Search Results (1,578)

Human metapneumovirus (hMPV) is an important respiratory pathogen and a major cause of respiratory tract infections, particularly among vulnerable populations. Although hMPV was identified in 2001, it remains less extensively studied than other major respiratory viruses, such as influenza virus and respiratory syncytial virus (RSV), hindering the development of effective preventive and therapeutic strategies. This review examines the primary mechanisms by which hMPV evades host immune responses. The virus disrupts early innate immune signaling pathways, particularly those involved in the induction and signaling of antiviral interferons (IFNs) and modulates inflammatory responses. At the level of adaptive immunity, hMPV impairs T-cell activation and the development of long-lasting immunological memory, which may contribute to susceptibility to reinfection. The virus also alters the functions of several immune and structural cell types, including macrophages, dendritic cells, and respiratory epithelial cells. In addition, hMPV may modulate host microRNA expression to promote immune evasion and prolong infection. The recurrent nature of hMPV infections highlights the need to further investigate the immune-evasion mechanisms. Such research is essential for developing safer and more effective vaccines, antiviral agents, and immunomodulatory therapies. Full article

A standardized extract of cultured Lentinula edodes mycelia (ECLM), commercially known as AHCC^®, shows anti-inflammatory, immunomodulatory, and organ-protective properties. Experimental studies have indicated that ECLM modulates innate and adaptive immunity, including natural killer (NK) cell activity, antigen-presenting cell function, T-cell responses, and cytokine balance. These effects are particularly relevant in oncology because surgical stress and ischemia–reperfusion injury (IRI) generate a transient perioperative environment characterized by immune suppression, inflammation, and conditions favorable for metastatic progression. Recent animal studies have demonstrated the protective effects of ECLM in intestinal and hepatic IRI models, providing a potential mechanistic rationale for improving the perioperative host microenvironment. Clinical studies on hepatocellular carcinoma, pancreatic cancer, and gynecological malignancies suggest that ECLM may offer potential benefits in immune preservation, nutritional support, symptom management, and recurrence prevention, although most studies are small and hypothesis-generating. Emerging evidence from patient-derived xenograft and spontaneous carcinogenesis models further suggests that ECLM may influence tumor biology beyond host immune activation, although the underlying mechanisms require elucidation. This review summarizes the mechanistic, preclinical, translational, and clinical evidence supporting the use of ECLM as a candidate for perioperative immunonutritional strategies. We propose the hypothesis that ECLM may function as a perioperative microenvironmental stabilizer that integrates immune preservation and intestinal barrier protection. Full article

5′-Adenosine monophosphate-activated protein kinase (AMPK) is the principal cellular energy sensor that coordinates metabolic adaptation by balancing anabolic and catabolic pathways in response to energic stress. Beyond its canonical role in maintaining energy homeostasis, AMPK has emerged as a central regulator of host–pathogen interactions by integrating lipid metabolism, autophagy, mitochondrial dynamics, oxidative stress, and innate immune signaling. Flaviviruses, including dengue virus, Zika virus, West Nile virus, Japanese encephalitis virus, and yellow fever virus, extensively remodel host metabolism to establish productive infection. As a master regulator of cellular metabolism, AMPK can either restrict or facilitate flavivirus replication in a context-dependent manner by regulating lipid droplet biogenesis, fatty acid synthesis and beta-oxidation, autophagy, mitochondrial homeostasis, and interferon-mediated antiviral responses. Conversely, flaviviruses actively manipulate AMPK signaling and its downstream metabolic networks to promote endoplasmic reticulum remodeling, replication organelle biogenesis, energy production, and immune evasion. In this review, we summarize recent advances in understanding the multifaceted roles of AMPK during flavivirus infection, with an emphasis on its regulation of metabolic reprogramming, organelle remodeling, and antiviral immunity. We further discuss the therapeutic potential of pharmacologically targeting AMPK and its downstream pathways as a host-directed strategy for broad-spectrum antiviral intervention against flaviviruses. Full article

Acanthamoeba keratitis is a severe, sight-threatening corneal infection caused by free-living amoebae widely distributed in soil, natural waters, and domestic or recreational water systems. Following entry into the corneal microenvironment, disease develops within a redox conflict in which host-derived reactive oxygen species (ROS) and reactive nitrogen species (RNS) may contribute to parasite control while simultaneously promoting inflammation and tissue injury. Acanthamoeba responds through an adaptable defense network involving superoxide dismutases, catalase, thioredoxin- and glutathione-dependent systems, peroxiredoxins, and mitochondrial mechanisms. However, most mechanistic evidence derives from in vitro trophozoite studies, whereas the contribution of individual redox pathways to mature cyst survival and persistence in the infected cornea remains poorly defined. This review critically integrates evidence on host oxidative and nitrosative responses, parasite antioxidant adaptation, bidirectional redox crosstalk, and redox-modulating therapeutic strategies. Current data support neither indiscriminate suppression nor uncontrolled amplification of reactive species. Instead, future interventions should achieve spatially, temporally, and stage-specifically controlled redox modulation that weakens parasite defenses while preserving corneal integrity and essential innate immune functions. Progress will require causal validation of redox targets, separate assessment of trophozoites and mature cysts, long-term excystation and regrowth assays, evaluation across clinical isolates and genotypes, and parallel assessment of host-cell toxicity in clinically relevant corneal models. Full article

The geographic range and outbreak intensity of vector-borne viral infections are increasing as climate, land use, urbanization, and human mobility reshape vector ecology and human exposure. Despite their growing importance to public health, effective antiviral and preventive options remain limited for many emerging and reemerging vector-borne viruses due to viral genetic diversity, rapid evolutionary capacity, sporadic outbreak patterns, and economic constraints. While these viruses differ in taxonomy, genome organization, vector specificity, tissue tropism, and clinical manifestations, they exploit a shared vulnerability in host antiviral defense, particularly the timing of innate antiviral immunity to support viral replication, immune evasion, inflammatory dysregulation, and disease progression. Rather than simply suppressing antiviral defense, vector-borne viruses can delay early viral nucleic acid sensing, attenuate interferon induction or responsiveness, and extend the initial phase for viral replication. As viral burden increases and infected tissues undergo stress or damage, delayed immune activation can shift toward excessive inflammatory amplification, contributing to disease-specific pathology. In this study, we examine this temporal rewiring of innate antiviral immunity in representative vector-borne viruses such as dengue virus, chikungunya virus, and severe fever with thrombocytopenia syndrome virus and propose that understanding these conserved host dependencies may lead to broader, stage-specific, adaptable antiviral strategies that complement conventional virus-directed approaches. Full article

Immune-mediated inflammatory diseases (IMIDs) arise from interactions among genetic susceptibility, epithelial barrier function, microbiota, diet, and other environmental exposures. Modern diets influence mucosal immunity not only through fibre intake, food processing, and microbiota composition, but also through a less explored exposure layer: plant-derived molecules with potential immune activity. Crop breeding, intensive agriculture, global trade, gluten-free substitutes, and plant-based food technologies have changed the spectrum, dose, concentration, and matrix in which plant defence proteins, antinutritional factors, endogenous toxicants, and novel plant antigens reach the intestinal surface. In this structured, hypothesis-generating narrative review, we propose dietary adjuvanticity as a mechanistic framework for considering how selected food-derived molecules may amplify mucosal immune responsiveness, modify antigen presentation, disturb barrier function, or lower tolerance thresholds without necessarily acting as classical autoantigens. The framework differs from general food-derived immunomodulation, nutritional exposomics, and diet-microbiota-host interaction models by focusing specifically on adjuvant-like immune amplification at the intestinal mucosa. The ASIA concept is used only in Shoenfeld’s functional sense, as an analogy for exogenous immune amplification through innate activation, danger signalling, bystander activation, epitope spreading, and loss of tolerance in susceptible hosts; it is not applied as a dietary diagnosis. Wheat amylase-trypsin inhibitors, gluten epitopes, lectins, potato glycoalkaloids, saponins, quinoa prolamins, emerging legume proteins, L-canavanine, and tolerance-promoting plant substrates are discussed with explicit separation of established clinical evidence, strong mechanistic evidence, preclinical/ex vivo evidence, and speculative disease-modifier hypotheses. Overall, plant-derived exposures are best interpreted as potential modifiers within the IMID exposome, not as primary causes of autoimmunity. Testing this model will require defined exposures, food-matrix and processing studies, biomarkers of barrier and immune activation, patient stratification, and controlled human studies. Full article

The red-spotted grouper nervous necrosis virus (RGNNV) exhibits high pathogenicity in larval C. sonnerati, yet the immune molecular mechanism remains unclear. Non-coding RNAs (ncRNAs) are vital in the host’s immune responses during viral infection. However, there has been no study on ncRNA research for this species to date. We systematically identified 105 DE microRNAs (miRNAs), 157 DE long non-coding RNAs (lncRNAs) and 31 DE circular RNAs between the infection group and control group. Functional enrichment analysis revealed that these differentially expressed genes were significantly enriched in pathways associated with innate immune defense, inflammatory, and cell death, such as JAK-STAT signaling pathway, NF-κB signaling pathway, apoptosis, and necroptosis. Furthermore, the lncRNA–miRNA–mRNA interaction network involving miR-93 was constructed, which may represent a promising candidate therapy target for future investigations. This study presents the first comprehensive ncRNA transcriptome dataset of C. sonnerati infected with RGNNV, identifies key antiviral defense and cell death-related genes and hub pathways, and thereby identifies miR-93-involved lncRNA–miRNA–mRNA network and key targeted genes (STAT1, TRIM25, UNC93B, IL12RB1, IRF8, CDKN1A, FCGR1A) as hub molecular regulators in immune response of this species. Full article

Immune checkpoint inhibitors targeting the PD-1 pathway have improved outcomes in advanced gastric cancer; however, substantial heterogeneity in treatment response remains. Current prediction strategies mainly rely on pretreatment biomarkers, which provide static assessments and may not capture the evolving interactions between tumor progression and host immunity. This study aimed to develop a dynamic prediction framework integrating longitudinal clinical trajectories and immune remodeling for continuous risk assessment during PD-1 inhibitor therapy. Methods: This retrospective study included 171 patients with gastric cancer receiving PD-1 inhibitor-based treatment. A landmark analysis framework was established using sequential 28-day follow-up windows to predict subsequent progressive disease (PD) or recurrence based on available clinical and immune information. Three nested models were developed: a baseline model (M0), a dynamic clinical model (M1), and an immune-integrated model (M2) incorporating longitudinal lymphocyte subset features. Model performance was evaluated using discrimination, calibration, and internal validation with patient-level resampling strategies. Results: Predictive performance improved progressively with incorporation of longitudinal information. The ROC AUC increased from 0.559 (95% CI, 0.429–0.690) in M0 to 0.737 (95% CI, 0.613–0.852) in M1 and 0.786 (95% CI, 0.681–0.883) in M2. Dynamic clinical information significantly improved discrimination compared with baseline prediction (ΔAUC = 0.178, p = 0.025), while additional immune features further enhanced risk stratification (ΔAUC = 0.049, p = 0.040). Interpretation analysis identified tumor burden evolution, neutrophil-to-lymphocyte ratio trajectories, and immune functional axes involving T-cell, innate cytotoxicity, and humoral immunity as major contributors to risk estimation. Landmark analyses demonstrated the feasibility of continuously updating PD/recurrence risk during treatment. Conclusions: This study establishes a dynamic landmark prediction framework integrating longitudinal clinical trajectories and immune remodeling for continuous risk assessment during PD-1 inhibitor therapy. Dynamic clinical and immune features provided complementary predictive information beyond baseline characteristics, supporting an adaptive approach for precision immunotherapy monitoring in gastric cancer. Full article

Trained immunity refers to the functional reprogramming of innate immune cells—such as monocytes, macrophages, and natural killer cells—those results in a modulated, and often heightened, response to secondary stimuli. This phenomenon challenges the traditional view that immunological memory is restricted to the adaptive immune system and has emerged as a concept linking host defense, vaccination, and inflammatory disease. This review synthesizes current evidence on the molecular basis of trained immunity, including chromatin remodeling, histone modifications, and metabolic rewiring, and examines how bacteria, viruses, and fungi induce, evade, or exploit these programs. The dual contribution of trained immunity to protective host defense and to immunopathology is discussed, along with its implications for vaccine design—including heterologous protection reported after BCG vaccination—and its potential as a therapeutic target in infectious and inflammatory disease. Key gaps, particularly the duration and reversibility of the trained state, the distinction between trained immunity and related processes such as innate tolerance, and the need for validated biomarkers, are highlighted, together with priorities for future translational research. Full article

Background: Butyrate is a microbiota-derived short-chain fatty acid with established roles in maintaining intestinal barrier integrity and regulating immune responses. Although its effects have been extensively investigated in immunocompetent models, systemic immune homeostasis in severely immunodeficient hosts remains incompletely understood. This exploratory study evaluated the impact of sodium butyrate (NaB) supplementation on tissue-associated microbial antigen detection and immune marker distribution along different organs in athymic nude mice. Methods: Female NU/J athymic mice were administered either regular drinking water (H₂O, n = 10) or NaB-supplemented water (150 mM, n = 5) for six weeks. Intestinal, liver, lung, and kidney tissues were collected for histopathological and immunohistochemical analyses. Expression of microbial antigens, including lipopolysaccharide (LPS) and lipoteichoic acid (LTA), as well as immune-associated markers (CD3, CD8a, CD68, CD278, and transglutaminase-2 [TGM2]), was assessed using a semiquantitative scoring system. Results: NaB supplementation did not significantly affect organ morphology but was associated with better weight gain. Histological examination revealed preserved tissue architecture in all organs, with only mild condensation of small intestinal crypts in NaB-treated mice. Immunohistochemical analysis showed consistently lower LPS expression in NaB-treated animals compared with controls in the small intestine, liver, and kidney, with a borderline reduction in the lungs. Reduced LPS detection was accompanied by significantly lower expression of the macrophage marker CD68 in the kidney. Conclusions: Oral NaB supplementation was associated with lower detection of bacterial antigens in tissues and reduced innate immune expression across multiple organs. These findings support a potential role for butyrate in limiting microbial expression and systemic inflammatory signaling in athymic mice. Full article

Acne vulgaris is a highly prevalent inflammatory skin condition involving the interaction between skin microbes and host immunity, which lead with the changes in composition and activities of the skin microbiota disturbing its homeostasis. Several probiotic strains have been tested for their anti-pathogenic activity against the main acne-responsible bacteria, their capacity to contrast pathogenic adhesion to HaCaT cells and the in vitro down-regulation of innate immunity. To investigate whether probiotics have direct effects on the growth of Cutibacterium acnes, Staphyloccoccus aureus, Streptococcus pyogenes and Streptococcus epidermidis, the antimicrobial activity of six probiotics was analyzed by two different methods (modified cross-streak and agar well diffusion). The in vitro blockage of pathogens’ adherence by the probiotic strains to HaCaT cells was also investigated, under three possible mechanisms: exclusion by adhered probiotics, displacement of adhered pathogens and competition for receptor sites. The inflammatory response was evaluated by the Luminex approach, targeting a selection of innate immune markers in the HaCaT cell culture media. All probiotic strains showed anti-pathogenic activity against the pathogens tested. The inhibition result on HaCaT cells highlights a significant (p < 0.05) competition of all probiotics against all pathogens. Each pathogenic strain alone led to an up-regulation of innate immune markers, while restoration of the microbiome diversity by probiotics presence may suppress inflammation via down-regulation of innate immunity. The results suggest that the tested probiotics could prevent colonization of the skin by relevant pathogens through barrier and interference mechanisms (mainly exclusion), suggesting a potential use in the future conventional therapies of skin disorders. Full article

Background/Objectives: Routine biomarkers and clinical scores do not directly assess functional immune responsiveness in suspected sepsis. We evaluated whether the TNF-α Release Assay (TARA), a whole-blood LPS-induced functional assay, is associated with an early cytokine-low immune phenotype in Emergency Department (ED) patients. Methods: In this prospective single-center cohort, adults with suspected sepsis and NEWS2 ≥ 3 were sampled at presentation, at 4 h and, when available, at 24 h. Immune phenotypes were defined independently of TARA by unsupervised k-means clustering of 12 circulating cytokines at 4 h, and a continuous Low-Response Cytokine Score (LRCS) was derived, with higher values indicating lower global cytokine concentrations. Results: Among 152 patients, three phenotypes were identified: C1 cytokine-low (n = 56), C2 inflammatory/intermediate (n = 63), and C3 IFN-γ/MCP-3/IL-17A-high (n = 33). Indicative TARA low-response status was independently associated with a higher LRCS after adjustment for clinical covariates and procalcitonin (PCT), both at presentation (β = 0.33; 95% CI, 0.14–0.53; p = 0.001) and at 4 h (β = 0.38; 95% CI, 0.19–0.57; p < 0.001). Indicative TARA low-response results at 4 h were most frequent in C1 and least frequent in C3 (75% vs. 45%). Exploratory clinical comparisons showed lower recorded early escalation in C1, whereas Sepsis-3 final diagnosis and in-hospital mortality were similar across phenotypes. Conclusions: A TARA low-response status was independently associated with an early circulating cytokine-low phenotype defined without reference to TARA or outcomes, providing information complementary to routine biomarkers and clinical severity scores. These exploratory findings support TARA as a complementary functional immune readout but require external validation and clinical-impact evaluation. Full article

Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), is a major infectious disease that poses a severe threat to the global swine industry. To investigate the role of miRNAs in the infection and susceptibility of PRRSV, four miRNA libraries were constructed and sequenced from PRRSV-infected and mock-infected of Tibetan pigs and Large White pigs at 7 days post-infection. A novel miRNA, miR-novel-80, was differentially expressed between PRRSV-infected and mock-infected porcine alveolar macrophages from 2 pig breeds. Importantly, the over-expression of miR-novel-80 inhibited the replication of a PRRSV-1 strain and multiple lineages (L1, L5, and L8) of PRRSV-2 strains in a dose-dependent manner. Bioinformatic predictions and experimental validation demonstrated that miR-novel-80 restricts viral replication through a dual antiviral mechanism. Directly, it targets the PRRSV nsp1-coding region within the ORF1a to suppress viral proliferation. Indirectly, miR-novel-80 specifically down-regulates the expression of host factor CXXC finger protein 4 (CXXC4). This reduction relieves the suppression of the Wnt/β-catenin signaling pathway, which in turn activates NF-κB-dependent innate immune responses to further inhibit PRRSV infection. Collectively, this study investigates the biological characteristics of miR-novel-80 and unveils its underlying molecular mechanisms in restricting PRRSV infection in vitro. However, its biological function and anti-PRRSV therapeutic effect in vivo need further investigation. Full article

The pet food industry is undergoing a significant transformation, driven by the growing trend of companion animal humanization and increasing concerns over the environmental sustainability of conventional protein and lipid sources. Consumers now seek diets that not only meet basic nutritional requirements but also offer preventive health benefits. Microalgae, including Arthrospira (Spirulina, a kind of cyanobacterium), Chlorella, Schizochytrium, and Euglena gracilis, have emerged as versatile biological platforms capable of addressing both functional and sustainability challenges. These microorganisms produce high-quality proteins, omega-3 long-chain polyunsaturated fatty acids (particularly docosahexaenoic acid, DHA), natural pigments, and immunomodulatory polysaccharides. This review synthesizes findings from peer-reviewed studies on the application of microalgae in pet nutrition, covering dogs, cats, and aquatic companion animals. We examine how algal ingredients influence gut microbiota, for instance, by enriching beneficial genera such as Turicibacter and Peptococcus, enhance vaccine responses and mucosal immunity, support cognitive function in aging pets, and contribute to weight management. Particular attention is given to Euglena gracilis and its paramylon (β-1,3-glucan), a pathogen-associated molecular pattern that engages the Dectin-1 pathway to train innate immunity and has demonstrated antiviral activity through host defense mechanisms. The review also surveys the patent landscape, highlighting trends in palatability enhancement, hypoallergenic formulations, and novel delivery formats. Key challenges remain, including ingredient standardization, safety validation, palatability optimization, and consumer acceptance. We outline a translational roadmap that prioritizes well-designed clinical trials in target species and processing methods that preserve bioactivity. Collectively, the evidence positions microalgae, and Euglena gracilis in particular, as promising candidates for next-generation functional pet foods that deliver health benefits alongside ecological sustainability. Full article

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma, also known clinically as gastric MALT lymphoma (GML) or MALToma, is an indolent B-cell neoplasm strongly associated with chronic Helicobacter pylori (H. pylori) infection. While early-stage disease is based on persistent antigenic stimulation and chronic inflammation, the metabolic and molecular transitions that drive monoclonal B-cell autonomy remain poorly understood. Importantly, H. pylori maintain this long-term colonization by defusing the host’s innate immunity; specifically, its lipid A portion features unique elongated acyl chains, composed of 16–18 carbon atoms, that fail to bind to and activate host TLR4/MD2 receptors, resulting in exceptionally weak endotoxic potency. Persistent colonization relies on key oncoproteins, particularly cytotoxin-associated gene A (CagA) and vacuolar cytotoxin A (VacA), which orchestrate early inflammatory infiltration (neutrophils, Th1, Th2 and Th17 cells) before shifting the microenvironment toward a suppressive regulatory T cell (Treg) phenotype. In this study, we propose a new critical step in the oncogenesis of gastric metastasis: chronic mitochondrial and immunometabolic adaptation within the gastric microenvironment. We claim that H. pylori act not only as a trigger for infection but also as a chronic driver of mitochondrial adaptation to oxidative stress and hypoxia, which subsequently results in defective mitophagy. CagA- and VacA-mediated mitochondrial damage induces reactive oxygen species (ROS) and functional hypoxia, stabilizing HIF-1α to force a glycolytic metabolic shift, while incomplete mitophagy rescues metabolically altered, apoptosis-resistant clones to drive monoclonal B-cell expansion. Within this ecological-microenvironmental framework, the predominantly cytoplasmic sequestration of BCL10 and the NF-κB subunit p65 observed in GML is reinterpreted not as evidence of signaling inactivity, but as a dynamically regulated adaptive state. This configuration is orchestrated by mitochondrial stress responses that enable adaptation to the chronic microenvironmental pressures imposed by H. pylori, acting in concert with the metabolic programs governed by MYC, NRF2, and BCL2. Overall, this review outlines the multi-step pathogenesis of H. pylori-mediated GML, highlighting how mitochondrial dysfunction and metabolic remodeling drive the transition from chronic infection to malignant transformation. Full article