Immune Adjuvant Research Articles

Engineered virus-mimicking nanovaccine with lymph node-tumor dual-targeting and STING-activating capacity for robust cancer immunotherapy.

Cancer vaccines have garnered considerable interest for cancer immunotherapy. However, their effectiveness is limited by inadequate proliferation, activation, and tumor infiltration of cytotoxic T lymphocytes (CTLs). Inspired by the potent immunostimulatory properties of viral components and the exposure of calreticulin during immunogenic cell death (ICD) triggered by viral infections; in this study, we describe cGAMP@vEVs, a virus-mimicking nanovaccine strategy by engineering tumor cell-derived extracellular vesicles through virus infection, which co-load both personalized and broad antigen repertoire as well as multiple immune adjuvants to potently elicit antitumor immunity. We demonstrate that cGAMP@vEVs exhibit both the commendable lymph node-tumor dual-targeting and stimulator of interferon genes (STING) pathway-activating capacity, which drive the proliferation and activation of tumor-specific CD8+ T cells in lymph nodes. Simultaneously, cGAMP@vEVs actively accumulate to tumor sites, and ameliorate immunosuppression tumor microenvironment, promoting the spontaneous tumor infiltration of CTLs. The coactivation of the immune response and TME reinitiate the self-sustaining cycle of cancer immunity, therefore efficiently inhibiting tumor progression, metastasis, and recurrence.

Injectable and Degradable Zwitterionic Cryogels as Cancer Vaccine Platforms to Prevent Cancer Recurrence after Surgery.

Cancer has become a highly prevalent disease and poses serious threats to human health. Conventional cancer treatments still face high risks of recurrence. Training the immune system to recognize and eliminate tumors via external stimulation, such as vaccines, emerges as a promising approach for cancer prevention and treatment. However, injectable vaccines may have limited immune activation, causing difficulties in maintaining long-term immune surveillance of tumorigenesis by tumor-specific cytotoxic T cells. Here, degradable zwitterionic cryogels were prepared using the cryogelation technique. The cryogenic preparation maintained the biological activities of tumor antigens and immune adjuvants loaded in the cryogels. The macroporous structure endowed the injectability of cryogels into the body via conventional syringes. In the presence of proteases, the cryogels degraded, allowing sustained release of antigens and adjuvants, ensuring continued dendritic cell (DC) recruitment and antigen presentation to maturing tumor-specific cytotoxic T cells. In vivo experiments demonstrated that the cryogel cancer vaccines elicited robust immune activation and effectively modulated tumor microenvironments. The combination with photothermal therapy significantly inhibited tumor growth, showing great potential for preventing postoperative recurrence. Additionally, the zwitterionic cryogels were biocompatible without obvious toxicities during degradation. The cryogels could serve as effective vaccine platforms to prevent cancer recurrence after surgery.

Photothermal-Triggered Extracellular Matrix Clearance and Dendritic Cell Maturation for Enhanced Osteosarcoma Immunotherapy.

Osteosarcoma, a predominant malignant tumor among adolescents, exhibits high mortality and suboptimal immunotherapy efficacy due to a collagen-dense extracellular matrix (ECM) that hinders cytotoxic T lymphocyte (CTL) infiltration. Herein, we developed mesoporous polydopamine (MPDA) nanoparticles encapsulating bromelain and the immune adjuvant R848 (M@B/R), aimed at enhancing photothermal immunotherapy. These nanoparticles efficiently accumulate at the tumor site following injection. Upon near-infrared (NIR) light irradiation, photothermal therapy (PTT) induces immunogenic cell death in tumor cells and, with the aid of R848, efficiently promotes dendritic cell maturation, activating antitumor immunity and leading to CTL infiltration into the tumor. Concurrently, NIR-induced heating activates bromelain, resulting in ECM degradation and improved CTL penetration into the tumor. Our in vivo evaluations demonstrate potent antitumor effects in osteosarcoma-bearing mice. This integrated approach offers a promising strategy for overcoming physical barriers in ECM-rich tumors, marking a significant advancement in the treatment of osteosarcoma.

Bimodal accurate H2O2 regulation to equalize tumor-associated macrophage repolarization and immunogenic tumor cell death elicitation.

Simultaneous implementation of tumor-associated macrophage (TAM) repolarization and immunogenic tumor cell death (ICD) elicitation enables tumor immunotherapy with high efficacy. However, the inconsistency of stimulation tolerance restricts simultaneous implementation. To address this obstacle, we validate that an H2O2-mediated regulatory strategy could achieve coordinated occurrences. To accomplish this, a bimodal responsive modulator is constructed, namely ZnO2-ATM (ATM: 3-amino-1,2,4-triazole), as an immune adjuvant to coordinate the occurrence of TAM repolarization and ICD elicitation through the endo/exogenous synergistic responsive production of H2O2. H2O2 produced by ZnO2-ATM reverses the immune-suppressive TAM from an M2 to an M1 phenotype, but induces tumor cell necrosis and promotes damage-related molecular pattern release, thereby evoking ICD. This H2O2-mediation bimodal responsive therapeutic strategy to induce the synergistic occurrence of TAM repolarization and ICD elicitation promotes effective immune effects against tumors, demonstrating that the ZnO2-ATM nanoadjuvant could be expected to provide new tools and paradigms for antitumor immunotherapy.

Polyinosinic/Polycytidylic Lipid Nanoparticles Enhance Immune Cell Infiltration and Improve Survival in the Glioblastoma Mouse Model.

Glioblastoma (GBM) immunotherapy is particularly challenging due to the pro-tumorigenic microenvironment, marked by low levels and inactive immune cells. Toll-like receptor (TLR) agonists have emerged as potent immune adjuvants but failed to show improved outcomes in clinical trials when administered as a monotherapy. We hypothesize that a combined nanoparticulate formulation of TLR agonist and immunogenic cell death-inducing drug (doxorubicin) will synergize to induce improved GBM immunotherapy. Lipid nanoparticle (LNP) formulations of the TLR agonists CpG and polyinosinic/polycytidylic (pIpC), with and without Dox, were first prepared, achieving an encapsulation efficiency >75% and a size <140 nm. In vitro studies identified that LNP pIpC was superior to CpG at activating bone marrow-derived immune cell populations (dendritic cells and macrophages) with minimal toxicity. It was also observed that the pIpC formulation can skew macrophage polarization toward the antitumorigenic M1 phenotype and increase macrophage phagocytosis of cancer cells. Upon intratumoral administration, pIpC Dox LNPs led to significant immune cell infiltration and activation. In survival models, the inclusion of Dox into pIpC LNP improved mice survival compared to control. However, addition of Dox did not show significant improvement in mice's survival compared to singly formulated pIpC LNP. This study has illustrated the potential of pIpC LNP formulations in prospective GBM immunotherapeutic regimes. Future studies will focus on optimizing dosage regimen and/or combination with other modalities, including the standard of care (temozolomide), immune checkpoint blockade, or cancer vaccines.

Local and systemic humoral immune responses to Histophilus somni recombinant antigens administered intranasally and subcutaneously to dairy calves

Bovine respiratory disease (BRD) causes significant economic losses in dairy calves. Induction of an early immune response via parenteral vaccination is complicated by the interference of colostral immunity. In this study, we investigated early immunization against selected conserved bacterial antigens. Calves were vaccinated twice intranasally and then subcutaneously with Histophilus somni recombinant proteins (rOMP40 or rHsp60) mixed with one of two adjuvants: CpG ODN2007 or MPLA. The control group (Con) was treated with PBS. The first immunization was done between 24 and 48 h of life and then twice in two weeks intervals. Blood, nasal, and saliva secretion samples were collected directly before vaccination (S1–S3) and then on 42–44 (S4) and 59–61 (S5) day of life. Antibodies (IgG1/IgG2/IgM/IgA in serum; IgG1/IgA in secretions) against both vaccine antigens were quantified in all samples. Intranasal and subcutaneous vaccinations using the described formulas did not increase antibody reactivity against the tested proteins. The reactivity of serum IgG1, IgM, and IgA anti-rOMP40 antibodies was significantly higher in S1 in all groups than that in the other samplings (p˂0.01). Significant differences in the reactivity of serum anti-rOMP40 antibodies between groups were identified in S1 (IgA reactivity was higher in the CpG vs. MPLA group; p < 0.05), S4 (IgM reactivity was higher in Con vs. CpG group; p < 0.05), and S5 (IgG1 reactivity was higher in MPLA vs. Con group; p < 0.05). The lack of consistent changes in antibodies after immunization (S4 and S5) hinders the drawing of conclusions regarding the effect of immunization on antibody reactivity. In the future, establishing a proper immunization window and adjuvants for nasal vaccines against bacterial pathogens causing BRD in calves remains to be determined.

Spleen-Targeted mRNA Vaccine Doped with Manganese Adjuvant for Robust Anticancer Immunity In Vivo.

The successful application of mRNA vaccines in preventing and treating infectious diseases highlights their potential as therapeutic vaccines for cancer treatment. However, unlike infectious diseases, effective antitumor therapy, particularly for solid tumors, necessitates the activation of more powerful cellular and humoral immunity to achieve clinical efficacy. Here, we report a spleen-targeted mRNA vaccine (Mn@mRNA-LNP) designed to deliver tumor antigen-encoding mRNA and manganese adjuvant (Mn2+) simultaneously to dendritic cells (DCs) in the spleen. This delivery system promotes DC maturation and surface antigen presentation and stimulates the production of cytotoxic T cells. Additionally, Mn2+ codelivered in the system serves as a safe and effective immune adjuvant, activating the stimulator of interferon genes (STING) signaling pathway and promoting the secretion of type I interferon, further enhancing the antigen-specific T cell responses. Mn@mRNA-LNP effectively inhibits tumor progression in established melanoma and colon tumor models as well as in a model of tumor recurrence after resection. Notably, the combination of Mn@mRNA-LNP with immune checkpoint inhibitors further enhances complete tumor suppression and prolonged the overall survival in mice. Overall, this "All-in-One" mRNA vaccine significantly boosts antitumor immunity responses by improving spleen targeting and immune activation, providing an attractive strategy for the future clinical translation of therapeutic mRNA vaccines.

Polydopamine Nanoformulations Induced ICD and M1 Phenotype Macrophage Polarization for Enhanced TNBC Synergistic Photothermal Immunotherapy.

Photothermal therapy (PTT) is a promising technology that can achieve the thermal ablation of tumors and induce immunogenic cell death (ICD). However, relying solely on the antitumor immune responses caused by PTT-induced ICD is insufficient to suppress tumor metastasis and recurrence effectively. Fortunately, multifunctional nanoformulation-based synergistic photothermal immunotherapy can eliminate primary and metastatic tumors and inhibit tumor recurrence for a long time. Herein, we select polydopamine (PDA) nanoparticles to serve as the carrier for our nanomedicine as well as a potent photothermal agent and modulator of macrophage polarization. PDA nanoparticles are loaded with the insoluble immune adjuvant Imiquimod (R837) to construct PDA(R837) nanoformulations. These straightforward yet highly effective nanoformulations demonstrate excellent performance, allowing for successful triple-negative breast cancer (TNBC) treatment through synergistic photothermal immunotherapy. Moreover, experimental results showed that PDA(R837) implementation of PTT is effective in the thermal ablation of primary tumors while causing ICD and releasing R837, further promoting dendritic cell (DC) maturation and activating the systemic antitumor immune response. Furthermore, PDA(R837) nanoformulations inhibit tumor metastasis and recurrence and achieve M1 phenotype macrophage polarization, achieving long-term and excellent antitumor efficacy. Therefore, the structurally simple PDA(R837) nanoformulations provide cancer treatment and have excellent clinical translational application prospects.

DNA-PK inhibition enhances neoantigen diversity and increases T cell responses to immunoresistant tumors.

Effective antitumor T cell activity relies on the expression and MHC presentation of tumor neoantigens. Tumor cells can evade T cell detection by silencing the transcription of antigens or by altering MHC machinery resulting in inadequate neoantigen-specific T cell activation. We identified DNA-PK inhibitor (DNA-PKi) NU7441 as a promising immunomodulator that reduced immunosuppressive proteins while increasing MHC-I expression in a panel of human melanoma cell lines. In tumor-bearing mice, combination therapy using NU7441 and immune adjuvants STING ligand and CD40 agonist (NU-SL40) substantially increased and diversified the neoantigen landscape, antigen presenting machinery, and consequently substantially increased both the number and repertoire of neoantigen-reactive tumor infiltrating lymphocytes (TILs). DNA-PK-inhibition or knockout promoted transcription and protein expression of various neoantigens in human and mouse melanomas and induced sensitivity to ICB in resistant tumors. In patients, PRKDC levels inversely correlated with MHC I expression and CD8 TILs but positively correlated with increased neoantigen loads and improved responses to ICB. These studies suggest that inhibiting DNA-PK activity can restore tumor immunogenicity by increasing neoantigen expression and presentation and broadening the neoantigen-reactive T cell population.

Basic Properties and Development Status of Aluminum Adjuvants Used for Vaccines.

Aluminum adjuvants, renowned for their safety and efficacy, act as excellent adsorbents and vaccine immunogen enhancers, significantly contributing to innate, endogenous, and humoral immunity. An ideal adjuvant not only boosts the immune response but also ensures optimal protective immunity. Aluminum adjuvants are the most widely used vaccine adjuvants and have played a crucial role in both the prevention of existing diseases and the development of new vaccines. With the increasing emergence of new vaccines, traditional immune adjuvants are continually being researched and upgraded. The future of vaccine development lies in the exploration and integration of novel adjuvant technologies that surpass the capabilities of traditional aluminum adjuvants. One promising direction is the incorporation of nanoparticles, which offer precise delivery and controlled release of antigens, thereby enhancing the overall immune response. This review summarizes the types, mechanisms, manufacturers, patents, advantages, disadvantages, and future prospects of aluminum adjuvants. Although aluminum adjuvants have certain limitations, their contribution to enhancing vaccine immunity is significant and cannot be ignored. Future research should continue to explore their mechanisms of action and address potential adverse reactions to achieve improved vaccine efficacy.

Bacterial Lysate-Based Bifunctional mRNA Nanoformulation for Efficient Colon Cancer Immunogene Therapy.

mRNA-based nonviral gene therapy has played an important role in cancer therapy, however, the limited delivery efficiency and therapeutic capacity still require further exploration and enhancement. Immunogene therapy provides a strategy for cancer treatment. Bacteria are tiny single-celled living organisms, many of which can be found in and on the human body and are beneficial to humans. Lactobacillus reuteri is a bacterial member of the gut flora, and recent research has shown that it can reduce intestinal inflammation by stimulating an immunomodulatory response. L. reuteri lysate represents an ideal resource for constructing advanced mRNA delivery systems with immune stimulation potential. Here, we prepared a bifunctional mRNA delivery system DMP-Lac (DOTAP-mPEG-PCL-L. reuteri lysate), which successfully codelivered L. reuteri lysate and IL-23A mRNA, exhibited a high mRNA delivery efficiency of 75.56% ± 0.85%, and strongly promoted the maturation and activation of the immune system in vivo. Both the CT26 abdominal metastasis model and the lung metastasis model also exhibited a good therapeutic effect, and the tumor inhibition rate of DMP-Lac/IL-23A group reached 97.92%. Protein chip technology verified that DMP acted as an immune adjuvant, demonstrating that the L. reuteri lysate could regulate the related immune cells, while IL-23 mRNA caused changes in downstream factors, thus producing the corresponding tumor treatment effect. The DMP-Lac/IL-23A complex exhibited strong anticancer immunotherapeutic effects. Our results demonstrated that this bifunctional mRNA formulation served as a tumor-specific nanomedicine, providing an advanced strategy for colon cancer immunogene therapy.

Biopolymer immune implants co-loaded with TMZ, R848 and IOX1 for perioperative therapy of glioblastoma

Glioblastoma (GBM), a prevalent and aggressive brain tumor, poses significant treatment challenges due to its rapid progression and the difficulty in achieving complete surgical resection. The current treatment regime, primarily surgery followed by radiotherapy and chemotherapy, offers limited success, with a five-year survival rate of less than 10 %. For addressing the challenges faced in the treatment of GBM, an approach using a biopolymer implant constructed with dynamic reversible covalent bonds, was designed to achieve controlled and constant-rate release of chemotherapy drug (Temozolomide, TMZ), immune adjuvant (Resiquimod, R848) and checkpoint inhibitor (5-carboxy-8-hydroxyquinoline, IOX1). The safety evaluation demonstrated the biocompatibility of the implants, with no significant inflammatory response or adverse effects on various systemic organs. In vivo antitumor study showed that the local delivery of drug combination via this implant significantly inhibited tumor recurrence of orthotopic GBM. Immune analysis revealed that the combination of the three drugs effectively activated systemic antitumor immune responses and induced memory effects. The synergistic mechanism of the drug combination was further validated by RNA whole sequencing. The innovative approach of combining chemotherapy and immunotherapy in biopolymer immune implants for GBM treatment showed promising and opens new avenues for treating GBM, particularly in addressing postoperative recurrence. Statement of significanceOur research introduces a pioneering approach in treating orthotopic brain glioblastoma (GBM), characterized by inevitable tumor recurrence, poor immune infiltration and the restrictive nature of the blood-brain barrier. To break the impasse of ineffective treatment for GBM, the innovative use of dynamically reversible covalent bonds in polymer matrix ensures the controlled, stable and sustained release of drug combinations of the chemotherapeutic agent temozolomide, immune adjuvants and checkpoint inhibitors, which maintains the optimal concentration in the tumor, overcoming problems associated with conventional chemotherapy such as systemic toxicity and low tumor targeting. Empirical evidence from in vivo experiments on the rat GBM model demonstrates significant outcomes: 90 % tumor size reduction and prolonged survival with over 70 % tumor cure rate.

Natural plant-derived polysaccharides targeting macrophage polarization: a promising strategy for cancer immunotherapy.

Tumor associated macrophages (TAMs) are the predominant innate immune cells in the tumor microenvironment (TME). Cytokines induce the differentiation of macrophages into distinct types of TAMs, primarily characterized by two phenotypes: M1-polarized and M2-polarized. Cancer growth is suppressed by M1-polarized macrophages and promoted by M2-polarized macrophages. The regulation of macrophage M1 polarization has emerged as a promising strategy for cancer immunotherapy. Polysaccharides are important bioactive substances found in numerous plants, manifesting a wide range of noteworthy biological actions, such as immunomodulation, anti-tumor effects, antioxidant capabilities, and antiviral functions. In recent years, there has been a significant increase in interest regarding the immunomodulatory and anti-tumor properties of polysaccharides derived from plants. The regulatory impact of polysaccharides on the immune system is mainly associated with the natural immune response, especially with the regulation of macrophages. This review provides a thorough analysis of the regulatory effects and mechanisms of plant polysaccharides on TAMs. Additionally, an analysis of potential opportunities for clinical translation of plant polysaccharides as immune adjuvants is presented. These insights have greatly advanced the research of plant polysaccharides for immunotherapy in tumor-related applications.

Intranasal Self-Adjuvanted Lipopeptide Vaccines Elicit High Antibody Titers and Strong Cellular Responses against SARS-CoV-2.

Despite concerted efforts to tackle the COVID-19 pandemic, the persistent transmission of SARS-CoV-2 demands continued research into novel vaccination strategies to combat the virus. In light of this, intranasally administered peptide vaccines, particularly those conjugated to an immune adjuvant to afford so-called "self-adjuvanted vaccines", remain underexplored. Here, we describe the synthesis and immunological evaluation of self-adjuvanting peptide vaccines derived from epitopes of the spike glycoprotein of SARS-CoV-2 covalently fused to the potent adjuvant, Pam2Cys, that targets toll-like receptor 2 (TLR2). When administered intranasally, these vaccines elicited a strong antigen-specific CD4+ and CD8+ T-cell response in the lungs as well as high titers of IgG and IgA specific to the native spike protein of SARS-CoV-2. Unfortunately, serum and lung fluid from mice immunized with these vaccines failed to inhibit viral entry in spike-expressing pseudovirus assays. Following this, we designed and synthesized fusion vaccines composed of the T-cell epitope discovered in this work, covalently fused to epitopes of the receptor-binding domain of the spike protein reported to be neutralizing. While antibodies elicited against these fusion vaccines were not neutralizing, the T-cell epitope retained its ability to stimulate strong antigen-specific CD4+ lymphocyte responses within the lungs. Given the Spike(883-909) region is still completely conserved in SARS-CoV-2 variants of concern and variants of interest, we envision the self-adjuvanting vaccine platform reported here may inform future vaccine efforts.

PEI-Engineered Lipid@PLGA Hybrid Nanoparticles for Multimodal Delivery of Antigens and Immune Adjuvants to the Respiratory Mucosa.

Antigen delivery via respiratory mucosal surfaces is an interesting needle-free option for vaccination. Nonetheless, it demands for the design of especially tailored formulations. Here, lipid/poly(lactic-co-glycolic) acid (PLGA) hybrid nanoparticles (hNPs) for the combined delivery of an antigen, ovalbumin (Ova), and an adjuvant, synthetic unmethylated cytosine-phosphate-guanine oligodeoxynucleotide (CpG) motifs, is developed. A panel of Ova/CpG-loaded lipid@PLGA hNPs with tunable size and surface is attained by exploiting two lipid moieties, 1,2 distearoil-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol) (DSPE-PEG) and monophosphoryl lipid A (MPLA), with or without polyethyleneimine (PEI). It is gained insights on the lipid@PLGA hNPs through a combination of techniques to analytically determine the specific moiety on the surface, the spatial distribution of the components and the internal structure of the nanoplatforms. The collected results suggest that PEI plays a role of paramount importance not only in promoting in vitro antigen escape from lysosomes and enhancing antigen cross-presentation, but also in determining the arrangement of the moieties in the final architecture of the hNPs. Though multicomponent PEI-engineered lipid@PLGA hNPs turn out as a viable strategy for delivery of antigens and adjuvant to the respiratory mucosa, tunable nanoparticle features are achievable only through the optimal selection of the components and their relative amounts.

Immunomodulatory Effects of Probiotic-Derived Extracellular Vesicles: Opportunities and Challenges.

Probiotics are known to modulate host immune responses in the course of many diseases. Recently, bacterial extracellular vesicles (EVs), which contain bioactive proteins, lipids, nucleic acids, and metabolites released by bacteria, have been identified as potentially important mediators of bacteria-bacterium and bacteria-host interactions. With the deepening of research, it has been found that probiotic-derived EVs play a significant role in regulating host immune function and, thus, exerting health-promoting effects. Nevertheless, current research is in its early stages, and there remains a long way to go to bridge the gap between basic research and clinical practice. In this review, we describe the fundamental aspects of probiotic-derived EVs, including their biogenesis, cargo sorting mechanism, and transport capabilities. We further discussed the potential mechanisms of probiotic-derived EVs in regulating the host's gut microbiota and immune responses. Finally, we speculate about the potential of probiotic-derived EVs as new postbiotics for applications in functional food, disease treatment substitutes, and immune regulatory adjuvants.

A carrier-free nanovaccine combined with cancer immunotherapy overcomes gemcitabine resistance

Drug resistance is a significant challenge in cancer chemotherapy and is a primary factor contributing to poor recovery for cancer patients. Although drug-loaded nanoparticles have shown promise in overcoming chemotherapy resistance, they often carry a combination of drugs and require advanced design and manufacturing processes. Furthermore, they seldom approach chemotherapy-resistant tumors from an immunotherapy perspective. In this study, we developed a therapeutic nanovaccine composed solely of chemotherapy-induced resistant tumor antigens (CIRTAs) and the immune adjuvant Toll-like receptor (TLR) 7/8 agonist R848 (CIRTAs@R848). This nanovaccine does not require additional carriers and has a simple production process. It efficiently delivers antigens and immune stimulants to dendritic cells (DCs) simultaneously, promoting DCs maturation. CIRTAs@R848 demonstrated significant tumor suppression, particularly when used in combination with the immune checkpoint blockade (ICB) anti-PD-1 (αPD-1). The combined therapy increased the infiltration of T cells into the tumor while decreasing the proportion of regulatory T cells (Tregs) and modulating the tumor microenvironment, resulting in long-term immune memory. Overall, this study introduces an innovative strategy for treating chemotherapy-resistant tumors from a novel perspective, with potential applications in personalized immunotherapy and precision medicine.

Shedding reduction and immunity modulation in piglets with an inactivated Mycoplasma hyopneumoniae vaccine encapsulated in nanostructured SBA-15 silica

Mycoplasma (M.) hyopneumoniae is a primary etiological agent of porcine enzootic pneumonia (PEP), a disease that causes significant economic losses to pig farming worldwide. Current commercial M. hyopneumoniae vaccines induce partial protection, decline in preventing transmission of this pathogen or inducing complete immunity, evidencing the need for improving vaccines against PEP. In our study, we aimed to test the effectiveness of the SBA-15 ordered mesoporous silica nanostructured particles as an immune adjuvant of a vaccine composed of M. hyopneumoniae strain 232 proteins encapsulated in SBA-15 and administered by intramuscular route in piglets to evaluate the immune responses and immune-protection against challenge. Forty-eight 24-day-old M. hyopneumoniae-free piglets were divided into four experimental groups with different protocols, encompassing a commercial vaccine against M. hyopneumoniae, SBA-15 vaccine, SBA-15 adjuvant without antigens and a non-immunized group. All piglets were challenged with the virulent strain 232 of M. hyopneumoniae. Piglets that received the SBA-15 and commercial vaccine presented marked immune responses characterized by anti-M. hyopneumoniae IgA and IgG antibodies in serum, anti-M. hyopneumoniae IgA antibodies in nasal mucosa and showed an upregulation of IL-17 and IL-4 cytokines and downregulation of IFN-γ in lungs 35 days post-infection. Piglets immunized with SBA-15 vaccine presented a reduction of bacterial shedding compared to piglets immunized with a commercial bacterin. In addition, piglets from SBA-15 adjuvant suspension group presented increased IL-17 gene expression in the lungs without involvement of Th1 and Th2 responses after challenge. These results indicated that SBA-15 vaccine induced both humoral and cell-mediated responses in the upper respiratory tract and lungs, first site of replication and provided protection against M. hyopneumoniae infection with a homologous strain with reduction of lung lesions and bacterial shedding. Finally, these results enhance the potential use of new technologies such as nanostructured particles applied in vaccines for the pig farming industry.

Astragalus Polysaccharide improves immunogenicity of influenza vaccine as well as modulate gut microbiota in BALB/c mice

BackgroundVaccination is the best way to prevent influenza virus infection, and insufficient antibodies make it difficult to resist influenza virus invasion. Astragalus Polysaccharide (APS) has a boosting effect on immunity, so we evaluate the effect of APS as an immune adjuvant for H1N1 influenza vaccines in this study. MethodsThe mice were immunized twice with influenza A (H1N1) vaccine and APS. Subsequently, the serum antibody levels were assessed using enzyme-linked immunosorbent assay (ELISA). The frequency of peripheral immune T cells was determined by flow cytometry. Following this, the immunized mice were exposed to a lethal dose of the virus, and changes in body weight and survival rates were recorded. Hematoxylin-eosin staining was employed to observe pathological alterations in lung and intestinal tissues. Western blot analysis was conducted to detect the expression of intestinal barrier function proteins (Occludin and Claudin-1). ELISA was utilized to measure the expression level of serum inflammatory cytokine TNF-α. Fresh mouse feces were collected after the initial immunization as well as after viral infection for 16S rRNA analysis aimed at detecting alterations in gut microbiota. ResultsCompared to the Hemagglutinin (HA) group, the APS group demonstrated higher levels of immunoglobulin G (IgG), IgG1, and IgG3, as well as neutralizing antibody levels. Additionally, it increased the frequency of CD8+ cells to enhance resistance against lethal infection. On day 14 post-infection, the high-dose APS group exhibited a higher survival rate (71.40 %) compared to the HA group (14.28 %), along with faster weight recovery. Furthermore, APS was found to ameliorate alveolar damage in lung tissue and rectify intestinal structural disorder. It also upregulated the expression levels of tight junction proteins Occludin and Claudin-1 in intestinal tissue while reducing serum TNF-α expression levels. In addition, populations of Colidextribacter, Peptococcaceae, and Ruminococcaceae were the dominant gut microbiota in the APS group after viral infection. ConclusionAPS has an immune-enhancing effect and is expected to be a novel adjuvant in the H1N1 influenza vaccine.

Targeted nanoprobe for magnetic resonance imaging-guided enhanced antitumor via synergetic photothermal/immunotherapy

Synergistic photothermal/immunotherapy has garnered significant attention for its potential to enhance tumor therapeutic outcomes. However, the fabrication of an intelligent system with a simple composition that simultaneously exerts photothermal/immunotherapy effect and imaging guidance function still remains a challenge. Herein, a glutathione (GSH)-responsive theranostic nanoprobe, named HA-MnO2/ICG, was elaborately constructed by loading photothermal agent (PTA) indocyanine green (ICG) onto the surface of hyaluronic acid (HA)-modified manganese dioxide nanosheets (HA-MnO2) for magnetic resonance (MR) imaging-guided synergetic photothermal/immuno-enhanced therapy. In this strategy, HA-MnO2 nanosheets were triggered by the endogenous GSH in tumor microenvironment to generate Mn2+ for MR imaging, where the longitudinal relaxation rate of HA-MnO2/ICG was up to 14.97 mM−1s−1 (∼24 times than that found in a natural environment), demonstrating excellent intratumoral MR imaging. Moreover, the HA-MnO2/ICG nanoprobe demonstrates remarkable photothermal therapy (PTT) efficacy, generating sufficient heat to induce immunogenic cell death (ICD) within tumor cells. Meanwhile the released Mn2+ ions from the nanosheets function as potent immune adjuvants, amplifying the immune response against cancer. In vivo experiments validated that HA-MnO2/ICG-mediated PTT was highly effective in eradicating primary tumors, while simultaneously enhancing immunogenicity to prevent the growth of distal metastasis. This hybrid HA-MnO2/ICG nanoprobe opened new avenues in the design of MR imaging-monitored PTT/immuno-enhanced synergistic therapy for advanced cancer.