Search Results (5,081)

Bone integrity is maintained through continuous remodeling, orchestrated by the coordinated actions of osteocytes, osteoblasts, and osteoclasts. Once considered passive bystanders, osteocytes are now recognized as central regulators of this process, mediating biochemical signaling and mechanotransduction. Malfunctioning osteocytes contribute to serious skeletal disorders such as osteoporosis. Mesenchymal stromal cells (MSCs), multipotent stem cells capable of differentiating into osteoblasts, have emerged as promising agents for bone regeneration, primarily through the paracrine effects of their secreted exosomes. MSC-derived exosomes are nanoscale vesicles enriched with proteins, lipids, and nucleic acids that promote intercellular communication, osteoblast proliferation and differentiation, and angiogenesis. Notably, they deliver osteoinductive microRNAs (miRNAs) that influence osteogenic markers and support bone tissue repair. In vivo investigations validate their capacity to enhance bone regeneration, increase bone volume, and improve biomechanical strength. Additionally, MSC-derived exosomes regulate the immune response, creating pro-osteogenic and pro-angiogenic factors, boosting their therapeutic efficacy. Due to their cell-free characteristics, MSC-derived exosomes offer benefits such as diminished immunogenicity and minimal risk of off-target effects. These properties position them as promising and innovative approaches for bone regeneration, integrating immunomodulatory effects with tissue-specific regenerative capabilities. Full article

Background: It is still challenging to develop effective vaccines against tumorigenic human gammaherpesviruses such as Epstein–Barr virus (EBV). A major obstacle is the lack of a small animal model that reproduces the natural infection course of human gammaherpesviruses to allow for proper assessment of vaccine efficacy. Murine gammaherpesvirus 68 (MHV68) is a natural pathogen of wild rodents and laboratory mice and therefore can be used as a surrogate for human gammaherpesviruses to evaluate vaccination strategies. Methods: In this study, two mRNA vaccine candidates were generated, one encoding a fusion protein of the MHV68 gH with the gL (gHgL-mRNA) and the other expressing the MHV68 gB protein (gB-mRNA). The immunogenicity and protective efficacy of the mRNA vaccine candidates were evaluated in a mouse model of MHV68 infection. Results: The gHgL-mRNA but not the gB-mRNA candidate vaccine was able to induce neutralizing antibodies in mice, whereas both vaccines could elicit antigen-specific T-cell responses. Following MHV68 intranasal inoculation, complete blocking of the establishment of viral latency was observed in some mice immunized with individual gHgL-mRNA or gB-mRNA vaccines. Notably, co-immunization with the two mRNA vaccines appeared to be more effective than individual vaccines, achieving sterile immunity in 50% of the vaccinated mice. Conclusions: This study demonstrates that immunization with mRNA platform-based subunit vaccines is indeed capable of preventing MHV68 latent infection, thus validating a safe and efficacious vaccination strategy that may be applicable to human gammaherpesviruses. Full article

Vaccination is the most effective method to counteract infectious diseases in farmed fish. It secures aquaculture production and safeguards the wild stock and aquatic ecosystem from catastrophic contagious diseases. In vaccine development, recombinant subunit vaccines are favorable candidates since they can be economically produced in large quantities without growing many pathogens, as in inactivated or attenuated vaccine production. However, recombinant subunit vaccines are often weak or deficient in immunogenicity, resulting in inadequate defenses against infections. Technologies that can increase the immunogenicity of recombinant subunit vaccines are in desperate need. Enhanced green fluorescence protein (EGFP) has a low antigenicity and is susceptible to folding changes and losing fluorescence after fusing with other proteins. Using these valuable features of EGFP, we comprehend two amphipathic alpha-helical peptides, AH1 and AH3, derived from Hepatitis C virus and Influenza A virus, respectively, that can induce high immune responses of their fused EGFP in fish without affecting their folding. AH3-EGFP has the most elevated cell binding, significantly 62% and 36% higher than EGFP and AH1-EGFP, respectively. Immunizations with AH1-EGFP or AH3-EGFP significantly induced higher anti-EGFP antibody levels 300–500-fold higher than EGFP immunization after the boost injection in rainbow trout. Our results suggest that AH1 and AH3 effectively increase the immunogenicity of EGFP without influencing its structure. Further validation of their value in other recombinant proteins is necessary to demonstrate their broader utility in enhancing the immunogenicity of subunit vaccines. We also suggest that EGFP and its variants are promising candidates for initially screening proper immunogenicity-enhancing peptides or proteins to advance recombinant subunit vaccine development. Full article

The cornea, the transparent anterior window of the eye, critically refracts light and protects intraocular structures. Corneal pathologies, including trauma, infection, chemical injury, metabolic diseases, genetic conditions, and age-related degeneration, can lead to significant visual impairment. While penetrating keratoplasty or full-thickness corneal transplantation remains a standard and effective intervention for severe corneal dysfunction, limitations in donor tissue availability and the risk of immunogenic graft rejection necessitate alternative therapeutic strategies. Furthermore, for cases of isolated epithelial disfunction, a full-thickness cornea graft may not be required or effective. This review examines the potential of corneal epithelial constructs derived from autologous stem cells with functional barrier properties for corneal reconstruction and in vitro pharmacotoxicity testing. In this review, we delineate the current limitations of corneal transplantation, the advantages of stem cell-based approaches, and recent advances in generating engineered corneal epithelium. Finally, we address remaining technical challenges and propose future research directions aimed at clinical translation. Full article

Background: Pain is a complex phenomenon characterized by unpleasant experiences with profound heterogeneity influenced by biological, psychological, and social factors. According to the National Health Interview Survey, 50.2 million U.S. adults (20.5%) experience pain on most days, with the annual cost of prescription medication for pain reaching approximately USD 17.8 billion. Theranostic pain nanomedicine therefore emerges as an attractive analgesic strategy with the potential for increased efficacy, reduced side-effects, and treatment personalization. Theranostic nanomedicine combines drug delivery and diagnostic features, allowing for real-time monitoring of analgesic efficacy in vivo using molecular imaging. However, clinical translation of these nanomedicines are challenging due to complex manufacturing methodologies, lack of standardized quality control, and potentially high costs. Quality by Design (QbD) can navigate these challenges and lead to the development of an optimal pain nanomedicine. Our lab previously reported a macrophage-targeted perfluorocarbon nanoemulsion (PFC NE) that demonstrated analgesic efficacy across multiple rodent pain models in both sexes. Here, we report PFC-free, biphasic nanoemulsions formulated with a biocompatible and non-immunogenic plant-based coconut oil loaded with a COX-2 inhibitor and a clinical-grade, indocyanine green (ICG) near-infrared fluorescent (NIRF) dye for parenteral theranostic analgesic nanomedicine. Methods: Critical process parameters and material attributes were identified through the FMECA (Failure, Modes, Effects, and Criticality Analysis) method and optimized using a 3 × 2 full-factorial design of experiments. We investigated the impact of the oil-to-surfactant ratio (w/w) with three different surfactant systems on the colloidal properties of NE. Small-scale (100 mL) batches were manufactured using sonication and microfluidization, and the final formulation was scaled up to 500 mL with microfluidization. The colloidal stability of NE was assessed using dynamic light scattering (DLS) and drug quantification was conducted through reverse-phase HPLC. An in vitro drug release study was conducted using the dialysis bag method, accompanied by HPLC quantification. The formulation was further evaluated for cell viability, cellular uptake, and COX-2 inhibition in the RAW 264.7 macrophage cell line. Results: Nanoemulsion droplet size increased with a higher oil-to-surfactant ratio (w/w) but was no significant impact by the type of surfactant system used. Thermal cycling and serum stability studies confirmed NE colloidal stability upon exposure to high and low temperatures and biological fluids. We also demonstrated the necessity of a solubilizer for long-term fluorescence stability of ICG. The nanoemulsion showed no cellular toxicity and effectively inhibited PGE2 in activated macrophages. Conclusions: To our knowledge, this is the first instance of a celecoxib-loaded theranostic platform developed using a plant-derived hydrocarbon oil, applying the QbD approach that demonstrated COX-2 inhibition. Full article

Glioblastoma (GBM) is a highly aggressive and heterogeneous brain tumor. Glioma stem-like cells (GSCs) play a central role in tumor progression, therapeutic resistance, and recurrence. Although immune cells are known to shape the GBM microenvironment, the impact of antigen-presenting-cell (APC) signature genes on tumor-intrinsic phenotypes remains underexplored. We analyzed both bulk- and single-cell RNA sequencing datasets of GBM to investigate the association between APC gene expression and tumor-cell states, including stemness and metabolic reprogramming. Signature scores were computed using curated gene sets related to APC activity, KEGG metabolic pathways, and cancer hallmark pathways. Protein–protein interaction (PPI) networks were constructed to examine the links between immune regulators and metabolic programs. The high expression of APC-related genes, such as HLA-DRA, CD74, CD80, CD86, and CIITA, was associated with lower stemness signatures and enhanced inflammatory signaling. These APC-high states (mean difference = –0.43, adjusted p < 0.001) also showed a shift in metabolic activity, with decreased oxidative phosphorylation and increased lipid and steroid metabolism. This pattern suggests coordinated changes in immune activity and metabolic status. Furthermore, TNF-α and other inflammatory markers were more highly expressed in the less stem-like tumor cells, indicating a possible role of inflammation in promoting differentiation. Our findings revealed that elevated APC gene signatures are associated with more differentiated and metabolically specialized GBM cell states. These transcriptional features may also reflect greater immunogenicity and inflammation sensitivity. The APC metabolic signature may serve as a useful biomarker to identify GBM subpopulations with reduced stemness and increased immune engagement, offering potential therapeutic implications. Full article

Background/Objectives: Mucosal vaccines, delivered intranasally or via inhalation, are being studied for respiratory infectious diseases like COVID-19 and influenza. These vaccines aim to provide non-invasive administration and strong immune responses at infection sites, making them a promising area of research. This systematic review and meta-analysis assessed their immunogenicity, safety, and protective efficacy. Methods: The study design was a systematic review and meta-analysis, searching PubMed and Cochrane databases up to 30 May 2025. Inclusion criteria followed the PICOS framework, focusing on mucosal vaccines for COVID-19, influenza, RSV, pertussis, and tuberculosis. Results: A total of 65 studies with 229,614 participants were included in the final analysis. Mucosal COVID-19 vaccines elicited higher neutralizing antibodies compared to intramuscular vaccines (SMD = 2.48, 95% CI: 2.17–2.78 for wild-type; SMD = 1.95, 95% CI: 1.32–2.58 for Omicron), with varying efficacy by route (inhaled VE = 47%, 95% CI: 22–74%; intranasal vaccine VE = 17%, 95% CI: 0–31%). Mucosal influenza vaccines protected children well (VE = 62%, 95% CI: 30–46%, I² = 17.1%), but seroconversion rates were lower than those of intramuscular vaccines. RSV and pertussis vaccines had high seroconversion rates (73% and 52%, respectively). Tuberculosis vaccines were reviewed systemically, exhibiting robust cellular immunogenicity. Safety was comparable to intramuscular vaccines or placebo, with no publication bias detected. Conclusions: Current evidence suggests mucosal vaccines are immunogenic, safe, and protective, particularly for respiratory diseases. This review provides insights for future research and vaccination strategies, though limitations include varying efficacy by route and study heterogeneity. Full article

With the increasing detection of artemisinin resistance to front-line antimalarials in Africa and notwithstanding the planned roll-out of RTS’S and R21 in Africa, the search for new vaccines with high efficacy remains an imperative. Towards this endeavour, we performed in silico screening to identify Plasmodium falciparum gametocyte stage genes that could be targets of protection or diagnosis. Through the analysis we identified a gene, Pf3D7_1105800, coding for a Plasmodium falciparum subtilisin-like domain-containing protein (PfSDP) and thus dubbed the gene Pfsdp. Genetic diversity assessment revealed the Pfsdp gene to be relatively conserved across continents with signs of directional selection. Using RT qPCR and Western blots, we observed that Pfsdp is expressed in all developmental stages of the parasite both at the transcript and protein level. Immunofluorescence assays found PfSDP protein co-localizing with PfMSP-1 and partially with Pfs48/45 at the asexual and sexual stages, respectively. Further, we demonstrated that anti-PfSDP peptide-specific antibodies inhibited erythrocyte invasion by 20–60% in a dose-dependent manner, suggesting that PfSDP protein might play a role in merozoite invasion. We also discovered that PfSDP protein is immunogenic in children from different endemic areas with antibody levels increasing from acute infection to day 7 post-treatment, followed by a gradual decay. The limited effect of antibodies on erythrocyte invasion could imply that it might be more involved in other processes in the development of the parasite. Full article

Background: Immune checkpoint inhibitors (ICIs) have limited efficacy in proficient mismatch repair (pMMR) and microsatellite stability (MSS) metastatic colorectal cancer (mCRC). Inhibition of vascular endothelial growth factor (VEGF) or cytotoxic chemotherapy can boost immunogenicity and has the potential to upregulate ICI efficacy. Methods: A comprehensive electronic literature search was conducted up to April 2025 to identify randomized controlled trials comparing cytotoxic chemotherapy plus bevacizumab with or without ICI. The primary outcome was progression-free survival (PFS), and secondary outcomes were overall survival (OS), objective response rate (ORR), and severe adverse events (AEs: grade 3 or more). A meta-analysis was performed using random-effects models to calculate hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs). Results: Four studies involving 986 patients (With-ICI group, n = 651; Without-ICI group, n = 335) were included. The meta-analysis demonstrated a significant improvement in PFS in the With-ICI group compared with the Without-ICI group, with an HR of 0.82 (95% CI: 0.70–0.96, p = 0.01) without statistical heterogeneity. No significant improvements were observed between the With- and Without-ICI groups in OS and ORR meta-analyses, but the With-ICI group had a favorable trend in OS. A significant increase in serious AEs was not observed in the With-ICI group. Conclusions: This meta-analysis suggests a potential benefit of adding ICIs to chemotherapy plus bevacizumab in pMMR mCRC; however, the evidence remains preliminary and hypothesis-generating, warranting further investigation in biomarker-driven trials and clarification of long-term outcomes. Full article

Circular RNAs (circRNAs) have emerged as a transformative class of RNA therapeutics, distinguished by their closed-loop structure conferring nuclease resistance, reduced immunogenicity, and sustained translational activity. While challenges in pharmacokinetic control and manufacturing standardization require resolution, emerging synergies between computational design tools and modular delivery platforms are accelerating clinical translation. In this review, we synthesize recent advances in circRNA therapeutics, with a focused analysis of their stability and immunogenic properties in vaccine and drug development. Notably, key synthesis strategies, delivery platforms, and AI-driven optimization methods enabling scalable production are discussed. Moreover, we summarize preclinical and emerging clinical studies that underscore the potential of circRNA in vaccine development and protein replacement therapies. As both a promising expression vehicle and programmable regulatory molecule, circRNA represents a versatile platform poised to advance next-generation biologics and precision medicine. Full article

Nipah virus (NiV) is a highly pathogenic bat-borne zoonotic pathogen that poses a significant threat to human and animal health, with fatality rates exceeding 70% in some outbreaks. Despite its significant public health impact, there are currently no licensed vaccines or specific therapeutics available. Various virological tools—such as reverse genetics systems, replicon particles, VSV-based pseudoviruses, and recombinant Cedar virus chimeras—have been widely used to study the molecular mechanisms of NiV and to support vaccine development. Building upon these platforms, we developed a replication-competent recombinant vesicular stomatitis virus (rVSVΔG-eGFP-NiV_BD F/G) expressing NiV attachment (G) and fusion (F) glycoproteins. This recombinant virus serves as a valuable tool for investigating NiV entry mechanisms, cellular tropism, and immunogenicity. The virus was generated by replacing the VSV G protein with NiV F/G through reverse genetics, and protein incorporation was confirmed via immunofluorescence and electron microscopy. In vitro, the virus exhibited robust replication, characteristic cell tropism, and high viral titers in multiple cell lines. Neutralization assays showed that monoclonal antibodies HENV-26 and HENV-32 effectively neutralized the recombinant virus. Furthermore, immunization of golden hamsters with inactivated rVSVΔG-eGFP-NiV_BD F/G induced potent neutralizing antibody responses, demonstrating its robust immunogenicity. These findings highlight rVSVΔG-eGFP-NiV_BD F/G as an effective platform for NiV research and vaccine development. Full article

Background/Objectives: Chemically or genetically detoxified pertussis toxin (PTx) is a crucial antigen component of the acellular pertussis vaccine. Chemical detoxification using glutaraldehyde generally causes significant structural changes to the toxin. However, how these structural changes in PTx affect its antigenic properties remains unclear. Additionally, there is limited knowledge regarding how many alterations in antigenic properties impact immunogenicity. Methods: To investigate the impact of structural changes on antigenic properties, we developed a sandwich ELISA to quantify the neutralizing epitopes on PTx. Subsequently, we analyzed different PTx toxoid (PTd) preparations with the assay. Additionally, we assessed the immunogenicity of various acellular pertussis vaccine candidates containing these PTd preparations. Finally, the assay was applied to evaluate the consistency of commercial batches of PTx and PTd intermediates. Results: The assay demonstrated reasonable specificity, accuracy, and precision, and it was sensitive enough to quantify variations in neutralizing epitopes among different PTd samples that shared the same protein concentration. Importantly, we found a positive correlation between the number of neutralizing epitopes in detoxified PTx and its immunogenicity, indicating that the amount of neutralizing epitopes present determines the immunogenicity of glutaraldehyde-inactivated PTx. Moreover, commercial batches of PTx and PTd intermediates exhibited minor variations in neutralizing epitopes. Conclusions: These findings have significant implications for developing acellular pertussis vaccines as they highlight the importance of preserving the neutralizing epitopes of PTx during detoxification to ensure the vaccine’s effectiveness. This assay is also valuable for the quality control of PTd as it more accurately represents the actual antigenic changes of PTx. Full article

Recombinant vesicular stomatitis virus (rVSV) is a promising viral vaccine vector for addressing the COVID-19 pandemic. Inducing mucosal immunity via the intranasal route is an ideal strategy for rVSV-based vaccines, but it requires extremely stringent safety standards. In this study, we constructed two rVSV variants with amino acid mutations in their M protein: rVSV-M2 with M33A/M51R mutations and rVSV-M4 with M33A/M51R/V221F/S226R mutations, and developed COVID-19 vaccines based on these attenuated vectors. By comparing viral replication capacity, intranasal immunization, intracranial injection, and blood cell counts, we demonstrated that the M protein mutation variants exhibit significant attenuation effects both in vitro and in vivo. Moreover, preliminary investigations into the mechanisms of virus attenuation revealed that these attenuated viruses can induce a stronger type I interferon response while reducing inflammation compared to the wild-type rVSV. We developed three candidate vaccines against SARS-CoV-2 using the wildtype VSV backbone with either wild-type M (rVSV-JN.1) and two M mutant variants (rVSV-M2-JN.1 and rVSV-M4-JN.1). Our results confirmed that rVSV-M2-JN.1 and rVSV-M4-JN.1 retain strong immunogenicity while enhancing safety in hamsters. In summary, the rVSV variants with M protein mutations represent promising candidate vectors for mucosal vaccines and warrant further investigation. Full article

Background: Soft tissue sarcomas (STSs) are a rare and heterogeneous group of mesenchymal tumors with limited response to current therapies, particularly in advanced stages. STS tumors were traditionally considered “cold” tumors, characterized by limited immune infiltration and low immunogenicity. However, emerging evidence is challenging this perception, highlighting a potentially critical role for the immune system in STS biology. Objective: Building on our previous findings suggesting impaired natural killer (NK) cell activity in STS patients, we aimed to perform an in-depth characterization of peripheral NK cells in STS. Methods: Peripheral blood samples from STS patients and sex- and age-matched healthy donors were analyzed to assess NK cell degranulation, IFNγ production, and receptor repertoire. Results: Functional assays revealed a notable reduction in both degranulation and IFNγ production in NK cells from STS patients. STS patients also exhibited dysregulated expression of activating and inhibitory NK cell receptors. Principal component analysis (PCA) identified CD27 and NKp44 as critical markers for distinguishing STS patients from healthy donors. Increased CD27 expression represents a shift towards a more regulatory NK cell phenotype, and we found that CD27 expression was negatively correlated with NK cell degranulation and IFNγ production. ROC curve analysis demonstrated strong potential to distinguish between the groups for both CD27 (AUC = 0.85) and NKp44 (AUC = 0.94). Conclusion: In conclusion, STS patients exhibited impaired NK cell function, altered receptor repertoire, and a shift towards a less cytotoxic and more regulatory phenotype. Full article