Search Results (368)

Background: Rabies remains a fatal zoonotic disease caused by rabies virus (RABV), posing substantial global health challenges. Current vaccine production faces challenges in manufacturing efficiency and cost-effectiveness. The RABV glycoprotein (RABV-G) serves as the key antigen for eliciting protective immunity. Methods: We developed a novel QS21+CpG-adjuvanted RABV-G subunit vaccine and systematically compared its performance against three control formulations: mRNA vaccine composed of H270P-targeted mutation packaged in lipid nanoparticles (LNP), named LNP-mRNA-G-H270P, commercial inactivated vaccine, and alum-adjuvanted RABV-G subunit vaccine. Results: The result show that the G+QS21+CpG subunit vaccine elicited superior humoral immunity, as evidenced by significantly higher RABV-G-specific IgG titers and virus-neutralizing antibody responses compared to all other groups. The LNP-mRNA-G-H270P vaccine maintained its expected cellular immunity advantage, with the G+QS21+CpG group exhibiting moderately reduced but still significant levels of IFN-γ-secreting splenocytes and levels of IL-2 in the supernatant of spleen cells, as well as IFN-γ-producing CD4+ T cells. Both LNP-mRNA-G-H270P and G+QS21+CpG vaccine groups provided 100% protection against lethal challenge (50LD₅₀ RABV). Conclusions: These findings provide novel vaccine/adjuvant strategies for rabies while elucidating platform-specific immunogenicity patterns, offering critical insights for pathogens requiring balanced humoral/cellular immunity. Full article

Messenger RNA (mRNA) vaccine technology has revolutionized the field of immunization, offering a non-infectious, non-genome-integrating platform that addresses many limitations of traditional vaccine modalities. Recent advancements in chemical modifications, delivery systems, and manufacturing processes have enhanced the stability, efficacy, and safety of RNA-based therapeutics, expanding their application beyond infectious diseases to include genetic disorders, cancer, and rare diseases. Central to the success of RNA vaccines is their ability to orchestrate a finely tuned immune response, leveraging both innate and adaptive immunity to achieve robust and durable protection. This review synthesizes current knowledge on the immunological mechanisms underpinning RNA vaccine efficacy, with a focus on the roles of pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and RIG-I-like receptors (RLRs) in sensing exogenous RNA, the impact of RNA modifications and manufacturing impurities on innate immune activation, and the subsequent cytokine and chemokine milieu that shapes adaptive responses. We also discuss the dual role of lipid nanoparticle (LNP) delivery systems as both carriers and adjuvants, highlighting their contribution to the vaccine’s immunogenicity and reactogenicity profile. Understanding these complex immune interactions is critical for optimizing RNA vaccine design, minimizing adverse effects, and expanding their therapeutic potential. This review aims to provide a comprehensive overview of the immune symphony orchestrated by RNA vaccines and to identify key areas for future research to further refine and expand the utility of this transformative technology. Full article

Melanoma is a type of skin cancer with high lethality and increasing incidence. Current treatments typically involve surgery as the first step, followed by adjuvant treatments, which are necessary in most cases. These adjuvant treatments may include radiotherapy, phototherapy, chemotherapy, immunotherapy, and combined therapies. However, patients with melanoma still face great difficulties, such as the inefficiency of therapies and serious side effects, in addition to uncomfortable scars. Most of these problems are related to limitations of antitumor therapies, such as the low bioavailability of drugs, degradation in biological fluids, rapid clearance, difficulty in reaching the tumors, the low capacity for accumulation and infiltration in tumor cells, toxicity to healthy cells, and systemic action. Thus, antitumor therapy for melanoma remains a challenge. In this line, nanotechnology has brought new perspectives and has been the subject of intensive research on the use of nanoparticles (liposomes, lipid nanoparticles, polymeric nanoparticles, inorganic nanoparticles, carbon nanotubes, dendrimers, nanogels, and biomimetic nanoparticles, among others) as carriers for the controlled release of drugs and tumor diagnosis. This work outlines the main limitations of current melanoma therapies and explores how nanoparticle-based drug delivery systems can overcome these challenges, highlighting recent research and clinical developments. Full article

Cucurbitacin B (CuB), a tetracyclic triterpenoid compound isolated from Cucurbitaceae plants, exhibits inhibitory effects on various tumor cells (e.g., liver, gastric, and colorectal cancer cells). Since the 1970s–1980s, cucurbitacin tablets containing CuB have been used as an adjuvant therapy for chronic hepatitis and primary liver cancer. CuB exerts anticancer effects through multiple mechanisms: inducing apoptosis, cell cycle arrest (G2/M or S phase), autophagy, and cytoskeleton disruption; inhibiting migration, invasion, and angiogenesis (via VEGF/FAK/MMP-9 and Wnt/β-catenin pathways); regulating metabolic reprogramming and immune responses; inducing pyroptosis, ferroptosis, and epigenetic changes; and reversing tumor drug resistance. These effects are associated with signaling pathways like JAK/STAT, PI3K/Akt/mTOR, and FOXM1-KIF20A. To improve its application potential, strategies such as structural modification (e.g., NO donor conjugation), combination therapy (with gemcitabine or cisplatin), and nanomaterial-based delivery (e.g., liposomes and exosome-mimicking nanoparticles) have been developed to enhance efficacy, reduce toxicity, and improve bioavailability. CuB shows broad-spectrum anticancer activity, but further research is needed to clarify the mechanisms underlying its cell-specific sensitivity and interactions with the immune system. This review systematically summarizes the physicochemical properties, anticancer mechanisms, and strategies for applying CuB and suggests future research directions, providing references for scientific research and clinical translation. Full article

Anthrax remains a formidable bioterrorism threat for which new, optimized and thermostable vaccines are needed. We previously demonstrated that five immunizations of rabbits with a multiple-antigenic-peptide (MAP) vaccine in either Freund’s adjuvant or human-use adjuvants can elicit antibody (Ab) against the loop-neutralizing determinant (LND), a cryptic neutralizing epitope in the 2β2-2β3 loop of protective antigen from Bacillus anthracis (B. anthracis), which mediates complete protection of rabbits from inhalation spore challenge with the B. anthracis Ames strain. To develop a more immunogenic vaccine, we molecularly constructed a virus-like particle (VLP) vaccine, comprising the Woodchuck hepatitis core antigen capsid (WHcAg) displaying 240 copies of the LND epitope on each nanoparticle. Initial studies showed that the LND-VLP was immunogenic in rabbits following two immunizations, and passive transfer of the rabbit sera into A/J mice conferred complete protection from aerosol challenge with B. anthracis. Further optimization of the vaccine revealed that the lyophilized LND-VLP vaccine was capable of eliciting highly protective levels of neutralizing antibody with two immunizations, and in some rabbits, a single immunization, using human-use adjuvants. A lyophilized LND-VLP nanoparticle vaccine may be an effective stand-alone vaccine or may complement PA-based vaccines as a future pre- or post-exposure vaccine for anthrax. Full article

The use of vaccines incorporating subunit proteins and viral components has significantly increased in recent decades, emphasizing the need for more effective and modular adjuvants. This study examined saponins from Saponaria officinalis, regarded as one of the most promising plant sources for developing an adjuvant platform using nanocomplex formation. A nanoparticle adjuvant containing saponins from Saponaria officinalis can be used to stimulate a humoral immune response; this ability was demonstrated using a model that included various viral proteins. The humoral immune response enhanced by saponin-containing adjuvants can increase from four to sixteen times, depending on the type of antigen used. Additionally, this response surpasses that triggered by antigens paired with aluminum hydroxide and is comparable to responses induced by adjuvants that contain Quil A. The further investigation of these platforms may yield a broader range of immunostimulants that can enhance vaccine effectiveness. Full article

Background/Objectives: Curcumin (CUR) is well known for its therapeutic properties, particularly attributed to its antioxidant and anti-inflammatory effects in managing chronic diseases such as arthritis. While CUR application for biomedical purposes is well known, the phytochemical has several restrictions given its poor water solubility, physicochemical instability, and low bioavailability. These limitations have led to innovative formulations, with nanocarriers emerging as a promising alternative. For this reason, this study aimed to address the potential advantages of associating CUR with nanocarrier systems in managing arthritis through a scoping review. Methods: A systematic literature search of preclinical (in vivo) and clinical studies was performed in PubMed, Scopus, and Web of Science (December 2024). General inclusion criteria include using CUR or natural derivatives in nano-based formulations for arthritis treatment. These elements lead to the question: “What is the impact of the association of CUR or derivatives in nanocarriers in treating arthritis?”. Results: From an initial 536 articles, 34 were selected for further analysis (31 preclinical investigations and three randomized clinical trials). Most studies used pure CUR (25/34), associated with organic (30/34) nanocarrier systems. Remarkably, nanoparticles (16/34) and nanoemulsions (5/34) were emphasized. The formulations were primarily presented in liquid form (23/34) and were generally administered to animal models through intra-articular injection (11/31). Complete Freund’s Adjuvant (CFA) was the most frequently utilized among the various models to induce arthritis-like joint damage. The findings indicate that associating CUR or its derivatives with nanocarrier systems enhances its pharmacological efficacy through controlled release and enhanced solubility, bioavailability, and stability. Moreover, the encapsulation of CUR showed better results in most cases than in its free form. Nonetheless, most studies were restricted to the preclinical model, not providing direct evidence in humans. Additionally, inadequate information and clarity presented considerable challenges for preclinical evidence, which was confirmed by SYRCLE’s bias detection tools. Conclusions: Hence, this scoping review highlights the anti-arthritic effects of CUR nanocarriers as a promising alternative for improved treatment. Full article

Background: Infectious bronchitis virus (IBV) is a gammacoronavirus that causes a highly contagious disease in chickens and seriously endangers the poultry industry. The GI-19 is a predominant lineage. However, no effective commercially available vaccines against this virus are available. Methods: In this present study, the CHO eukaryotic and the E.coli prokaryotic expression system were used to express S1-SpyTag and AP205-SpyCatcher, respectively. Subsequently, the purified S1-SpyTag and AP205-SpyCatcher were coupled to form the nanoparticles AP205-S1 (nAP205-S1) in PBS buffer at 4 °C for 48 h. S1-SpyTag and nAP205-S1 were formulated into vaccines with white oil adjuvant and employed to immunize 1-day-old SPF chickens for the comparative evaluation of their immune efficacy. Results: The nAP205-S1 vaccine in chickens induced robust IBV-specific humoral and cellular immune responses in vivo. Importantly, the humoral and cellular immune responses elicited by the nAP205-S1 vaccine were more robust than those induced by the IBV S1-SpyTag vaccine at both the same dose and double the dose, with a notably significant difference observed in the cellular immune response. Furthermore, experimental data revealed that chicken flocks vaccinated with nAP205-S1 achieved 100% group protection following a challenge, exhibiting a potent protective immune response and effectively inhibiting viral shedding. Conclusions: These results reveal the potential of developing a novel nanoparticle vaccine with broadly protective immunity against GI-19 IBV. Full article

Vaccine adjuvants are non-immunogenic agents that enhance or modulate immune responses to co-administered antigens and are essential to modern vaccines. Despite their importance, few are approved for human use. The rise of new pathogens and limited efficacy of some existing vaccines underscore the need for more advanced and effective formulations, particularly for vulnerable populations. Aluminum-based adjuvants are commonly used in vaccines and effectively promote humoral immunity. However, they mainly induce a Th2-biased response, making them suboptimal for diseases requiring cell-mediated immunity. In contrast, saponin-based adjuvants from the Quillajaceae family elicit a more balanced Th1/Th2 response and generate antigen-specific cytotoxic T cells (CTL). Due to ecological damage and limited availability caused by overharvesting Quillaja saponaria Molina barks, efforts have intensified to identify alternative plant-derived saponins with enhanced efficacy and lower toxicity. Quillaja brasiliensis (A.St.-Hil. and Tul.) Mart. (syn. Quillaja lancifolia D.Don), a related species native to South America, is considered a promising renewable source of Quillajaceae saponins. In this review, we highlight recent advances in vaccine adjuvant research, with a particular focus on saponins extracted from Q. brasiliensis leaves as a sustainable alternative to Q. saponaria saponins. These saponin fractions are structurally and functionally comparable, exhibiting similar adjuvant activity when they were formulated with different viral antigens. An alternative application involves formulating saponins into nanoparticles known as ISCOMs (immune-stimulating complexes) or ISCOM-matrices. These formulations significantly reduce hemolytic activity while preserving strong immunoadjuvant properties. Therefore, research advances using saponin-based adjuvants (SBA) derived from Q. brasiliensis and their incorporation into new vaccine platforms may represent a viable and sustainable solution for the development of more less reactogenic, safer, and effective vaccines, especially for diseases that require a robust cellular immunity. Full article

Background: Chitosan, a family of polysaccharides composed of glucosamine and N-acetyl glucosamine, is a promising adjuvant candidate for eliciting potent immune response. Methods: This study compared the adjuvant effects of chitosan to those of empty lipid nanoparticles (eLNPs) and aluminum hydroxide (alum) following administration of recombinant SARS-CoV-2 spike immunogen in adult mice. Mice received the adjuvanted recombinant protein vaccine in a prime-boost regimen with four weeks interval. Subsequent analyses included serological assessment of antibody responses, evaluation of T cell activity, immune cell recruitment and cytokine profiles at injection site. Results: Compared to alum, chitosan induced a more balanced Th1/Th2 response, akin to that observed with eLNPs, demonstrating its ability to modulate both the humoral and cellular immune pathways. Chitosan induced a different proinflammatory cytokine (e.g., IL-1⍺, IL-2, IL-6, and IL-7) and chemokine (e.g., Eotaxin, IP-10, MIP-1a) profile compared to eLNPs and alum at the injection site and in the draining lymph nodes. Moreover, chitosan potentiated the recruitment of innate immune cells, with neutrophils accounting for about 40% of the infiltrating cells in the muscle, representing a ~10-fold increase compared to alum and a comparable level to eLNPs. Conclusions: These findings collectively indicate that chitosan has the potential to serve as an effective adjuvant, offering comparable, and potentially superior, properties to those of currently approved adjuvants. Full article

Objectives: Research on the immunocastration vaccine is of great significance for animal management. In this study, the gonadotropin-releasing hormone (GnRH) ferritin nanoparticle vaccine was constructed using Spy Catcher-Spy Tag (SC-ST) as a delivery system; Methods: The Spy Catcher was constructed to fuse with the expression vector pET-30a-SF of ferritin nanoparticles. Two polypeptides, STG1: Spy Tag-GnRH I-PADRE and STG2: Spy Tag-GnRH I-GnRH II, coupled to SF in vitro to form two nanoparticles, were designed and synthesized to detect castration effects in mice. We mixed them with the adjuvant MONTANIDE ISA 206 VG to explore the adjuvant’s effect on immunogenicity; Results: All immunized groups produced anti-GnRH specific antibodies after the second immunization, which was significantly higher in the immunized group and the combined adjuvant group than in the control group, and the immune response could still be detected at the 12th week. The concentrations of testosterone, follicle-stimulating hormone, and luteinizing hormone in serum were significantly decreased. The number of sperm in the epididymis of mice in each immune group was significantly reduced, and the rate of sperm deformity was high; Conclusions: The two ferritin-based GnRH nanoparticles developed in this study can significantly cause testicular atrophy, decreased gonadal hormone concentration, decreased sperm count, and increased deformity rate in male mice. These findings provide experimental evidence supporting their potential application in animal immunocastration. 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

Background: Ophidism is a globally neglected health problem. In Argentina, Crotalus durissus terrificus (C.d.t., South American rattlesnake) is one of the species of greatest medical importance since its venom contains mainly crotoxin (CTX), a potent enzyme–toxin with PLA₂ activity, which is responsible for its high lethality. Objective: In this work, we aimed to generate nanovenoms (NVs), complexes formed by CTX adsorbed onto 150 nm silica nanoparticles (SiNPs), and to study their physicochemical, biological, and immunomodulatory activities for potential use as adjuvants (ADJs) in antivenom (AV) production. Methods: CTX was isolated and corroborated by SDS-PAGE. Then, CTX was adsorbed on the synthetized Stöber SiNPs’ surfaces, forming a monolayer and retaining its biological activity (as observed by the MTT cell proliferation assay using the THP-1 cell line). Results: Immunomodulatory activity revealed a high pro-inflammatory (IL-1β) response induced by SiNPs followed by NVs. In the case of the anti-inflammatory response, NVs presented significant differences for TGF-β only after cell activation with LPS. No significant differences were observed in IL-10 levels. Conclusions: Thus, these results suggest that NVs together with SiNPs could increase immunogenicity and enhance immune response, turning them into potential tools for the generation of new antivenoms. Full article

Virus-like nanoparticles (VNPs) based on Moloney murine leukemia virus represent a well-established platform for the expression of heterologous molecules such as cytokines, cytokine receptors, peptide MHC (pMHC) and major allergens, but their application for inducing protective anti-viral immunity has remained understudied as of yet. Here, we variably fused the wildtype SARS-CoV-2 spike, its receptor-binding domain (RBD) and nucleocapsid (NC) to the minimal CD16b-GPI anchor acceptor sequence for expression on the surface of VNP. Moreover, a CD16b-GPI-anchored single-chain version of IL-12 was tested for its adjuvanticity. VNPs expressing RBD::CD16b-GPI alone or in combination with IL-12::CD16b-GPI were used to immunize BALB/c mice intramuscularly and subsequently to investigate virus-specific humoral and cellular immune responses. CD16b-GPI-anchored viral molecules and IL-12-GPI were well-expressed on HEK-293T-producer cells and purified VNPs. After the immunization of mice with VNPs, RBD-specific antibodies were only induced with RBD-expressing VNPs, but not with empty control VNPs or VNPs solely expressing IL-12. Mice immunized with RBD VNPs produced RBD-specific IgM, IgG_2a and IgG₁ after the first immunization, whereas RBD-specific IgA only appeared after a booster immunization. Protein/peptide microarray and ELISA analyses confirmed exclusive IgG reactivity with folded but not unfolded RBD and showed no specific IgG reactivity with linear RBD peptides. Notably, booster injections gradually increased long-term IgG antibody avidity as measured by ELISA. Interestingly, the final immunization with RBD–Omicron VNPs mainly enhanced preexisting RBD Wuhan Hu-1-specific antibodies. Furthermore, the induced antibodies significantly neutralized SARS-CoV-2 and specifically enhanced cellular cytotoxicity (ADCC) against RBD protein-expressing target cells. In summary, VNPs expressing viral proteins, even in the absence of adjuvants, efficiently induce functional SARS-CoV-2-specific antibodies of all three major classes, making this technology very interesting for future vaccine development and boosting strategies with low reactogenicity. Full article

Background: Vaccines have revolutionized disease prevention, yet their effectiveness is challenged by variable immunogenicity, individual response differences, and emerging variants. Biomimetic strategies, inspired by natural immune processes, offer new avenues to enhance vaccine performance. Objectives: This narrative review examines how bioinspired approaches—grounded in evolutionary medicine, immunology, and host–microbiota interactions—can improve vaccine immunogenicity and long-term protection. We further examine the evolutionary foundations of immune responses, highlighting how an evolutionary perspective can inform the development of durable, broadly protective, and personalized vaccines. Furthermore, mechanistic insights at the molecular and cellular level are explored, including Toll-like receptor (TLR) engagement, dendritic cell activation pathways, and MHC-I/MHC-II-mediated antigen presentation. These mechanisms are often mimicked in biomimetic systems to enhance uptake, processing, and adaptive immune activation. Results: The review highlights how immunosenescence, maternal immunity, genetic variation, and gut microbiota composition influence vaccine responses. Biomimetic platforms—such as nanoparticle carriers and novel adjuvants—enhance antigen presentation, boost adaptive immunity, and may overcome limitations in traditional vaccine approaches. Additionally, co-administration strategies, delivery systems, and microbiota-derived immunomodulators show promise in improving vaccine responsiveness. Conclusions: Integrating biomimetic and evolutionary principles into vaccine design represents a promising path toward safer, longer-lasting, and more effective immunizations Full article