Search Results (332)

Background/Objectives: Intramuscular immunization elicits systemic IgG and is the primary route of vaccine administration in humans. However, there is growing interest in utilizing other routes of administration to tailor antibody profiles, increase immunity at primary sites of infection, simplify administration, and eliminate needle waste. Here, we investigated the antibody profiles elicited by immunization with bacteriophage virus-like particle vaccine platforms at various routes of administration. Methods: We chose two model bacteriophage vaccines for investigation: bacteriophage MS2 virus-like particles (VLPs) recombinantly displaying a short, conserved peptide from Chlamydia trachomatis major outer membrane protein (MS2) and bacteriophage Qβ VLPs displaying oxycodone through chemical conjugation (Qβ). We comprehensively characterized the antibodies elicited systemically and at various mucosal sites when the vaccines were administered intramuscularly, intranasally or periocularly with or without an intramuscular prime using various prime/boost schemes. Results: Intranasal and periocular immunization elicited robust mucosal and systemic IgA responses for both MS2 and Qβ. The intramuscular prime followed by intranasal or periocular boosts elicited broad antibody responses, and increased antibodies titers at certain anatomical sites. Conclusions: These findings demonstrate the tractability of bacteriophage VLP-based vaccines in generating specific antibody profiles based on the prime–boost regimen and route of administration. Full article

Avian influenza A viruses (IAVs) pose a persistent threat to the poultry industry, causing substantial economic losses. Although traditional vaccines have helped reduce the disease burden, they typically rely on multivalent antigens, emphasize humoral immunity, and require intensive production. This study aimed to establish a genetically matched host–cell system to evaluate antigen-specific immune responses and identify conserved CD8+ T cell epitopes in avian influenza viruses. To this end, we developed an MHC class I genotype (B21)-matched host (Lohmann VALO SPF chicken) and cell vector (DF-1 cell line) model. DF-1 cells were engineered to express the hemagglutinin (HA) gene of clade 2.3.4.4b H5N1 either transiently or stably, and to stably express the matrix 1 (M1) and nucleoprotein (NP) genes of A/chicken/South Korea/SL20/2020 (H9N2, Y280-lineage). Following prime-boost immunization with HA-expressing DF-1 cells, only live cells induced strong hemagglutination inhibition (HI) and virus-neutralizing (VN) antibody titers in haplotype-matched chickens. Importantly, immunization with DF-1 cells transiently expressing NP induced stronger IFN-γ production than those expressing M1, demonstrating the platform’s potential for differentiating antigen-specific cellular responses. CD8+ T cell epitope mapping by mass spectrometry identified one distinct MHC class I-bound peptide from each of the HA-, M1-, and NP-expressing DF-1 cell lines. Notably, the identified HA epitope was conserved in 97.6% of H5-subtype IAVs, and the NP epitope in 98.5% of pan-subtype IAVs. These findings highlight the platform’s utility for antigen dissection and rational vaccine design. While limited by MHC compatibility, this approach enables identification of naturally presented epitopes and provides insight into conserved, functionally constrained viral targets. Full article

Background: Angiosarcomas (ASs) represent a heterogeneous and highly aggressive subset of tumors that respond poorly to systemic treatments and are associated with short progression-free survival (PFS) and overall survival (OS). The aim of this study was to develop and validate an immune-related prognostic model—termed the AS score—using data from two independent sarcoma cohorts. Methods: A prognostic model was developed using a previously characterized cohort of 25 angiosarcoma samples. Candidate genes were identified via the Maxstat algorithm (Maxstat v0.7-25 for R), combined with log-rank testing. The AS score was then computed by weighing normalized gene expression levels according to Cox regression coefficients. For external validation, transcriptomic data from TCGA Sarcoma cohort (n = 253) were analyzed. The Immunoscore—which reflects the tumor immune microenvironment—was inferred using the ESTIMATE package (v1.0.13) in R. All statistical analyses were performed in RStudio (v 4.0.3). Results: Four genes—IGF1R, MAP2K1, SERPINE1, and TCF12—were ultimately selected to construct the prognostic model. The resulting AS score enabled the classification of angiosarcoma cases into two prognostically distinct groups (p = 0.00012). Cases with high AS score values, which included both cutaneous and non-cutaneous forms, exhibited significantly poorer outcomes, whereas cases with low AS scores were predominantly cutaneous. A significant association was observed between the AS score and the Immunoscore (p = 0.025), with higher Immunoscore values found in high-AS score tumors. Validation using TCGA sarcoma cohort confirmed the prognostic value of both the AS score (p = 0.0066) and the Immunoscore (p = 0.0029), with a strong correlation between their continuous values (p = 2.9 × 10⁻⁸). Further survival analysis, integrating categorized scores into four groups, demonstrated robust prognostic significance (p = 0.00021). Notably, in tumors with a low Immunoscore, AS score stratification was not prognostic. In contrast, among cases with a high Immunoscore, the AS score effectively distinguished outcomes (p < 0.0001), identifying a subgroup with poor prognosis but potential sensitivity to immunotherapy. Conclusions: This combined classification using the AS score and Immunoscore has prognostic relevance in sarcoma, suggesting that angiosarcomas with an immunologically active microenvironment (high Immunoscore) and poor prognosis (high AS score) may be prime candidates for immunotherapy and this approach warrants prospective validation. Full article

Hypertension (HTN) is a major contributor to global morbidity and manifests in several variants, including salt-sensitive hypertension (SSHTN). SSHTN is defined by an increase in blood pressure (BP) in response to high dietary salt, and is associated with heightened cardiovascular risk, renal damage, and immune system activation. However, the role of granulocyte-macrophage colony-stimulating factor (GM-CSF) has not yet been explored in the context of SSHTN. Previously, we reported that GM-CSF is critical in priming bone marrow-derived (BMD)-macrophages (BMD-Macs) and BMD-dendritic cells (BMD-DCs) to become activated (CD38+) in response to salt. Further exploration revealed these cells differentiated into BMD-M1 Macs, CD38+ BMD-M1 Macs, BMD-type-2 conventional DCs (cDC2s), and CD38+ BMD-cDC2s. Additionally, BMD-monocytes (BMDMs) grown with GM-CSF and injected into SSHTN mice traffic to the kidneys and differentiate into Macs, CD38+ Macs, DCs, and CD38+ DCs. In the current study, we treated SSHTN mice with an anti-GM-CSF antibody (aGM) and found that preventive aGM treatment mitigated BP, prevented renal inflammation, and altered renal immune cells. In mice with established SSHTN, aGM treatment attenuated BP, reduced renal inflammation, and differentially affected renal immune cells. Adoptive transfer of aGM-treated BMDMs into SSHTN mice resulted in decreased renal trafficking. Additionally, aGM treatment of BMD-Macs, CD38+ BMD-M1 Macs, BMD-DCs, and CD38+ BMD-cDC2s led to decreased pro-inflammatory gene expression. These findings suggest that GM-CSF plays a role in SSHTN and may serve as a potential therapeutic target. Full article

Background: Vaccines that stimulate systemic and mucosal immunity to a level required to prevent SARS-CoV-2 infection and transmission are an unmet need. Highly protective hepatitis B and human papillomavirus nanoparticle vaccines highlight the potential of multivalent nanoparticle vaccine platforms to provide enhanced immunity. Here, we report the construction and characterization of self-assembling 60-subunit icosahedral nanoparticle SARS-CoV-2 vaccines using the bacterial enzyme lumazine synthase (LuS). Methods and Results: Nanoparticles displaying prefusion-stabilized SARS-CoV-2 spike ectodomains fused to the surface-exposed amino terminus of LuS were designed using structure-guided approaches. Negative stain-electron microscopy studies of purified nanoparticles were consistent with self assembly into 60-mer nanoparticles displaying 20 spike trimers. After two intramuscular doses, these purified spike-LuS nanoparticles elicited significantly higher SARS-CoV-2 neutralizing activity than spike trimers in vaccinated mice. Furthermore, intramuscular DNA priming and intranasal boosting with a SARS-CoV-2 LuS nanoparticle vaccine stimulated mucosal IgA responses. Conclusion: These data identify LuS nanoparticles as highly immunogenic SARS-CoV-2 vaccine candidates and support the further development of this platform against SARS-CoV-2 and its emerging variants. Full article

Powdery mildew caused by Sphaerotheca fusca poses a significant threat to cucumber (Cucumis sativus L.) production worldwide, underscoring the need for sustainable disease management strategies. This study investigates the potential of L-lysine, abundantly produced by Bacillus subtilis M 320 (BSM320), to prime systemic acquired resistance (SAR) pathways in cucumber plants. Liquid chromatography–mass spectrometry analysis identified L-lysine as the primary bioactive metabolite in the BSM320 culture filtrate. Foliar application of purified L-lysine significantly reduced powdery mildew symptoms, lowering disease severity by up to 92% at concentrations ≥ 2500 mg/L. However, in vitro spore germination assays indicated that L-lysine did not exhibit direct antifungal activity, indicating that its protective effect is likely mediated through the activation of plant immune responses. Quantitative reverse transcription PCR revealed marked upregulation of key defense-related genes encoding pathogenesis-related proteins 1 and 3, lipoxygenase 1 and 23, WRKY transcription factor 20, and L-type lectin receptor kinase 6.1 within 24 h of treatment. Concurrently, salicylic acid (SA) levels increased threefold in lysine-treated plants, confirming the induction of an SA-dependent SAR pathway. These findings highlight L-lysine as a sustainable, residue-free priming agent capable of enhancing broad-spectrum plant immunity, offering a promising approach for amino acid-based crop protection. Full article

Obesity and pediatric fatty liver disease are increasingly prevalent, yet the underlying mechanisms linking these conditions to heightened inflammatory and immune responses remain poorly understood. Using a murine model reflecting early-life obesity and hepatic steatosis, we tested the hypothesis that obesity-driven hepatic inflammation intensifies systemic immune responses and exacerbates vascular dysfunction following innate immune activation. Newly weaned C57BL/6 mice were fed either a high-saturated-fat, high-cholesterol diet (HFD) or a control diet (CD) for four weeks, modeling adolescence in humans. HFD-fed mice exhibited hepatic and splenic enlargement, elevated plasma cholesterol levels, increased activity levels of liver enzymes (alanine and aspartate aminotransferases), and higher plasma serum amyloid A (SAA) concentrations. Following a sublethal dose of lipopolysaccharide (LPS), the expression of hepatic inflammatory genes (VCAM-1 and iNOS) was significantly elevated in HFD-fed mice, indicating an exaggerated local immune response. Mice fed an HFD also showed significant impairment in endothelium-dependent vasorelaxation compared to CD mice and saline-treated controls, while endothelium-independent responses remained intact. These vascular changes occurred in the context of hepatic inflammation, suggesting that early-life diet-induced steatosis sensitizes the vasculature to inflammatory insult. These findings suggest that obesity-driven hepatic inflammation primes exaggerated systemic immune responses to innate immune stimuli, potentially contributing to the vascular dysfunction and variable clinical morbidity observed in pediatric inflammatory conditions. Full article

Although vaccine development has primarily focused on inducing neutralizing antibodies, increasing evidence supports an important role of CD8⁺ T cell responses in vaccine effectiveness. Routine assays, which are mainly based on antibody titers, may therefore not accurately reflect the full immune response elicited by vaccination. Assessing antigen-specific T cell responses upon vaccination poses several challenges. A common issue in studying T cells specific to a vaccine antigen is their low frequency in circulation, which can limit their ex vivo analysis. Moreover, the use of human cell-based models is crucial for studying and optimizing the induction of T cell responses to design effective vaccines. We developed an innovative in vitro approach of human CD8⁺ T cell priming, based on the rapid mobilization of dendritic cells (DCs) directly from unfractionated peripheral blood mononuclear cells (PBMCs). This simple and original method allows for side-by-side comparisons of multiple test parameters in a standardized system, providing both quantitative and qualitative readouts of primed antigen-specific CD8⁺ T cells. Here, we discuss the genesis of this approach and its versatile applications, including monitoring antigen-specific T cell responses, evaluating an individual’s T cell priming capacity, and conducting preclinical studies on potential adjuvants and vaccine candidates. Full article

Exposure to chronic stress creates vulnerability to drug misuse and presents a barrier to sustained recovery for many individuals experiencing substance use disorders (SUDs). Preclinical literature demonstrates that stress modulates psychostimulant intake and seeking, yet there are wide gaps in our understanding of the specific mechanisms by which stress promotes brain changes that may govern addiction-related behaviors. Recent data suggest that microglia, innate immune cells in the central nervous system, are highly responsive to chronic stressors, and several mechanistic links have been explored highlighting the critical role microglia play in stress-related brain adaptation. Importantly, psychostimulants may engage similar microglial machinery, which opens the door for investigation into how microglia may be involved in shaping motivation for psychostimulants, especially in the context of stress exposure. The aims of this review are threefold: 1. Offer a brief overview of microglial biology in the adult brain. 2. Review current methods of interrogating microglial function with a focus on morphometric analyses. 3. Highlight preclinical research describing how microglia contribute to brain changes following chronic stress and/or psychostimulant exposure. Ultimately, this review serves to prime investigators studying the intersection of stress and SUDs to consider the relevant impacts of microglial actions. Full article

Mycobacterium bovis is the causative pathogen of bovine tuberculosis (bTB), a disease that affects cattle and other mammals, including humans. Currently, there is no efficient vaccine against bTB, underscoring the need for novel immunization strategies. The M72 fusion protein, composed of three polypeptides derived from Mycobacterium tuberculosis and M. bovis, has demonstrated protective efficacy against M. tuberculosis in clinical trials when combined with the AS01E adjuvant. Given the established efficacy of nanocapsule formulations as vaccine delivery systems, this study evaluated a novel immunization strategy combining BCG with either full-length M72 or a truncated M72 fused to a streptococcal albumin-binding domain (ABDsM72). Both antigens were encapsulated in chitosan/alginate nanocapsules and assessed in a murine M. bovis challenge model. Priming with BCG followed by an M72 boost significantly improved splenic protection compared to BCG alone, but it did not enhance pulmonary protection. Notably, boosting with ABDsM72 further increased the proportion of CD4+KLRG1-CXCR3+ T cells in the lungs of M. bovis-challenged mice, a key correlate of protective immunity. These findings demonstrate that chitosan/alginate-encapsulated antigens enhance BCG-induced immunity, supporting their potential as next-generation vaccine candidates for bTB control. Full article

Inflammation is a crucial component of the immune response essential for host defense and tissue repair. However, when the immune response becomes dysregulated, it can contribute to the pathogenesis of chronic diseases. While acute inflammation is a short-lived, protective response, chronic inflammation is sustained over time and can lead to immune dysfunction, tissue damage, and disease progression. The chronic inflammation theory of disease suggests that persistent immune activation/inflammation underlies both infectious and non-infectious conditions and serves as a unifying mechanism across distinct pathological states. In this review article, we argue that human immunodeficiency virus (HIV) infection represents a prime model for studying chronic inflammation, and that despite effective viral suppression with antiretroviral therapy (ART), people living with HIV (PLWH) exhibit persistent immune activation, systemic inflammation, and an increased risk of cardiovascular, metabolic, and neurodegenerative diseases. Here, the interplay between microbial translocation, immune dysregulation, and metabolic reprogramming fuels a state of chronic inflammation that accelerates disease progression beyond HIV itself. Key factors such as T-cell exhaustion, persistent monocyte/macrophage activation, and immunometabolic dysfunction contribute to such a sustained inflammatory state. This review explores the molecular and cellular mechanisms driving chronic inflammation in HIV infection with a focus on immunometabolism and its implications for broader inflammatory diseases. By understanding such pathways, we can identify novel therapeutic targets to mitigate inflammation-driven disease progression not only in HIV but across a spectrum of chronic inflammatory conditions. Full article

Microglia, the resident immune cells of the central nervous system (CNS), play essential roles in maintaining brain homeostasis. While transient activation is protective, chronic microglial reactivity contributes to neuroinflammatory damage and neurodegeneration. The mitochondrial mechanisms underlying this shift remain poorly understood. Here, we investigated whether lipopolysaccharide (LPS) induces coordinated mitochondrial and metabolic alterations in BV-2 microglial cells. LPS stimulation (100 ng/mL, 24 h) induced a reactive phenotype, with increased Iba1 (+82%), F4/80 (+132%), and Cd68 (+44%), alongside elevated hydrogen peroxide (~6-fold) and nitrite (~45-fold). Cytotoxicity increased by 40% (LDH assay), and cell viability dropped to ~80% of the control (MTT). Extracellular lactate increased, indicating glycolytic reprogramming. However, LPS-primed cells showed greater ATP depletion under antimycin A challenge, reflecting impaired metabolic flexibility. Hoechst staining revealed a ~4-fold increase in pyknotic nuclei, indicating apoptosis. Mitochondrial dysfunction was confirmed by a 30–40% reduction in membrane potential (TMRE, JC-1), a ~30% loss of Tomm20, and changes in dynamics: phospho-Drp1 increased (+23%), while Mfn1/2 decreased (33%). Despite a ~70% rise in Lamp2 signal, Tomm20–Lamp2 colocalization decreased, suggesting impaired mitophagy. High-resolution respirometry revealed decreased basal (−22%), ATP-linked (24%), and spare respiratory capacity (41%), with increased non-mitochondrial oxygen consumption. These findings demonstrate that LPS induces mitochondrial dysfunction, loss of metabolic adaptability, and increased apoptotic susceptibility in microglia. Mitochondrial quality control and energy flexibility emerge as relevant targets to better understand and potentially modulate microglial responses in neuroinflammatory and neurodegenerative conditions. Full article

The rapid expansion of aquaculture is vital for global food security, yet it faces persistent threats from disease outbreaks, vaccine inefficacy, and antibiotic overuse, all of which undermine sustainability. Conventional vaccines often fail to induce robust mucosal immunity, spurring interest in probiotics as adjuvants to enhance immunogenicity. Probiotics such as Bacillus subtilis and Lactobacillus casei modulate fish microbiomes, fortify mucosal barriers, and activate innate immune responses via mechanisms including Toll-like receptor signaling and cytokine production. These actions prime the host environment for prolonged adaptive immunity, improving antigen uptake and pathogen clearance. Experimental advances—such as Bacillus subtilis-engineered spores increasing survival rates to 86% in Vibrio anguillarum-challenged European seabass—demonstrate the potential of this synergy. Innovations in delivery systems, including chitosan–alginate microcapsules and synbiotic formulations, further address oral vaccine degradation, enhancing practicality. Probiotics also suppress pathogens while enriching beneficial gut taxa, amplifying mucosal IgA and systemic IgM responses. However, challenges such as strain-specific variability, environmental dependencies, and unresolved ecological risks persist. Optimizing host-specific probiotics and advancing multi-omics research is critical to unlocking this synergy fully. Integrating probiotic mechanisms with vaccine design offers a pathway toward antibiotic-free aquaculture, aligning with One Health principles. Realizing this vision demands interdisciplinary collaboration to standardize protocols, validate field efficacy, and align policies with ecological sustainability. Probiotic–vaccine strategies represent not merely a scientific advance but an essential evolution for resilient, ecologically balanced aquaculture systems. Full article

Many stressors contribute to productivity and quality losses in agricultural production, ranging from the rising global population to shrinking agricultural lands. To boost yield and quality, plants must be protected from abiotic and biotic stressors. Seed priming is the process of boosting germination and seedling development by treating seeds with particular pre-treatments before germination. Seed priming is used to improve plant yield and germination. Plant defense elicitors stimulate the plant’s natural immune system when administered externally, strengthening the plant and making it more resistant/tolerant to diseases. β-Aminobutyric Acid (BABA) is a plant defense elicitor, and in this study, the effect of BABA seed priming on Clavibacter michiganensis ssp. michiganensis (Cmm), which causes bacterial cancer in tomato (Solanum lycopersicum L.), was investigated. Tomato seeds were subjected to seed priming for 72 h with 12 mM BABA (BABA priming) or water (water priming) as the control group. Tomato seedlings that germinated normally were utilized as a positive control. When the plants reached the 3–4 leaf stage, they were infected with Cmm. According to the data, BABA priming was the most effective experimental group in reducing disease severity. Furthermore, it has been shown that the use of BABA as a spray or water-priming application gives better protection than the control treatment. To understand the molecular basis of this suppression, plant samples were obtained at two separate time points (0th and the 7th day), and transcriptional changes of essential plant immunity genes (NPR1, PAL, PR1, WRKY70, WRKY33b, TPK1b, and PR5) were studied. The qRT-PCR results showed that NPR1 gene expression increased considerably with the BABA priming treatment compared to the control. BABA priming at the 0th hour enhanced NPR1 gene expression by approximately five times. In addition, BABA priming increased PR1 gene expression. Furthermore, foliar spraying of BABA (BABA priming+BABA-Sp) on seed-primed plants resulted in a nine-fold increase in PR1 gene expression. At day 7, the BABA priming+Cmm treatment increased PR5 gene expression. Along with the control of other genes, the molecular architecture of BABA seed priming has been attempted to be discovered. The application of BABA seed priming is expected to contribute to the literature and have favorable impacts on plant protection against Cmm. Full article

Parkinson’s disease (PD) is a neurodegenerative disorder primarily defined by the deterioration of motor function and characterized by the loss of dopaminergic neurons in the nigrostriatal system. Although it is the second most prevalent disorder of the central nervous system, current treatments primarily focus on symptom management and modestly slowing disease progression, ultimately failing to preserve the long-term quality of life of a substantial proportion of affected individuals. Innovative therapies that can restore neuronal function have emerged, such as the use of the secretome of Mesenchymal Stem Cells (MSCs) due to their rich composition of bioactive molecules. This therapy exhibits robust paracrine activity that drives most of the self-renewal capacity, differentiation potential, and immune regulation of MSCs without presenting compatibility issues often associated with stem cell-based therapies. While conceptually appealing, the clinical application of this approach is still limited by the availability and proliferation capacity of MSCs, as it impacts not only secretome production but also its quality. Various protocols have been developed to enhance secretome action by adding various compounds to cell culture media, given the high environmental plasticity of MSCs. Some of the compounds already used are Caloric Restriction Mimetics (CRMs), molecules that mimic Caloric Restriction (CR) conditions, which have been demonstrated to extend lifespan and reduce age-related diseases in various organisms. While not sufficient to cure neurodegenerative disorders, these compounds may potentiate secretome efficiency by enhancing autophagy pathways and relieving oxidative stress burden from MSCs. Therefore, in this article, we aim to explore the effects of CRMs priming on MSCs and how it may help bridge existing gaps in regenerative therapies for PD. Full article