Search Results (397)

The protein p53, often referred to as the “guardian of the genome,” is essential for preserving cellular balance and preventing cancerous transformations. As one of the most commonly altered genes in human cancers, its impaired function is associated with tumor initiation, development, and resistance to treatment. Exploring the diverse roles of p53, which include regulating the cell cycle, repairing DNA, inducing apoptosis, reprogramming metabolism, and modulating immunity, provides valuable insights into cancer mechanisms and potential treatments. This review integrates recent findings on p53′s dual nature, functioning as both a tumor suppressor and an oncogenic promoter, depending on the context. Wild-type p53 suppresses tumors by inducing cell cycle arrest or apoptosis in response to genotoxic stress, while mutated variants often lose these functions or gain novel pro-oncogenic activities. Emerging evidence highlights p53′s involvement in non-canonical pathways, such as regulating tumor microenvironment interactions, metabolic flexibility, and immune evasion mechanisms. For instance, p53 modulates immune checkpoint expression and influences the efficacy of immunotherapies, including PD-1/PD-L1 blockade. Furthermore, advancements in precision diagnostics, such as liquid biopsy-based detection of p53 mutations and AI-driven bioinformatics tools, enable early cancer identification and stratification of patients likely to benefit from targeted therapies. Therapeutic strategies targeting p53 pathways are rapidly evolving. Small molecules restoring wild-type p53 activity or disrupting mutant p53 interactions, such as APR-246 and MDM2 inhibitors, show promise in clinical trials. Combination approaches integrating gene editing with synthetic lethal strategies aim to exploit p53-dependent vulnerabilities. Additionally, leveraging p53′s immunomodulatory effects through vaccine development or adjuvants may enhance immunotherapy responses. In conclusion, deciphering p53′s complex biology underscores its unparalleled potential as a biomarker and therapeutic target. Integrating multi-omics analyses, functional genomic screens, and real-world clinical data will accelerate the translation of p53-focused research into precision oncology breakthroughs, ultimately improving patient outcomes. Full article

High rates of childhood vaccination defaulting remain a significant barrier to achieving full vaccination coverage in sub-Saharan Africa, contributing to preventable morbidity and mortality. This study evaluated the utility of machine learning algorithms for predicting childhood vaccination defaulters in Ghana, addressing the limitations of traditional statistical methods when handling complex, high-dimensional health data. Using a merged dataset from two malaria vaccine pilot surveys, we engineered novel temporal features, including vaccination timing windows and birth seasonality. Six algorithms, namely logistic regression, support vector machine, random forest, gradient boosting machine, extreme gradient boosting, and artificial neural networks, were compared. Models were trained and validated on both original and synthetically balanced and augmented data. The results showed higher performance across the ensemble tree classifiers. The random forest and extreme gradient boosting models reported the highest F1 scores (0.92) and AUCs (0.95) on augmented unseen data. The key predictors identified include timely receipt of birth and week six vaccines, the child’s age, household wealth index, and maternal education. The findings demonstrate that robust machine learning frameworks, combined with temporal and contextual feature engineering, can improve defaulter risk prediction accuracy. Integrating such models into routine immunization programs could enable data-driven targeting of high-risk groups, supporting policymakers in strategies to close vaccination coverage gaps. Full article

This review focuses on the synthesis of spacer-armed phosphooligosaccharides structurally related to the capsular phosphoglycans of pathogenic bacteria, including the Haemophilus influenzae serotypes a, b, c, and f, Neisseria meningitidis serogroups a and x, the Streptococcus pneumoniae serotypes 6a, 6b, 6c, 6f, 19a, and 19f, and the Campylobacter jejuni serotype HS:53, strain RM1221, in which the phosphodiester linkage is a structural component of a phosphoglycan backbone. Also, in this review, we summarize the current knowledge on the preparation and immunogenicity of neoglycoconjugates based on synthetic phosphooligosaccharides. The discussed data helps evaluate the prospects for the development of conjugate vaccines on the basis of synthetic phosphooligosaccharide antigens. Full article

Outer-membrane vesicles (OMVs), naturally secreted by Gram-negative bacteria, have gained recognition as a versatile platform for the development of next-generation vaccines. OMVs are essential contributors to bacterial pathogenesis, horizontal gene transfer, cellular communication, the maintenance of bacterial fitness, and quorum sensing. Their intrinsic immunogenicity, adjuvant properties, and scalability establish OMVs as potent tools for combating infectious diseases and cancer. Recent advancements in genetic engineering and biotechnology have further expanded the utility of OMVs, enabling the incorporation of multiple epitopes and antigens from diverse pathogens. These developments address critical challenges such as antigenic variability and co-infections, offering broader immune coverage and cost-effective solutions. This review explores the unique structural and immunological properties of OMVs, emphasizing their capacity to elicit robust immune responses. It critically examines established and emerging engineering strategies, including the genetic engineering of surface-displayed antigens, surface conjugation, glycoengineering, nanoparticle-based OMV engineering, hybrid OMVs, and in situ OMV production, among others. Furthermore, recent advancements in preclinical research on OMV-based vaccines, including synthetic OMVs, OMV-based nanorobots, and nanodiscs, as well as emerging isolation and purification methods, are discussed. Lastly, future directions are proposed, highlighting the potential integration of synthetic biology techniques to accelerate research on OMV engineering. Full article

Brucellosis continues to be a significant global zoonotic infection, with diagnosis largely relying on the detection of antibodies against the Brucella O-polysaccharide (O-PS) A and M antigens. In this study, computational methods, including homology modeling, molecular docking, and molecular dynamics simulations, were applied to investigate the interaction of the four murine monoclonal antibodies (mAbs) YsT9.1, YsT9.2, Bm10, and Bm28 with hexasaccharide fragments of the A and M epitopes. Through stringent stability criteria, based on interaction energies and mobility of the antigens, high-affinity binding of A antigen with YsT9.1 antibody and M antigen with Bm10 antibody was predicted. In both the complexes hydrophobic interactions dominate the antigen–antibody binding. These findings align well with experimental epitope mapping, indicating YsT9.1’s preference for internal sequences of the A epitope and Bm10’s preference for internal elements of the M epitope. Interestingly, no stable complexes were identified for YsT9.2 or Bm28 interacting with A or M antigen. This study provides valuable insights into the mechanism of molecular recognition of Brucella O-antigens that can be applied for the development of improved diagnostics, synthetic glycomimetics, and improved vaccine strategies. Full article

Biologic therapeutics, particularly monoclonal antibodies (mAbs), have revolutionized disease treatment paradigms; however, their clinical success is often hindered by immunogenicity. Host immune recognition of these biologics can induce anti-drug antibody (ADA) formation, leading to reduced therapeutic efficacy, altered pharmacokinetics and serious adverse events, such as infusion reactions and loss of response. Overcoming these immunogenicity challenges is essential to maximize the clinical effect of biologics and ensure patient safety. This paper offers an overview of the mechanisms underlying the formation of anti-drug antibodies and explores potential nanotechnology-based strategies to reduce or eliminate these responses. Specifically, the review examines how the immune system recognizes biologics and develops ADAs, which can impact drug efficacy and safety. The review then investigates various nanotechnology approaches aimed at mitigating ADA formation, potentially improving the therapeutic outcomes of biologic drugs. Full article

Monkeypox virus (Mpox) has recently drawn global attention due to outbreaks beyond its traditional endemic regions. Understanding the immune response to Mpox infection is essential for improving disease management and guiding vaccine development. In this study, we used several machine learning algorithms to analyze time series gene expression data from macaques infected with Mpox, aiming to uncover key immune-related genes involved in different stages of infection. The dataset covered early infection, late infection, and rechallenge phases. We applied nine feature ranking methods to analyze the feature importance, obtaining nine feature lists. Then, the incremental feature selection method was applied to each list to extract key genes and build efficient prediction models and classification rules for each list. This procedure employed twelve classification algorithms and the Synthetic Minority Oversampling Technique. Key genes—such as CD19, MS4A1, and TLR10—were repeatedly identified from multiple feature lists, and are known to play vital roles in B-cell activation, antibody production, and innate immunity. Furthermore, we identified several novel key genes (HS3ST1, SPAG16, and MTARC2) that have not been reported previously. These findings offer valuable insights into the host immune response and highlight potential molecular targets for monitoring and intervention in Mpox infections. Full article

Avian influenza is an economically significant disease affecting poultry worldwide and is caused by influenza A viruses that can range from low to highly pathogenic strains. These viruses primarily target the respiratory, digestive, and nervous systems of birds, leading to severe outbreaks that threaten poultry production and pose zoonotic risks. The ectodomain of the avian influenza virus (AIV) matrix protein 2 (M2e), known for its high conservation across influenza strains, has emerged as a promising candidate for developing a universal influenza vaccine in a mouse model. However, the efficacy of such expression against poultry AIVs remains limited. The objective of this study was to evaluate the immunogenicity of nodavirus-like particles displaying the M2e proteins. In this study, three synthetic heterologous M2e genes originated from AIV strains H5N1, H9N2 and H5N2 were fused with the nodavirus capsid protein (NVC) of the giant freshwater prawn Macrobrachium rosenbergii (NVC-3xAvM2e) prior to immunogenicity characterisations in chickens. The expression vector pTRcHis-TARNA2 carrying the NVC-3xAvM2e gene cassette was introduced into E. coli TOP-10 cells. The recombinant proteins were purified, inoculated into one-week-old specific pathogen-free chickens subcutaneously and analysed. The recombinant protein NVC-3xAvM2e formed virus-like particles (VLPs) of approximately 25 nm in diameter when observed under a transmission electron microscope. Dynamic light scattering (DLS) analysis revealed that the VLPs have a polydispersity index (PDI) of 0.198. A direct ELISA upon animal experiments showed that M2e-specific antibodies were significantly increased in vaccinated chickens after the booster, with H5N1 M2e peptides having the highest mean absorbance value when compared with those of H9N2 and H5N2. A challenge study using low pathogenic AIV (LPAI) strain A/chicken/Malaysia/UPM994/2018 (H9N2) at 10^6.5 EID₅₀ showed significant viral load in the lung and cloaca, but not in the oropharyngeal of vaccinated animals when compared with the unvaccinated control group. Collectively, this study suggests that nodavirus-like particles displaying three heterologous M2e have the potential to provide protection against LPAI H9N2 in chickens, though the vaccine’s efficacy and cross-protection across different haemagglutinin (HA) subtypes should be further evaluated. Full article

Background/Objectives: Syphilis, a chronic sexually transmitted disease caused by the spirochete Treponema pallidum subspecies pallidum (T. pallidum), is still endemic in low- and middle-income countries and has been resurgent for decades in many high-income nations despite being treatable. Improving our understanding of syphilis pathogenesis, immunology, and T. pallidum biology could result in novel measures to curtail syphilis spread, including new therapeutics, a preventive vaccine, and, most importantly, improved diagnostics. Methods: Using overlapping synthetic peptides spanning the length of the T. pallidum Tp0435 mature lipoprotein, an abundant antigen known to induce an immunodominant humoral response during both natural and experimental infection, we evaluated which Tp0435 linear epitopes are most significantly recognized by antibodies from an infected host. Specifically, we used sera from 63 patients with syphilis at different stages, sera from non-syphilis patients (n = 40), and sera longitudinally collected from 10 rabbits infected with either the Nichols or SS14 isolates of T. pallidum, which represent the model strains for the two known circulating clades of this pathogen, to further evaluate the use of this animal model for syphilis studies. Recognized amino acid sequences were then mapped to the experimentally determined Tp0435 structure. Results: Reactive epitopes in both serum groups mapped predominantly to the α-helix preceding Tp0435 soluble β-barrel and the loops of the barrel. Conclusions: In the current effort to improve current syphilis diagnostics, the peptides corresponding to these immunodominant epitopes could help develop epitope-based assays such as peptide-based ELISAs and lateral flow point-of-care tests to improve the performance of treponemal tests and expedite diagnosis in low-income settings, where the infection is still a significant concern for public health and access to facilities with laboratories equipped to perform complex procedures might be challenging. Full article

The emergence of complex and rapidly evolving pathogens necessitates innovative vaccine platforms that move beyond traditional methods. This review explores the transformative potential of next-generation vaccine technologies, focusing on the combined use of synthetic biology, nanotechnology, and systems immunology. Synthetic biology provides modular tools for designing antigenic components with improved immunogenicity, as seen in mRNA, DNA, and peptide-based platforms featuring codon optimization and self-amplifying constructs. At the same time, nanotechnology enables precise antigen delivery and controlled immune activation through engineered nanoparticles such as lipid-based carriers, virus-like particles, and polymeric systems to improve stability, targeting, and dose efficiency. Systems immunology aids these advancements by analyzing immune responses through multi-omics data and computational modeling, which assists in antigen selection, immune profiling, and adjuvant optimization. This approach enhances both humoral and cellular immunity, solving challenges like antigen presentation, response durability, and vaccine personalization. Case studies on SARS-CoV-2, Epstein–Barr virus, and Mycobacterium tuberculosis highlight the practical application of these platforms. Despite promising progress, challenges include scalability, safety evaluation, and ethical concerns with data-driven vaccine designs. Ongoing interdisciplinary collaboration is crucial to fully develop these technologies for strong, adaptable, globally accessible vaccines. This review emphasizes next-generation vaccines as foundational for future immunoprophylaxis, especially against emerging infectious diseases and cancer immunotherapy. Full article

Staphylococcus aureus is a leading cause of severe infections in humans and animals, and the emergence of multidrug-resistant strains highlights the need to develop effective vaccines to prevent such diseases. Epitope-based vaccines use short antigen-derived peptides corresponding to immune epitopes, which are administered to trigger protective humoral and cellular immune responses. In this study, in silico MHC affinity measurement methods were used to predict possible binding regions, and five 20-mer synthetic TRAP peptides (TRAPP) were synthesized. Epitope-based vaccines, named PT and PTR, incorporating the identified CD4⁺ T and B cell epitopes, were constructed. Peptides TRAP_20–39 and TRAP_94–113 elicited significant peptide-stimulated T-cell proliferation responses in vivo. Additionally, high levels of IFN-γ and IL-17A, along with moderate levels of IL-4, were detected in ex vivo stimulated CD4⁺ T cells isolated from rTRAP- and TRAPP-immunized mice, suggesting that these peptides are classified as Th1 and Th17 epitopes. Immunization with PT or PTR induces robust humoral and cellular immune responses. Moreover, the epitope-based vaccine, PT, exhibited a stronger protective immune response than the intact TRAP in a murine systemic S. aureus infection model. Based on the results presented herein, an epitope-based vaccine is a promising and potentially more effective candidate. Full article

Self-amplifying RNA-based (saRNA) technology represents the last frontier in using synthetic RNA in vaccinology. Typically, saRNA consists of positive-strand RNA molecules of viral origin (almost exclusively from alphaviruses) where the sequences of structural proteins are replaced with the open reading frame coding the antigen of interest. For in vivo delivery, they are complexed with lipid nanoparticles (LNPs), just like current COVID-19 vaccines based on synthetic messenger RNA (mRNA). Given their ability to amplify themselves inside the cell, optimal intracellular levels of the immunogenic antigen can be achieved by delivering lower amounts of saRNA molecules compared to mRNA-based vaccines. However, the excessive intracellular accumulation of saRNA may represent a relevant drawback since, as already described in alphavirus-infected cells, the recipient cell may react by incorporating excessive RNA molecules into extracellular vesicles (EVs). These EVs can shed and enter neighboring as well as distant cells, where the EV-associated saRNA can start a new replication cycle. This mechanism could lead to an unwanted and unnecessary spread of saRNA throughout the body, posing relevant safety issues. This perspective article discusses the molecular mechanisms through which saRNAs can be transmitted among different cells/tissues. In addition, a simple way to control the possible excessive saRNA intercellular propagation through the co-expression of an EV-anchored protein inhibiting the saRNA replication is proposed. Based on current knowledge, a safety improvement of saRNA-based vaccines appears to be mandatory for their usage in healthy humans. Full article

Escherichia coli and Klebsiella pneumoniae are major contributors to the global challenge of antimicrobial resistance, posing serious threats to public health. Among current preventive strategies, conjugate vaccines that utilize bacterial surface polysaccharides have emerged as a promising and effective approach to counter multidrug-resistant strains. In this study, both the Wzy/Wzx-dependent and ABC transporter-dependent biosynthetic pathways for antigenic polysaccharides were introduced into E. coli W3110 cells. This dual-pathway engineering enabled the simultaneous biosynthesis of two structurally distinct polysaccharides within a single host, offering a streamlined and potentially scalable strategy for vaccine development. Experimental findings confirmed that both polysaccharide types were successfully produced in the engineered strains, although co-expression levels were moderately reduced. A weak competitive interaction was noted during the initial phase of induction, which may be attributed to competition for membrane space or the shared use of activated monosaccharide precursors. Interestingly, despite a reduction in plasmid copy number and transcriptional activity of the biosynthetic gene clusters over time, the overall polysaccharide yield remained stable with prolonged induction. This suggests that extended induction does not adversely affect final product output. Additionally, two glycoproteins were efficiently generated through in vivo bioconjugation of the synthesized polysaccharides with carrier proteins, all within the same cellular environment. This one-cell production system simplifies the workflow and enhances the feasibility of generating complex glycoprotein vaccines. Whole-cell proteomic profiling followed by MFUZZ clustering and Gene Ontology analysis revealed that core biosynthetic genes were grouped into two functional clusters. These genes were predominantly localized to the cytoplasm and were enriched in pathways related to translation and protein binding. Such insights not only validate the engineered biosynthetic routes but also provide a molecular basis for optimizing future constructs. Collectively, this study presents a robust synthetic biology platform for the co-expression of multiple polysaccharides in a single bacterial host. The approach holds significant promise for the rational design and production of multivalent conjugate vaccines targeting drug-resistant pathogens. Full article

Vaccines remain one of the most effective tools in combating infectious diseases, though traditional platforms are constrained by limitations including suboptimal immunogenicity, safety concerns, and manufacturing complexity. Circular RNA (circRNA) vaccines have recently emerged as a novel vaccine modality, demonstrating unique advantages including high stability, low innate immunogenicity, and sustained antigen expression. Although early research has predominantly focused on viral targets, accumulating evidence now supports the application potential of circRNA vaccines against diverse pathogens, particularly antibiotic-resistant bacteria. Through encoding critical antigens or virulence factors, these circRNA vaccines demonstrate capability to induce protective immune responses, presenting a viable alternative to conventional antimicrobial strategies. This review highlights recent advances in circRNA vaccine development, spanning synthetic circularization techniques, delivery approaches, and immunological mechanisms. We emphasize their potential against viral, bacterial, fungal, and parasitic infections, while addressing current challenges and future research directions of this emerging platform. Collectively, these insights underscore circRNA’s multifaceted versatility and its expanding relevance in next-generation vaccine innovation. Full article

Nanoclays have gained attention in biological applications due to their biocompatibility, low toxicity, and cost-effectiveness. Layered double hydroxides (LDHs) are synthetic nanoclays that have been used as adjuvants and antigen carriers in nanovaccines developed through passive bioconjugation. However, performing active bioconjugation to bind antigens covalently and generate subunit nanovaccines remains unexplored. In this study, we investigated the synthesis, functionalization, and active conjugation of LDH nanoparticles to produce subunit nanovaccines with peptides from SARS-CoV-2. The synthesis of Mg-Al LDHs via a coprecipitation and hydrothermal treatment rendered monodisperse particles averaging 100 nm. Their functionalization with (3-aminopropyl)triethoxysilane was better than it was with other organosilanes. Glutaraldehyde was used as a linker to bind lysine as a model biomolecule to establish the best conditions for reductive amination. Finally, two peptides, P₂ and P₅ (epitopes of the SARS-CoV-2 spike protein), were bound on the surface of the LDH to produce two subunit vaccine candidates, reaching peptide concentrations of 125 and 270 µg/mL, respectively. The particles were characterized using DLS, TEM, XRD, TGA, DSC, and FTIR. The cytotoxicity studies revealed that the conjugate with P₂ was non-toxic up to 250 µg/mL, while the immunogenicity studies showed that this conjugate induced similar IgG titers to those reached when aluminum hydroxide was used as an adjuvant. Full article