Search Results (2,156)

Leishmaniasis is caused by parasitic protozoans of the Leishmania genus and has been classified as a Neglected Tropical Disease. Control of this parasite relies mainly on chemotherapy; however, conventional available drugs are unsatisfactory. Phytomedicine, particularly essential oils, is a promising alternative. In this study, the chemical composition and antileishmanial properties of essential oil from leaves of Schinus terebinthifolia Raddi (EO-St) were determined. Chemical components were identified by GC-MS. Antileishmanial activity on promastigotes of L. amazonensis was assayed, followed by the evaluation of the essential oil’s effects on the mitochondrial membrane potential and redox state of the parasite. Finally, the activity was confirmed on intracellular amastigotes and compared with cytotoxicity on peritoneal macrophages from BALB/c mice. In the essential oil, 78 compounds were identified. The major component was δ-3-carene with 14.8%. The IC₅₀ values of 18.2 ± 1.4 µg/mL and 15.0 ± 1.6 µg/mL against promastigote and amastigote forms, respectively, were obtained. The cytotoxicity for the host cells was approximately four-fold higher than those for the parasite. The essential oil was able to cause a disruption in the mitochondrial membrane potential. The quantified redox parameters showed statistical differences (p < 0.05) between EO-St-treated cultures and control groups (untreated and treated with DMSO). In summary, EO-St was active in vitro against both forms of L. amazonensis, possible mediated by mitochondrial dysfunction and redox imbalance. Full article

Background/Objectives: Hand, foot, and mouth disease (HFMD) is a major public health concern primarily caused by human enterovirus A71 (EV-A71), coxsackievirus A16 (CVA16), coxsackievirus A6 (CVA6), and certain coxsackievirus B serotypes. Currently available EV-A71 vaccines lack cross-protective efficacy against other serotypes, highlighting the urgent need for multivalent and broadly effective enterovirus vaccines. Methods: Immunoinformatics approaches were used to predict highly immunogenic B-cell and T-cell epitopes, which were assembled to construct a novel multivalent epitope vaccine, rCV-A3V, followed by in silico validation. Recombinant protein expression was confirmed by Western blotting and immunofluorescence assays. The immunogenicity was evaluated in Balb/c mice following intranasal immunization. Results: A preliminary safety evaluation demonstrated that the rCV-A3V vaccine was well tolerated in the mouse model, with no abnormal changes in body weight observed after immunization. In addition, the target protein was successfully expressed. Intranasal immunization induced a strong Th1-biased immune response, robust serum neutralizing and IgG antibody responses, and pronounced mucosal immunity, including elevated sIgA and IgG levels in nasal lavage fluid, sIgA in feces, and substantial sIgA responses in milk. Dominant epitope peptides were also identified. Conclusions: The intranasal live attenuated rCV-A3V vaccine successfully induced humoral, mucosal, and cellular immune responses against EV-A71, CVA16, CVA6, and CVB3, demonstrating broad immunogenicity. These findings provide experimental evidence supporting its potential as a candidate vaccine for HFMD. Full article

Background: Exercise modulates the immune system and may enhance anti-cancer activity, offering potential synergy with cancer immunotherapy. Tumours with low immune cell infiltration (“cold” tumours) often respond poorly to immunotherapy and are associated with poor prognosis. Here, we demonstrate that exercise can reshape the immune landscape of tumours across the cold spectrum. Methods: C57BL/6 mice underwent orthotopic implantation of PANC02 (murine pancreatic adenocarcinoma) cells and BALB/c mice underwent intraperitoneal injections of AB-1 (murine mesothelioma) cells. Mice were then divided into groups; exercise with anti-Programmed Cell Death Protein 1 (PD-1), exercise with isotype, no exercise with anti-PD-1 and no exercise with isotype. Treadmill-running was performed for 20 min/day, 4 days/week at a speed of 12 metres/minute. Resistance training consisted of hanging upside down on a wire-mesh screen for 1 min 2 days/week. Flow cytometry was used to measure TME immune populations. Tumour and liver samples were harvested, paraffin wax-embedded/sectioned and analysed using SlideViewer 2.9.0™. A total of 22 healthy volunteers underwent a single bout of high-intensity interval cycling. Blood was collected pre- and post-exercise. Flow cytometry was used to measure leucocyte subpopulations. MSTO-211H (mesothelioma) and PANC-1 (pancreatic cancer) cells were cultured with pre- and post-exercise serum, with/without HSV1716, and viability determined using alamarBlue^®. PANC-1 apoptosis and migration were assessed using caspase-3/7 and scratch assays, respectively. Results: In an orthotopic pancreatic cancer mouse model, combining exercise with immunotherapy significantly increased tumour necrosis and reduced metastatic potential. In both pancreatic cancer and mesothelioma models, this combination remodelled the tumour microenvironment, enhancing cytotoxic CD8⁺ T cell infiltration, upregulating Programmed Cell Death Protein 1 (PD-1), and reducing Myeloid-Derived Suppressor Cells and regulatory T cells (Tregs). Complementary human studies revealed an acute systemic release of Natural Killer cells and a reduction in Tregs following high-intensity interval exercise in healthy volunteers. Moreover, exercise-conditioned serum from these participants exerted anti-cancer effects on pancreatic cancer and mesothelioma cell lines. Conclusions: Altogether, these findings highlight exercise as a promising adjunct to immunotherapy for poorly immunogenic cancers such as pancreatic cancer and mesothelioma. Full article

Background: Coxsackievirus B2 (CVB2) causes a range of diseases, including hand, foot, and mouth disease; myocarditis; acute flaccid paralysis; meningitis; and encephalitis. However, no specific antiviral drugs or vaccines are currently available for CVB2. Methods: We used plaque purification, virus titre determination, and serial passaging to screen and identify an inactivated CVB2 vaccine candidate strain, KM31-C05, which exhibited high viral titres and good genetic stability. Comprehensive biological characterization of this candidate strain was performed, including phylogenetic analysis, virulence assessment in BALB/c mice, one-step growth curve analysis, optimization of the multiplicity of infection, as well as determination of viral load, pathological evaluation, and immunohistochemical analysis in tissues of BALB/c suckling mice post-challenge. An experimental inactivated vaccine was prepared using KM31-C05 to evaluate its immunogenicity and protective efficacy. Results: The viral titres of KM31-C05 reached 10⁸ CCID50/mL. After 20 serial passages, only three amino acid mutations were identified (VP3-G165V, VP1-N84K, and VP1-D129N). Although the two VP1 mutations were located in surface-exposed loops, the strain maintained high neutralizing titres across passages, indicating good genetic stability. However, whether these sites affect virulence and replication requires further investigation. Phylogenetic analysis revealed that this strain belonged to genotype C, which is consistent with the strains circulating in mainland China in recent years. The experimental inactivated vaccine prepared from KM31-C05 induced effective neutralizing antibodies (1:128–1:256) in BALB/c mice and provided complete protection to suckling mice against lethal challenge with this CVB2 strain in maternal antibody protection experiments. Conclusions: KM31-C05 demonstrates potential as a CVB2 vaccine candidate in China and provides a theoretical basis for the development of a CVB2 vaccine. Full article

Objectives: Interstitial lung disease (ILD) is a major cause of morbidity and mortality in patients with systemic sclerosis (SSc). This study aimed to evaluate interobserver variability and the relationship between lung ultrasonography (LUS) findings and histological fibrosis severity in a bleomycin (BLM)-induced mouse model of SSc. Materials and Methods: Twenty female BALB/c mice were randomly assigned to a control group (n = 10) or a BLM-treated group (n = 10). Pulmonary fibrosis was induced by daily subcutaneous administration of BLM for three weeks. Two blinded observers (a radiologist and a rheumatologist) performed LUS using a high-frequency linear probe and calculated scores based on B-line distribution. Lung fibrosis was evaluated by Masson’s trichrome staining and quantified using the Ashcroft scoring system. Interobserver agreement was assessed with Cohen’s kappa, and correlations were analyzed using Spearman’s rank test. Results: Control mice exhibited normal lung architecture, whereas all BLM-treated mice developed moderate to severe fibrosis, with significantly higher Ashcroft scores. LUS revealed multiple B-lines, pleural irregularities, and loss of A-lines in BLM-treated mice. LUS scores were considerably higher in the BLM group (p < 0.001). Radiologist-assessed scores showed a strong correlation with Ashcroft scores (ρ = 0.78), while rheumatologist-assessed scores demonstrated a moderate correlation (ρ ≈ 0.62). Interobserver agreement was moderate, with discrepancies mainly in intermediate fibrosis stages. Conclusions: LUS is a useful non-invasive method for semiquantitative assessment of pulmonary fibrosis in this SSc model. Its correlation with histological severity supports clinical relevance, while moderate interobserver variability highlights the need for standardized protocols and training. Full article

According to the World Health Organization, antibiotic research remains insufficient, emphasizing the urgent need for new active molecules, particularly against resistant bacteria. Based on known antibacterial scaffolds, new fluoroquinolone derivatives have been synthesized by our research group, including compound 7a, a difluoroboranyl-fluoroquinolone that previously demonstrated activity against sensitive strains. Methods: The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of compound 7a were determined against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli. The selective development of ciprofloxacin-resistant S. aureus was induced by reseeding the isolate on seven consecutive days with an antibiotic concentration that was not capable of inhibiting its development. Pharmacokinetic and toxicological properties were predicted using SwissADME, Way2Drug, and molecular docking (AutoDock Vina). In vivo toxicity was evaluated in BALB/c mice through histopathological liver and kidney analysis and serum biochemical markers. The antibacterial efficacy of 7a (80 mg/kg/day) was assessed in a murine pneumonia model induced by ciprofloxacin-resistant S. aureus. DNA gyrase inhibition was confirmed through plasmid electrophoresis assays in E. coli DH5-α cells. Results: Compound 7a exhibited both MIC and MBC values of 0.25 μg/mL, while ciprofloxacin-resistant S. aureus strains did not exhibit a detectable MIC within the concentration range tested (up to 1024 μg/mL). In silico predictions revealed favorable ADME profiles, low toxicity, and strong interaction with DNA gyrase. In vivo, 7a showed no signs of hepatotoxicity or nephrotoxicity and effectively reduced pneumonic tissue to 1.99% in infected mice. Electrophoretic assays confirmed DNA gyrase inhibition consistent with the mechanism of fluoroquinolones. Conclusions: Compound 7a evidenced activity against ciprofloxacin-resistant S. aureus in vitro and reduced infection progression in vivo. It also displays favorable drug-like properties, low predicted toxicity, and DNA gyrase inhibition. Full article

Background: The global spread of monkeypox virus (MPXV) highlights an urgent need for thermostable and easily administrable vaccines. Current orthopoxvirus vaccines are limited by cold-chain dependence and inconvenient injection-based delivery. Objectives: This study aimed to develop a dissolvable microneedle (DMN) vaccine against monkeypox based on a replication-deficient orthopoxvirus platform, through systematic formulation screening, stabilization mechanism exploration, and rigorous in vivo immunogenicity evaluation. Methods: A film-based approach was adopted for efficient, high-throughput formulation screening and thermostability assessment. NTV was mixed with excipients and dried into solid films. Stability was monitored via RT-qPCR after storage at 4 °C to 40 °C. The lead formulation was physically characterized, then used to fabricate MVA-BN-loaded DMN patches, which were further evaluated for in vivo immunogenicity via immunization in BALB/c mice. Results: The optimal formulation F2 (containing dextran, L-threonine, and BSA/HSA) showed a potency loss of only ~1 log₁₀ after 2 months at 25 °C, and <1 log₁₀ loss after 1 week at 37 °C. SEM revealed a porous virus-entrapment morphology, and FTIR indicated enhanced hydrogen bonding between the virus and the dextran matrix. The formulation was successfully manufactured into DMNs that dissolved within 5 min. In mice, these DMNs elicited robust MPXV-specific IgG and neutralizing antibody responses, with immunogenicity comparable to that induced by conventional intramuscular injection. Conclusions: This study successfully established a thermostable formulation and dissolvable microneedle delivery platform for replication-deficient orthopoxvirus vaccines against monkeypox. The optimized DMN vaccine induced robust MPXV-specific immune responses in mice with immunogenicity comparable to intramuscular injection, addressing the core limitations of current vaccines and providing a promising solution for monkeypox prevention. Full article

Background/Objectives: Multidrug-resistant (MDR) Acinetobacter baumannii (Ab) has emerged as a significant bacterial pathogen responsible for nosocomial infections. The most common clinical manifestations of Ab infection include ventilator-associated pneumonia and catheter-related bloodstream/urinary infections. Given the extensive MDR phenotype of Ab, preventive vaccination strategies are crucial for protecting susceptible populations. Methods: We utilized immunoinformatics to identify candidate peptides containing both putative B- and T-cell epitopes from proteins associated with Ab pathogenesis. Subsequently, we designed novel Acinetobacter Multi-Epitope Vaccines (AMEVs), each comprising an Ab thioredoxin A (TrxA) leader protein, five to seven of the identified peptide antigens, and a C-terminal His(6x)-tag to facilitate protein purification. Results: Subcutaneous vaccination of C57BL/6 mice with AMEV1 or AMEV2, formulated with TiterMax adjuvant, conferred 60% and 80% protection, respectively, against intraperitoneal Ab challenge. AMEV vaccination induced a robust antibody response to each corresponding whole protein and most of its component peptides. We then constructed an improved vaccine, AMEV5, which included the Ab TrxA protein and seven confirmed B-cell epitope peptides. Subcutaneous immunization of BALB/c mice (n = 10 per group) with rAMEV5 emulsified in Adda03 adjuvant activated antigen-specific IL-5-secreting T cells and antibody-producing B cells. Evaluation of vaccine efficacy demonstrated that AMEV2- and AMEV5-immunized mice were protected from a lethal intraperitoneal Ab challenge, with survival rates of 70% and 90%, respectively. Conclusions: These study results provide insights into the application of reverse vaccinology to combat the rise of MDR Acinetobacter infection. Full article

Background/Objectives: Chimpanzee adenoviral-vectored vaccines have proven to be both safe and effective, with a manufacturing and distribution pipeline capable of rapid global supply, as demonstrated during the COVID-19 pandemic. Yellow fever is a mosquito-borne viral hemorrhagic disease endemic in parts of Africa and Latin America, and although an effective live attenuated vaccine exists, its use is limited by safety and eligibility restrictions. Moreover, large outbreaks continue to expose critical challenges, such as an insufficient vaccine supply, reliance on fractional dosing, and slow and difficult-to-scale manufacturing processes. Here, we report the design, development and in vivo immunogenicity of multiple yellow fever virus (YFV) antigen constructs based on the pre-membrane (prM) and envelope (E) proteins—with or without the transmembrane domain (TM or ΔTM)—delivered using the ChAdOx1 adenoviral vector. Methods: Four ChAdOx1 YF vaccines were developed, and immunogenicity was evaluated. The efficacy of the full-length YF envelope vaccine was also tested in Balb/c mice. Results/Conclusions: In contrast to previously described orthoflavivirus vaccines on the same platform, the full-length antigen elicited superior immunogenicity and conferred protection against intracranial challenge with the YF17D virus in mice. Notably, this protection was comparable to that induced by the licensed YF17D vaccine, highlighting the promise of this platform as a next-generation yellow fever vaccine candidate. Full article

To compare the respiratory lesions and nervous system damage in cotton rats and BALB/c mice following respiratory syncytial virus (RSV) infection, and to evaluate their suitability as models for RSV-related respiratory and nervous system diseases, cotton rats and BALB/c mice were infected with RSV via intranasal instillation, monitored daily for weight and temperature. At 3, 5, and 7 days post-infection (dpi), viral loads in the nasal turbinates, lungs, and brain tissues were quantified. Pathological changes and neuroinflammatory responses in the lungs and brain were assessed using hematoxylin and eosin (H&E) staining, Nissl staining, immunofluorescence, and Western blotting analysis, while the mRNA expression levels of inflammatory factors were specifically analyzed at 5 dpi. The results showed that viral loads in the nasal turbinates and lungs of cotton rats were significantly higher than those in BALB/c mice, accompanied by more extensive pulmonary inflammatory factor gene upregulation at 5 dpi and more pronounced lung histopathological alterations. In contrast, RSV RNA and antigens were detected in the brain tissues of BALB/c mice, at levels markedly lower than those in respiratory tissues, along with viral antigens primarily localized to the choroid plexus epithelium. No significant pathological or neuroinflammatory changes were observed in the brains of cotton rats at any examined time point. In conclusion, cotton rats provide advantages for modeling RSV-associated respiratory tract infection and pulmonary pathology, whereas under the experimental conditions of this study, BALB/c mice may be more appropriate for investigating RSV-associated CNS inflammatory responses, although the clinical relevance of these findings remains to be further validated. Full article

Background: Porcine epidemic diarrhoea virus (PEDV) is a highly contagious pathogen causing severe diarrhoea and high mortality in neonatal piglets. Methods: In this study, consensus sequences encoding the N-terminal domain of spike subunit 1 (S1-NTD) and nucleocapsid (N) protein of PEDV were cloned into a eukaryotic expression vector pJHL204 and transformed into an attenuated Salmonella Typhimurium strain JOL2500. Antigen expression was confirmed by Western blot and immunofluorescence analyses. The recombinant strains were evaluated in vivo for safety, persistence, and immunogenicity. Immunogenicity was characterised by measuring antibody response, virus neutralising assays, cytokine profiling, and flow cytometric analysis of T cell subpopulation. Protective efficacy against salmonellosis in dams and passive transfer of neutralising antibodies to suckling mice were evaluated. Results: Vaccinated mice exhibited no adverse effects or bacterial persistence in major organs, confirming the vaccine’s safety. Immunisation elicited robust PEDV- and Salmonella-specific humoral and cell-mediated immune responses. Upon Salmonella challenge, vaccinated mice showed significantly reduced bacterial loads in splenic tissues. Furthermore, vaccinated dams and their offspring induced detectable anti-PEDV neutralising antibodies, indicating successful passive antibody transfer. Conclusion: Our findings indicate that the designed vaccine constructs provide a promising platform for inducing multifaceted immuno-protectivity against PEDV and salmonellosis. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by epidermal barrier dysfunction and dysregulated immune responses, particularly an imbalance between T helper type 1 (Th1) and type 2 (Th2) cytokines. Natural products with immunomodulatory activity have attracted increasing attention as potential strategies for regulating allergic inflammation. In this study, we investigated the immunomodulatory effects of bioprocessed black rice bran (BRB-F) and bioprocessed balloon flower root (BFR-F). In vitro assays using human B cells, mast cells, and keratinocytes were conducted to evaluate IgE production, mast cell degranulation, and epithelial inflammatory mediator release. The efficacy of the BRB-F:BFR-F mixture was further evaluated in BALB/c mice with 2,4-dinitrochlorobenzene (DNCB)/Dermatophagoides farinae extract (DFE)-induced AD-like dermatitis. BRB-F and BFR-F suppressed IgE production, attenuated mast cell degranulation and thymic stromal lymphopoietin (TSLP) release, and reduced keratinocyte-derived inflammatory mediators (thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and IL-6). In mice, dietary supplementation with the BRB-F:BFR-F mixture (10–80 mg/kg/day) dose-dependently improved clinical skin lesions and histopathological changes, with serum IgE reduced by up to 87.1% at the highest dose. The treatment significantly suppressed Th2 cytokine mRNA expression in ear tissue (IL-4, IL-5, and IL-13) by 37.2%, 32.7%, and 34.0%, respectively, compared with the positive control. In contrast, splenic Th1 cytokine mRNA expression (IL-2, IL-12, and IFN-γ) was partially restored by 37.1%, 22.5%, and 18.7%, respectively. These findings indicate that BRB-F and BFR-F modulate multiple immune pathways and help restore Th1/Th2 immune balance, suggesting their potential as functional materials for regulating immune dysregulation associated with AD. Full article

Lacticaseibacillus rhamnosus CRL1505 enhances antiviral immunity at mucosal sites, but its capacity to modulate liver immune responses remains unclear. Therefore, this study evaluated whether this immunomodulatory bacterium protects against Toll-like receptor 3 (TLR3)-mediated acute hepatitis induced by poly(I:C), and whether this effect depends on mucosal adhesion. BALB/c mice received the wild-type CRL1505 strain or the Δmbf CRL1505 mutant lacking the mucus-binding factor gene prior to poly(I:C) challenge. Liver injury, serum transaminases, and hepatic expression of interferons (IFNs), antiviral factors, inflammatory mediators, and regulatory cytokines were evaluated 48 h later. Poly(I:C) challenge induced acute hepatitis characterized by increased ALT/AST levels, leukocyte infiltration, and elevated hepatic IFNs and proinflammatory cytokines. The CRL1505 strain administration significantly reduced TNF-α, IL-1β, and IL-6 while enhancing IFNs, antiviral factors, and the regulatory cytokines IL-10 and IL-27, resulting in improved transaminase levels and attenuated liver damage. Notably, the Δmbf CRL1505 mutant conferred protection comparable to the wild-type strain. These findings demonstrate that L. rhamnosus CRL1505 exerts immunomodulatory and hepatoprotective effects during TLR3-driven hepatitis and that mbf-mediated adhesion is not required for this protection. Overall, CRL1505 emerges as a promising preventive strategy to enhance antiviral defenses and limit inflammation-associated liver injury. Full article

High-fat diets (HFDs) containing dietary fats with different fatty acid (FA) compositions alter gut microbiota composition in a fat-source-dependent manner. Immunoglobulin A (IgA) and unabsorbed lipids in the distal gut are potential regulators of the gut microbiota. However, their roles in mediating gut microbiota alterations induced by dietary fats with different FA compositions remain unclear. This study aims to examine the associations of these two factors with fat-source-dependent gut microbiota alterations. BALB/c mice were fed a normal diet, a high-lard diet, a high-olive oil diet, or a high-soybean oil diet for 27 weeks. Fecal samples were collected to assess microbiota composition, the IgA coating index (ICI)—which quantifies the extent of IgA coating on gut microbiota—and fecal fatty acid concentrations. At the phylum level, the concentration of fecal total long-chain fatty acids (LCFAs) was positively correlated with the relative abundance (RA) of Bacillota and negatively correlated with that of Bacteroidota. In addition, a trend toward a positive association between the RA and the ICI was observed for Bacillota but not for Bacteroidota. At the genus level, the RAs of 12 taxa were positively correlated with fecal LCFA concentrations, whereas those of 6 taxa were negatively correlated. Although the RAs of most taxa appeared to be influenced by unabsorbed lipids and additional factors, only four Bacillota genera exhibited a positive correlation between the RA and the ICI. Our observations suggest that IgA coating of the gut microbiota may have a minimal association with fat-source-specific alterations in gut microbiota composition during HFD intake. Full article

Background/Objectives: The large size of commonly used regulatory elements such as the cytomegalovirus (CMV) immediate-early promoter imposes a significant burden on the already restricted payload capacity of first-generation adenoviral vectors, potentially hindering the development of multi-antigen vaccine candidates. To address this limitation, we have engineered a panel of novel, small, semi-synthetic promoters designed to leverage the changes in transcriptomic milieu following adenoviral vector entry. Methods: Eight synthetic enhancer modules (SE1–SE8) were designed in silico, each composed of transcription factor binding sites (TFBSs) previously found in host genes that are upregulated during early adenoviral infection. These synthetic enhancers were coupled with a minimal CMV core promoter to generate a panel of compact semi-synthetic promoters (cSE1–cSE8), and their activity was evaluated in the context of ChAdOx1 viral vectors expressing GFP or a modified Plasmodium falciparum circumsporozoite (CSN) antigen. Promoter performance was characterised in vitro via flow cytometry, RT-qPCR, and Western blotting, and in vivo by quantifying antigen-specific T-cell (IFN-γ ELISpot) and IgG antibody (ELISA) responses in BALB/c mice. Results: In vitro characterisation revealed a wide range of promoter activity across the panel, with cSE3 and cSE5 driving transgene expression levels comparable to the benchmark CMV promoters despite their markedly reduced genomic footprint. In vivo, ChAdOx1 vectors incorporating cSE3 and cSE5 elicited potent antigen-specific T-cell and IgG responses that were comparable to those induced by the larger CMV control promoters. Conclusions: We have successfully developed semi-synthetic promoters that match the potency of the much larger, frequently used CMV promoters whilst simultaneously reducing genomic footprint. These novel regulatory elements will facilitate the design of next-generation vaccines, particularly those requiring large antigens or multi-antigen cassettes. Full article