Displaying alphavirus physicochemical consensus antigens on immunogenic liposomes enhances antibody elicitation in mice.

Cobalt-porphyrin phospholipid displays recombinant protein antigens on liposome surfaces via antigen polyhistidine-tag (His-tag), and when combined with monophosphorylated lipid A and QS-21 yields the "CPQ" vaccine adjuvant system. In this proof of principle study, CPQ was used to generate vaccine prototypes that elicited antibodies for two different alphaviruses (AV). Mice were immunized with computationally designed, His-tagged, physicochemical property consensus (PCPcon) protein antigens representing the variable B-domain of the envelope protein 2 (E2) from the serotype specific Venezuelan Equine Encephalitis Virus (VEEVcon) or a broad-spectrum AV-antigen termed EVCcon. The CPQ adjuvant enhanced the antigenicity of both proteins without eliciting detectable anti-His-tag antibodies. Antibodies elicited from mice immunized with antigens admixed with CPQ showed orders-of-magnitude higher levels of antigen-specific IgG compared to alternative control adjuvants. The ELISA results correlated with antiviral activity against VEEV strain TC83 and more weakly to Chikungunya virus 118/25. Thus, display of E.coli-produced His-tagged E2 protein segments on the surface of immunogenic liposomes elicits high levels of antigen-specific and AV neutralizing antibodies in mice with vaccination, while facilitating vaccine preparation and providing dose-sparing potential.

A critical analysis of the effect of OM-85 for the prevention of recurrent respiratory tract infections or wheezing/asthma from systematic reviews with meta-analysis.

Acute respiratory tract infections (RTIs) are one of the most common causes of pediatric consultations/hospitalizations and a major trigger for asthma exacerbations. Some consensus statements have recommended the use of immunostimulants to boost natural defenses against severe or repeated infections. One of the most common immunostimulants is OM-85; while several randomized clinical trials (RCTs) have evaluated its efficacy in preventing acute RTIs and wheezing/asthma exacerbations, results have been conflicting. Similarly, various systematic reviews with meta-analyses (SRMs) on OM-85 have used different strategies, populations, and outcomes; moreover, SRM conclusions are limited when the original studies are highly heterogeneous or have a low quality, hindering the generalizability of the findings. Here we summarize the evidence on the effect of OM-85 to prevent acute RTIs, wheezing/asthma episodes, or loss of asthma control in children, by including and critically evaluating all SRMs published to date. We searched for SRMs on OM-85 in three publication databases and found nine SRMs (seven for RTI, and two for wheezing/asthma). Among those, one had a high confidence evaluation of quality (AMSTAR-2 tool) and found a reduction in the total number of acute RTIs among the OM-85 group. Overall, no strong recommendations can be derived from the existing literature, mainly due to the high heterogeneity among included RCTs and SRMs. Further, large, high-quality RCTs are needed to confirm the true efficacy of OM-85 for the prevention of acute RTIs, asthma development, and asthma exacerbations.

Novel mRNA adjuvant ImmunER enhances prostate cancer tumor-associated antigen mRNA therapy via augmenting T cell activity.

Prostate cancer (PCa) is characterized as a "cold tumor" with limited immune responses, rendering the tumor resistant to immune checkpoint inhibitors (ICI). Therapeutic messenger RNA (mRNA) vaccines have emerged as a promising strategy to overcome this challenge by enhancing immune reactivity and significantly boosting anti-tumor efficacy. In our study, we synthesized Tetra, an mRNA vaccine mixed with multiple tumor-associated antigens, and ImmunER, an immune-enhancing adjuvant, aiming to induce potent anti-tumor immunity. ImmunER exhibited the capacity to promote dendritic cells (DCs) maturation, enhance DCs migration, and improve antigen presentation at both cellular and animal levels. Moreover, Tetra, in combination with ImmunER, induced a transformation of bone marrow-derived dendritic cells (BMDCs) to cDC1-CCL22 and up-regulated the JAK-STAT1 pathway, promoting the release of IL-12, TNF-α, and other cytokines. This cascade led to enhanced proliferation and activation of T cells, resulting in effective killing of tumor cells. In vivo experiments further revealed that Tetra + ImmunER increased CD8+T cell infiltration and activation in RM-1-PSMA tumor tissues. In summary, our findings underscore the promising potential of the integrated Tetra and ImmunER mRNA-LNP therapy for robust anti-tumor immunity in PCa.

Next-Generation Vaccine Development with Nanomaterials: Recent Advances, Possibilities, and Challenges.

Nanomaterials are becoming important tools for vaccine development owing to their tunable and adaptable nature. Unique properties of nanomaterials afford opportunities to modulate trafficking through various tissues, complement or augment adjuvant activities, and specify antigen valency and display. This versatility has enabled recent work designing nanomaterial vaccines for a broad range of diseases, including cancer, inflammatory diseases, and various infectious diseases. Recent successes of nanoparticle vaccines during the coronavirus disease 2019 (COVID-19) pandemic have fueled enthusiasm further. In this review, the most recent developments in nanovaccines for infectious disease, cancer, inflammatory diseases, allergic diseases, and nanoadjuvants are summarized. Additionally, challenges and opportunities for clinical translation of this unique class of materials are discussed.

Research and Application of Chitosan Nanoparticles in Orthopedic Infections.

Orthopedic infection is one of the most intractable orthopedic problems. Bacteria resistant to antibiotics also develop gradually. Chitosan is widely used in the Biomedical field because of its high biocompatibility, biodegradability, and antibacterial activity. Chitosan-based drug delivery systems are frequently utilized to produce controlled medication release. When combined with antibiotics, synergistic antibacterial effects can be achieved. Chitosan-based nanoparticles are one of the most widely used applications in drug delivery systems. The focus of this review is to provide information on new methods being developed for chitosan-based nanoparticles in the field of bone infection treatment, including chitosan nanoparticles for antibacterial purposes, Ch-loaded with antibiotics, Ch-loaded with metal, and used as immune adjuvants. It may Provide ideas for the fundamental research and the prospects of future clinical applications of orthopedic infections.

Immunostimulant effect of dates (Phoenix dactylifera) on humoral and cellular immunity cells and their functions.

The study aimed to assess the immunomodulatory effects of Phoenix dactylifera (dates) fruit, a traditional remedy used by Moroccans to enhance immunity against pathogens. This research sought to evaluate the impacts of this fruit on immune cells and their functions. To achieve this, we conducted tests using date extracts on splenocytes, thymocytes, and macrophages, focusing on their functions: antibody production, phagocytosis, and T-lymphocyte toxicity. The results obtained demonstrated that the aqueous extract of P. dactylifera fruit exhibited significant immunostimulatory effects on humoral immunity. It achieved this by enhancing complement activity and increasing splenocyte (including B-lymphocytes) proliferation by 142.5% compared to control cells. Similarly, in the same conditions, there was notable stimulation of cellular immunity through thymocyte activity, resulting in a remarkable increase in cell proliferation (225%) and a boost in thymocyte function (245.9%), which plays a role in safeguarding against cancer. Moreover, the date extract demonstrated anti-inflammatory properties. This was evident in the increased phagocytosis activity mediated by macrophages under the ethyl acetate extract, effectively eliminating pathogens. Assessing the cosmetic potential of date extracts showed that the ethyl acetate extract possesses both anti-inflammatory and strong antioxidant effects, exhibited high photo absorption of ultraviolet-B rays. Based on these findings, we propose to study the utilization of this extract for sun protection as a sunscreen. Furthermore, the Fourier-transform infrared spectroscopy analysis indicated that the most active compounds present were flavonoids. These outcomes substantiate the traditional usage of this fruit for reinforcing immunity.

Solid Phase Peptide Carrier Conjugation.

Conjugation to carrier proteins is necessary for peptides to be able to induce antibody formation when injected into animals together with a suitable adjuvant. This is usually performed by conjugation in solution followed by mixing with the adjuvant. Alternatively, the carrier may be adsorbed onto a solid support followed by activation and conjugation with the peptide by solid-phase chemistry. Different reagents can be used for conjugation through peptide functional groups (-SH, -NH2, -COOH), and various carrier proteins may be used depending on the peptides and the intended use of the antibodies. The solid phase may be an ion exchange matrix, from which the conjugate can subsequently be eluted and mixed with adjuvant. Alternatively, the adjuvant aluminum hydroxide may be used as the solid-phase matrix, whereupon the carrier is immobilized and conjugated with peptide. The resulting adjuvant-carrier-peptide complexes may then be used directly for immunization.

Cyclic Peptide Conjugate Vaccines and Physically Mixed Cyclic Peptide Vaccines for Subcutaneous Immunization.

Immune stimulants (adjuvants) enhance immune system recognition to provide an effective and individualized immune response when delivered with an antigen. Synthetic cyclic deca-peptides, co-administered with a toll-like receptor targeting lipopeptide, have shown self-adjuvant properties, dramatically boosting the immune response in a murine model as a subunit peptide-based vaccine containing group A Streptococcus peptide antigens.Here, we designed a novel peptide and lipid adjuvant system for the delivery of group A Streptococcus peptide antigen and a T helper peptide epitope. Following linear peptide synthesis on 2-chlorotrityl chloride resin, the linear peptide was cleaved and head-to-tail cyclized in solution. The selective arrangement of amino acids in the deca-peptide allowed for selective conjugation of lipids and/or peptide antigens following cyclisation. Using both solution-phase peptide chemistry and copper-catalyzed azide-alkyne cycloaddition reaction were covalently (and selectively) ligated lipid and/or peptide antigens onto the cyclic deca-peptide core. Subcutaneous administration of the vaccine design to mice resulted in the generation of a large number of serum immunoglobulin (Ig) G antibodies.

Integrated microbiome and metabolome analysis reveals that new insight into Radix pseudostellariae polysaccharide enhances PRRSV inactivated vaccine.

In this study, we investigated how Radix pseudostellariae polysaccharide (RPP) enhances the immune response of the inactivated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine through interactions with the microbiome and metabolome. We pretreated sows with 10 mg/kg body weight of RPP via drinking water for 7 days prior to intramuscular injection of the PRRSV vaccine. This significantly increased the concentrations of PRRSV GP5 protein antibody, interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-γ. Oral administration of RPP also significantly improved the abundance of beneficial bacteria in the stool, such as Parabacteroides distasonis, Prevotella_copri, Eubacterium_sp., and Clostridium_sp._CAG:226, and decreased the levels of potentially pathogenic bacteria, such as Paraeggerthella and [Clostridium] innocuum, compared to the vaccine alone. These bacterial changes were confirmed using quantitative real-time polymerase chain reaction (Q-PCR). Moreover, RPP treatment significantly increased the blood concentrations of L-theanine, taurodeoxycholic acid (TDCA), and N-arachidonoyl proline, and decreased the levels of L-glutamine, oclacitinib, lipoxin C4, and leukotriene C5 in sows after immunization (p< 0.05). The concentrations of various blood metabolites were validated using sandwich enzyme-linked immunosorbent assay (ELISA), confirming the accuracy of the metabolomics data. Intriguingly, the integration of microbiome and metabolome analyses highlighted the significance of Prevotella_copri and TDCA. We consequently developed a mouse immunity model using GP5 protein and discovered that oral administration of RPP significantly enhanced the levels of GP5 protein antibodies, IL-2, IL-4, IL-10, and IFN-γ in mouse serum. It also increased the number of CD3+ and CD3+CD4+ cells in the spleen. Additionally, Prevotella_copri was administered into the large intestine via the anus for 7 days prior to the intramuscular injection of the PRRSV GP5 protein. The results demonstrated a significant increase in TDCA and GP5 antibody concentration in the mouse serum, indicating that RPP modulates Prevotella_copri to elevate its metabolite TDCA, thereby enhancing the GP5 antibody level. In conclusion, oral administration of 10 mg/kg RPP optimizes gut flora diversity and blood metabolites, particularly Prevotella_copri and TDCA, thereby improving the immune response to the inactivated PRRSV vaccine.

Environment-responsive dendrobium polysaccharide hydrogel embedding manganese microsphere as a post-operative adjuvant to boost cascaded immune cycle against melanoma.

Rationale: Surgical resection is a primary treatment for solid tumors, but high rates of tumor recurrence and metastasis post-surgery present significant challenges. Manganese (Mn2+), known to enhance dendritic cell-mediated cancer immunotherapy by activating the cGAS-STING pathway, has potential in post-operative cancer management. However, achieving prolonged and localized delivery of Mn2+ to stimulate immune responses without systemic toxicity remains a challenge. Methods: We developed a post-operative microenvironment-responsive dendrobium polysaccharide hydrogel embedded with Mn2+-pectin microspheres (MnP@DOP-Gel). This hydrogel system releases Mn2+-pectin microspheres (MnP) in response to ROS, and MnP shows a dual effect in vitro: promoting immunogenic cell death and activating immune cells (dendritic cells and macrophages). The efficacy of MnP@DOP-Gel as a post-surgical treatment and its potential for immune activation were assessed in both subcutaneous and metastatic melanoma models in mice, exploring its synergistic effect with anti-PD1 antibody. Result: MnP@DOP-Gel exhibited ROS-responsive release of MnP, which could exert dual effects by inducing immunogenic cell death of tumor cells and activating dendritic cells and macrophages to initiate a cascade of anti-tumor immune responses. In vivo experiments showed that the implanted MnP@DOP-Gel significantly inhibited residual tumor growth and metastasis. Moreover, the combination of MnP@DOP-Gel and anti-PD1 antibody displayed superior therapeutic potency in preventing either metastasis or abscopal brain tumor growth. Conclusions: MnP@DOP-Gel represents a promising drug-free strategy for cancer post-operative management. Utilizing this Mn2+-embedding and ROS-responsive delivery system, it regulates surgery-induced immune responses and promotes sustained anti-tumor responses, potentially increasing the effectiveness of surgical cancer treatments.

Virus-like Particles as Vaccines for Allergen-Specific Therapy: An Overview of Current Developments.

Immune engineering and modulation are the basis of a novel but powerful tool to treat immune diseases using virus-like particles (VLPs). VLPs are formed by the viral capsid without genetic material making them non-infective. However, they offer a wide variety of possibilities as antigen-presenting platforms, resulting in high immunogenicity and high efficacy in immune modulation, with low allergenicity. Both animal and plant viruses are being studied for use in the treatment of food allergies. These formulations are combined with adjuvants, T-stimulatory epitopes, TLR ligands, and other immune modulators to modulate or enhance the immune response toward the presented allergen. Here, the authors present an overview of VLP production systems, their immune modulation capabilities, and the applicability of actual VLP-based formulations targeting allergic diseases.

The Impact of Chemical Modifications on the Interferon-Inducing and Antiproliferative Activity of Short Double-Stranded Immunostimulating RNA.

A short 19 bp dsRNA with 3'-trinucleotide overhangs acting as immunostimulating RNA (isRNA) demonstrated strong antiproliferative action against cancer cells, immunostimulatory activity through activation of cytokines and Type-I IFN secretion, as well as anti-tumor and anti-metastatic effects in vivo. The aim of this study was to determine the tolerance of chemical modifications (2'-F, 2'-OMe, PS, cholesterol, and amino acids) located at different positions within this isRNA to its ability to activate the innate immune system. The obtained duplexes were tested in vivo for their ability to activate the synthesis of interferon-α in mice, and in tumor cell cultures for their ability to inhibit their proliferation. The obtained data show that chemical modifications in the composition of isRNA have different effects on its individual functions, including interferon-inducing and antiproliferative effects. The effect of modifications depends not only on the type of modification but also on its location and the surrounding context of the modifications. This study made it possible to identify leader patterns of modifications that enhance the properties of isRNA: F2/F2 and F2_S/F2 for interferon-inducing activity, as well as F2_S5/F2_S5, F2-NH2/F2-NH2, and Ch-F2/Ch-F2 for antiproliferative action. These modifications can improve the pharmacokinetic and pharmacodynamic properties, as well as increase the specificity of isRNA action to obtain the desired effect.

A synthetic TLR4 agonist significantly increases humoral immune responses and the protective ability of an MDCK-cell-derived inactivated H7N9 vaccine in mice.

Antigenically divergent H7N9 viruses pose a potential threat to public health, with the poor immunogenicity of candidate H7N9 vaccines demonstrated in clinical trials underscoring the urgent need for more-effective H7N9 vaccines. In the present study, mice were immunized with various doses of a suspended-MDCK-cell-derived inactivated H7N9 vaccine, which was based on a low-pathogenic H7N9 virus, to assess cross-reactive immunity and cross-protection against antigenically divergent H7N9 viruses. We found that the CRX-527 adjuvant, a synthetic TLR4 agonist, significantly enhanced the humoral immune responses of the suspended-MDCK-cell-derived H7N9 vaccine, with significant antigen-sparing and immune-enhancing effects, including robust virus-specific IgG, hemagglutination-inhibiting (HI), neuraminidase-inhibiting (NI), and virus-neutralizing (VN) antibody responses, which are crucial for protection against influenza virus infection. Moreover, the CRX-527-adjuvanted H7N9 vaccine also elicited cross-protective immunity and cross-protection against a highly pathogenic H7N9 virus with a single vaccination. Notably, NI and VN antibodies might play an important role in cross-protection against lethal influenza virus infections. This study showed that a synthetic TLR4 agonist adjuvant has a potent immunopotentiating effect, which might be considered worth further development as a means of increasing vaccine effectiveness.

Immunogenic profiling of Mycobacterium tuberculosis Rv1513 reveals its ability to switch on Th1 based immunity.

Tuberculosis (TB) is one of the infectious diseases caused by the pathogen Mycobacterium tuberculosis that continuously threatens the global human health. Bacillus Calmette-Guérin (BCG) vaccine is the only vaccine that has been used clinically to prevent tuberculosis in recent centuries, but its limitations in preventing latent infection and reactivation of tuberculosis do not provide full protection. In this study, we selected the membrane-associated antigen Rv1513 of Mycobacterium. In order to achieve stable expression and function of the target gene, the prokaryotic expression recombinant vector pET30b-Rv1513 was constructed and expressed and purified its protein. Detection of IFN- γ levels in the peripheral blood of TB patients stimulated by whole blood interferon release assay (WBIA) and multi-microsphere flow immunofluorescence luminescence (MFCIA) revealed that the induced production of cytokines, such as IFN-γ and IL-6, was significantly higher than that in the healthy group. Rv1513 combined with adjuvant DMT (adjuvant system liposomes containing dimethyldioctadecylammonium bromide (DDA), monophospholipid A (MPL), and trehalose-660-dibenzoic acid (TDB)) was used to detect serum specific antibodies, cytokine secretion from splenic suprasplenic cell supernatants, and multifunctional T-cell levels in splenocytes in immunised mice. The levels of IFN-γ, TNF-α, and IL-2 secreted by mouse splenocytes were found in the Rv1513+DMT group and the BCG+Rv1513+DMT group. The serum levels of IgG and its subclasses and the number of IFN-γ+T cells, TNF-α+T and IFN-γ+TNF-α+T cells in the induced CD4+/CD8+T cells in mice were significantly higher than those in the BCG group, and the highest levels were found in the BCG+Rv1513+DMT group. These findings suggest that Rv1513/DMT may serve as a potential subunit vaccine candidate that may be effective as a booster vaccine after the first BCG vaccination.

Induction of protective immune responses at respiratory mucosal sites.

Many pathogens enter the host through mucosal sites. Thus, interfering with pathogen entry through local neutralization at mucosal sites therefore is an effective strategy for preventing disease. Mucosally administered vaccines have the potential to induce protective immune responses at mucosal sites. This manuscript delves into some of the latest developments in mucosal vaccination, particularly focusing on advancements in adjuvant technologies and the role of these adjuvants in enhancing vaccine efficacy against respiratory pathogens. It highlights the anatomical and immunological complexities of the respiratory mucosal immune system, emphasizing the significance of mucosal secretory IgA and tissue-resident memory T cells in local immune responses. We further discuss the differences between immune responses induced through traditional parenteral vaccination approaches vs. mucosal administration strategies, and explore the protective advantages offered by immunization through mucosal routes.

Malaria transmission blocking activity of Anopheles stephensi alanyl aminopeptidase N antigen formulated with MPL, CpG, and QS21 adjuvants.

BACKGROUNDS: Malaria, a preventive and treatable disease, is still responsible for annual deaths reported in most tropical regions, principally in sub-Saharan Africa. Subunit recombinant transmission-blocking vaccines (TBVs) have been proposed as promising vaccines to succeed in malaria elimination and eradication. Here, a provisional study was designed to assess the immunogenicity and functional activity of alanyl aminopeptidase N (APN1) of Anopheles stephensi, as a TBV candidate, administered with MPL, CpG, and QS21 adjuvants in the murine model. METHODOLOGY/PRINCIPAL FINDINGS: The mouse groups were immunized with recombinant APN1 (rAPN1) alone or formulated with CpG, MPL, QS-21, or a combination of adjuvants (CMQ), and the elicited immune responses were evaluated after the third immunization. The standard membrane feeding assay (SMFA) measured the functional activity of antibodies against bacterial-expressed APN1 protein in adjuvanted vaccine groups on transmission of P. falciparum (NF54) to An. stephensi mosquitoes. Evaluation of mice vaccinated with rAPN1 formulated with distinct adjuvants manifested a significant increase in the high-avidity level of anti-APN1 IgG and IgG subclasses; however, rAPN1 induced the highest level of high-avidity anti-APN1 IgG1, IgG2a, and IgG2b antibodies in the immunized vaccine group 5 (APN1/CMQ). In addition, vaccine group 5 (receiving APN1/CMQ), had still the highest level of anti-APN1 IgG antibodies relative to other immunized groups after six months, on day 180. The SMFA data indicates a trend towards higher transmission-reducing activity in groups 2 and 5, which received the antigen formulated with CpG or a combination of three adjuvants. CONCLUSIONS/SIGNIFICANCE: The results have shown the capability of admixture to stimulate high-affinity and long-lasting antibodies against the target antigen to hinder Plasmodium parasite development in the mid-gut of An. stephensi. The attained results authenticated APN1/CMQ and APN1/CpG as a potent APN1-based TBV formulation which will be helpful in designing a vaccine in the future.

Current status and future directions for the development of human papillomavirus vaccines.

The development of human papillomavirus (HPV) vaccines has made substantive progress, as represented by the approval of five prophylactic vaccines since 2006. Generally, the deployment of prophylactic HPV vaccines is effective in preventing newly acquired infections and incidences of HPV-related malignancies. However, there is still a long way to go regarding the prevention of all HPV infections and the eradication of established HPV infections, as well as the subsequent progression to cancer. Optimizing prophylactic HPV vaccines by incorporating L1 proteins from more HPV subtypes, exploring adjuvants that reinforce cellular immune responses to eradicate HPV-infected cells, and developing therapeutic HPV vaccines used either alone or in combination with other cancer therapeutic modalities might bring about a new era getting closer to the vision to get rid of HPV infection and related diseases. Herein, we summarize strategies for the development of HPV vaccines, both prophylactic and therapeutic, with an emphasis on the selection of antigens and adjuvants, as well as implications for vaccine efficacy based on preclinical studies and clinical trials. Additionally, we outline current cutting-edge insights on formulation strategies, dosing schedules, and age expansion among HPV vaccine recipients, which might play important roles in addressing barriers to vaccine uptake, such as vaccine hesitancy and vaccine availability.

Ag85B with c-di-AMP as mucosal adjuvant showed immunotherapeutic effects on persistent Mycobacterium tuberculosis infection in mice.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains the leading cause of mortality by a single infectious agent in the world. M. tuberculosis infection could also result in clinical chronic infection, known as latent TB infection (LTBI). Compared to the current limited treatment, several subunit vaccines showed immunotherapeutic effects and were included in clinical trials. In this study, a subunit vaccine of Ag85B with a novel mucosal adjuvant c-di-AMP (Ag85B:c-di-AMP) was delivered intranasally to a persistent M. tuberculosis H37Ra infection mouse model, which also presented the asymptomatic characteristics of LTBI. Compared with Ag85B immunization, Ag85B:c-di-AMP vaccination induced stronger humoral immune responses, significantly higher CD4+ T cells recruitment, enhanced Th1/Th2/Th17 profile response in the lung, decreased pathological lesions of the lung, and reduced M. tuberculosis load in mice. Taken together, Ag85B:c-di-AMP mucosal route immunization provided an immunotherapeutic effect on persistent M. tuberculosis H37Ra infection, and c-di-AMP, as a promising potential mucosal adjuvant, could be further used in therapeutic or prophylactic vaccine strategies for persistent M. tuberculosis infection as well as LTBI.

Immunostimulatory effects of Toll-like receptor ligands as adjuvants in establishing a novel mouse model for pemphigus vulgaris.

BACKGROUND: The meticulous selection of appropriate vaccine adjuvants is crucial for optimizing immune responses. Traditionally, pemphigus vulgaris (PV), an autoimmune disorder, has been modelled using complete Freund's adjuvant (CFA). In this study, we aimed to discern potential variations in immune responses elicited by Toll-like receptor (TLR) ligands as compared to CFA. METHODS: A comprehensive investigation was conducted, comparing the effects of these adjuvants in conjunction with ovalbumin or desmoglein-3. Flow cytometry was employed to analyse distinct cell subsets, while enzyme-linked immunosorbent assay quantified antigen-specific antibodies and cytokine levels. Histological examination of harvested skin tissues and transcriptome analysis of skin lesions were performed to identify differentially expressed genes. RESULTS: TLR ligands demonstrated efficacy in inducing PV-like symptoms in wild-type mice, in contrast to CFA. This underscored the substantial impact of the adjuvant on self-antigen tolerance. Furthermore, we proposed an enhanced method for establishing a PV model through adoptive transfer, substituting CFA with TLR ligands. Our results revealed that in contrast to the perception that CFA being the most potent immunopotentiator reported, CFA promoted regulatory T cells (Treg), follicular regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10. This suggested potential implications for the recruitment and activation of Treg subsets. While B cell and CD8+ T cell responses exhibited similarity, CFA induced less activation in dendritic cell subsets. A novel mouse model of PV and systemic comparison of immunostimulatory effects of adjuvants were provided by this study. CONCLUSIONS: The systematic comparison of CFA and TLR ligands shed light on the distinctive properties of these adjuvants, presenting innovative mouse models for the investigation of pemphigus. This study significantly contributes to adjuvant research and advances our understanding of PV pathogenesis. KEY POINTS/HIGHLIGHTS: Immunization with desmoglein 3 and Toll-like receptor (TLR) ligands effectively induces pemphigus symptoms in wild-type mice, whereas complete Freund's adjuvant (CFA) fails. TLR ligands heightened the autoreactivity of donor cells in the adoptive transfer pemphigus model. CFA promoted regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10, leading to more effective immune responses.

Polymeric nanocarrier-based adjuvants to enhance a locally produced mucosal coryza vaccine in chicken.

Infectious coryza (IC) is an acute upper respiratory disease of chicken caused by Avibacterium (A.) paragallinarum. This disease results in an increased culling rate in meat chicken and a marked decrease in egg production (10% to more than 40%) in laying and breeding hens. Vaccines were first used against IC and effectively controlled the disease. Nanotechnology provides an excellent way to develop a new generation of vaccines. NPs have been widely used in vaccine design as adjuvants and antigen delivery vehicles and as antibacterial agents; thus, they can be used as inactivators for bacterial culture. In this research, the antibacterial effects of several nanoparticles (NPs), such as silicon dioxide with chitosan (SiO2-CS), oleoyl-chitosan (O.CS), silicon dioxide (SiO2), and iron oxide (Fe3O4), on A. paragallinarum were studied. Additionally, different A. paragallinarum vaccines were made using the same nanomaterials at a concentration of 400 µg/ml to help control infectious coryza disease in chicken. A concentration of 400 µg/ml of all the NPs tested was the best concentration for the inactivation of A. paragallinarum. Additionally, this study showed that the infectious coryza vaccine adjuvanted with SiO2 NPs had the highest immune response, followed by the infectious coryza vaccine adjuvanted with Fe3O4 NPs, the infectious coryza vaccine adjuvanted with SiO2-CS NPs, and the infectious coryza vaccine adjuvanted with O.CS NPs in comparison with the infectious coryza vaccine adjuvanted with liquid paraffin (a commercial vaccine).