Search Results (92)

Influenza’s pandemic threat is driven by antigenic drift, which limits the efficacy of conventional vaccines. To address this challenge, we established a clinical serum-anchored computational design pipeline for a broad-spectrum multi-epitope mRNA vaccine (MEMV), bridging the gap between pure in silico design and clinical applicability. Using 36 longitudinal sera (d0/d28/d365) from 12 well-characterized human cohorts (6 vaccine recipients and 6 influenza patients) and high-density antibody-peptide microarrays, we empirically identified 12 immunodominant B-cell linear epitopes from the nucleoprotein (NP) of influenza A (H1N1/H3N2) and B viruses. These experimentally validated epitopes were combined with in silico-predicted conserved helper T-lymphocyte (HTL)/cytotoxic T-lymphocyte (CTL) epitopes (from NP/HA/NA) to construct MEMVs candidates, ensuring high antigenicity, non-toxicity, and 95.63% global HLA coverage. Molecular docking and 100 ns molecular dynamics (MD) simulations confirmed favorable conformational compatibility between MEMVs and Toll-like receptor 3 (TLR3) in silico immunization via C-ImmSim predicted robust B/T-cell responses and protective cytokine (IFN-γ/IL-10) production. Collectively, this pipeline shortens the preliminary design cycle for influenza vaccines, provides a standard epitope-combination strategy, and offers direct targets for follow-up in vitro/in vivo experiments. Full article

Background/Objectives: Polysaccharide-protein conjugate vaccines have proven highly effective, yet they remain limited by manufacturing complexity, cost, and variable performance across serotypes, while carrier proteins can add unwanted immunological and production burdens. To address these constraints, we explored a carrier-protein-free conjugate vaccine concept in which a broadly MHC class II-binding helper epitope (PADRE) replaces the conventional protein carrier to provide T-cell help for a pneumococcal capsular polysaccharide antigen. Methods: Using serotype 15C CPS as a model, we generated CPS–PADRE conjugates and compared designs with or without a putative cleavable motif (RR) at the junction, alongside a conventional protein conjugate as a benchmark. Results: In mice, the CPS–protein conjugate induced the strongest CPS-specific IgG response, whereas CPS–PADRE conjugates elicited clear but overall lower antibody levels. Notably, incorporation of the cleavable motif did not improve immunogenicity and instead reduced humoral responses relative to the non-cleavable design. Conclusion: These findings support the feasibility of carrier-protein-free polysaccharide-peptide conjugate vaccines, while highlighting that cleavable junctions are not universally advantageous and must be empirically optimized for polysaccharide-helper epitope architectures. Full article

Background: Adjuvants enhance the immune response to antigens incorporated in vaccine formulations. Given that the majority of infectious agents enter the body through mucosal surfaces, efficacious vaccines must generate protective immunity at these sites, which serve as the first line of defense. There is a need for mucosal adjuvants; hence, we explored the potential of repurposing existing drugs with established safety profiles in humans. Polymyxins are a class of clinically used antibiotics. They are cationic peptides and mast cell activators, which are a novel class of vaccination adjuvants. The goal was to assess the adjuvant properties of Polymyxin B microparticles in combination with vaccine candidates previously developed in our laboratory, such as microparticulate gonorrhea, influenza, measles, Zika, and canine coronavirus vaccines, and to compare their performance with FDA-licensed adjuvants, such as MF59 and Alum. Methods: Polymyxin microparticles were formulated using a double emulsion method, and the toxicity profile and autophagosome generation of Polymyxin B microparticles were assessed. The immunogenic potential of Polymyxin B in these vaccines was studied using multiple parameters such as nitric oxide release using Griess assay and immune profiling using flow cytometry for markers such as MHC I, MHC II, CD40, and CD80. Results: Polymyxin B microparticles were found to be non-cytotoxic to dendritic cells up to 500 μg/mL. Polymyxin B promoted autophagosome formation and nitric oxide release, and showed the upregulation of MHC I, MHC II, CD80, and CD40 pathways. Conclusions: The adjuvant activity of Polymyxin B across various vaccine platforms is significantly comparable to FDA-approved adjuvants, which is a critical requirement for generating T cell responses such as helper T cell and cytotoxic CD8+ T cell responses. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disorder associated with immune dysregulation, skin barrier dysfunction, and microbial dysbiosis characterized by Staphylococcus aureus overcolonization and reduced bacterial diversity. Beyond its classical role in calcium homeostasis, Vitamin D (VD) influences skin immunity and microbial composition. This review summarizes current knowledge on VD metabolism, its immunological pathways in AD, and its interactions with the skin microbiome. Recent evidence positions the skin as an active immunological organ rather than a passive barrier. Commensal bacteria such as Staphylococcus epidermidis not only inhibit pathogens by producing bacteriocins and modulins but also generate ceramides and short-chain fatty acids (SCFAs) that stabilize the lipid barrier. Moreover, dermal fibroblasts and preadipocytes produce antimicrobial peptides, while resident γδ T cells release growth factors like fibroblast growth factor 7 (FGF7), linking host defense with tissue regeneration. VD modulates AD by suppressing T helper 2 cells/T helper 17 cell responses, enhancing regulatory T cell development, inducing antimicrobial peptides, and strengthening skin and gut barrier integrity. Its interaction with the microbiome and pathways such as SCFA and aryl hydrocarbon receptor (AhR) signaling supports its potential as an adjunctive therapy in AD management. Evidence from mechanistic studies and animal models suggests that VD supplementation may modulate inflammation and microbial diversity. Clinical implications, therapeutic perspectives, and future research directions highlight the potential of VD as a therapeutic adjunct in AD management. Full article

Duck viral hepatitis (DVH), a highly contagious disease, is caused primarily by duck hepatitis A virus (DHAV). The viral genotypes exhibit significant diversity, creating a challenge as monovalent vaccines fail to provide cross-genotype protection in ducklings. This study aimed to design a multi-epitope peptide vaccine targeting different genotypes of DHAV. Using immunoinformatics approaches, we systematically identified key antigenic determinants, including linear B-cell epitopes, cytotoxic T-cell epitopes (CTL), and helper T-cell epitopes (HTL). Based on these, a novel vaccine candidate was developed. The vaccine construct was subjected to rigorous computational validation: (1) Molecular docking with Toll-like receptors (TLRs) predicted immune interaction potential. (2) Molecular dynamics simulations assessed complex stability. (3) In silico cloning ensured prokaryotic expression feasibility. Then, we conducted preliminary experimental validation for the actual effect of the vaccine candidate, including recombinant protein expression in E. coli, enzyme-linked immunosorbent assay (ELISA) quantification of humoral responses, and Western blot analysis of cross-reactivity. ELISA results demonstrated that the vaccine candidate could induce high-titer antibodies in immunized animals, with potency reaching up to 1:128,000, and the immune serum showed strong reactivity with recombinant VP proteins. Western blot analysis using duck sera confirmed epitope conservancy across genotypes. Collectively, the multi-epitope vaccine candidate developed in this study represents a highly promising broad-spectrum strategy against DHAV. The robust humoral immunity it elicits, coupled with its demonstrated cross-reactivity, constitutes compelling proof-of-concept, laying a solid foundation for advancing to subsequent challenge trials and translational applications. Full article

Dengue virus remains a major global health threat due to the lack of a safe and broadly effective vaccine. Traditional antibody-based vaccines often show limited protection and can exacerbate disease severity in individuals without prior exposure. A new generation of T-cell epitope-based vaccines offers a promising and safer approach by activating the cellular arm of the immune system to complement antibody responses. Instead of targeting only surface structural proteins, these vaccines focus on highly conserved peptide regions within non-structural proteins, particularly NS3 and NS5, that are shared across all four dengue virus serotypes. Peptides such as DTTPFGQQR, KPGTSGSPI, and MYFHRRDLRL have been identified as potent immunogenic targets capable of inducing strong cytotoxic and helper T-cell responses, promoting viral clearance and long-term immune memory. Advanced immunoinformatic enables precise prediction and selection of epitopes with high binding affinity to human leukocyte antigens and broad cross-serotype conservation. These peptides can be integrated into next-generation vaccine delivery systems, including messenger RNA and nanoparticle platforms, which enhance antigen presentation, improve molecular stability, and reduce the risk of antibody-dependent disease enhancement. Together, this integrative design represents a rational path toward a safer, cross-protective, and durable dengue vaccine that closely mimics the balanced cellular and humoral immunity observed after natural infection, offering renewed hope for effective global dengue prevention. Full article

Acquired Immunodeficiency Syndrome (AIDS) is caused by Human Immunodeficiency Virus (HIV), and continues to be responsible for a substantial number of deaths worldwide each year. Development of a robust and efficient HIV-1 vaccine remains a critical priority. Structural analysis of viral proteins provides a foundational approach to designing peptide-based immunogenic vaccines. In the current experiment, we used computational prediction approaches alongside molecular docking and molecular dynamics (MD) simulations to identify potential epitopes within gp120 and Nef proteins. The selected co-epitopes were fused with the HBsAg-binding protein (SBP), a 344-amino acid protein previously identified in our laboratory through screening of a human liver cDNA expression library against HBsAg, to facilitate efficient delivery to and uptake by dendritic cells (DCs), thereby enhancing antigen (Ag) presentation. Flexible linkers are used to connect B cells, Helper T Lymphocytes (HTLs), and Cytotoxic T Lymphocytes (CTLs) in a sequential manner. The assembled vaccine construct comprises 757 amino acids, corresponding to a recombinant protein of 83.64 kDa molecular weight. Structural analysis through docking studies, MD simulations, and 3D structure validation revealed that the designed protein exhibits high structural stability and potential for interaction with Toll-like receptors (TLRs). These findings support the vaccine’s ability to enhance cellular and humoral feedback, including the stimulation of T and B cells and induction of antibody (Ab) production. The results underscore the promise of this in silico designed co-epitope vaccine as a viable candidate for HIV-1 prevention and suggest that such constructs may serve as effective immunogens in future HIV-1 vaccine strategies. Full article

Human Leukocyte Antigen (HLA) Class II (HLA-II) molecules bind peptides of phagocytosed non-self proteins and present them on the cell surface to circulating CD4+ T lymphocytes. A successful binding of the presented peptide with the T cell receptor (TCR) activates the CD4+ T cell, leading to the production of antibodies against the peptide (and the protein of its origin) by the B cell and augmentation of the cytotoxic and memory functions of CD8+ T cells. The first and essential step in this process is the successful formation of a stable peptide-HLA-II complex (pHLA-II), which is achieved when the peptide binds with high affinity to the HLA-II molecule. Such highly antigenic non-self peptides occur in melanoma-associated proteins and could be used as antitumor agents when bound to a matching HLA-II molecule. The objective of this study was to identify such peptides from 15 melanoma-associated proteins. We determined in silico the predicted binding affinity (IC₅₀) of all pHLA-II pairs between 192 common HLA-II molecules and all possible linear 15-amino acid (15-mer) peptides (epitopes) of 15 known melanoma-associated antigens (N = 3466 epitopes) for a total of 192 × 3466 = 665,472 determinations. From this set, we identified epitopes with strong antigenicity (predicted best binding affinity [PBBA] IC₅₀ < 50 nM). Of a total of 665,472 pHLA-II tested, 5941 (0.89%) showed strong PBBA, stemming from 117 HLA-II alleles and 679 distinct epitopes. This set of 5941 pHLA-II pairs with predicted high antigenicity possesses the requisite information for devising multipeptide vaccines with those epitopes alone or in combination with the corresponding HLA-II molecules. The results obtained have a major implication for cancer therapy, namely that the administration of subsets of the 679 high antigenicity epitopes above, alone or in combination with their associated HLA-II molecules, would be successful in engaging CD4+ T helper lymphocytes to augment the cytotoxic action and memory of CD8+ T lymphocytes and induce the production of antitumor antibodies by B cells. This therapy would be effective in other solid tumors (in addition to melanoma) and would be enhanced by concomitant immunotherapy with immune checkpoint inhibitors. Full article

Inflammatory facial dermatoses (atopic dermatitis [AD], acne vulgaris, contact dermatitis, seborrheic dermatitis, rosacea, perioral dermatitis, and demodicosis, etc.) often profoundly impact patients’ appearance and psychological well-being. In this narrative review, we wanted to present the current knowledge on the role of skin microbiota in common facial dermatoses. Skin keratinocytes are the primary producers of antimicrobial peptides (AMPs) and express Toll-like receptors (TLRs), which stimulate the T helper (Th1) immune response, with the production of interferon (IFN). They can also produce certain pro-inflammatory cytokines, namely IL-1β, IL-18, IL-6, IL-10, and the tumor necrosis factor (TNF). In healthy infants, the bacterial skin microbiota is predominantly composed of Firmicutes (genera Staphylococcus and Streptococcus), as well as Actinobacteria, Proteobactera, and Bacteroidota. The genera Cutibacterium and Staphylococcus, which have antimicrobial effects and compete with pathogens for nutrients/ecological niches, coexist symbiotically on the skin and can reduce the expression of TLR2 and TLR4. In patients with AD, lesional/non-lesional skin was found to have increased colonization by Staphylococcus aureus which reduces effector T lymphocytes’ ability to produce cytokines, such as IL-17A and IFN-γ, leading to decreased AMP production and impaired skin microbiota immune functionality. In patients with rosacea, the overexpression of TLR2 may stimulate elevated pro-inflammatory cytokine production (IL-8, IL-1β, and TNF-α, etc.), exacerbating the inflammatory response. Also, increased colonization by Malassezia yeasts triggers a Th2 immune response and cytokine secretion (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, TNF-α, beta-defensin, IFN-γ, nitric oxide, and histamine), and participates in signaling pathways. Insight into these factors may further improve clinical approaches to patients with facial dermatoses. Full article

Fasciola gigantica (F. gigantica) is a vital parasite that causes fasciolosis. Liver fluke infections affect livestock animals, and the Fasciola species (Fasciola spp.) vaccine has been tested for many types of these diseases. Currently, computer-based vaccine design represents an attractive alternative for constructing vaccines. Thus, this study aimed to design the epitopes of linear B-cells (BCL) and helper T lymphocytes (HTL) using an immunoinformatic approach and to investigate in silico and the mice’s immune response. A non-conserved host region, overlapping F. gigantica cathepsin B proteins (FgCatB), and the highest conserved residue percentages were the criteria used to construct epitopes. The GPGPG linker was used to link epitopes in the multi-epitope Fasciola gigantica cathepsin B (MeFgCatB) peptide. The MeFgCatB peptide has high antigenicity, non-allergenicity, non-toxicity, good solubility, and a high-quality structure. The molecular docking between the MeFgCatB peptide and Toll-like receptor 2 (TLR-2) was evaluated. The IgM, IgG1, and IgG2 levels were elevated in silico. In mice, the MeFgCatB peptide was synthesized and administered as an injection. The MeFgCatB-specific IgG1 and IgG2a levels were elevated after week 2, showing a predominance of IgG1. The rFgCatB1, rFgCatB2, and rFgCatB3 were detected using the MeFgCatB peptide-immunized sera. The MeFgCatB peptide-immunized sera were detected at approximately 28–34 kDa in the whole body. In addition, the MeFgCatB immunized sera can positively signal at the caecal epithelium in the NEJ, 4WKJ, and adult stages. In summary, the MeFgCatB peptide is able to induce mixed Th1/Th2 immune responses with Th2 dominating and to detect the native protein of F. gigantica. The MeFgCatB peptide should help against F. gigantica in future experiments. Full article

Background/Objectives: Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer, with limited responsiveness to immune checkpoint inhibitors (ICIs). Cancer vaccine therapy is a promising novel immunotherapeutic approach that stimulates tumor-specific T cells. Receptor tyrosine kinase-like orphan receptor 1 (ROR1), which is overexpressed in malignant tumors but minimally expressed in normal tissues, presents a promising target for immunotherapy. This study aimed to evaluate ROR1 as a target for helper T lymphocyte (HTL)-based peptide vaccine immunotherapy in HNSCC. Methods: ROR1 expression in HNSCC tissues was assessed by immunohistochemistry. A novel ROR1-derived epitope (ROR1_403–417) was identified and used to generate ROR1-reactive HTLs. Functional assays measuring IFN-γ and granzyme B secretion, as well as direct cytotoxicity, were performed. The effects of ICIs on HTL activity were also examined. The presence of ROR1-reactive T cells in the peripheral blood of patients with HNSCC was evaluated. Results: ROR1 positivity rates in HNSCC tissues were significantly higher (80.0%) than those in healthy controls (16.7%), and high ROR1 expression correlated with advanced clinical stages. HTL lines recognized the ROR1_403–417 peptide in a human leukocyte antigen (HLA)-DR-restricted manner, secreted effector cytokines, and exhibited direct cytotoxicity against ROR1+ tumor cells. Dual PD-L1/PD-L2 blockade further enhanced HTL responses. ROR1-reactive T cells were detected in the peripheral blood of patients with HNSCC. Conclusions: ROR1 represents a promising target for immunotherapy in HNSCC. The ROR1_403–417 peptide can elicit ROR1-reactive HTLs that exhibit antitumor responses against HNSCC cell lines, which can be enhanced by ICIs. These findings support the potential of ROR1-targeted peptide vaccine therapy for HNSCC. Full article

Background: Group A Streptococcus (GAS) is a major human pathogen associated with serious diseases. Evaluating immune responses against GAS vaccines—immunogenicity, quality, and efficacy—is complicated by interference from co-infections, like Staphylococcus aureus (S. aureus). We aimed to evaluate peptide-based GAS vaccines in mice for antisera efficacy against standard and mutant GAS strains and to assess immunological methods under co-infection conditions. Methods: Female C57BL/6 mice were infected with S. aureus and immunized with various M-protein-derived peptide antigens: J8, J8i, J8i-J8i, and the native p145 sequence. Two novel, conserved M-protein-derived antigens (NTD and CTD2) were also evaluated. Enzyme-linked immunosorbent assays (ELISAs) were used to assess immunogenicity and GAS-specific antibody responses. Peptide antigens were either conjugated to or physically mixed with the PADRE T-helper epitope and tested for enhanced antisera immunogenicity and opsonic efficacy. Result: ELISA against the immunizing peptides as coating antigens reflected the immunogenicity, while p145-based ELISA correlated with GAS-specific antibody titres without S. aureus interference for J8-based vaccines. Immunogenicity ranked J8 > J8i ≈ J8i-J8i > p145. NTD and CTD2 antisera demonstrated opsonic activity, indicating protective potential. PADRE–J8 conjugates significantly enhanced antibody magnitude and quality, producing strong opsonic bactericidal responses against both standard and p145-mutant GAS strains. PADRE–J8i was effective only against standard strains. This is the first report to suggest at least two B-cell epitopes within the J8i peptide. Conclusion: These findings support the diagnostic utility of p145, NTD, and CTD2 under co-infection settings, and the vaccine potential of J8, NTD, and CTD2, particularly when conjugated to a T helper for enhanced antigen presentation. Full article

Introduction: Gestational diabetes (GD) is a common pregnancy metabolic disorder involving immune alterations. While there is a link between immune cells and GD, the specific roles of NKT/NK, helper/cytotoxic T, and B1/B2 lymphocyte ratios in complicated/uncomplicated pregnancies with and without GD are underexplored. This cross-sectional study hypothesized that specific imbalances in these lymphocyte ratios would be present in GD, and that these ratios would correlate with key metabolic parameters in pregnancy. Methods: We compared these lymphocyte ratios in 162 third-trimester pregnant women across four groups: healthy uncomplicated (n = 40), healthy complicated (n = 40), GD uncomplicated (n = 42), and GD complicated (n = 40), using flow cytometry and by measuring biochemical parameters. Results: No significant differences in lymphocyte ratios were found between GD and healthy pregnancies. Novel correlations emerged: in the entire cohort, the NKT/NK ratio positively correlated with C-peptide and triglycerides, and negatively with HDL cholesterol. The helper/cytotoxic ratio negatively correlated with insulin and C-peptide. In the GD group, NKT/NK correlated positively with C-peptide, and helper/cytotoxic negatively with insulin. Conclusion: These findings suggest a subtle yet significant link between immune cell subsets and metabolic status in pregnancy and GD, warranting further investigation. Full article

Necrotic enteritis (NE), caused by pathogenic Clostridium perfringens, poses a significant threat to global poultry health, with estimated annual losses exceeding USD 6 billion. The rising incidence of NE has been associated with the reduced use of antibiotic growth promoters, underscoring the urgent need for alternative control measures such as vaccination. Collagen adhesin protein (CNA), a key virulence factor in NE pathogenesis, represents a promising vaccine target. The US Food and Drug Administration has begun phasing out animal testing requirements for biologics and monoclonal antibody drugs. In this study, a computational multi-epitope vaccine (MEV) targeting CNA was designed by integrating predicted Cluster of Differentiation (CD)4⁺ helper T lymphocyte (Th), CD8⁺ cytotoxic T lymphocyte (CTL), and B-cell epitopes. Bioinformatics tools were used to identify immunogenic, antigenic, and non-allergenic epitopes assembled into a 115-amino-acid peptide vaccine construct. The candidate demonstrated strong stability and solubility. In silico immune simulation predicted robust immune responses, including elevated IgG and IgM antibody levels, plasma cell proliferation, Th memory formation, and CTL activation, comparable to responses elicited by a full-length CNA. These findings support the potential of the designed peptide as one of the multiple effective NE vaccine components, offering a promising alternative to antibiotic-based approaches in poultry disease management. Full article

Objectives: Little is known about the impact of patient age and biological sex on immune responses to melanoma vaccines, especially CD4⁺ T cell immune responses to peptides presented by Class II MHC molecules. Methods: We assessed the impact of age and sex on CD4+ T cell and antibody responses to a mixture of six melanoma helper peptides (6MHP) and on CD8+ T cell responses when vaccinating with 12 class I MHC-restricted melanoma peptides (12MP) plus either 6MHP or a tetanus helper T cell peptide (Tet). We hypothesized that immune responses would be greater in men and in younger patients. Results: We found differences in immune response by sex, but they favored female patients and were only evident for helper T cell responses to Tet with a weak trend to higher T cell responses to 12MP in female patients vaccinated with 12MP + Tet. The age-based differences favored younger patients but only for immune response to 12MP when inoculated with 12MP + Tet. Conclusions: These findings reinforce the importance of assessing sex- and age-based differences in immune responses to cancer vaccines and other immune therapies. There is also a need to understand the reasons for such differences. Full article