In vivo edited eosinophils reconcile antigen specific Th2 response and mitigate airway allergy.

BACKGROUND: Improvement is needed in the remedies used to control Th2 polarization. Bioengineering approaches have modified immune cells that have immunosuppressive functions. This study aims to generate modified eosinophils (Meos) in vivo and use Meos to balance Th2 polarization and reduce airway allergy. METHODS: A cell editor was constructed. The editor contained a peptide carrier, an anti-siglec F antibody, MHC II, ovalbumin, and LgDNA (DNA extracted from a probiotic, Lactobacillus rhamnosus GG). Which was designated as Cedit. Meos are eosinophils modified using Cedits. An airway Th2 polarization mouse model was established used to test the effect of Meos on suppressing airway allergy. RESULTS: The Cedits remained physically and chemically stable in solution (pH7.2) for at least 96 h. Cedits specifically bound to eosinophils, which are designated as Meos. Meos produced programmed death ligand-1 (PD-L1); the latter induced antigen specific CD4+ T cell apoptosis. Administration of Cedits through nasal instillations generated Meos in vivo, which significantly reduced the frequency of antigen specific CD4+ T cells in the airways, and mitigated airway Th2 polarization. CONCLUSIONS: We constructed Cedit, which could edit eosinophils into Meos in vivo. Meos could induce antigen specific CD4+ T cell apoptosis, and reconcile airway Th2 polarization.

Postnatal Allergic Inhalation Induces Glial Inflammation in the Olfactory Bulb and Leads to Autism-Like Traits in Mice.

Autism spectrum disorder (ASD) is one of the most prevalent neurodevelopmental disorders. To explore its pathophysiology, we investigated the association between neonatal allergic exposure and behavioral changes. Adult female C57BL/6J mice were immunized with adjuvant (aluminum hydroxide) or ovalbumin emulsified with adjuvant. After immunization, the mice were mated, and offspring were born at full term. The postnatal dams and infants were then simultaneously exposed to an allergen (ovalbumin) or vehicle via inhalation. After weaning, behavioral testing and histopathological analyses were conducted on male offspring. Compared with the vehicle-exposed offspring, the ovalbumin-exposed offspring had decreased sociability and increased repetitive behavior, thus representing an ASD-like phenotype in mice. Moreover, histopathological analyses revealed that the ovalbumin-exposed mice had increased astroglial, microglial, and eosinophilic infiltration in the olfactory bulb, as well as increased eosinophils in the nasal mucosa. The ovalbumin-exposed mice also had decreased dendritic spine density and a lower proportion of mature spines, suggesting the impairment of stimulus-induced synaptogenesis. In conclusion, postnatal allergic exposure induced an ASD-like phenotype, as well as allergic rhinitis, which was followed by glial inflammation in the olfactory bulb parenchyma.

[The role and its regulatory significance of interleukin-25 in ovalbumin induced atopic dermatitis of mice].

OBJECTIVE: To investigate the effect of interleukin-25 (IL-25) on ovalbumin (OVA) induced atopic dermatitis of mice, and the significance of regulating IL-25. METHODS: In this study, 90 healthy male 6-week-old specific pathogen free (SPF) BALB/c mice were divided into 6 groups (15 in each group): ① subcutaneous injection of phosphate buffered saline (PBS) group (normal control group); ② subcutaneous injection of mouse IL-25 group (IL-25 group); ③ subcutaneous injection of anti-mouse IL-25 monoclonal antibody (anti-IL-25 group), each group received subcutaneous injection once a day for 1 week, 2 weeks apart, repeated daily subcutaneous injections for 1 week, 2 weeks apart, and repeated daily subcutaneous injections for 1 week, for a total of 7 weeks; ④ OVA treated group (model group); ⑤ OVA treated and IL-25 subcutaneous injection group (IL-25 treated dermatitis group); ⑥ OVA treated and anti-mouse IL-25 monoclonal antibody injection group (anti-IL-25 treated dermatitis group). The ⑤ and ⑥ groups in the process of treatment with OVA, IL-25 or anti-IL-25 antibody were given in the same way as the ② and ③ groups. Scratching behavior and skin performance of the mice were recorded during the seven-week-treatment. Twenty four hours after the final treatment, blood was taken from the mouse heart, and the serum was separated to detect the total IgE, IL-4, IL-5, IL-13, etc. The skin samples of the treatment sites were used for hematoxylin-eosin (HE) staining, immunohistochemistry, real-time PCR and Western blot detections. A single factor (ANOVA) analysis of variance was used to compare the differences in various indicators between the groups. RESULTS: The frequency of scratches in the IL-25 treated dermatitis group was higher than that in the model group, and the scratching behavior of the anti-IL-25 treated dermatitis group was significantly lower than that in the model group. The appearance of atopic dermatitis, thickening of the epidermis and the degree of dermal inflammation in the IL-25 treated dermatitis group were more serious than those in the model group and the anti-IL-25 treated dermatitis group. The levels of serum IgE, IL-4, IL-5, and IL-13 in the IL-25 treated dermatitis group were significantly higher than that in the model group and the anti-IL-25 treated dermatitis group. There were significantly more CD4+ T cells in the dermis of IL-25 treated dermatitis group than that in the anti-IL-25 treated dermatitis group. The expression levels of filaggrin and defensin ß2 proteins in the IL-25 treated dermatitis group were significantly lower than those in the model group and the anti-IL-25 treated dermatitis group. CONCLUSION: In the OVA induced atopic dermatitis mice model, IL-25 can significantly promote the damage of the epidermal barrier function and aggravate the OVA-induced dermatitis. Antagonizing IL-25 can alleviate OVA induced dermatitis to a certain extent.

Internalization of therapeutic antibodies into dendritic cells as a risk factor for immunogenicity.

Introduction: Immunogenicity, the unwanted immune response triggered by therapeutic antibodies, poses significant challenges in biotherapeutic development. This response can lead to the production of anti-drug antibodies, potentially compromising the efficacy and safety of treatments. The internalization of therapeutic antibodies into dendritic cells (DCs) is a critical factor influencing immunogenicity. Using monoclonal antibodies, with differences in non-specific cellular uptake, as tools to explore the impact on the overall risk of immunogenicity, this study explores how internalization influences peptide presentation and subsequently T cell activation. Materials and methods: To investigate the impact of antibody internalization on immunogenicity, untargeted toolantibodies with engineered positive or negative charge patches were utilized. Immature monocyte-derived DCs (moDCs), known for their physiologically relevant high endocytic activity, were employed for internalization assays, while mature moDCs were used for MHC-II associated peptide proteomics (MAPPs) assays. In addition to the lysosomal accumulation and peptide presentation, subsequent CD4+ T cell activation has been assessed. Consequently, a known CD4+ T cell epitope from ovalbumin was inserted into the tool antibodies to evaluate T cell activation on a single, shared epitope. Results: Antibodies with positive charge patches exhibited higher rates of lysosomal accumulation and epitope presentation compared to those with negative charge patches or neutral surface charge. Furthermore, a direct correlation between internalization rate and presentation on MHC-II molecules could be established. To explore the link between internalization, peptide presentation and CD4+ T cell activation, tool antibodies containing the same OVA epitope were used. Previous observations were not altered by the insertion of the OVA epitope and ultimately, an enhanced CD4+ T cell response correlated with increased internalization in DCs and peptide presentation. Discussion: These findings demonstrate that the biophysical properties of therapeutic antibodies, particularly surface charge, play a crucial role in their internalization into DCs. Antibodies internalized faster and processed by DCs, are also more prone to be presented on their surface leading to a higher risk of triggering an immune response. These insights underscore the importance of considering antibody surface charge and other properties that enhance cellular accumulation during the preclinical development of biotherapeutics to mitigate immunogenicity risks.

Synergistic immune augmentation enabled by covalently conjugating TLR4 and NOD2 agonists.

Enhancing the efficacy of subunit vaccines relies significantly on the utilization of potent adjuvants, particularly those capable of triggering multiple immune pathways. To achieve synergistic immune augmentation by Toll-like receptor 4 agonist (TLR4a) and nucleotide-binding oligomerization-domain-containing protein 2 agonist (NOD2a), in this work, we conjugated RC529 (TLR4a) and MDP (NOD2a) to give RC529-MDP, and evaluated its adjuvanticity for OVA antigen. Compared to the unconjugated RC529+MDP, RC529-MDP remarkably enhanced innate immune responses with 6.8-fold increase in IL-6 cytokine, and promoted the maturation of antigen-presenting cells (APCs), possibly because of the conjugation of multiple agonists ensuring their delivery to the same cell and activation of various signaling pathways within that cell. Furthermore, RC529-MDP improved OVA-specific antibody response, T cells response and the memory T cells ratio relative to the unconjugated mixture. Therefore, covalently conjugating TLR4 agonist and NOD2 agonist was an effective strategy to enhance immune responses, providing the potential to design and develop more effective vaccines.

Isoorientin alleviates ovalbumin-stimulated allergic rhinitis in mice by restoring Th1/Th2 balance.

Allergic rhinitis (AR) is a chronic, non-infectious inflammatory condition of the nasal mucosa mediated by IgE. There is a need for the development of novel medications to treat this ailment. Isoorientin is a naturally occurring flavonoid that possesses antioxidant, anti--inflammatory, and various other advantageous characteristics. However, its potential effects on AR remain unclear. This study evaluates the therapeutic effects of isoorientin on ovalbumin (OVA)-induced allergic rhinitis (AR) in mice and explores the underlying mechanism. Our study revealed that isoorientin administration effectively decreased the frequency of nose rubbing and sneezing in AR mice. The groups treated with isoorientin showed a significant decrease in serum levels of IgE and histamine, with reductions of 40% and 30%, respectively. Isoorientin ameliorated inflammation of the nasal mucosa and restored the Th1/Th2 balance. In addition, isoorientin inhibited the activation of the NF-κB pathway in nasal tissues. In summary, Isoorientin alleviates OVA-stimulated AR in mice by restoring Th1/Th2 balance and blocking the NF-κB pathway. Thus, isoorientin exhibits promise as a natural therapeutic agent for allergic rhinitis.

Allergo-immunopathology mechanism of thymol-inhibiting airway remodeling in asthmatic mice by regulating TGF-ß/Smad3 pathway.

Allergic asthma is an important public health problem and is a complicated respiratory sickness that is characterized by bronchial inflammation, bronchoconstriction, and breathlessness. Asthma is orchestrated by type 2 immune response and remodeling is one of the important outputted problem in chronic asthma. Thymol is a naturally occurring monocyclic phenolic, it has a series of biological properties, and its immunomodulatory and anti-remodeling effects on allergic asthma were evaluated. The OVA-LPS-induced asthmatic mice were treated with thymol. Methacholine challenge test, eosinophil count, and levels of IL-4, IL-5, IL-13, and IL-33 in bronchoalveolar lavage fluid, total and OVA-specific IgE levels in serum, remodeling factors, gene expression of TGF-ß, Smad2, Smad3, and lung histopathology were done. Treatment with thymol could control AHR, eosinophil percentage levels of Th2 cytokines and Igs, remodeling factors, expression of TGF-ß, Smad2 and Smad3 genes, inflammation, goblet cell hyperplasia, and mucus production in asthmatic mice. Thymol can control asthma pathogens and related remodeling and fibrosis bio-factors and can be a potential treatment of asthma.

Effect of Polysaccharides Isolated from Saussurea salicifolia (L.) DC on Th2-Dependent Immune Response.

The effect of polysaccharides isolated from the aboveground parts of Saussurea salicifolia (L.) DC on Th2 type immune response reactions was studied. Administration of water-soluble polysaccharides presented by arabino-galacturonans (weight average molecular weight 158.49 kDa) to mice against the background of experimental Th2 immunity reduced the severity of anaphylactic and local immediate type hypersensitivity reactions. It also suppressed the production of ovalbumin-specific IgE and IgG1 and increased the stability of mast cell membranes. The studied polysaccharide complex increased IFNγ secretion and inhibited IL-4 synthesis. These findings suggest that these polysaccharides may be considered as potential anti-allergic agents that suppress the development of allergy in its early stages.

A Magnetically Driven Biodegradable Microsphere with Mass Production Capability for Subunit Vaccine Delivery and Enhanced Immunotherapy.

Subunit vaccines have emerged as a promising strategy in immunotherapy for combating viral infections and cancer. Nevertheless, the clinical application of subunit vaccines is hindered by limitations in antigen delivery efficiency, characterized by rapid clearance and inadequate cellular uptake. Here, a novel subunit vaccine delivery system utilizing ovalbumin@magnetic nanoparticles (OVA@MNPs) encapsulated within biodegradable gelatin methacryloyl (GelMA) microspheres was proposed to enhance the efficacy of antigen delivery. OVA@MNPs-loaded GelMA microspheres, denoted as OMGMs, can be navigated through magnetic fields to deliver subunit vaccines into the lymphatic system efficiently. Moreover, the biodegradable OMGMs enabled the sustained release of subunit vaccines, concentrating OVA around lymph nodes and enhancing the efficacy of induced immune response. OMGMs were produced through a microfluidic droplet generation technique, enabling mass production. In murine models, OMGMs successfully accumulated antigens in lymph nodes abundant in antigen-presenting cells, leading to enhanced cellular and humoral immunity and pronounced antitumor effects with a single booster immunization. In conclusion, these findings highlight the promise of OMGMs as a practical subunit vaccination approach, thus addressing the limitations associated with antigen delivery efficiency and paving the way for advanced immunotherapeutic strategies.

Preparation of viromimetic rod-like nanoparticle vaccines (RLNVax) and study of their humoral immune activation efficacy.

Virus-like nanoparticle vaccines can efficiently activate the humoral immune response by cross-linking B cell receptors with their surface multivalent antigen arrays. This structurally dependent mechanism makes it crucial to regulate and optimize structural parameters to enhance the efficacy of nanoparticle vaccines. In this study, we prepared nanoparticle vaccines with different aspect ratios by chemically modifying antigen proteins onto the surfaces of poly(amino acid) nanoparticles of various shapes (spherical, ellipsoidal, and rod-like). This allowed us to investigate the impact of structural anisotropy on the humoral immune activation efficacy of nanoparticle vaccines. Furthermore, the end-group molecules of poly(amino acid) materials possess aggregation-induced emission (AIE) properties, which facilitate monitoring the dynamics of nano-assemblies within the body. Results showed that rod-like nanoparticle vaccines (RLNVax) with a higher aspect ratio (AR = 5) exhibited greater lymph node draining efficiency and could elicit more effective B cell activation compared to conventional isotropic spherical nanoparticle vaccines. In a murine subcutaneous immunization model using ovalbumin (OVA) as a model antigen, RLNVax elicited antigen-specific antibody titers that were about 64 times and 4.6 times higher than those induced by free antigen proteins and spherical nanoparticle vaccines, respectively. Additionally, when combined with an aluminum adjuvant, antibody titers elicited by RLNVax were further enhanced by 4-fold. These findings indicate that the anisotropic rod-like structure is advantageous for improving the humoral immune activation efficacy of nanoparticle vaccines, providing significant insights for the design and optimization of next-generation nanoparticle vaccines.

Therapeutic efficacy of JEW-M449, an anti-TCTP monoclonal antibody, administered via the nasal route in a BALB/c mouse model of ovalbumin-induced acute asthma.

Numerous studies have highlighted the role of translationally controlled tumor protein (TCTP) as a key inflammatory mediator of asthma and allergies. Our previous study revealed that blocking the cytokine-like activity of TCTP using JEW-M449, an anti-TCTP monoclonal antibody (mAb), alleviated allergic inflammation in asthmatic mice. This study aimed to determine whether directly delivering JEW-M449 into the respiratory tract is a more effective way of mitigating airway inflammation in a mouse model of ovalbumin (OVA)-induced allergic airway inflammation than delivering this antibody via the intraperitoneal (IP) route. OVA-sensitized mice were intranasally administered JEW-M449 to enable its direct delivery to the respiratory tract before OVA challenge. We evaluated the changes in the levels of bronchoalveolar lavage fluid (BALF) cells, T helper type 2 (Th2) cytokines, OVA-specific immunoglobulin E (IgE), and histopathological alterations in the lung tissues. Intranasal (IN) administration of JEW-M449 significantly ameliorated the pathological changes associated with OVA-induced lung injury, including reduced inflammatory cell infiltration and mucus hypersecretion. Mice IN administered JEW-M449 also showed decreased OVA-mediated induction of Th2 cytokines in BALF and lung homogenates. Importantly, JEW-M449 delivered via the IN route reached the lung tissue more effectively and exerted superior anti-inflammatory effects in OVA-challenged mice than the IP-delivered JEW-M449. This study is the first to demonstrate the efficacy of directly delivering JEW-M449 anti-TCTP mAb into the respiratory tract to alleviate the asthma phenotype in a mouse model, thereby highlighting a potential delivery strategy for novel inhaled mAb therapeutics for human asthma.

Deciphering the mechanisms of the IL-6/CXCL1 and NOD-like receptor signaling pathways in otitis media with effusion in rodents.

BACKGROUND: Otitis media with effusion (OME) often leads to pediatric hearing loss and is influenced by innate and adaptive immune responses. Innate immunity serves as the non-specific first line of defense against OME. METHODS: We induced OME in rats using ovalbumin. We administered IL-6 monoclonal antibodies intranasally to inhibit IL-6, and we injected an NF-κB inhibitor intraperitoneally to explore the role of IL-6 in innate immunity and its interaction with the NOD-like receptor signaling pathway. We analyzed RNA-sequencing data with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways to assess signaling pathways involved in OME. We also utilized Western blot, quantitative real-time PCR, and immunohistochemistry on middle ear samples and used microscopy to identify immune cells in ear wash fluids. RESULTS: Our study suggests a pivotal role for IL-6 in the immune pathways of rats with OME via the regulation of CXCL1-mediated pathways. Increased levels of IL-6 and CXCL1 were observed in the middle ear tissues, and activation of the NLRP3 inflammasome in OME rats led to an immune response via NF-κB, thus promoting IL-6 and CXCL1 production, which was reduced by IL-6 antibody treatment. CONCLUSIONS: Our findings confirm that IL-6 and CXCL1 play significant roles in the innate immune response in OME in rodents, predominantly via the NOD-like receptor signaling pathway and NLRP3 inflammasome activation. This research sheds light on OME pathogenesis and its immune-related mechanisms.

Fecal microbiota transplantation as a new way for OVA-induced atopic dermatitis of juvenile mice.

Children all over the world suffer from atopic dermatitis (AD), a prevalent condition that impairs their health. Corticosteroids, which have long-term negative effects, are frequently used to treat AD. There has been a growing body of research on the gut microbiota's function in AD. Nevertheless, the function and underlying mechanisms of fecal microbiota transplantation (FMT) in AD children remain to be established. Therefore, in order to assess the preventive effects of FMT treatment on AD and investigate the mechanisms, we constructed an ovalbumin (OVA)-induced juvenile mouse AD model in this investigation. This study explored the role and mechanism of FMT treatment in AD through 16S RNA sequencing, pathological histological staining, molecular biology, and Flow cytometry. Results demonstrated that the FMT treatment improved the gut microbiota's diversity and composition, bringing it back to a level similar to that of a close donor. Following FMT treatment, OVA-specific antibodies were inhibited, immunoglobulin (Ig) E production was decreased, the quantity of mast cells and eosinophils was decreased, and specific inflammatory markers in the skin and serum were decreased. Further mechanistic studies revealed that FMT treatment induced CD103+ DCs and programmed cell death ligand 1 (PD-L1)/programmed cell death 1 (PD-1) expression in skin-draining lymph nodes and promoted Treg production to induce immune tolerance and suppress skin inflammation. Meanwhile, changes in the gut microbiota were substantially correlated with Th2 cytokines, OVA-specific antibodies, and PD-L1/PD-1. In conclusion, FMT regulates the Th1/Th2 immunological balance and the gut microbiota. It may also inhibit AD-induced allergy responses through the PD-L1/PD-1 pathway, and providing a unique idea and possibly a fresh approach to the treatment of AD.

Maternal High-Fat Diet Exacerbates Epicutaneous Sensitization and Oral Challenge-Induced Food Allergy to Ovalbumin in Offspring Mice.

Dietary factors have been associated with an increased prevalence of food allergy (FA). However, little is known about how an unhealthy diet in early life affects FA reactions in offspring. The objective of this study is to provide a scientific foundation for developing and promoting healthy dietary patterns in early life. In this study, we found that maternal high-fat diet (HFD) during pregnancy and lactation exacerbates FA (HFD-FA) in offspring mice, leading to increased serum levels of mast cell protease 1. First, we studied the systemic immunity of the HFD-FA mice and observed elevated levels of proinflammatory cytokines (IL-4, IL-6, and IL-1ß) and a reduced frequency of Treg cells in splenocytes. Additionally, the HFD-FA mice showed increased gut permeability, accumulation of intestinal mast cells, and a decrease in the Treg cell frequency in the mesenteric lymph nodes. Furthermore, our findings also indicated a reduction in gut microbial diversity and abundance in HFD-FA mice. Importantly, lipid metabolism profiling revealed unique lipid profiles in the HFD-FA mice, with significant upregulation of triglycerides and downregulation of sphingolipids. Taken together, our results suggest that maternal HFD alters intestinal homeostasis and increases FA susceptibility in offspring mice.

The Immune Memory Response of In Vitro-Polarised Th1, Th2, and Th17 Cells in the Face of Ovalbumin-Transgenic Leishmania major in a Mouse Model.

Th1 and Th2 cytokines determine the outcome of Leishmania major infection and immune protection depends mainly on memory T cells induced during vaccination. This largely hinges on the nature and type of memory T cells produced. In this study, transgenic Leishmania major strains expressing membrane-associated ovalbumin (mOVA) and soluble ovalbumin (sOVA) were used as a model to study whether fully differentiated Th1/Th2 and Th17 cells can recall immune memory and tolerate pathogen manipulation. Naïve OT-II T cells were polarised in vitro into Th1/Th2 cells, and these cells were transferred adoptively into recipient mice. Following the transferral of the memory cells, the recipient mice were challenged with OVA transgenic Leishmania major and a wild-type parasite was used a control. The in vitro-polarised T helper cells continued to produce the same cytokine signatures after being challenged by both forms of OVA-expressing Leishmania major parasites in vivo. This suggests that antigen-experienced cells remain the same or unaltered in the face of OVA-transgenic Leishmania major. Such ability of these antigen-experienced cells to remain resilient to manipulation by the parasite signifies that vaccines might be able to produce immune memory responses and defend against parasitic immune manipulation in order to protect the host from infection.

Changes in respiratory tract and gut microbiota in AR mice and their relationship with Th1/Th2/Treg.

BACKGROUND: The etiology of allergic rhinitis (AR) is not fully understood. Studies have shown that the maturation of children's immune systems is closely related to microecology. However, few studies have focused simultaneously on changes in respiratory and gut microbiota in AR and their correlation between microecological changes and Th1/Th2/Treg. OBJECTIVE: The aim is to investigate the pathogenesis of AR based on respiratory microecology, gut microecology, and Th1/Th2/Treg levels by applying microbiome techniques and correlation analysis. METHODS: Standardized OVA-induced AR mice were established. Serum OVA-sIgE, IL-4, IFN-γ, IL-10 were measured by ELISA, Tregs in lymph nodes were determined by flow cytometry, and the histological characteristics of nasal tissues were evaluated by Hematoxylin & Eosin (H&E). Nasal symptoms were observed to determine the reliability of the AR mouse model. Nasal lavage fluid (NALF) and fecal samples were collected after the last OVA challenge. The composition of respiratory microbiota in NALF and gut microbial in feces samples via 16S rRNA gene sequencing between the two groups, further explored the relationship between microbiota and Th1/Th2/Treg levels. RESULTS: In the AR group, the incidence of nose rubbing and sneezing in each mouse was significantly increased compared with the control group (all P < 0.001) and the inflammatory cell infiltration of NALF shows a significant increase in eosinophilic and neutrophilic infiltrates upon the AR group; H&E showed that the nasal mucosa of AR mice infiltration of massive eosinophils cells and neutrophils cells. OVA-sIgE and IL-4 in the AR group were increased (P < 0.01, P < 0.05) and IFN-γ, IL-10 were significantly decreased (P < 0.01, P < 0.05). Tregs showed a downward trend in the AR group, but there was no statistical difference. Compared with the control group, the respiratory microbiota of AR mice did not change significantly, while the gut microbiota changed significantly. In gut microbiota, compared to the control group, Shannon index in the AR group revealed a significant decrease at the genus level (P < 0.01), and Simpson index was significantly increased at all levels (all P < 0.05). PCoA also showed significant differences in beta diversity between the two groups (all P < 0.05). Compared to the control group, Deferribacteres at phylum level, Roseburia, Ruminiclostridium, Anaerotruncus at genus level were significantly decreased in the AR group (all P < 0.05). Spearman's rank correlation showed that OVA-sIgE was positively correlated with Bacteroidetes, Muribaculaceae and Erysipelotrichaceae (all P < 0.05); IL-4 was significantly negatively correlated with Epsilonbacteraeota and Deferribacteres (all P < 0.05). Treg was significantly positively correlated with Patescibacteria, Lachnospiraceae, and Saccharimonadaceae in gut microecology. CONCLUSION: Our results showed that the respiratory microbiota of AR mice was not significantly altered, but the gut microbiota varied significantly and there was a correlation between gut microbiota and Th1/Th2/Treg.

Pickering emulsion-guided monomeric delivery of monophosphoryl lipid A for enhanced vaccination.

Immunological adjuvants are vaccine components that enhance long-lasting adaptive immune responses to weakly immunogenic antigens. Monophosphoryl lipid A (MPLA) is a potent and safe vaccine adjuvant that initiates an early innate immune response by binding to the Toll-like receptor 4 (TLR4). Importantly, the binding and recognition process is highly dependent on the monomeric state of MPLA. However, current vaccine delivery systems often prioritize improving the loading efficiency of MPLA, while neglecting the need to maintain its monomeric form for optimal immune activation. Here, we introduce a Pickering emulsion-guided MPLA monomeric delivery system (PMMS), which embed MPLA into the oil-water interface to achieve the monomeric loading of MPLA. During interactions with antigen-presenting cells, PMMS functions as a chaperone for MPLA, facilitating efficient recognition by TLR4 regardless of the presence of lipopolysaccharide-binding proteins. At the injection site, PMMS efficiently elicited local immune responses, subsequently promoting the migration of antigen-internalized dendritic cells to the lymph nodes. Within the draining lymph nodes, PMMS enhanced antigen presentation and maturation of dendritic cells. In C57BL/6 mice models, PMMS vaccination provoked potent antigen-specific CD8+ T cell-based immune responses. Additionally, PMMS demonstrated strong anti-tumor effects against E.G7-OVA lymphoma. These data indicate that PMMS provides a straightforward and efficient strategy for delivering monomeric MPLA to achieve robust cellular immune responses and effective cancer immunotherapy.

Development of an engineered extracellular vesicles-based vaccine platform for combined delivery of mRNA and protein to induce functional immunity.

mRNA incorporated in lipid nanoparticles (LNPs) became a new class of vaccine modality for induction of immunity against COVID-19 and ushered in a new era in vaccine development. Here, we report a novel, easy-to-execute, and cost effective engineered extracellular vesicles (EVs)-based combined mRNA and protein vaccine platform (EVX-M+P vaccine) and explore its utility in proof-of-concept immunity studies in the settings of cancer and infectious disease. As a first example, we engineered EVs, natural nanoparticle carriers shed by all cells, to contain ovalbumin mRNA and protein (EVOvaM+P vaccine) to serve as cancer vaccine against ovalbumin-expressing melanoma tumors. EVOvaM+P administration to mice with established melanoma tumors resulted in tumor regression associated with effective humoral and adaptive immune responses. As a second example, we generated engineered EVs that contain Spike (S) mRNA and protein to serve as a combined mRNA and protein vaccine (EVSpikeM+P vaccine) against SARS-CoV-2 infection. EVSpikeM+P vaccine administration in mice and baboons elicited robust production of neutralizing IgG antibodies against RBD (receptor binding domain) of S protein and S protein specific T cell responses. Our proof-of-concept study describes a new platform with an ability for rapid development of combination mRNA and protein vaccines employing EVs for deployment against cancer and other diseases.

Spatiotemporal coordination of antigen presentation and co-stimulatory signal for enhanced anti-tumor vaccination.

Controlled-release systems enhance anti-tumor effects by leveraging local antigen persistence for antigen-presenting cells (APCs) recruitment and T cell engagement. However, constant antigen presentation alone tends to induce dysfunction in tumor-specific CD8+ T cells, neglecting the synergistic effects of co-stimulatory signal. To address this, we developed a soft particle-stabilized emulsion (SPE) to deliver lipopeptides with controlled release profiles by adjusting their hydrophobic chain lengths: C6-SPE (fast release), C10-SPE (medium release), and C16-SPE (slow release). Following administration, C6-SPE release antigen rapidly, inducing early antigen presentation, whereas C16-SPE's slow-release delays antigen presentation. Both scenarios missed the critical window for coordinating with the expression of CD86, leading to either T cell apoptosis or suboptimal activation. In contrast, C10-SPE achieved a spatiotemporally synergetic effect of the MHC-I-peptide complex and co-stimulatory signal (CD86), leading to effective dendritic cell (DC) activation, enhanced T cell activation, and tumor regression in EG7-OVA bearing mice. Additionally, co-delivery of cytosine-phosphate-guanine (CpG) with SPE provided a sustained expression of the CD86 window for DC activation, improving the immune response and producing robust anti-tumor effects with C6-SPE comparable to C10-SPE. These findings highlight that synchronizing the spatiotemporal dynamics of antigen presentation and APC activation may confer an optimal strategy for enhanced vaccinations.

Turmeric extract alleviates airway inflammation via oxidative stress-driven MAPKs/MMPs pathway.

Turmeric (Curcuma longa L.) extract (CLE) has been shown to elicit several pharmacological properties and is widely used in Asian traditional medicine. Herein, we assessed the impact of CLE on airway inflammation in BALB/c mice and A549 cells to clarify the underlying mechanism. An asthmatic mouse model was established by administering ovalbumin (OVA). CLE (100 or 300 mg/kg/day) was orally administered daily from days 18 to 23, with dexamethasone (3 mg/kg/day) used as the positive control. Human airway epithelial cells, A549, were stimulated using recombinant tumor necrosis factor-α. The CLE100 and CLE400 groups exhibited a significant downregulation in eosinophil counts, cytokine levels, and immunoglobulin-E levels. Moreover, CLE administration dose-dependently suppressed oxidative stress and airway inflammation in the lung tissue. CLE administration inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and the expression and activity of matrix metalloproteinase (MMP)-9. In vitro, CLE treatment reduced mRNA levels of proinflammatory cytokines, MAPK phosphorylation, and the expression and activity of MMP-2 and MMP-9. Additionally, 50 µg/mL CLE and 2.5 µg/mL curcumin showed similar anti-inflammatory effects. Collectively, our findings revealed that CLE could suppress airway inflammation in asthmatic mice and A549 cells via oxidative stress-driven MAPK/MMPs signaling, suggesting that CLE could be developed as a potential treatment option for patients with asthma.