Search Results (5,335)

A reassessment of the risk-benefit balance of the two lipid nanoparticle (LNP)-based vaccines, Pfizer’s Comirnaty and Moderna’s Spikevax, is currently underway. While the FDA has approved updated products, their administration is recommended only for individuals aged 65 years or older and for those aged 6 months or older who have at least one underlying medical condition associated with an increased risk of severe COVID-19. Among other factors, this change in guidelines reflect an expanded spectrum and increased incidence of adverse events (AEs) and complications relative to other vaccines. Although severe AEs are relatively rare (occurring in < 0.5%) in vaccinated individuals, the sheer scale of global vaccination has resulted in millions of vaccine injuries, rendering post-vaccination syndrome (PVS) both clinically significant and scientifically intriguing. Nevertheless, the cellular and molecular mechanisms of these AEs are poorly understood. To better understand the phenomenon and to identify research needs, this review aims to highlight some theoretically plausible connections between the manifestations of PVS and some unique structural properties of mRNA-LNPs. The latter include (i) ribosomal synthesis of the antigenic spike protein (SP) without natural control over mRNA translation, diversifying antigen processing and presentation; (ii) stabilization of the mRNA by multiple chemical modification, abnormally increasing translation efficiency and frameshift mutation risk; (iii) encoding for SP, a protein with multiple toxic effects; (iv) promotion of innate immune activation and mRNA transfection in off-target tissues by the LNP, leading to systemic inflammation with autoimmune phenomena; (v) short post-reconstitution stability of vaccine nanoparticles contributing to whole-body distribution and mRNA transfection; (vi) immune reactivity and immunogenicity of PEG on the LNP surface increasing the risk of complement activation with LNP disintegration and anaphylaxis; (vii) GC enrichment and double proline modifications stabilize SP mRNA and prefusion SP, respectively; and (viii) contaminations with plasmid DNA and other organic and inorganic elements entailing toxicity with cancer risk. The collateral immune anomalies considered are innate immune activation, T-cell- and antibody-mediated cytotoxicities, dissemination of pseudo virus-like hybrid exosomes, somatic hypermutation, insertion mutagenesis, frameshift mutation, and reverse transcription. Lessons from mRNA-LNP vaccine-associated AEs may guide strategies for the prediction, prevention, and treatment of AEs, while informing the design of safer next-generation mRNA vaccines and therapeutics. Full article

Alzheimer’s disease (AD) is the most common cause of dementia, characterized by progressive cognitive decline and neuropathological hallmarks, including amyloid-β (Aβ) plaques, neurofibrillary tangles (NFTs), and neurodegeneration. Since the amyloid cascade hypothesis was proposed, Aβ has remained a central therapeutic target, with interventions aiming to reduce Aβ production, aggregation, or downstream toxicity. This review first outlines the historical development of the Aβ hypothesis and the two major APP processing pathways (α-cleavage and β-cleavage), highlighting the role of biomarkers in early diagnosis, patient stratification, and regulatory approval. We then summarize the development and clinical outcomes of anti-Aβ small-molecule drugs, including β-secretase inhibitors, γ-secretase modulators, Aβ aggregation inhibitors, receptor/synapse modulators, and metabolic or antioxidant modalities. We further review the progression of biologic therapies, with a particular focus on monoclonal antibodies, vaccines, and emerging gene-silencing strategies, such as small interfering RNA (siRNA) and antisense oligonucleotides. Finally, we discuss future perspectives, including next-generation biologics, multi-target approaches, optimized delivery platforms, and early-prevention strategies. Collectively, these efforts underscore both the challenges and opportunities in translating anti-Aβ therapies into meaningful clinical benefits for patients with AD. Full article

HSV-2 is the main pathogen causing genital herpes, and its infection increases the infection and transmission of HIV-1. Currently, there are no vaccines to prevent HSV-2 infection or treatment that can fully cure it. Mining key host factors that regulate HSV-2 replication and elucidating their specific regulatory mechanisms are crucial for understanding virus–host interactions and discovering new antiviral targets. In the current study, we identified DDX43 as a cellular factor involved in the suppression of HSV-2 replication through comparative transcriptomic analyses of HSV-2-infected epithelial cells, followed by experimental validation. Comprehensive transcriptomic profiling revealed distinct host cellular gene expression patterns in HeLa and ARPE-19 cell lines post HSV-2 infection. Subsequent orthogonal partial least-squares discriminant analysis (OPLS-DA) pinpointed DDX43 as one of the principal mediators distinguishing the host response between HSV-2-infected HeLa and ARPE-19 cells. Furthermore, overexpression of DDX43 inhibited HSV-2 replication, whereas knockdown of endogenous DDX43 enhanced HSV-2 replication. Additional experiments revealed that human DDX43 inhibits HSV-2 replication in an interferon-independent manner. This study demonstrates that DDX43 serves as a host regulator against HSV-2 infection, underscoring the power of comparative transcriptomics in identifying novel host proteins that modulate viral replications. Full article

Virus-like particles (VLPs) formed as a result of self-assembly of viral capsid proteins are widely used as a platform for antigen presentation in vaccine development. However, since the inclusion of a foreign peptide into the capsid protein can alter its spatial structure and interfere with VLP assembly, such insertions are usually limited to short peptides. In this study, we have demonstrated the potential of capsid protein (CP) of single-stranded RNA phage PQ465 to present long peptides using green fluorescent protein (GFP) as a model. GFP was genetically linked to either the N- or C-terminus of PQ465 CP. Hybrid proteins were expressed in Escherichia coli and Nicotiana benthamiana plants. Spherical virus-like particles (~35 nm according to transmission electron microscopy) were successfully formed by both N- and C-terminal fusions expressed in E. coli, and by plant-produced CP with GFP fused to the C-terminus. ELISA revealed that GFP in VLPs was accessible for specific antibodies suggesting that it is exposed on the surface of PQ465-GFP particles. VLPs carrying GFP were recognized by anti-CP antibodies with less efficiency than VLPs formed by empty CP, which indicates shielding of the CP core in PQ465-GFP particles. Therefore, PQ465 CP can be used as a chimeric VLP platform for the display of relatively large protein antigens, which can operate in bacterial and plant expression systems. Full article

Animal toxins contain various bioactive peptides and proteins which have evolved to interact in specific ways. As such, they are a good starting point for developing new drugs and vaccines. This paper examines three natural neurotoxins derived from the black mamba (Dendroaspis polylepis), which show significant pharmacological potential: mambalgins, fasciculins and dendrotoxins. All three may be of value in the treatment of pain, cancer and neurodegenerative disease. Mambalgins provide similar pain relief to opioids but without the risk of addiction; they act by selectively blocking acid-sensitive ion channels (ASICs), especially ASIC1a. Thanks to this inhibitory activity they also demonstrate selective activity against glioblastoma, melanoma and leukemia cells as innovative anticancer drugs. Fasciculins are very strong inhibitors of acetylcholinesterase (AChE) and hence offer promise in multi-target drugs and as treatments for treating Alzheimer’s disease. Dendrotoxins such as DTX-K and DTX-I are able to modulate neuronal excitability and synaptic transmission by blocking voltage-gated potassium channels (Kv1.1, Kv1.2, Kv1.6); both have been shown to be effective against cancer cells, and to influence the cardiovascular, immune, and digestive systems. Recent advances in recombinant biotechnology and protein engineering have allowed their safe production with increased therapeutic value. The review examines the translational potential of D. polylepis venom proteins and highlights the need for additional preclinical research on bioactive molecules of toxin origin. Full article

Pseudorabies virus (PRV), a major swine pathogen, causes severe neurological, respiratory, and reproductive disorders, resulting in substantial economic losses to the global swine industry. Previous studies have shown that the gD glycoprotein of PRV has an effective protective effect. In this study, we constructed a plasmid DNA vaccine (pVAX1-GD-Fc) encoding a gD protein fused with pig IgG Fc and evaluated the adjuvant effects of porcine cGAS, the universal STING complex mimic (UniSTING), or IFN-α in mice. The mice were immunized three times (days 0, 14, and 21) with pVAX1-GD-Fc in the presence or absence of an adjuvant, followed by lethal challenge with PRV-HLJ8 3 days after the final immunization. The results revealed that the pVAX1-GD-Fc group exhibited 20% mortality (1/5 mice) on day 7 postchallenge, and all adjuvanted groups achieved 100% survival during the 14-day observation period. Flow cytometric analysis of splenocytes one week after the second immunization revealed significantly greater CD8+ T cell proportions in the adjuvant groups than in both the mock and pVAX1-GD-Fc-only control groups (p < 0.01). Furthermore, T cell proliferation assays demonstrated a significantly increased stimulation index in the adjuvant-treated mice, confirming enhanced cellular immunity. These findings demonstrate that cGAS, UniSTING, and IFN-α can serve as effective vaccine adjuvants to rapidly enhance cellular immune responses to PRV, highlighting their potential application in veterinary vaccines. Full article

Background: EHEC O157:H7 causes severe gastrointestinal illness by first colonizing the large intestine. It intimately attaches to the epithelial lining, orchestrating distinctive “attaching and effacing” lesions that disrupt the host’s cellular landscape. While much is known about the well-established virulence factors, there are much to learn about the surface proteins’ roles in a living host. Methods: This study presents the first in vivo characterisation of the surface proteome, i.e., proteosurfaceome, of Escherichia coli O157:H7 EDL933 during intestinal infection, revealing spatial and temporal adaptations critical for colonisation and survival. Using a murine ileal loop model, surface proteomic profiles were analysed at early (3 h) and late (10 h) infection stages across the ileum and colon. Results: In total, 272 proteins were identified, with only 13 shared across all conditions, reflecting substantial niche-specific adaptations. Gene ontology enrichment analyses highlighted dominant roles in metabolic, cellular, and binding functions, while subcellular localisation prediction uncovered cytoplasmic moonlighting proteins with surface activity. Comparative analyses revealed dynamic changes in protein abundance. Conclusions: These findings indicate a coordinated shift from stress adaptation and virulence to nutrient acquisition and persistence and provide a comprehensive view of EHEC O157:H7 surface proteome dynamics during infection, highlighting key adaptive proteins that may serve as targets for future therapeutic and vaccine strategies. 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

Background/Objectives: In response to the COVID-19 pandemic, we developed a vaccine candidate against SARS-CoV-2. Spike Ferritin Nanoparticle (SpFN) comprises 24 identical prefusion-stabilized spike proteins anchored to a self-assembled nanoparticle. Organized along the three-fold axis of the ferritin particle, eight SARS-CoV-2 spike trimers are presented per nanoparticle. Methods: Here, we describe the CGMP processes for manufacturing SpFN using transient transfection of Expi293F cells. Results: The final yield of SpFN was ~10 mg per liter of media supernatant. The resulting protein is stable in cold storage for two years at −20 °C, as well as for a month at room temperature, and can withstand multiple freeze/thaw cycles. SpFN material produced using the CGMP protocols adjuvanted with Army Liposomal Formulation-QS-21 (ALFQ) elicited potent neutralizing antibodies against WA-1, Alpha, Beta, and Delta variants in mice as measured by a pseudovirus neutralization assay. Conclusions: This work demonstrates rapid development and scaled-up production of clinical-grade SARS-CoV-2 vaccine protein material, allowing permissive storage and transport conditions, and serves as a framework for recombinant protein production for future emergent pathogens. Full article

Background/Objectives: Innovative intranasal delivery systems have emerged as a strategy to overcome the limitations of conventional COVID-19 vaccines, including suboptimal mucosal immunity, limited antigen retention, and vaccine hesitancy. This study aimed to evaluate physicochemical properties and murine safety of a novel COVID-19 intranasal vaccine candidate based on CHIVAX 2.1 (CVX)-loaded chitosan nanoparticles (CNPs). Methods: The CVX recombinant protein was encapsulated into CNPs using the ionic gelation method. The nanoparticles were characterized by their physicochemical properties (mean size, zeta potential, morphology, and encapsulation efficiency) and spectroscopic profiles. Mucin adsorption and in vitro release profiles in simulated nasal fluid were also assessed. In vivo compatibility was evaluated through histopathological analysis of tissues in male C-57BL/6J mice following intranasal administration. Results: CNPs exhibited controlled size distribution (38.5–542.5 nm) and high encapsulation efficiency (65.4–92.2%). Zeta potential values supported colloidal stability. TEM analysis confirmed spherical morphology and successful CVX encapsulation, and immunogenic integrity was also demonstrated. Mucin adsorption analysis demonstrated effective nasal retention, particularly in particles ≈90 nm. In vitro release studies revealed a biphasic protein profile, where ≈80% of the recombinant protein was released within 2 h. Importantly, histopathological analyses and weight monitoring of intranasally immunized mice revealed no signs of adverse effects related to toxicity. Conclusions: The ionic gelation encapsulation process preserved the physical and immunological integrity of CVX antigen. Furthermore, the intranasal administration of the CVX-loaded CNPs demonstrated a favorable safety profile in vivo. These findings support the potential of the CVX intranasal vaccine formulation for further immunogenicity studies, with no apparent biosafety concerns. Full article

Introduction/Background: Rift Valley fever virus (RVFV) and peste des petits ruminants virus (PPRV) are significant pathogens affecting small ruminants, causing substantial economic losses in the affected regions. The development of effective vaccines against both viruses is crucial for disease control. Recombinant viruses expressing heterologous antigens have shown promise as multivalent vaccine candidates. Unlike conventional PPRV vaccines, our recombinant RVFV-vectored vaccines offer a novel dual-protection strategy against RVF and PPR, combining safety, immunogenicity, and a DIVA strategy. Methods: Recombinant RVFVs (ZH548 strain) were generated to express either the hemagglutinin (H) or fusion (F) proteins from the PPRV strain Nigeria 75/1. The stability of these recombinant viruses was assessed through consecutive passages in cell culture. Immunogenicity studies were carried out in both mice and sheep to assess the induction of cellular and humoral immune responses capable of providing protection against RVFV and PPRV. These studies included intracellular cytokine staining (ICS), IFN-γ ELISAs, standard ELISAs for antibody detection, and virus neutralization assays. Results: The recombinant RVFVs expressing PPRV H or F proteins demonstrated stability in cell culture, maintaining high viral titers and consistent transgene expression over four passages. Immunization of mice resulted in the production of serum antibodies capable of neutralizing both RVFV and PPRV in vitro as well as cell-mediated immune responses specific to PPRV and RVFV antigens. In mice vaccinated with a high dose (10⁵ pfu), RVFV neutralizing titers reached ≥1:160 and PPRV neutralizing titers ranged from 1:40 to 1:80 by day 30 post-immunization. In sheep, neutralizing antibody titers against RVFV exceeded 1:160 as early as 2 days post-inoculation, while PPRV-specific neutralization titers reached up to 1:80 by day 21 in responsive individuals. In mice, administration of rZH548ΔNSs:F_PPRV elicited a detectable CD8+ IFNγ+ T-cell response against PPRV, with levels ranging from 1.29% to 1.56% for the low and high doses, respectively. In sheep, rZH548ΔNSs:F_PPRV also induced a robust IFNγ production against PPRV at 14 and 21 days post-infection (dpi). Conclusions: The successful generation and characterization of recombinant RVFVs expressing PPRV antigens demonstrate the potential of using rationally attenuated RVFV as a vector for multivalent vaccine development. Notably, the strategy proved more effective for the recombinant virus expressing the F protein, as it consistently induced more robust cellular and humoral immune responses. These results suggest that this approach could be a viable strategy for simultaneous immunization against Rift Valley fever and other prevalent ruminant diseases, such as peste des petits ruminants. Even though challenge studies were not performed in target species, the strong immune response observed supports including them in future studies. Full article

The breach of an interspecies barrier by RNA viruses has facilitated the emergence of lethal hCoVs, particularly SARS-CoV-2, resulting in significant socioeconomic setbacks and public health risks globally in recent years. Moreover, the high evolutionary plasticity of hCoVs has led to the continuous emergence of diverse variants, complicating clinical management and public health responses. Studying the evolutionary trajectory of hCoVs, which provides a molecular roadmap for understanding viruses’ adaptation, tissue tropism, spread, virulence, and immune evasion, is crucial for addressing the challenges of zoonotic spillover of viruses. Tracing the evolutionary trajectory of lethal hCoVs provides essential genomic insights required for risk stratification, variant/sub-variant classification, preparedness for outbreaks and pandemics, and the identification of critical viral elements for vaccine and therapeutic development. Therefore, this review examines the evolutionary landscape of the three known lethal hCoVs, presenting a focused narrative on SARS-CoV-2 variants under monitoring (VUMs) as of May 2025. Using advanced bioinformatics approaches and data visualization, the review highlights key spike protein substitutions, particularly within the receptor-binding domain (RBD), which drive transmissibility, immune escape, and potential resistance to therapeutics. The article highlights the importance of real-time genomic surveillance and intervention strategies in mitigating emerging variant/sub-variant risks within the ongoing COVID-19 landscape. Full article

Background: One of the primary strategies for preventing and reducing infectious diseases is vaccination. There are numerous licensed vaccinations of various kinds that can prevent viral infection by triggering the immune system’s reaction to specific antigens beforehand. To elicit a stronger immune response, however, two elements of the immune system—humoral and cellular immunity—should be addressed. Since they target proteins that are difficult to alter, recent innovative techniques for vaccine delivery systems—such as liposomes, nanogels, microemulsions, etc.—have shown excellent immunogenicity qualities. Methods: PubMed, ScienceDirect, and Google Scholar were used as the databases for literature search, and keywords such as “Virosomes”, “Hemagglutinin”, and “IRIV” were selected to ensure relevant articles were included. Results: This article examines a cutting-edge method called virosomes, which are an effective way to deliver pharmaceutically active ingredients that target a variety of illnesses and ailments, as well as vaccines. This resulted from the fact that virosomes possess numerous structural characteristics that might trigger sophisticated immune reactions by utilizing the inactivated virus’s envelope or by imitating it through recombinant methods. Conclusions: Here, we will walk you through the history of virosome development, explore various manufacturing techniques, provide an overview of the latest patents, and conclude with the potential for more virosomal revolutions. Full article

Pasteurella multocida is a Gram-negative bacterium causing significant livestock diseases, like fowl cholera and hemorrhagic septicemia in cattle, and wound infection in humans. Classified into four subspecies and five capsular serotypes, it possesses multiple virulence factors, including capsular polysaccharides (CPSs), lipopolysaccharides (LPSs), outer membrane proteins (OMPs), iron acquisition proteins, and toxins that serve as vaccine targets. Antimicrobial treatment is challenging, so vaccination is key. Commercial vaccines include killed and live attenuated types, which are commonly used, though they have intrinsic problems. Advanced vaccines like recombinant subunit and DNA vaccines are emerging. Subunit vaccines targeting OMPs (OmpH, OmpA, PlpE, VacJ, and PmSLP) and recombinant Pasteurella multocida toxin (rPMT) show high efficacy in animal models, and their recombinant proteins induce strong immune responses. DNA vaccines have promise but limited use. The challenges in vaccine development are the strain diversity, short-term immunity, and inconsistent cross-protection. There is also a lack of research on recombinant and subunit vaccine development for small ruminants. Future research should focus on multivalent vaccines, optimization, including improving adjuvants and optimizing DNA vaccine delivery. Full article

Snakebite envenoming is a neglected tropical disease contributing to a significant number of morbidities and mortalities globally. Reports indicate that venom variation influences antivenom efficacy, which might affect treatment outcomes. The venom composition of Daboia russelii (Russell’s viper), one of the big four snakes in India, has been extensively studied from different geographical regions of India. Nonetheless, the Russell’s viper venom proteome from Kerala (Western Ghats region), together with its study in comparison with the same species’ venom from Tamil Nadu, has not been explored yet. In the current study, Daboia russelii venom from Irula (RVi) and the Western Ghats region in Kerala (RVwg) was characterized through mass spectrometry-based proteomics and few functional assays. The proteomics study identified 52 proteins from 14 snake protein families in RVi and 61 proteins from 17 snake venom protein families in RVwg. Some of the protein families, including DNase and hyaluronidase, as well as vascular endothelial growth factor, were exclusively identified in RVwg venom. Comparative functional analysis indicated that RVwg exhibited higher fibrinogenolytic and hyaluronidase activities, while RVi venom showed higher phospholipase A₂ and L-amino acid oxidase activities. Through ELISA, RVi venom showed an end-point titration value of 1:24,300 for all the antivenoms used in this study, whereas for RVwg, compared to PSAV (Premium serums and vaccines) (1:2700), Virchow and VINS (both 1:8100) antivenoms showed better immunological cross-reactivity. Immunoblotting experiments indicated differential binding and recognition of antigenic epitopes present in both venoms by the polyvalent antivenoms used in the current study. All these findings highlight that the venom proteome varies according to the geographical location, and this significantly influences antivenom efficacy. Full article