Hederagenin reduces Aß-induced oxidative damage, decreases Aß deposition and promotes cell survival by the P13†K/Akt signaling pathway.

Alzheimer's disease (AD) is a neurodegenerative disease characterized by memory loss and cognitive impairment. ß-amyloid (Aß) is one of the typical pathological features of AD, and its accumulation leads to neuronal death from oxidative stress. Here, we found that hederagenin (HG), a natural product, exhibits anti-tumor, anti-inflammatory, anti-depressant, anti-neurodegenerative biological activities. However, whether HG has anti-Aß activity remains unclear. Based on the characteristics of HG, it is hypothesized that HG has biological activity against Aß injury. Therefore, Aß-injured SH-SY5Y cells were constructed, and the protective effect of HG against Aß injury was further evaluated using C. elegans. The results showed that HG increased superoxide dismutase activity, effectively reduced Aß-induced oxidative damage, and reduced apoptosis via the PI3 K/Akt signaling pathway. HG inhibited Aß deposition and delayed senescence and paralysis in the C. elegans strain, CL4176. HG showed inhibitory effects on Aß; therefore, more natural active products are expected to be applied in AD therapy.

Self-adjuvant multiepitope nanovaccine based on ferritin induced long-lasting and effective mucosal immunity against H3N2 and H1N1 viruses in mice.

The influenza A virus (IAV) is a ubiquitous and continuously evolving respiratory pathogen. The intranasal vaccination mimicking natural infections is an attractive strategy for controlling IAVs. Multiepitope vaccines accurately targeting multiple conserved domains have the potential to broaden the protective scope of current seasonal influenza vaccines and reduce the risk of generating escape mutants. Here, multiple linear epitopes from the matrix protein 2 ectodomain (M2e) and the hemagglutinin stem domain (HA2) are fused with the Helicobacter pylori ferritin, a self-assembled nanocarrier and mucosal adjuvant, to develop a multiepitope nanovaccine. Through intranasal delivery, the prokaryotically expressed multiepitope nanovaccine elicits long-lasting mucosal immunity, broad humoral immunity, and robust cellular immunity without any adjuvants, and confers complete protection against H3N2 and H1N1 subtypes of IAV in mice. Importantly, this intranasal multiepitope nanovaccine triggers memory B-cell responses, resulting in secretory immunoglobulin A (sIgA) and serum immunoglobulin G (IgG) levels persisting for more than five months post-immunization. Therefore, this intranasal ferritin-based multiepitope nanovaccine represents a promising approach to combating respiratory pathogens.

Self-Assembled Multiepitope Nanovaccine Provides Long-Lasting Cross-Protection against Influenza Virus.

Seasonal influenza vaccines typically provide strain-specific protection and are reformulated annually, which is a complex and time-consuming process. Multiepitope vaccines, combining multiple conserved antigenic epitopes from a pathogen, can trigger more robust, diverse, and effective immune responses, providing a potential solution. However, their practical application is hindered by low immunogenicity and short-term effectiveness. In this study, multiple linear epitopes from the conserved stem domain of hemagglutinin and the ectodomain of matrix protein 2 are combined with the Helicobacter pylori ferritin, a stable self-assembled nanoplatform, to develop an influenza multiepitope nanovaccine, named MHF. MHF is prokaryotically expressed in a soluble form and self-assembles into uniform nanoparticles. The subcutaneous immunization of mice with adjuvanted MHF induces cross-reactive neutralizing antibodies, antibody-dependent cell-mediated cytotoxicity, and cellular immunity, offering complete protection against H3N2 as well as partial protection against H1N1. Importantly, the vaccine cargo delivered by ferritin triggers epitope-specific memory B-cell responses, with antibody level persisting for over 6 months post-immunization. These findings indicate that self-assembled multiepitope nanovaccines elicit potent and long-lasting immune responses while significantly reducing the risk of vaccine escape mutants, and offer greater practicality in terms of scalable manufacturing and genetic manipulability, presenting a promising and effective strategy for future vaccine development.

Receptor modulators associated with the hypothalamus -pituitary-thyroid axis.

The hypothalamus-pituitary-thyroid (HPT) axis maintains normal metabolic balance and homeostasis in the human body through positive and negative feedback regulation. Its main regulatory mode is the secretion of thyrotropin (TSH), thyroid hormones (TH), and thyrotropin-releasing hormone (TRH). By binding to their corresponding receptors, they are involved in the development and progression of several systemic diseases, including digestive, cardiovascular, and central nervous system diseases. The HPT axis-related receptors include thyrotropin receptor (TSHR), thyroid hormone receptor (TR), and thyrotropin-releasing hormone receptor (TRHR). Recently, research on regulators has become popular in the field of biology. Several HPT axis-related receptor modulators have been used for clinical treatment. This study reviews the developments and recent findings on HPT axis-related receptor modulators. This will provide a theoretical basis for the development and utilisation of new modulators of the HPT axis receptors.

Enhancement of Neutralization Responses through Sequential Immunization of Stable Env Trimers Based on Consensus Sequences from Select Time Points by Mimicking Natural Infection.

HIV-1 vaccines have been challenging to develop, partly due to the high level of genetic variation in its genome. Thus, a vaccine that can induce cross-reactive neutralization activities will be needed. Studies on the co-evolution of antibodies and viruses indicate that mimicking the natural infection is likely to induce broadly neutralizing antibodies (bnAbs). We generated the consensus Env sequence for each time point in subject CH505, who developed broad neutralization activities, and selected five critical time points before broad neutralization was detected. These consensus sequences were designed to express stable Env trimers. Priming with the transmitted/founder Env timer and sequential boosting with these consensus Env trimers from different time points induced broader and more potent neutralizing activities than the BG505 Env trimer in guinea pigs. Analysis of the neutralization profiles showed that sequential immunization of Env trimers favored nAbs with gp120/gp41 interface specificity while the BG505 Env trimer favored nAbs with V2 specificity. The unique features such as consensus sequences, stable Env trimers and the sequential immunization to mimic natural infection likely has allowed the induction of improved neutralization responses.

Combined Nano-Vector Mediated-Transfer to Suppress HIV-1 Infection with Targeted Antibodies in-vitro.

Introduction: Broadly neutralizing antibodies (bNAbs) have the ability to neutralize a considerable breadth of genetically diverse human immunodeficiency virus (HIV) strains. Passive immunization can potentially provide protection against HIV infection in animal models. However, the direct antibody infusion effect is limited due to the short half-life and deficient immunogenicity of the antibody. As an alternative strategy, we propose the use of nano viral vectors, specifically the adeno-associated virus (AAV), to continuously and systematically produce bNAbs against HIV. Methods: Plasmids expressing bNAbs PG9, PG16, 10E8, and NIH45-46 antibodies were constructed, targeting three different epitopes of HIV. Additionally, the bNAbs gene mediated by rAAV8 was administered to generate long-term expression with a single injection. We established both single and combined immunization groups. The neutralizing activity of antibodies expressed in mice sera was subsequently evaluated. Results: The expression of bNAbs in BALB/c mice can last for >24 weeks after a single intramuscular injection of rAAV8. Further studies show that neutralization of the HIV pseudovirus by sera from co-immunized mice with rAAV8 expressing 10E8 and PG16 was enhanced compared with mice immunized with 10E8 or PG16 alone. Conclusion: The prolonged expression of neutralizing antibodies can be maintained over long periods in BALB/c mice. This combined immunization is a promising candidate strategy for HIV treatment.

Characterizations of microRNAs involved in the molecular mechanisms underlying the therapeutic effects of noni (Morinda citrifolia L.) fruit juice on hyperuricemia in mice.

Background: Hyperuricemia is generally defined as the high level of serum uric acid and is well known as an important risk factor for the development of various medical disorders. However, the medicinal treatment of hyperuricemia is frequently associated with multiple side-effects. Methods: The therapeutic effect of noni (Morinda citrifolia L.) fruit juice on hyperuricemia and the underlying molecular mechanisms were investigated in mouse model of hyperuricemia induced by potassium oxonate using biochemical and high-throughput RNA sequencing analyses. Results: The levels of serum uric acid (UA) and xanthine oxidase (XOD) in mice treated with noni fruit juice were significantly decreased, suggesting that the noni fruit juice could alleviate hyperuricemia by inhibiting the XOD activity and reducing the level of serum UA. The contents of both serum creatinine and blood urine nitrogen of the noni fruit juice group were significantly lower than those of the model group, suggesting that noni fruit juice promoted the excretion of UA without causing deleterious effect on the renal functions in mice. The differentially expressed microRNAs involved in the pathogenesis of hyperuricemia in mice were identified by RNA sequencing with their target genes further annotated based on both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases to explore the metabolic pathways and molecular mechanisms underlying the therapeutic effect on hyperuricemia by noni fruit juice. Conclusion: Our study provided strong experimental evidence to support the further investigations of the potential application of noni fruit juice in the treatment of hyperuricemia.

Molecular and biochemical investigations of the anti-fatigue effects of tea polyphenols and fruit extracts of Lycium ruthenicum Murr. on mice with exercise-induced fatigue.

Background: The molecular mechanisms regulating the therapeutic effects of plant-based ingredients on the exercise-induced fatigue (EIF) remain unclear. The therapeutic effects of both tea polyphenols (TP) and fruit extracts of Lycium ruthenicum (LR) on mouse model of EIF were investigated. Methods: The variations in the fatigue-related biochemical factors, i.e., lactate dehydrogenase (LDH), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-2 (IL-2), and interleukin-6 (IL-6), in mouse models of EIF treated with TP and LR were determined. The microRNAs involved in the therapeutic effects of TP and LR on the treatment of mice with EIF were identified using the next-generation sequencing technology. Results: Our results revealed that both TP and LR showed evident anti-inflammatory effect and reduced oxidative stress. In comparison with the control groups, the contents of LDH, TNF-α, IL-6, IL-1ß, and IL-2 were significantly decreased and the contents of SOD were significantly increased in the experimental groups treated with either TP or LR. A total of 23 microRNAs (21 upregulated and 2 downregulated) identified for the first time by the high-throughput RNA sequencing were involved in the molecular response to EIF in mice treated with TP and LR. The regulatory functions of these microRNAs in the pathogenesis of EIF in mice were further explored based on Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses with a total of over 20,000-30,000 target genes annotated and 44 metabolic pathways enriched in the experimental groups based on GO and KEGG databases, respectively. Conclusion: Our study revealed the therapeutic effects of TP and LR and identified the microRNAs involved in the molecular mechanisms regulating the EIF in mice, providing strong experimental evidence to support further agricultural development of LR as well as the investigations and applications of TP and LR in the treatment of EIF in humans, including the professional athletes.

Mechanism Exploration of Amyloid-ß-42 Disaggregation by Single-Chain Variable Fragments of Alzheimer's Disease Therapeutic Antibodies.

Alzheimer's disease (AD) is a specific neurodegenerative disease. This study adopts single-chain variable fragments (scFvs) as a potential immunotherapeutic precursor for AD. According to the remarkable effects of monoclonal antibodies, such as the depolymerization or promotion of Aß42 efflux by Crenezumab, Solanezumab, and 12B4, it is attractive to prepare corresponding scFvs targeting amyloid-ß-42 protein (Aß42) and investigate their biological activities. Crenezumab-like scFv (scFv-C), Solanezumab-like scFv (scFv-S), and 12B4-like scFv (scFv-12B4) were designed and constructed. The thermal stabilities and binding ability to Aß42 of scFv-C, scFv-S, and scFv-12B4 were evaluated using unfolding profile and enzyme-linked immunosorbent assay. As the results indicated that scFv-C could recognize Aß42 monomer/oligomer and promote the disaggregation of Aß42 fiber as determined by the Thioflavin-T assay, the potential mechanism of its interaction with Aß42 was investigated using molecular dynamics analysis. Interactions involving hydrogen bonds and salt bonds were predicted between scFv-C and Aß42 pentamer, suggesting the possibility of inhibiting further aggregation of Aß42. The successfully prepared scFvs, especially scFv-C, with favorable biological activity targeting Aß42, might be developed for a potentially efficacious clinical application for AD.

Improvement of B Cell Responses by an HIV-1 Amphiphilic Polymer Nanovaccine.

The human immunodeficiency virus (HIV) has infected over 84 million people since its discovery and is a huge threat to human health. While an HIV vaccine is urgently needed to curb this devastating pandemic, it has been notoriously difficult to develop, partly due to the extraordinary high level of genetic variation of HIV. We designed a new HIV-1 envelope glycoprotein nanoparticle (Env/NP) vaccine using amphiphilic polymers. The Env/NP vaccine induced more potent and broader neutralizing activities against multiple HIV-1 subtypes. Moreover, it elicits similar neutralizing antibody responses after the storage at -80 °C, 4 °C or room temperature post lyophilization. These results demonstrate that the new Env/NP vaccine not only improves the HIV vaccine immune responses but also is stable under different storage conditions. This new nanovaccine approach can readily apply to other protein-based vaccines.

Celastrol attenuates hepatitis C virus translation and inflammatory response in mice by suppressing heat shock protein 90ß.

Hepatitis C virus (HCV) infection is one of the major factors to trigger a sustained hepatic inflammatory response and hence hepatocellular carcinoma (HCC), but direct-acting-antiviral (DAAs) was not efficient to suppress HCC development. Heat shock protein 90 kDa (HSP90) is highly abundant in different types of cancers, and especially controls protein translation, endoplasmic reticulum stress, and viral replication. In this study we investigated the correlation between the expression levels of HSP90 isoforms and inflammatory response marker NLRP3 in different types of HCC patients as well as the effect of a natural product celastrol in suppression of HCV translation and associated inflammatory response in vivo. We identified that the expression level of HSP90ß isoform was correlated with that of NLRP3 in the liver tissues of HCV positive HCC patients (R2 = 0.3867, P < 0.0101), but not in hepatitis B virus-associated HCC or cirrhosis patients. We demonstrated that celastrol (3, 10, 30 µM) dose-dependently suppressed the ATPase activity of both HSP90α and HSP90ß, while its anti-HCV activity was dependent on the Ala47 residue in the ATPase pocket of HSP90ß. Celastrol (200 nM) halted HCV internal ribosomal entry site (IRES)-mediated translation at the initial step by disrupting the association between HSP90ß and 4EBP1. The inhibitory activity of celastrol on HCV RNA-dependent RNA polymerase (RdRp)-triggered inflammatory response also depended on the Ala47 residue of HSP90ß. Intravenous injection of adenovirus expressing HCV NS5B (pAde-NS5B) in mice induced severe hepatic inflammatory response characterized by significantly increased infiltration of immune cells and hepatic expression level of Nlrp3, which was dose-dependently ameliorated by pretreatment with celastrol (0.2, 0.5 mg/kg, i.p.). This study reveals a fundamental role of HSP90ß in governing HCV IRES-mediated translation as well as hepatic inflammation, and celastrol as a novel inhibitor of HCV translation and associated inflammation by specifically targeting HSP90ß, which could be developed as a lead for the treatment of HSP90ß positive HCV-associated HCC.

Self-assembled multiepitope nanovaccine based on NoV P particles induces effective and lasting protection against H3N2 influenza virus.

Current seasonal influenza vaccines confer only limited coverage of virus strains due to the frequent genetic and antigenic variability of influenza virus (IV). Epitope vaccines that accurately target conserved domains provide a promising approach to increase the breadth of protection; however, poor immunogenicity greatly hinders their application. The protruding (P) domain of the norovirus (NoV), which can self-assemble into a 24-mer particle called the NoV P particle, offers an ideal antigen presentation platform. In this study, a multiepitope nanovaccine displaying influenza epitopes (HMN-PP) was constructed based on the NoV P particle nanoplatform. Large amounts of HMN-PP were easily expressed in Escherichia coli in soluble form. Animal experiments showed that the adjuvanted HMN-PP nanovaccine induced epitope-specific antibodies and haemagglutinin (HA)-specific neutralizing antibodies, and the antibodies could persist for at least three months after the last immunization. Furthermore, HMN-PP induced matrix protein 2 extracellular domain (M2e)-specific antibody-dependent cell-mediated cytotoxicity, CD4+ and CD8+ T-cell responses, and a nucleoprotein (NP)-specific cytotoxic T lymphocyte (CTL) response. These results indicated that the combination of a multiepitope vaccine and self-assembled NoV P particles may be an ideal and effective vaccine strategy for highly variable viruses such as IV and SARS-CoV-2. Electronic Supplementary Material: Supplementary material is available in the online version of this article at 10.1007/s12274-023-5395-6.

A biepitope, adjuvant-free, self-assembled influenza nanovaccine provides cross-protection against H3N2 and H1N1 viruses in mice.

Currently, the incorporation of multiple epitopes into vaccines is more desirable than the incorporation of a single antigen for universal influenza vaccine development. However, epitopes induce poor immune responses. Although the use of adjuvants can overcome this obstacle, it may raise new problems. Effective antigen delivery vehicles that can function as both antigen carriers and intrinsic adjuvants are highly desired for vaccine development. Here, we report a biepitope nanovaccine that provides complete protection in mice against H3N2 virus as well as partial protection against H1N1 virus. This vaccine (3MCD-f) consists of two conserved epitopes (matrix protein 2 ectodomain (M2e) and CDhelix), and these epitopes were presented on the surface of ferritin in a sequential tandem format. Subcutaneous immunization with 3MCD-f in the absence of adjuvant induces robust humoral and cellular immune responses. These results provide a proof of concept for the 3MCD-f nanovaccine that might be an ideal candidate for future influenza pandemics.

Quantitative detection of Ganodermati lucidum immunomodulatory protein-8 by a peptide-antigen-antibody sandwich ELISA.

In order to rapidly determine the concentration of recombinant Ganoderma lucidum immunomodulatory protein-8 (rLZ-8) at a lower cost, a peptide-antigen-antibody sandwich ELISA method was developed based on a dodecapeptide LTPHKHHKHLHA with higher affinity for rLZ-8, which was identified from phage display after four rounds of screening. The binding mode between rLZ-8 and the peptide ligand was further simulated and revealed by molecular docking. Standard addition and repetitive testing were carried out to evaluate the accuracy, reproducibility and feasibility of the developed ELISA detection method. The method based on this peptide ligand was then successfully applied in the quantitative determination of rLZ-8 concentrations in fermentation broth. In summary, the peptide-antigen-antibody sandwich ELISA method developed here could be conveniently applied in the detection of rLZ-8 during fermentation and might provide new insights for the detection of other specific proteins.

An insulin growth factor-I/II-neutralizing monoclonal antibody in combination with epidermal growth factor receptor inhibitors potently inhibits tumor cell growth.

The insulin-like growth factors (IGFs), IGF-1 and IGF-II, which bind to the IGF receptor type 1 (IGF-1R) and the insulin receptor (IR), have been implicated in the growth, survival, and metastasis of tumor cells. We have previously identified a novel human monoclonal antibody (mAb), m708.5, which neutralizes both human IGF-I and IGF-II, and potently inhibits phosphorylation of the IGF-1R and the IR in breast cancer cells. In this study, m708.5 exhibited very strong synergy with the epidermal growth factor receptor (EGFR) inhibitor gefitinib, and synergy with chemotherapeutic agents in vitro against either neuroblastoma or breast cancer cells. In xenografted models, the combination of m708.5 and gefitinib significantly inhibited LAN-1 cell growth better than single agent alone. Taken together, these results support the clinical development of m708.5 for solid tumors with potential for synergy with chemotherapy and EGFR inhibitors.

A self-assembling nanoparticle vaccine targeting the conserved epitope of influenza virus hemagglutinin stem elicits a cross-protective immune response.

Various vaccine strategies have been developed to provide broad protection against diverse influenza viruses. The hemagglutinin (HA) stem is the major potential target of these vaccines. Enhancing immunogenicity and eliciting cross-protective immune responses are critical for HA stem-based vaccine designs. In this study, the A helix (Ah) and CD helix (CDh) from the HA stem were fused with ferritin, individually, or in tandem, yielding Ah-f, CDh-f and (A + CD)h-f nanoparticles (NPs), respectively. These NPs were produced through a prokaryotic expression system. After three immunizations with AS03-adjuvanted NPs in BALB/c mice via the subcutaneous route, CDh-f and (A + CD)h-f induced robust humoral and cellular immune responses. Furthermore, CDh-f and (A + CD)h-f conferred complete protection against a lethal challenge of H3N2 virus, while no remarkable immune responses and protective effects were detected in the Ah-f group. These results indicate that the CDh-based nanovaccine represents a promising vaccine platform against influenza, and the epitope-conjugated ferritin NPs may be a potential vaccine platform against other infectious viruses, such as SARS-COV-2.

Hemagglutinin-based DNA vaccines containing trimeric self-assembling nanoparticles confer protection against influenza.

Influenza viruses continue to threaten public health, and currently available vaccines provide insufficient immunity against seasonal and pandemic influenza. The use of recombinant trimeric hemagglutinin (HA) as an Ag provides an attractive alternative to current influenza vaccines. Aiming to develop an effective vaccine with rapid production, robust immunogenicity, and high protective efficiency, a DNA vaccine was designed by fusing influenza virus HA with self-assembled ferritin nanoparticles, denoted as HA-F. This candidate vaccine was prepared and purified in a 293-6E cell eukaryotic expression system. After BALB/c mice were immunized with 100 µg of HA-F DNA 3 times, HA-F elicited significant HA-specific humoral immunity and T cell immune responses. The HA-F DNA vaccine also conferred protection in mice against a lethal infection of homologous A/17/California/2009/38 (H1N1) virus. These results suggest that the HA-F DNA vaccine is a competitive vaccine candidate and presents a promising vaccination approach against influenza viruses.

Self-assembling ferritin nanoparticles coupled with linear sequences from canine distemper virus haemagglutinin protein elicit robust immune responses.

BACKGROUND: Canine distemper virus (CDV), which is highly infectious, has caused outbreaks of varying scales in domestic and wild animals worldwide, so the development of a high-efficiency vaccine has broad application prospects. Currently, the commercial vaccine of CDV is an attenuated vaccine, which has the disadvantages of a complex preparation process, high cost and safety risk. It is necessary to develop a safe and effective CDV vaccine that is easy to produce on a large scale. In this study, sequences of CDV haemagglutinin (HA) from the Yanaka strain were aligned, and three potential linear sequences, termed YaH3, YaH4, and YaH5, were collected. To increase the immunogenicity of the epitopes, ferritin was employed as a self-assembling nanoparticle element. The ferritin-coupled forms were termed YaH3F, YaH4F, and YaH5F, respectively. A full-length HA sequence coupled with ferritin was also constructed as a DNA vaccine to compare the immunogenicity of nanoparticles in prokaryotic expression. RESULT: The self-assembly morphology of the proteins from prokaryotic expression was verified by transmission electron microscopy. All the proteins self-assembled into nanoparticles. The expression of the DNA vaccine YaHF in HEK-293T cells was also confirmed in vitro. After subcutaneous injection of epitope nanoparticles or intramuscular injection of DNA YaHF, all vaccines induced strong serum titres, and long-term potency of antibodies in serum could be detected after 84 days. Strong anti-CDV neutralizing activities were observed in both the YaH4F group and YaHF group. According to antibody typing and cytokine detection, YaH4F can induce both Th1 and Th2 immune responses. The results of flow cytometry detection indicated that compared with the control group, all the immunogens elicited an increase in CD3. Simultaneously, the serum antibodies induced by YaH4F and YaHF could significantly enhance the ADCC effect compared with the control group, indicating that the antibodies in the serum effectively recognized the antigens on the cell surface and induced NK cells to kill infected cells directly. CONCLUSIONS: YaH4F self-assembling nanoparticle obtained by prokaryotic expression has no less of an immune effect than YaHF, and H4 has great potential to become a key target for the easy and rapid preparation of epitope vaccines.

Identification of Linear Peptide Immunogens with Verified Broad-spectrum Immunogenicity from the Conserved Regions within the Hemagglutinin Stem Domain of H1N1 Influenza Virus.

BACKGROUND: Influenza A viruses (IAVs) induce acute respiratory disease and cause severe epidemics and pandemics. Since IAVs exhibit antigenic variation and genome reassortment, the development of broad-spectrum influenza vaccines is crucial. The stem of the hemagglutinin (HA) is highly conserved across IAV strains and thus has been explored in broad-spectrum influenza vaccine studies. The present study aimed to identify viral epitopes capable of eliciting effective host immune responses, which can be explored for the development of broad-spectrum non-strain specific prophylactic options against IAV. METHODS: In this study, a series of conserved linear sequences from the HA stem of IAV (H1N1) was recognized by sequence alignment and B/T-cell epitope prediction after being chemically coupled to the Keyhole Limpet Hemocyanin (KLH) protein. The predicted linear epitopes were identified by enzyme-linked immunosorbent assay (ELISA) after animal immunization and then fused with ferritin carriers. RESULTS: Three predicted linear epitopes with relatively strong immunogenicity, P3, P6 and P8 were fused with ferritin carriers P3F, P6F and P8F, respectively to further improve their immunogenicity. Antibody titre of the sera of mice immunized with the recombinant immunogens revealed the elicitation of specific antibody-binding activities by the identified sequences. While hemagglutinin-inhibition activities were not detected in the antisera, neutralizing antibodies against the H1 and H3 virus subtypes were detected by the microneutralization assay. CONCLUSION: The linear epitopes fused with ferritin identified in this study can lay the foundation for future advancements in development of broad-spectrum subunit vaccine against IAV (H1N1), and give rise to the potential future applicability of ferritin-based antigen delivery nanoplatforms.

Surface-Functionalized Silica-Coated Calcium Phosphate Nanoparticles Efficiently Deliver DNA-Based HIV-1 Trimeric Envelope Vaccines against HIV-1.

Human immunodeficiency virus type 1 (HIV-1) infection remains one of the worst crises in global health. The prevention of HIV-1 infection is a crucial task that needs to be addressed due to the absence of a licensed vaccine against HIV-1. DNA vaccines present a promising alternative approach to combat HIV-1 infection due to their excellent safety profile, lack of severe side effects, and relatively rapid fabrication. Traditional vaccines composed of a monomeric envelope or peptide fragments have been indicated to lack protective efficacy mediated by inducing HIV-1-specific neutralizing antibodies in clinical trials. The immunogenicity and protection against HIV-1 induced by DNA vaccines are limited due to the poor uptake of these vaccines by antigen-presenting cells and their ready degradation by DNases and lysosomes. To address these issues of naked DNA vaccines, we described the feasibility of CpG-functionalized silica-coated calcium phosphate nanoparticles (SCPs) for efficiently delivering DNA-based HIV-1 trimeric envelope vaccines against HIV-1. Vaccines comprising the soluble BG505 SOSIP.664 trimer fused to the GCN4-based isoleucine zipper or bacteriophage T4 fibritin foldon motif with excellent simulation of the native HIV-1 envelope were chosen as trimer-based vaccine platforms. Our results showed that SCP-based DNA immunization could significantly induce both broad humoral immune responses and potent cellular immune responses compared to naked DNA vaccination in vivo. To the best of our knowledge, this study is the first to assess the feasibility of CpG-functionalized SCPs for efficiently delivering DNA vaccines expressing a native-like HIV-1 trimer. These CpG-functionalized SCPs for delivering DNA-based HIV-1 trimeric envelope vaccines may lead to the development of promising vaccine candidates against HIV-1.