses-are underexplored. Using a focused short hairpin RNA (shRNA)-mediated screen, we identified CTP synthetase 1 (CTPS1), a rate-limiting enzyme of pyrimidine synthesis, as a negative regulator of interferon induction. Mechanistically, CTPS1 interacts with and deamidates interferon regulatory factor 3 (IRF3). Deamidation at N85 impairs IRF3 binding to promoters containing IRF3-responsive elements, thus muting interferon (IFN) induction. Employing CTPS1 conditional deletion and IRF3 deamidated or deamidation-resistant knockin mice, we demonstrated that CTPS1-driven IRF3 deamidation restricts IFN induction in response to viral infection in vivo. However, during immune activation, IRF3 deamidation by CTPS1 is inhibited by glycogen synthase kinase 3 beta (GSK3β) to promote IFN induction. This work demonstrates how CTPS1 tames innate immunity independent of its role in pyrimidine synthesis, thus expanding the functional repertoire of metabolic enzymes into immune regulation.

Exploring the regulatory role of small RNAs in modulating host-pathogen interactions: implications for bacterial and viral infections

MicroRNAs (miRNAs) and transfer RNA-derived stress-induced RNAs (tiRNAs) have emerged as crucial players in the post-transcriptional regulation of gene expression in various cellular processes, including immunity and host defense against infections. In recent years, increasing evidence has highlighted their complex role in influencing the host response during viral and bacterial infections. miRNAs have been shown to play multiple roles in host-pathogen interaction like TLR activation and altered disease virulence during bacterial infections. In the context of viral infections, miRNAs are involved in regulating viral replication, pathogenesis, and immune evasion. Similarly, tiRNAs have recently emerged as novel players in bacterial and viral infections such as modulating bacterial growth, adaptation to stress conditions, host antiviral responses, and impacting viral replication and pathogenesis. This review provides a comprehensive analysis of the potential of miRNA expression profiles as diagnostic biomarkers to differentiate between bacterial and viral infections. Further discusses the key pathways through which small RNAs regulate bacterial and viral infection-related diseases.

Buffalo Immune Competence Under Infectious and Non-Infectious Stressors

Immune competence is a critical aspect of protecting animals from the negative consequences of disease. The activation of the immune response from inflammation is part of adaptive homeostasis that serves to eliminate danger, induce tissue repair, and restore tissue homeostasis. Therefore, the main goal for the organism is to control both the induction and suppression of inflammation and resist the onset of disease. In this condition, modulators of inflammatory responses are produced, including small proteins called cytokines, which exert a pro- or anti-inflammatory action in a context-dependent manner. Indeed, the cytokine profile could be considered a useful biomarker to determine the pathophysiology of certain diseases, such as mastitis, endometritis, change-induced heat stress, and zoonoses. Recently, buffalo breeding has attracted the interest of the research communities due to their high resilience; however, little is known about the immune mechanism activated under specific stressors. This review describes the complex immune competence of the buffalo in the presence of the most common infectious and non-infectious stressors. In addition, a brief description of methods for early diagnosis of disease using cytokine quantification will be introduced.

Stimuli-responsive and targeted nanomaterials: Revolutionizing the treatment of bacterial infections

Bacterial infections have emerged as a major threat to global public health. The effectiveness of traditional antibiotic treatments is waning due to the increasing prevalence of antimicrobial resistance, leading to an urgent demand for alternative antibacterial technologies. In this context, antibacterial nanomaterials have proven to be powerful tools for treating antibiotic-resistant and recurring infections. Targeting nanomaterials not only enable the precise delivery of bactericidal agents but also ensure controlled release at the infection site, thereby reducing potential systemic side effects. This review collates and categorizes nanomaterial-based responsive and precision-targeted antibacterial strategies into three key types: exogenous stimuli-responsive (including light, ultrasound, magnetism), bacterial microenvironment-responsive (such as pH, enzymes, hypoxia), and targeted antibacterial action (involving electrostatic interaction, covalent bonding, receptor-ligand mechanisms). Furthermore, we discuss recent advances, potential mechanisms, and future prospects in responsive and targeted antimicrobial nanomaterials, aiming to provide a comprehensive overview of the field's development and inspire the formulation of novel, precision-targeted antimicrobial strategies.

The immunomodulatory effects of psychedelics in Alzheimer's disease-related dementia

Dementia is an increasing disorder, and Alzheimer's disease (AD) is the cause of 60% of all dementia cases. Despite all efforts, there is no cure for stopping dementia progression. Recent studies reported potential effects of psychedelics on neuroinflammation during AD. Psychedelics by 5HT2AR activation can reduce proinflammatory cytokine levels (TNF-α, IL-6) and inhibit neuroinflammation. In addition to neuroinflammation suppression, psychedelics induce neuroplasticity by increasing Brain-derived neurotrophic factor (BDNF) levels through Sigma-1R stimulation. This review discussed the effects of psychedelics on AD from both neuroinflammatory and neuroplasticity standpoints.

Epigenetics in Skin Homeostasis and Ageing

The skin, the largest organ of the human body, plays numerous essential roles, including protection against environmental hazards and the regulation of body temperature. The processes of skin homeostasis and ageing are complex and influenced by many factors, with epigenetic mechanisms being particularly significant. Epigenetics refers to the regulation of gene expression without altering the underlying DNA sequence. The dynamic nature of the skin, characterized by constant cellular turnover and responsiveness to environmental stimuli, requires precise gene activity control. This control is largely mediated by epigenetic modifications such as DNA methylation, histone modification, and regulation by non-coding RNAs. The present review endeavours to provide a comprehensive exploration and elucidation of the role of epigenetic mechanisms in regulating skin homeostasis and ageing. By integrating our current knowledge of epigenetic modifications with the latest advancements in dermatological research, we can gain a deeper comprehension of the complex regulatory networks that govern skin biology. Understanding these mechanisms also presents promising avenues for therapeutic interventions aimed at improving skin health and mitigating age-related skin conditions.

Bacterial ghosts: A breakthrough approach to cancer vaccination

Cancer is a devastating disease worldwide with high mortality rates and is a foremost concern for society. Immunotherapy has emerged as a promising strategy for treating cancer, harnessing the power of immune system to recognize and kill tumor cells. Bacterial ghosts (BGs), a novel platform in cancer vaccination, are suitable for personalized and effective immunotherapeutic interventions. BG are empty bacterial cell envelopes generated through a controlled lysis process, leaving behind empty but structurally intact cell membranes. BGs have been used as vaccine adjuvants and vaccine delivery vehicles worldwide. They possess inherent immunogenicity, enabling them to be used for controlled release and targeted drug delivery. Recently, the potential of BGs has been explored for tumor inhibition, making them suitable carrier vehicles. This review highlights cancer immunotherapy, methods of BG preparation, characterization of BGs, the interaction of BGs with the immune system, and research progress on BG-based cancer vaccines with future insights.

USP5 inhibits anti-RNA viral innate immunity by deconjugating K48-linked unanchored and K63-linked anchored ubiquitin on IRF3

Interferon regulatory factor 3 (IRF3) is a central hub transcription factor that controls host antiviral innate immunity. The expression and function of IRF3 are tightly regulated by the post-translational modifications. However, it is unknown whether unanchored ubiquitination and deubiquitination of IRF3 involve modulating antiviral innate immunity against RNA viruses. Here, we find that USP5, a deubiquitinase (DUB) regulating unanchored polyubiquitin, is downregulated during host anti-RNA viral innate immunity in a type I interferon (IFN-I) receptor (IFNAR)-dependent manner. USP5 is further identified to inhibit IRF3-triggered antiviral immune responses through its DUB enzyme activity. K48-linked unanchored ubiquitin promotes IRF3-driven transcription of IFN-β and induction of IFN-stimulated genes (ISGs) in a dose-dependent manner. USP5 simultaneously removes both K48-linked unanchored and K63-linked anchored polyubiquitin chains on IRF3. Our study not only provides evidence that unanchored ubiquitin regulates anti-RNA viral innate immunity but also proposes a novel mechanism for DUB-controlled IRF3 activation, suggesting that USP5 is a potential target for the treatment of RNA viral infectious diseases.

Modified lipids from Trypanosoma cruzi amastigotes down-regulate the pro-inflammatory response and increase the expression of alternative activation markers in macrophages

Herein, we analyzed the in vitro effect induced by total lipid extracts from Trypanosoma cruzi amastigotes of RA and K98 strains, which were obtained after overnight incubation (RAinc and K98inc) to mimic phospholipid hydrolytic processes that occurred adjacent to degenerating amastigote nests in tissues of Chagas disease patients. We demonstrated that RAinc and K98inc might possess bioactive lipid molecules with anti-inflammatory bias since they inactivated the NF-κB pathway, in contrast to intact lipids. Moreover, different M1/M2 macrophage phenotype markers of polarization were analyzed by RT-qPCR which evidenced that RAinc and K98inc promoted an increased expression of the M2 markers Arginase-1, IL-10, FIZZ and YM-1, and a decreased expression of iNOS and proinflammatory cytokines IL-6 and TNF-α. All these results indicate the relevant role of T. cruzi in bioactive lipid molecules, deepening thus our understanding of their contribution to immunomodulatory mechanisms as well as to macrophage polarization that occurs during the course of Chagas disease.

Differential TLR2 and TLR4 mediated inflammatory and apoptotic responses in asymptomatic and symptomatic Leptospira interrogans infections in canine uterine tissue

Leptospirosis is major zoonotic disease with global implications, affecting both domestic animals and humans. It is caused by Leptospira interrogans (L. interrogans), which can damage multiple organs, including the kidneys, liver, testes, and uterus. Despite this, L. interrogans can also persist asymptomatically in tissues, akin to nonpathogenic strains. The mechanisms driving asymptomatic infections remain poorly understood. This study investigated the role of L. interrogans in asymptomatic infection within the uterine tissue of canines, focusing on the differential expression of Toll-like receptors (TLRs)2 and 4 and their roles in inflammatory and apoptotic pathways. We hypothesized that TLR2 and TLR4 coexpression is crucial for eliciting inflammation and apoptosis, whereas TLR4 alone might be insufficient. Our findings revealed that in symptomatic infections, both TLR2 and TLR4 are coexpressed, leading to markedly elevated levels of the proinflammatory cytokines IL-10, IL-1β, TNF-α, and IL-6. This enhanced inflammatory response is further evidenced by increased CD4 expression, indicating robust T helper cell activation. In contrast, asymptomatic infections are characterized by exclusive TLR4 expression, with inflammatory markers remaining at baseline levels. Additionally, we observed that L. interrogans induces apoptosis in symptomatic animals through TLR2 and TLR4 mediated activation of Caspase 8 and Caspase 3. These findings illustrate that L. interrogans drives both inflammation and apoptosis via the combination of TLR2 and TLR4 actions. When only TLR4 is activated, the immune response is insufficient, resulting in an asymptomatic disease course. This study provides novel insights into the differential roles of TLR receptors in leptospirosis, offering potential directions for targeted therapeutic strategies.

Therapeutic targeting of neuroinflammation in methamphetamine use disorder

Methamphetamine (METH) is a highly addictive illicit psychostimulant with a significant annual fatality rate. Emerging studies highlight its role in neuroinflammation and a range of neurological disorders. This review examines the current landscape of potential drug targets for managing neuroinflammation in METH use disorders (MUDs), with a particular focus on the rationale behind targeting Toll-like receptor 4 (TLR4), the NLR family pyrin domain containing 3 (NLRP3) inflammasome, and other promising targets. Given the multifactorial neurological effects of METH, including cognitive impairment and neurodegeneration, addressing METH-induced neuroinflammation has shown considerable promise in partially mitigating the damaging effects on the central nervous system and improving behavioral outcomes. This article provides an overview of the existing understanding while charting a promising path forward for developing innovative MUD treatments, focusing on neuroinflammation as a therapeutic target. Targeting neuroinflammation in METH-induced neurological disorders shows significant promise in mitigating cognitive impairment and neurodegeneration, offering a potential therapeutic strategy for improving outcomes in MUD. While challenges remain in optimizing treatments, ongoing research into combination therapies, novel drug delivery systems, and neuroprotective agents suggests a positive outlook for more effective interventions.

Primary sensory neuron-derived miR-let-7b underlies stress-elicited psoriasis

Psoriasis, a chronic autoimmune skin condition with significant global morbidity, badly impairs patients' quality of life. Stress has been identified as a prominent trigger for psoriasis, and effectively management of stress can ameliorate its pathological manifestations. However, the precise mechanisms by which stress influences psoriasis remain elusive. In this study, we found that mice subjected to chronic social defeat stress (CSDS) exhibit severer imiquimod (IMQ)-induced psoriasis with increased epidermal scaling, epidermal hyperplasia, number of epidermal ridges, itch, and skin inflammation than control mice. Mechanistic study reveals that CSDS leads to an elevated release of miR-let-7b, an endogenous ligand of Toll-like receptor 7 (TLR7), from the peripheral terminal of dorsal root ganglia (DRG) neurons into the skin. This process can stimulate skin-resident macrophages to release cytokines (such as IL-6 and TNF-a) and chemokines (such as MCP-1), subsequently promoting the recruitment of additional macrophages into the skin. Notably, the specific blockade of miR-let-7b in DRG neurons effectively relieve stress-induced exacerbations of psoriasis. Furthermore, intradermal injection of synthetic miR-let-7b can induce a psoriasis-like phenotype in wildtype mice, a phenomenon that can be countered by the application of a TLR7 antagonist. Additionally, microfluidic chamber coculture assays demonstrated that miR-let-7b released by DRG neurons activates macrophages via TLR7 expressed on these immune cells. Totally, this study found that stress-induced upregulation and release of miR-let-7b from DRG neurons stimulates macrophages to secrete more inflammatory cytokines and chemokines, thereby exacerbating skin inflammation and the psoriatic phenotype. These findings provide a potential therapeutic strategy targeting the miR-let-7b/TLR7 pathway to alleviate stress-induced exacerbation of psoriasis.

Engineering mesoporous polydopamine-based potentiate STING pathway activation for advanced anti-biofilm therapy

The biofilm-induced "relatively immune-compromised zone" creates an immunosuppressive microenvironment that is a significant contributor to refractory infections in orthopedic endophytes. Consequently, the manipulation of immune cells to co-inhibit or co-activate signaling represents a crucial strategy for the management of biofilm. This study reports the incorporation of Mn2+ into mesoporous dopamine nanoparticles (Mnp) containing the stimulator of interferon genes (STING) pathway activator cGAMP (Mncp), and outer wrapping by M1-like macrophage cell membrane (m-Mncp). The cell membrane enhances the material's targeting ability for biofilm, allowing it to accumulate locally at the infectious focus. Furthermore, m-Mncp mechanically disrupts the biofilm through photothermal therapy and induces antigen exposure through photodynamic therapy-generated reactive oxygen species (ROS). Importantly, the modulation of immunosuppression and immune activation results in the augmentation of antigen-presenting cells (APCs) and the commencement of antigen presentation, thereby inducing biofilm-specific humoral immunity and memory responses. Additionally, this approach effectively suppresses the activation of myeloid-derived suppressor cells (MDSCs) while simultaneously boosting the activity of T cells. Our study showcases the efficacy of utilizing m-Mncp immunotherapy in conjunction with photothermal and photodynamic therapy to effectively mitigate residual and recurrent infections following the extraction of infected implants. As such, this research presents a viable alternative to traditional antibiotic treatments for biofilm that are challenging to manage.

Impact of zinc on immunometabolism and its putative role on respiratory diseases

Zinc is the second most abundant trace mineral in the human body and plays a critical role in immune cell function and metabolism. Zinc deficiency impairs immune cell function and is associated with increased susceptibility to respiratory diseases, including pneumonia, influenza, and COVID-19. Zinc homeostasis, maintained by numerous zinc transporters and metal-binding proteins (ie, metallothionein), is essential for coordinating immune cell signaling, gene expression, and enzymatic activities in response to respiratory infections. This article highlights the emerging role of zinc in various aspects of immune function, particularly through its influence on cellular metabolism. Given the significant global burden of respiratory diseases, there is a need to identify effective nutritional interventions that could be readily leveraged to prevent and/or mitigate respiratory disease risk, particularly in older adults who are prone to zinc deficiency. However, the immunometabolic mechanisms underlying zinc's protective effects remain poorly characterized. Future research should focus on elucidating how micronutrients, such as zinc, can support changes in immune cell metabolism in response to infections. Such efforts will help determine how zinc metabolism and zinc intervention strategies may best be leveraged to prevent or mitigate respiratory disease.

Toll-like receptor agonists as cancer vaccine adjuvants

Cancer immunotherapy has emerged as a promising strategy to treat cancer patients. Among the wide range of immunological approaches, cancer vaccines have been investigated to activate and expand tumor-reactive T cells. However, most cancer vaccines have not shown significant clinical benefit as monotherapies. This is likely due to the antigen targets of vaccines, "self" proteins to which there is tolerance, as well as to the immunosuppressive tumor microenvironment. To help circumvent immune tolerance and generate effective immune responses, adjuvants for cancer vaccines are necessary. One representative adjuvant family is Toll-Like receptor (TLR) agonists, synthetic molecules that stimulate TLRs. TLRs are the largest family of pattern recognition receptors (PRRs) that serve as the sensors of pathogens or cellular damage. They recognize conserved foreign molecules from pathogens or internal molecules from cellular damage and propel innate immune responses. When used with vaccines, activation of TLRs signals an innate damage response that can facilitate the development of a strong adaptive immune response against the target antigen. The ability of TLR agonists to modulate innate immune responses has positioned them to serve as adjuvants for vaccines targeting infectious diseases and cancers. This review provides a summary of various TLRs, including their expression patterns, their functions in the immune system, as well as their ligands and synthetic molecules developed as TLR agonists. In addition, it presents a comprehensive overview of recent strategies employing different TLR agonists as adjuvants in cancer vaccine development, both in pre-clinical models and ongoing clinical trials.

Three Unrelated Patients of Roma Ethnicity from a Single Center Carrying the Same Deletion in MYD88 Gene: A Founder Effect?

MyD88 deficiency is a rare inborn error of immunity (IEI) characterized by susceptibility to pyogenic infections without overt signs of inflammation. Half of the reported patients belong to Roma descent, an itinerant ethnic group living mostly in Europe, with an increased risk of childhood mortality due to limited access to healthcare services. We describe three unrelated patients from the Campania region in Italy with MyD88 deficiency, all belonging to Roma descent and displaying severe or recurrent infections in early infancy. They underwent a comprehensive immunological work-up including targeted next-generation sequencing for IEIs that identified a homozygous pathogenic in-frame deletion c.157_159del p.(Glu53del) in MYD88 gene, already described in this ethnic group, suggesting a founder effect. A high level of alert should be kept in patients of Roma ethnicity with early onset severe infections. Moreover, being associated with increased Immunoglobulin E (IgE) levels, this condition should be included in the differential diagnosis of Hyper-IgE syndromes.

The predominant role of FliC contributes to the flagella-related pathogenicity of ST34 S. Typhimurium monophasic variant

Over the past two decades, the monophasic variant of Salmonella enterica serovar Typhimurium (S. Typhimurium) has rapidly emerged and increased worldwide. This upsurge is especially true for the European clone of the ST34 S. Typhimurium monophasic variant. The key distinction between ST34 S. Typhimurium and its monophasic variant is that the genes that encode for second-phase flagellin (FljB) and the regions around it have been replaced with various multidrug resistance cassettes. To determine if the loss of fljB or the retention of fliC,-the gene coding for first-phase flagellin (FliC)-, would impact its pathogenicity, we constructed various mutations, including deletions of fljB, fliC, fliC/fljB, and strains where fliC was replaced with fljB. Our results showed that the loss of fljB in ST34 S. Typhimurium and its monophasic variant does not affect bacterial motility, cell infection ability, survival in macrophages, induced pro-inflammatory cytokines secretion, virulence, or persistent infection in mice. However, the deletion of fliC caused a significant decrease in these outcomes for both strains, while the replacement of fliC with fljB only partially restored these capabilities. Consequently, we determined that FliC is predominant in the flagellar expression of ST34 S. Typhimurium other than FljB. This finding demonstrates that replacing the fljB gene with various resistance regions in ST34 S. Typhimurium monophasic variants can enhance bacterial survival under specific antibiotic farming practices and spread globally.

Ex Vivo Delivery of mRNA to Immune Cells via a Nonendosomal Route Obviates the Need for Nucleoside Modification

Base modification and the use of lipid nanoparticles are thought to be essential for efficient in vivo delivery and expression of mRNA. However, for ex vivo immune cell engineering, the need for either of the two is unclear. Previous reports have suggested that nucleic acids may be efficiently delivered to immune cells ex vivo, through a nonendosomal delivery route, but the need for base modification has not been determined. Herein, we demonstrate that when a nonendosomal delivery method is used, unmodified mRNA performs equally well to the commonly used base-modified mRNA, including the N 1 methyl pseudouridine modification, in terms of protein expression and inflammatory response in cells. However, if an endosomal delivery route is used, then N 1 methyl pseudouridine modification is necessary for high expression and low inflammatory response, as demonstrated by others as well. Overall, we show that nonendosomal mRNA delivery renders nucleoside modifications nonessential and that unmodified mRNA combined with nonendosomal delivery route may be used for efficient ex vivo mRNA-based engineering of immune cells.

Nucleotide-binding oligomerization domain 1 (NOD1) regulates microglial activation in pseudorabies virus infection

The primary cause of viral encephalitis (VE) is invasion of the central nervous system (CNS) by the virus, which leads to neuroinflammation and poses a significant threat to global public health. Microglia, as CNS-resident macrophages, play a crucial role in neuroinflammation and are often identified as the preferred target for the prevention or treatment of VE. In this study, we used pseudorabies virus (PRV)-induced VE in mice and pigs as a model to investigate the regulation of microglial responses during viral encephalitis and explored the mechanism of microglial activation. Cellular experiments revealed that microglial activation was accompanied by cell migration, characteristic morphological changes, phagocytosis, inflammatory cytokine production, and antigen presentation. Transcriptome analysis revealed that genes related to inflammation in PRV-infected BV2 cells were significantly enriched. The expression of the NOD1 gene in BV2 cells was significantly increased during PRV infection, after which NOD1 in BV2 cells was silenced by siRNA and overexpressed via a plasmid. NOD1 was found to be involved in the secretion of cytokines in BV2 cells by regulating the MAPK/NF-κB signalling pathway. Mouse and pig experiments have shown that NOD1 is involved in the secretion of cytokines by microglia by regulating the MAPK/NF-κB signalling pathway during PRV infection.

Immunoinformatic based designing of highly immunogenic multi-epitope subunit vaccines to stimulate an adaptive immune response against Junin virus

The Junin virus causes Argentine hemorrhagic fever, leading to severe complications such as high fever, malaise, muscle pain, and bleeding disorders, including hemorrhages in the skin and mucous membranes. Neurological issues like confusion, seizures, and coma can also occur. Without prompt and effective treatment, the disease can be fatal, with mortality rates reaching up to 30%. Taking serious measures is essential to mitigate the spread of the disease. Vaccination is the most effective choice to neutralize the Junin virus in the current situation. Consequently, to design the highly immunogenic and non-allergenic multi-epitope subunit vaccine against the Junin virus, we employed the immunoinformatic approach to screen the glycoprotein, nucleoprotein, and RDRP protein for potential immunogenic CTL (Cytotoxic T Lymphocyte), HTL (Helper T Lymphocyte) and B (B Lymphocyte) cell epitopes. Afterward, the predicted epitopes were subjected to 3D modeling and validation. The strong binding affinity of the constructed vaccines with the human TLR3 was confirmed through molecular docking, with scores of - 333 kcal/mol for glycoprotein, - 297 kcal/mol for nucleoprotein, - 308 kcal/mol for RDRP, and - 305 kcal/mol for combined vaccines. Additionally, the binding free energies recorded were - 63.54 kcal/mol, - 64.16 kcal/mol, - 56.81 kcal/mol, and - 51.52 kcal/mol, respectively. Furthermore, the dynamic stability, residual fluctuation, and compactness of vaccine-TLR-3 complexes were confirmed by the molecular dynamic simulation. The codon adaptation index (CAI) values and high GC content confirmed the stable expression of constructed vaccines in the pET-28a ( +) expression vector. The immune simulation analysis demonstrated that administering booster doses of the developed vaccines resulted in a notable increase in IgG, IgM, interleukins, and cytokines levels, indicating effective antigen clearance over time. In conclusion, our study provides preclinical evidence for designing a highly effective Junin virus vaccine, necessitating further in-vitro and in-vivo experiments.

Viral sepsis: diagnosis, clinical features, pathogenesis, and clinical considerations

Sepsis, characterized as life-threatening organ dysfunction resulting from dysregulated host responses to infection, remains a significant challenge in clinical practice. Despite advancements in understanding host-bacterial interactions, molecular responses, and therapeutic approaches, the mortality rate associated with sepsis has consistently ranged between 10 and 16%. This elevated mortality highlights critical gaps in our comprehension of sepsis etiology. Traditionally linked to bacterial and fungal pathogens, recent outbreaks of acute viral infections, including Middle East respiratory syndrome coronavirus (MERS-CoV), influenza virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), among other regional epidemics, have underscored the role of viral pathogenesis in sepsis, particularly when critically ill patients exhibit classic symptoms indicative of sepsis. However, many cases of viral-induced sepsis are frequently underdiagnosed because standard evaluations typically exclude viral panels. Moreover, these viruses not only activate conventional pattern recognition receptors (PRRs) and retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) but also initiate primary antiviral pathways such as cyclic guanosine monophosphate adenosine monophosphate (GMP-AMP) synthase (cGAS)-stimulator of interferon genes (STING) signaling and interferon response mechanisms. Such activations lead to cellular stress, metabolic disturbances, and extensive cell damage that exacerbate tissue injury while leading to a spectrum of clinical manifestations. This complexity poses substantial challenges for the clinical management of affected cases. In this review, we elucidate the definition and diagnosis criteria for viral sepsis while synthesizing current knowledge regarding its etiology, epidemiology, and pathophysiology, molecular mechanisms involved therein as well as their impact on immune-mediated organ damage. Additionally, we discuss clinical considerations related to both existing therapies and advanced treatment interventions, aiming to enhance the comprehensive understanding surrounding viral sepsis.

Corneal strain influences keratocyte proliferation and migration through upregulation of ALDH3A1 expression

Keratocytes are the primary resident cells in the corneal stroma. They play an essential role in maintaining corneal physiological function. Studying the factors that affect the phenotype and behavior of keratocytes offers meaningful perspectives for improving the understanding and treatment of corneal injuries. In this study, 3% strain was applied to human keratocytes using the Flexcell® Tension Systems. Real-time quantitative PCR (RT-qPCR) and western blot were used to investigate the influence of strain on the expression of intracellular aldehyde dehydrogenase 3A1 (ALDH3A1). ALDH3A1 knockdown was achieved using double-stranded RNA-mediated interference (RNAi). Immunofluorescence (IF) staining was employed to observe the impact of changes in ALDH3A1 expression on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) nuclear translocation. Keratocyte proliferation and migration were assessed by bromodeoxyuridine (BrdU) assay and scratch wound healing assay, respectively. Mouse injury models and single-cell RNA sequencing of keratocytes from keratoconus patients were used to assess how strain influenced ALDH3A1 in vivo. Our results demonstrate that 3% strain suppresses keratocyte proliferation and increases ALDH3A1. Increased ALDH3A1 inhibits NF-κB nuclear translocation, a key step in the activation of the NF-κB signaling pathway. Conversely, ALDH3A1 knockdown promotes NF-κB nuclear translocation, ultimately enhancing keratocyte proliferation and migration. Elevated ALDH3A1 levels were also observed in mouse injury models with increased corneal strain and keratoconus patients. These findings provide valuable insights for further research into the role of corneal strain and its connection to corneal injury repair.

[The impact of innate immune response on the efficacy of oncolytic viruses]

Oncolytic viruses represent a promising class of immunotherapeutic agents for the treatment of malignant tumors. The proposed mechanism of action of various oncolytic viruses has initially been explained by the ability of such viruses to selectively lyse tumor cells without damaging healthy ones. Recently, there have emerged more studies determining the effect of the antiviral immunostimulating mechanisms on the effectiveness of treatment in cancer patients. Stimulation of innate immune cells by an oncolytic virus can initiate an adaptive antitumor immune response, yet at the same time, the antiviral mechanisms of the immune system can limit the spread of the virus, thereby reducing its effectiveness. Thus, the success of the clinical application of the oncolytic viruses directly depends on the three key components: tumor immunosuppression, antiviral responses, and antitumor immune responses. The review presents current data on the influence of pattern recognition receptors on the effectiveness of oncolytic viruses.

Pathological mechanisms of glial cell activation and neurodegenerative and neuropsychiatric disorders caused by Toxoplasma gondii infection

Toxoplasma gondii is an intracellular opportunistic parasite that exists in a latent form within the human central nervous system (CNS), even in immune-competent hosts. During acute infection, T. gondii traverses the blood-brain barrier (BBB). In the subsequent chronic infection phase, the infiltration of immune cells into the brain, driven by T. gondii infection and the formation of parasitic cysts, leads to persistent activation and proliferation of astrocytes and microglia. This process results in neuronal damages that are fatal in some cases. Through inducing systemic immune responses, T. gondii infection can dramatically alter the behavior of rodents and increase the risk of various neuropsychiatric disorders in humans. In this review, we explore some recent research progress on the major events involved in BBB disruption, glial cell activation and neuronal damage following T. gondii infection in hosts. It further discusses potential pathological mechanisms and the feasible treatment approaches for the neurodegenerative and neuropsychiatric disorders caused by T. gondii infection to extend our understanding for pathogenesis and preventive control of toxoplasmosis in humans.

Lipopolysaccharide Triggers Luminal Acidification to Promote Defense Against Bacterial Infection in Vaginal Epithelium

The vaginal epithelium plays pivotal roles in host defense against pathogen invasion, contributing to the maintenance of an acidic microenvironment within the vaginal lumen through the activity of acid-base transport proteins. However, the precise defense mechanisms of the vaginal epithelium after a bacterial infection remain incompletely understood. This study showed that bacterial lipopolysaccharide (LPS) potentiated net proton efflux by up-regulating the expression of Na+-H+ exchanger 1 (NHE1) in vaginal epithelial cells. Pharmacologic inhibition or genetic knockdown of Toll-like receptor-4 and the extracellular signal-regulated protein kinase signaling pathway effectively counteracted the up-regulation of NHE1 and the enhanced proton efflux triggered by LPS in vaginal epithelial cells. In vivo studies revealed that LPS administration led to luminal acidification through the up-regulation of NHE1 expression in the rat vagina. Moreover, inhibition of NHE exhibited an impaired defense against acute bacterial infection in the rat vagina. These findings collectively indicate the active involvement of vaginal epithelial cells in facilitating luminal acidification during acute bacterial infection, offering potential insights into the treatment of bacterial vaginosis.

Synergistic immune augmentation enabled by covalently conjugating TLR4 and NOD2 agonists

Enhancing the efficacy of subunit vaccines relies significantly on the utilization of potent adjuvants, particularly those capable of triggering multiple immune pathways. To achieve synergistic immune augmentation by Toll-like receptor 4 agonist (TLR4a) and nucleotide-binding oligomerization-domain-containing protein 2 agonist (NOD2a), in this work, we conjugated RC529 (TLR4a) and MDP (NOD2a) to give RC529-MDP, and evaluated its adjuvanticity for OVA antigen. Compared to the unconjugated RC529+MDP, RC529-MDP remarkably enhanced innate immune responses with 6.8-fold increase in IL-6 cytokine, and promoted the maturation of antigen-presenting cells (APCs), possibly because of the conjugation of multiple agonists ensuring their delivery to the same cell and activation of various signaling pathways within that cell. Furthermore, RC529-MDP improved OVA-specific antibody response, T cells response and the memory T cells ratio relative to the unconjugated mixture. Therefore, covalently conjugating TLR4 agonist and NOD2 agonist was an effective strategy to enhance immune responses, providing the potential to design and develop more effective vaccines.

Berberine Mitigates Sepsis-Associated Acute Kidney Injury in Aged Rats by Preserving Mitochondrial Integrity and Inhibiting TLR4/NF-κB and NLRP3 Inflammasome Activations

Sepsis-associated acute kidney injury (SA-AKI) presents a severe challenge in the elderly due to increasing incidence, high mortality, and the lack of specific effective treatments. Exploring novel and secure preventive and/or therapeutic approaches is critical and urgent. Berberine (BBR), an isoquinoline alkaloid with anti-inflammatory, antioxidant, and immunomodulatory properties, has shown beneficial effects in various kidney diseases. This study examined whether BBR could protect against SA-AKI in aged rats. Sepsis was induced in 26-month-old male Wistar rats by cecal ligation and puncture (CLP), either with or without BBR pretreatment. CLP induction led to SA-AKI, as indicated by elevated serum levels of malondialdehyde, tumor necrosis factor-alpha, urea nitrogen, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL), along with histopathological features of kidney damage. Key indicators of kidney oxidative stress, mitochondrial dysfunction, apoptosis, and activations of the Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling, including the nucleotide-binding domain, leucine-rich-containing family, and pyrin domain-containing-3 (NLRP3) inflammasome pathway, were also elevated following CLP induction. BBR pretreatment substantially mitigated these adverse effects, suggesting that it protects against SA-AKI in aged rats by reducing oxidative stress, preserving mitochondrial integrity, and inhibiting key inflammatory pathways. These findings highlight the potential of BBR as a therapeutic agent for managing SA-AKI in elderly populations.

The role of pyroptosis in cancer: key components and therapeutic potential

Pyroptosis is a lytic and inflammatory form of gasdermin protein-mediated programmed cell death that is typically initiated by inflammasomes. The inflammasome response is an effective mechanism for eradicating germs and cancer cells in the event of cellular injury. The gasdermin family is responsible for initiating pyroptosis, a process in which holes are made in the cell membrane to allow inflammatory chemicals to escape. Mounting evidence indicates that pyroptosis is critical for controlling the development of cancer. In this review, we provide a general overview of pyroptosis, examine the relationship between the primary elements of pyroptosis and tumors, and stress the necessity of pyroptosis-targeted therapy in tumors. Furthermore, we explore its dual nature as a double-edged sword capable of both inhibiting and facilitating the growth of cancer, depending on the specific conditions. Ultimately, pyroptosis is a phenomenon that has both positive and negative effects on tumors. Using this dual impact in a reasonable manner may facilitate investigation into the initiation and progression of tumors and offer insights for the development of novel treatments centered on pyroptosis.

The Importance of Including Maternal Immune Activation in Animal Models of Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is a perinatal brain injury that is the leading cause of cerebral palsy, developmental delay, and poor cognitive outcomes in children born at term, occurring in about 1.5 out of 1000 births. The only proven therapy for HIE is therapeutic hypothermia. However, despite this treatment, many children ultimately suffer disability, brain injury, and even death. Barriers to implementation including late diagnosis and lack of resources also lead to poorer outcomes. This demonstrates a critical need for additional treatments for HIE, and to facilitate this, we need translational models that accurately reflect risk factors and interactions present in HIE. Maternal or amniotic infection is a significant risk factor and possible cause of HIE in humans. Maternal immune activation (MIA) is a well-established model of maternal infection and inflammation that has significant developmental consequences largely characterized within the context of neurodevelopmental disorders such as autism spectrum disorder and schizophrenia. MIA can also lead to long-lasting changes within the neuroimmune system, which lead to compounding negative outcomes following a second insult. This supports the importance of understanding the interaction of maternal inflammation and hypoxic-ischemic outcomes. Animal models have been invaluable to understanding the pathophysiology of this injury and to the development of therapeutic hypothermia. However, each model system has its own limitations. Large animal models such as pigs may more accurately represent the brain and organ development and complexity in humans, while rodent models are more cost-effective and offer more possible molecular techniques. Recent studies have utilized MIA or direct inflammation prior to HIE insult. Investigators should thoughtfully consider the risk factors they wish to include in their HIE animal models. In the incorporation of MIA, investigators should consider the type, timing, and dose of the inflammatory stimulus, as well as the timing, severity, and type of hypoxic insult. Using a variety of animal models that incorporate the maternal-placental-fetal system of inflammation will most likely lead to a more robust understanding of the mechanisms of this injury that can guide future clinical decisions and therapies.

A novel immunomodulating peptide with potential to complement oligodeoxynucleotide-mediated adjuvanticity in vaccination strategies

The identification of adjuvants to improve vaccination efficacy is a major unmet need. One approach is to augment the functionality of dendritic cells (DCs) by using Toll-like receptor-9 (TLR9) agonists such as cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs) as adjuvants. Another approach is adjuvant selection based on production of bioactive interleukin-12 (IL-12). We report a D-peptide isomer, designated D-15800, that induces monocyte differentiation to the DC phenotype in vitro and more effectively stimulates IL-12p70 production upon T cell receptor (TCR) activation than the L-isomer. In the absence of TCR activation and either IL-12p70 or interleukin-2 production, only D-15800 activates CD4+ T and natural killer cells. In the presence of CpG ODN, D-15800 synergistically enhances production of interferon-alpha (IFN-α). Taken together with its biostability in human serum and depot retention upon injection, co-delivery of D-15800 with TLR9 agonists could serve to improve vaccine efficacy.

The emerging field of viroimmunotherapy for pediatric brain tumors

Pediatric brain tumors are the most common solid tumors in children. Even to date, with the advances in multimodality therapeutic management, survival outcomes remain dismal in some types of tumors, such as pediatric-type diffuse high-grade gliomas or central nervous system embryonal tumors. Failure to understand the complex molecular heterogeneity and the elusive tumor and microenvironment interplay continues to undermine therapeutic efficacy. Developing a strategy that would improve survival for these fatal tumors remains unmet in pediatric neuro-oncology. Oncolytic viruses (OVs) are emerging as a feasible, safe, and promising therapy for brain tumors. The new paradigm in virotherapy implies that the direct cytopathic effect is followed, under certain circumstances, by an antitumor immune response responsible for the partial or complete debulking of the tumor mass. OVs alone or combined with other therapeutic modalities have been primarily used in adult neuro-oncology. A surge in encouraging preclinical studies in pediatric brain tumor models recently led to the clinical translation of OVs with encouraging results in these tumors. In this review, we summarize the different virotherapy tested in preclinical and clinical studies in pediatric brain tumors, and we discuss the limitations and future avenues necessary to improve the response of these tumors to this type of therapy.

MicroRNA-146a-5p protects retinal ganglion cells through reducing neuroinflammation in experimental glaucoma

Neuroinflammation plays important roles in retinal ganglion cell (RGC) degeneration in glaucoma. MicroRNA-146 (miR-146) has been shown to regulate inflammatory response in neurodegenerative diseases. In this study, whether and how miR-146 could affect RGC injury in chronic ocular hypertension (COH) experimental glaucoma were investigated. We showed that in the members of miR-146 family only miR-146a-5p expression was upregulated in COH retinas. The upregulation of miR-146a-5p was observed in the activated microglia and Müller cells both in primary cultured conditions and in COH retinas, but mainly occurred in microglia. Overexpression of miR-146a-5p in COH retinas reduced the levels pro-inflammatory cytokines and upregulated the levels of anti-inflammatory cytokines, which were further confirmed in the activated primary cultured microglia. Transfection of miR-146a-5p mimic increased the percentage of anti-inflammatory phenotype in the activated BV2 microglia, while transfection of miR-146a-5p inhibitor resulted in the opposite effects. Transfection of miR-146a-5p mimic/agomir inhibited the levels of interleukin-1 receptor associated kinase (IRAK1) and TNF receptor associated factor 6 (TRAF6) and phosphorylated NF-κB subunit p65. Dual luciferase reporter gene assay confirmed that miR-146a-5p could directly target IRAK1 and TRAF6. Moreover, downregulation of IRAK1 and TRAF6 by siRNA techniques or blocking NF-κB by SN50 in cultured microglia reversed the miR-146a-5p inhibitor-induced changes of inflammatory cytokines. In COH retinas, overexpression of miR-146a-5p reduced RGC apoptosis, increased RGC survival, and partially rescued the amplitudes of photopic negative response. Our results demonstrate that overexpression of miR-146a-5p attenuates RGC injury in glaucoma by reducing neuroinflammation through downregulating IRAK1/TRAF6/NF-κB signaling pathway in microglia.

Loganin inhibits the ROS-NLRP3-IL-1β axis by activating the NRF2/HO-1 pathway against osteoarthritis

Loganin (LOG), a bioactive compound derived from Cornus officinalis Siebold & Zucc, has been understudied in the context of osteoarthritis (OA) treatment. In this study, we induced an inflammatory response in chondrocytes using lipopolysaccharide (LPS) and subsequently treated these cells with LOG. We employed fluorescence analysis to quantify reactive oxygen species (ROS) levels and measured the expression of NLRP3 and nuclear factor erythropoietin-2-related factor 2 (NRF2) using real-time quantitative polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence (IF) techniques. Additionally, we developed an OA mouse model by performing medial meniscus destabilization (DMM) surgery and monitored disease progression through micro-computed tomography (micro-CT), hematoxylin and eosin (H&E) staining, safranin O and fast green (S&F) staining, and immunohistochemical (IHC) analysis. Our results indicate that LOG significantly reduced LPS-induced ROS levels in chondrocytes, inhibited the activation of the NLRP3 inflammasome, and enhanced NRF2/heme oxygenase 1 (HO-1) signaling. In vivo, LOG treatment mitigated cartilage degradation and osteophyte formation triggered by DMM surgery, decreased NLRP3 expression, and increased NRF2 expression. These findings suggest that LOG has a protective effect against OA, potentially delaying disease progression by inhibiting the ROS-NLRP3-IL-1β axis and activating the NRF2/HO-1 pathway.