Traditional Adjuvants Research Articles

Toxoplasma gondii Proteasome Subunit Alpha Type 1 with Chitosan: A Promising Alternative to Traditional Adjuvant.

As an important zoonotic protozoan, Toxoplasma gondii (T. gondii) has spread around the world, leading to infections in one-third of the population. There is still no effective vaccine or medicine against T. gondii, and recombinant antigens entrapped within nanospheres have benefits over traditional vaccines. In the present study, we first expressed and purified T. gondii proteasome subunit alpha type 1 (TgPSA1), then encapsulated the recombinant TgPSA1 (rTgPSA1) in chitosan nanospheres (CS nanospheres, rTgPSA1/CS nanospheres) and incomplete Freund’s adjuvant (IFA, rTgPSA1/IFA emulsion). Antigens entrapped in CS nanospheres reached an encapsulation efficiency of 67.39%, and rTgPSA1/CS nanospheres showed a more stable release profile compared to rTgPSA1/IFA emulsion in vitro. In vivo, Th1-biased cellular and humoral immune responses were induced in mice and chickens immunized with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion, accompanied by promoted production of antibodies, IFN-γ, IL-4, and IL-17, and modulated production of IL-10. Immunization with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion conferred significant protection, with prolonged survival time in mice and significantly decreased parasite burden in chickens. Furthermore, our results also indicate that rTgPSA1/CS nanospheres could be used as a substitute for rTgPSA1/IFA emulsion, with the optimal administration route being intramuscular in mass vaccination. Collectively, the results of this study indicate that rTgPSA1/CS nanospheres represent a promising vaccine to protect animals against acute toxoplasmosis.

In vitro Inhibitory Activity of IgY Antibodies Against Salmonella Ser. Newport Isolated from Horses

Equine salmonellosis is caused by several Salmonella serotypes, including Salmonella Newport, which cause enterocolitis and diarrhea. Treatment usually includes the administration of antibiotics. However, since multidrug-resistant Salmonella is commonly detected, alternative options to control the pathogen are needed. One of these options is the use of specific egg yolk antibodies (IgY) for passive immunotherapy. Thus, the aim of our work was to produce IgY antibodies against an equine S. Newport strain and assess their in vitro inhibitory activity. To this end, laying hens were immunized with an inactivated S. Newport strain by using either Freund's or Montanide adjuvant and egg yolk extracts were obtained. The levels of specific IgY antibodies against Salmonella in sera and egg extracts were determined by dot-blot and microagglutination. Besides, the IgY extracts were characterized by total protein analysis, SDS-PAGE, Western Blot, and inhibition of bacterial motility. IgY extracts showed high purity (87.7 to 91.8 %), high microagglutination titers, and the ability to inhibit the motility of the bacterium. The results using Montanide were similar to those using the traditional Freund's adjuvant. Thus, Montanide may also be a good adjuvant to produce IgY. IgY-technology represents a potential tool for the control of salmonellosis in horses.

Antibacterial and COX-2 Inhibitory Tetrahydrobisbenzylisoquinoline Alkaloids from the Philippine Medicinal Plant Phaeanthus ophthalmicus.

Phaeanthus ophthalmicus (Roxb. ex G.Don) J.Sinclair (previously known as P. ebracteolatus (Presl) Merr) is a Philippine medicinal plant occurring as evergreen shrub in the lowland forests of Luzon islands. It is used traditionally by Filipinos to treat bacterial conjunctivitis, ulcer and wound infections. Based on previous investigations where cyclooxygenase-2 (COX-2) functions as immune-linked factor in infectious sensitivities to bacterial pathogens by triggering pro-inflammatory immune-associated reactions, we investigated the antimicrobial and COX inhibitory activities of the extracts and tetrahydrobisbenzylisoquinoline alkaloids of P. ophthalmicus in vitro and in silico to validate its ethnomedicinal uses. Thus, the dichloromethane–methanol (DCM–MeOH) crude extract and alkaloid extracts exhibiting antibacterial activities against drug-resistant bacterial strains such as methicillin-resistance Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Klebsiella pneumoniae + CRE and Pseudomonas aeruginosa + MBL afforded (+)-tetrandrine (1) and (+)-limacusine (2) as the major biologically active tetrahydrobisbenzylisoquinoline alkaloidal constituents after purification. Both tetrahydrobisbenzylisoquinoline alkaloids 1 and 2 showed broad spectrum antibacterial activity with strongest inhibition against the Gram-negative bacteria MβL-Pseudomonas aeruginosa Klebsiella pneumoniae + CRE. Interestingly, the alkaloid limacusine (2) showed selective inhibition against ovine COX-2 in vitro. These results were ascertained by molecular docking and molecular dynamics simulation experiments where alkaloid 2 showed strong affinity in the catalytic sites of Gram-negative bacterial enzymes P. aeruginosa elastase and K. pneumoniae KPC-2 carbapenemase (enzymes involved in infectivity mechanisms), and of ovine COX-2. Overall, our study provides credence on the ethnomedicinal use of the Philippine medicinal plant P. ophthalmicus as traditional plant-based adjuvant to treat bacterial conjunctivitis and other related infections. The antibacterial activities and selective COX-2 inhibition observed for limacusine (2) point to its role as the biologically active constituent of P. ophthalmicus. A limited number of drugs with COX-2 inhibitory properties like celecoxib also confer antibacterial activity. Thus, tetrahydrobisbenzyl alkaloids, especially 2, are promising pharmaceutical inspirations for developing treatments of bacterial/inflammation-related infections.

Preparation and application of oil emulsion adjuvant of animal vaccines containing flavonoid saponins

With the development of immunology, the application of vaccines plays an important role in controlling the epidemic of animal diseases, and the development of adjuvants is particularly important. Immune adjuvant is a kind of non-specific immune enhancer. It can effectively induce long-term and high-efficiency specific immune response and improve the self-protection ability of the body when injected with antigen or in advance. In this paper, a flavonoid saponin extracted from persimmon leaves was added on the basis of traditional oil adjuvant. The animal potency test showed that the oil emulsion adjuvant containing flavonoid saponin was more effective than single use, and could be widely used in the development of animal vaccine.

Developing Translational Vaccines against Heroin and Fentanyl through Investigation of Adjuvants and Stability.

The nearly insurmountable adversity that accompanies opioid use disorder (OUD) creates life-altering complications for opioid users. To worsen matters, existing small-molecule drugs continue to inadequately address OUD due to their engagement of the opioid receptor, which can leave the user to deal with side effects and financial hardships from their repeated use. An alternative therapeutic approach utilizes endogenously generated antibodies through active vaccination to reduce the effect of opioids without modulating the opioid receptor. Here, we explore different adjuvants and storage conditions to improve opioid vaccine efficacy and shelf life. Our results revealed that inulin-based formulations (Advax) containing a CpG oligodeoxynucleotide (ODN) acted as effective adjuvants when combined with a heroin conjugate: immunized mice showed excellent recovery from heroin-induced antinociception accompanied by high titer, high opioid affinity serum antibodies similar to the immunopotentiating properties of traditional alum-based adjuvants. Moreover, nonhuman primates vaccinated with a heroin/fentanyl combination vaccine demonstrated potent antibody responses against opioids when formulated with both inulin and alum adjuvants. Finally, storing a freeze-dried opioid vaccine formulation maintained efficacy for up 1 year at room temperature. The results from our studies represent an advance toward a clinically feasible opioid vaccine.

Shaping Modern Vaccines: Adjuvant Systems Using MicroCrystalline Tyrosine (MCT®).

The concept of adjuvants or adjuvant systems, used in vaccines, exploit evolutionary relationships associated with how the immune system may initially respond to a foreign antigen or pathogen, thus mimicking natural exposure. This is particularly relevant during the non-specific innate stage of the immune response; as such, the quality of this response may dictate specific adaptive responses and conferred memory/protection to that specific antigen or pathogen. Therefore, adjuvants may optimise this response in the most appropriate way for a specific disease. The most commonly used traditional adjuvants are aluminium salts; however, a biodegradable adjuvant, MCT®, was developed for application in the niche area of allergy immunotherapy (AIT), also in combination with a TLR-4 adjuvant—Monophosphoryl Lipid A (MPL®)—producing the first adjuvant system approach for AIT in the clinic. In the last decade, the use and effectiveness of MCT® across a variety of disease models in the preclinical setting highlight it as a promising platform for adjuvant systems, to help overcome the challenges of modern vaccines. A consequence of bringing together, for the first time, a unified view of MCT® mode-of-action from multiple experiments and adjuvant systems will help facilitate future rational design of vaccines while shaping their success.

Self-Assembled Cationic-Covered Nanoemulsion as A Novel Biocompatible Immunoadjuvant for Antiserum Production Against Tityus serrulatus Scorpion Venom

This study assesses the efficacy of different nanoemulsion formulations as new and innovative adjuvants for improving the in vivo immunization against the Tityus serrulatus scorpion venom. Nanoemulsions were designed testing key-variables such as surfactants, co-solvents, and the influence of the temperature, which would be able to induce the phase transition from a liquid crystal to a stable nanoemulsion, assessed for four months. Additionally, cationic-covered nanoemulsion with hyper-branched poly(ethyleneimine) was prepared and its performance was compared to the non-cationic ones. The physicochemical properties of the selected nanoemulsions and the interactions among their involved formulation compounds were carefully monitored. The cytotoxicity studies in murine macrophages (RAW 264.7) and red blood cells were used to compare different formulations. Moreover, the performance of the nanoemulsion systems as biocompatible adjuvants was evaluated using mice immunization protocol. The FTIR shifts and the zeta potential changes (from −18.3 ± 1.0 to + 8.4 ± 1.4) corroborated with the expected supramolecular anchoring of venom proteins on the surface of the nanoemulsion droplets. Cell culture assays demonstrated the non-toxicity of the formulations at concentrations less than 1.0 mg/mL, which were able to inhibit the hemolytic effect of the scorpion venom. The cationic-covered nanoemulsion has shown superior adjuvant activity, revealing the highest IgG titer in the immunized animals compared to both the non-cationic counterpart and the traditional aluminum adjuvant. In this approach, we demonstrate the incredible potential application of nanoemulsions as adjuvants, using a nanotechnology platform for antigen delivery system on immune cells. Additionally, the functionalization with hyper-branched poly(ethyleneimine) enhances this recognition and improves its action in immunization.

An overview of cytokine used as adjuvants in fish: current state and future trends

AbstractVaccination is the most appropriate way to control pathogens that threaten the global aquaculture industry. Unfortunately, vaccines generally do not provide satisfactory immune protection, especially those based on inactivated pathogens or recombinant antigens. Thus, it is necessary for adjuvants or immunostimulants to be used to improve the vaccine efficacy. Traditional adjuvants such as aluminium salts adjuvant and Freund’s adjuvant, are the most effective known adjuvants in aquaculture; however, due to their disadvantages, such as low adjuvanticity, short lasting time and serious side effects in vivo were also occurred. Searching for some combinations or alternative molecules of them as adjuvants is feasible to increase animal welfare without lowering the levels of immune protection. Recent advances in immunology confirmed that cytokines used as adjuvants have the advantages of eliciting the expression of costimulatory molecular and polarization of antigen‐presenting cells compared with aluminium slats adjuvant and oil adjuvant in fish farming. Moreover, the effects of most adjuvants are exerted mainly through the induction of cytokines production. Nowadays, cytokines have been evaluated for their abilities to offer effective adjuvant activities in both animal models and human studies. In this review, we summarized previous studies performed with different Th cytokines used as adjuvants on different types of fish vaccines, focusing on their protective efficacies and effects on the fish immune system as they delivered in vivo.

Polyanhydride Nanoparticles Induce Low Inflammatory Dendritic Cell Activation Resulting in CD8+ T Cell Memory and Delayed Tumor Progression.

IntroductionAdjuvants and immunotherapies designed to activate adaptive immunity to eliminate infectious disease and tumors have become an area of interest aimed at providing a safe and effective strategy to prevent or eliminate disease. Existing approaches would benefit from the development of immunization regimens capable of inducing efficacious cell-mediated immunity directed toward CD8+ T cell-specific antigens. This goal is critically dependent upon appropriate activation of antigen-presenting cells (APCs) most notably dendritic cells (DCs). In this regard, polyanhydride particles have been shown to be effectively internalized by APCs and induce activation.MethodsHere, a prophylactic vaccine regimen designed as a single-dose polyanhydride nanovaccine encapsulating antigen is evaluated for the induction of CD8+ T cell memory in a model system where antigen-specific protection is restricted to CD8+ T cells. Bone marrow-derived dendritic cells (BMDCs) are used as an in vitro model system to evaluate the magnitude and phenotype of APC activation. Primary DCs, particularly those with described ability to activate CD8+ T cells, are also evaluated for their in vitro responses to polyanhydride nanoparticles.ResultsHerein, polyanhydride nanoparticles are shown to induce potent in vitro upregulation of costimulatory molecules on the cell surface of BMDCs. In contrast to the classically used TLR agonists, nanoparticles did not induce large amounts of pro-inflammatory cytokines, did not induce characteristic metabolic response of DCs, nor produce innate antimicrobial effector molecules, such as nitric oxide (NO). The polyanhydride nanovaccine results in protective CD8+ T cell responses as measured by inhibition of tumor progression and survival.DiscussionTogether, these results suggest that the use of a polyanhydride-based nanovaccine can be an effective approach to inducing antigen-specific CD8+ T cell memory by providing antigen delivery and DC activation while avoiding overt inflammatory responses typically associated with traditional adjuvants.

Subunit Nanovaccine with Potent Cellular and Mucosal Immunity for COVID-19.

To combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, we formulated the S1 subunit of the virus with two adjuvants, amphiphilic adjuvant monophosphoryl lipid A for Toll-like receptor 4 and CpG oligodeoxynucleotide for Toll-like receptor 9, into cationic liposomes to produce a potent, safer, and translatable nanovaccine. The nanovaccine can efficiently elicit a humoral immune response and strong IgA antibodies in mice. The sera from the vaccinated mice significantly inhibit SARS-CoV-2 from infecting Vero cells. Moreover, relative to the free S1 with a traditional Alum adjuvant, the nanovaccine can elicit strong T-cell immunity by activating both CD4+ and CD8+ cells.

Abstract 5259: HSPA6 may be a new target by thyraquinone inhibiting migration and invasion of breast cancer cells

Abstract Background and Objective: Breast cancer is the malignant tumor with the highest incidence and the second highest mortality among women, and the incidence of breast cancer in China is increasing year by year. The treatment of breast cancer includes radiotherapy, chemotherapy, endocrine therapy, biological targeted therapy and traditional Chinese medicine adjuvant therapy; but the efficacy still needs to be further improved to benefit the patients. Thymoquinone (TQ) is a key component of black grass seed oil and has anti-cancer properties in a variety of tumors. Preliminary studies in our laboratory demonstrated that TQ has a significant inhibitory effect on the migration and invasion of triple negative breast cancer cells. Methods: To find the new target genes for the inhibition of migration and invasion of breast cancer cells by TQ, RNA-sequencing (RNA-seq) was conducted with and without TQ in human breast cancer cell line BT-549 with high invasion and migration characteristics. Quantitative and semi-quantitative RT-PCR was used to further verify the genes regulated by TQ, and then Western Blotting was used to compare the changes of the genes regulated by TQ at the protein level. Finally, the molecular mechanism of TQ inhibiting migration and invasion of human breast cancer cells was investigated by increasing or decreasing the expression of these genes. Results: Eighteen differentially expressed genes, which were closely related to the carcinomas in the experimental group and the control group, were obtained by RNA-seq. HSPA6 gene changed significantly, and showed an up-regulation after adding TQ, which was consistent with the results of RNA-seq. By RT-PCR and Western Blotting from different cell lines (BT549, MCF-7, ZR-75-30, SiHa, Caski), we found that the expression of HSPA6 in the experimental group was higher than that in the control group. The subsequent TQ treatment after knockdown / over-expression will be completed for HSPA6 protein functional effects by TQ. Conclusion: HSPA6 may be a new target gene for TQ to inhibit the migration and invasion of breast cancer cells. The success of this study will provide a new candidate target for clinical treatment of breast cancer. Funding support: National Natural Science Foundation of China (Grant No. 81672887, 81172049) Citation Format: Shiyi Shen, Ting Xiao, Ju Zhou, Chunli Wei, Junjiang Fu. HSPA6 may be a new target by thyraquinone inhibiting migration and invasion of breast cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5259.

Rotavirus Inner Capsid VP6 Acts as an Adjuvant in Formulations with Particulate Antigens Only.

Novel adjuvants present a concern for adverse effects, generating a need for alternatives. Rotavirus inner capsid VP6 protein could be considered a potential candidate, due to its ability to self-assemble into highly immunogenic nanospheres and nanotubes. These nanostructures exhibit immunostimulatory properties, which resemble those of traditional adjuvants, promoting the uptake and immunogenicity of the co-administered antigens. We have previously elucidated an adjuvant effect of VP6 on co-delivered norovirus and coxsackievirus B1 virus-like particles, increasing humoral and cellular responses and sparing the dose of co-delivered antigens. This study explored an immunostimulatory effect of VP6 nanospheres on smaller antigens, P particles formed by protruding domain of a norovirus capsid protein and a short peptide, extracellular matrix protein (M2e) of influenza A virus. VP6 exhibited a notable improving impact on immune responses induced by P particles in immunized mice, including systemic and mucosal antibody and T cell responses. The adjuvant effect of VP6 nanospheres was comparable to the effect of alum, except for induction of superior mucosal and T cell responses when P particles were co-administered with VP6. However, unlike alum, VP6 did not influence M2e-specific immune responses, suggesting that the adjuvant effect of VP6 is dependent on the particulate nature of the co-administered antigen.

Comparison of oil emulsion, mannosylated chitosan, and Bacillus vector adjuvants for vaccination against influenza in chickens

Summary Vaccination against influenza continues to be the primary method of control in many countries, but there is still a strong reliance on autogenous vaccines adjuvated with mineral oil emulsions known to induce overly high local inflammatory responses and lesions at the site of injection. The studies presented herein investigate various combinations of mannosylated chitosan adjuvant (MCA) and/or recombinant Bacillus construct adjuvant (BCA) containing highly conserved influenza antigens to assess their ability to function as an effective alternative adjuvant in influenza vaccination. In experiment 1, broilers were vaccinated via subcutaneous and/or drinking water application with an inactivated swine influenza in combination with MCA or commercial oil emulsion adjuvant. Subcutaneous or oral prime, followed by oral boost, resulted in the highest improvement in day 21 serum IgG hemagglutination inhibition (HI) titer, compared to the non-vaccinated control group. Experiment 2 tested BCA and MCA adjuvants, mixed with inactivated avian influenza virus in broilers. The group receiving combined subcutaneous and oral prime, followed by an oral boost containing both MCA and BCA adjuvants, exhibited significantly improved tracheal IgA HI titers. Experiment 3 investigated the ability of these adjuvated vaccines to protect against both homologous and heterologous highly pathogenic avian influenza challenge in layers. Groups receiving a subcutaneous prime followed by either subcutaneous or oral boost survived at 100%. Groups receiving only oral vaccine administrations did not exhibit improved survival. MCA and BCA adjuvants were found to improve immune responses in both broiler and layer-type chickens, equivalently matching immunogenicity and protection to the traditional mineral oil emulsion adjuvant. These studies suggest protective mucosal immunity can be achieved with vaccination strategies that incorporate MCA or BCA, but primary parenteral administration remains an important component of the vaccination strategy to achieve protective immunity.

Better Adjuvants for Better Vaccines: Progress in Adjuvant Delivery Systems, Modifications, and Adjuvant-Antigen Codelivery.

Traditional aluminum adjuvants can trigger strong humoral immunity but weak cellular immunity, limiting their application in some vaccines. Currently, various immunomodulators and delivery carriers are used as adjuvants, and the mechanisms of action of some of these adjuvants are clear. However, customizing targets of adjuvant action (cellular or humoral immunity) and action intensity (enhancement or inhibition) according to different antigens selected is time-consuming. Here, we review the adjuvant effects of some delivery systems and immune stimulants. In addition, to improve the safety, effectiveness, and accessibility of adjuvants, new trends in adjuvant development and their modification strategies are discussed.

Multifunctional Protein Conjugates with Built-in Adjuvant (Adjuvant-Protein-Antigen) as Cancer Vaccines Boost Potent Immune Responses.

SummaryMany cancer vaccines are not successful in clinical trials, mainly due to the challenges associated with breaking immune tolerance. Herein, we report a new strategy using an adjuvant-protein-antigen (three-in-one protein conjugates with built-in adjuvant) as an anticancer vaccine, in which both the adjuvant (small-molecule TLR7 agonist) and tumor-associated antigen (mucin 1, MUC1) are covalently conjugated to the same carrier protein (BSA). It is shown that the protein conjugates with built-in adjuvant can increase adjuvant's stimulation, prevent adjuvant's systemic toxicities, facilitate the codelivery of adjuvants and antigens, and enhance humoral and cellular immune responses. The IgG antibody titers elicited by the self-adjuvanting three-in-one protein conjugates were significantly higher than those elicited by the vaccine mixed with TLR7 agonist (more than 15-fold) or other traditional adjuvants. Importantly, the potent immune responses against cancer cells suggest that this new vaccine construct is an effective strategy for the personalized antitumor immunotherapy.

Evaluation of immunogenicity and protective effect of DNA vaccine encoding surface antigen1 (SAG1) of Toxoplasma gondii and TLR-5 ligand as a genetic adjuvant against acute toxoplasmosis in BALB/c mice

AimsToxoplasma gondii is an obligate intracellular, protozoan that causes a high incidence of serious zoonotic parasitic disease in humans. In the present study the immune-protective efficacy of a DNA vaccine encoding SAG1 in combination with a gene sequence encoding FliC of Salmonella typhimurium (Toll-like receptor 5 agonist) was evaluated against acute T. gondii infection in mice. Methods and resultsNinety-nine female inbred BALB/c mice were divided into nine groups of 11 mice and were immunized intramuscularly three times at three-week intervals (days 0, 21 and 42) and challenged with virulent T. gondii RH strain 4 weeks later. The immunization of pVAX1-SAG1 administered with pVAX1-fliC in mice indicated specific humoral responses, with higher IgG antibody titers and a mixed IgG1/IgG2a response than in other groups (with a predominance of IgG2a over IgG2b and IgG1). Also, the cellular immune response elicited high levels of IFN-γ and IL-12 cytokines and low levels of IL-4 production compared to traditional adjuvants. Furthermore, the mice vaccinated with pVAX1-SAG1+pVAX1-fliC survived for slightly longer after the last immunization and challenge with the T. gondii. ConclusionThis investigation indicated that cocktail DNA vaccine encoded SAG1 gene of T. gondii and FliC can protect against acute toxoplasmosis.

Amino-Modified Polymer Nanoparticles as Adjuvants to Activate the Complement System and to Improve Vaccine Efficacy in Vivo.

Subunit vaccines are safer but often poorly immunogenic in comparison to traditional vaccines, and thus, adjuvants and delivery vehicles are needed to enhance the immune response. The complement system is a part of the innate immune system, which plays an important role in innate and adaptive immunity. Therefore, the activation of the complement system could be utilized as a potential strategy for vaccine applications. Herein, cysteamine hydrochloride was grafted onto a methoxy poly(ethylene glycol)-block-poly (allyl glycidyl ether)-block-poly(ε-caprolactone) copolymer to synthesize a triblock polymer mPEG5k-PAGE15(NH2)-PCL5k(TPCAH) with amino groups on the side chain. The positive charge of the amino groups could bind with the negatively charged protein (like ovalbumin (OVA)) to form a stable complex by electrostatic interaction. The triblock copolymer TPCAH we designed can easily self-assemble into polymer nanomicelles, and the size of the nanoparticles is similar to that of the pathogens, which was beneficial to the uptake by lymphocytes. Furthermore, the amino groups modified on the side chain can not only integrate with proteins but also activate the complement system, thereby enhancing the immune response of subunit vaccines. The results showed that the complex TPCAH@OVA could efficiently promote powerful anti-OVA-specific antibody production, enhance CD4+ T- and CD8+ T-cell activation, improve the lymphocyte proliferation efficiency, and increase the secretion of different cytokines. In addition, the abundant amino groups on the surface of TPCAH@OVA could effectively activate the complement system to further enhance adaptive immunity. Overall, these results indicated that the triblock copolymer TPCAH as an adjuvant and carrier can effectively improve the ability of innate and adaptive immune responses to resist pathogens, making it a potential candidate for vaccine applications.

Bisphosphonate-loaded Bone Cement as a Local Adjuvant Therapy for Giant Cell Tumor of Bone: A 1 to 12-Year Follow-up Study.

Historically, nontargeted adjuvant therapies such as liquid nitrogen, phenol, argon beam, and alcohol have been applied locally after curettage of giant cell tumors (GCT) in the extremities. Systemic bisphosphonates (BP) and denosumab have emerged as osteoclast-targeting therapies because osteoclast-like giant cells, responsible for aggressive bone resorption, are susceptible to BP or denosumab. However, such drugs may cause systemic side effects. We examined the effects of an alternative intraoperative local delivery of BP on GCTs. In total, 17 patients with GCTs underwent extended surgical curettage procedures consisting of high-speed burring, traditional adjuvant therapy, and application of BP-loaded polymethylmethacrylate bone cement. Clinical data and follow-up radiographs were reviewed to investigate local recurrence (LR) rate and complications in a retrospective manner. There were 6 males and 11 females (mean age, 33.7 y). There were no cases of pulmonary metastases. Patient follow-up ranged from 1 to 12 years. There was 1 LR during the follow-up period for an LR rate of 5.9%. The mean final Musculoskeletal Tumor Society (MSTS) score was 29. There were no systemic or localized avascular necrosis or atypical fractures related to BPs noted. BP-loaded polymethylmethacrylate is a targeted local adjuvant therapy that is feasible, safe, and may reduce LRs while alleviating the risk of systemic side effects of BPs such as avascular necrosis of jaw and atypical femur fractures. Future prospective randomized clinical trials will strengthen the level of evidence of this proposed targeted therapy. Therapeutic level IV-see instructions for authors for a complete description of evidence.

Tocopherol Emulsions as Functional Autoantigen Delivery Vehicles Evoke Therapeutic Efficacy in Experimental Autoimmune Encephalomyelitis.

Contemporary approaches to treating autoimmune diseases like multiple sclerosis broadly modulate the immune system and leave patients susceptible to severe adverse effects. Antigen-specific immunotherapies (ASIT) offer a unique opportunity to selectively suppress autoreactive cell populations but have suffered from marginal efficacy even when employing traditional adjuvants to improve delivery. The development of immunologically active antigen delivery vehicles could potentially increase the clinical success of antigen-specific immunotherapies. An emulsion of the antioxidant tocopherol delivering an epitope of proteolipid protein autoantigen (PLP139-151) yielded significant efficacy in mice with experimental autoimmune encephalomyelitis (EAE). In vitro studies indicated tocopherol emulsions reduced oxidative stress in antigen-presenting cells. Ex vivo analysis revealed that tocopherol emulsions shifted cytokine responses in EAE splenocytes. In addition, IgG responses against PLP139-151 were increased in mice treated with tocopherol emulsions delivering the antigen, suggesting a possible skew in immunity. Overall, tocopherol emulsions provide a functional delivery vehicle for ASIT capable of ameliorating autoimmunity in a murine model.

Development of a novel oil-in-water emulsion and evaluation of its potential adjuvant function in a swine influenza vaccine in mice

BackgroundVaccination is the principal strategy for prevention and control of diseases, and adjuvant use is an effective strategy to enhance vaccine efficacy. Traditional mineral oil-based adjuvants have been reported with post-immunization reactions. Developing new adjuvant formulations with improved potency and safety will be of great value.ResultsIn the study reported herein, a novel oil-in-water (O/W) Emulsion Adjuvant containing Squalane (termed EAS) was developed, characterized and investigated for swine influenza virus immunization. The data show that EAS is a homogeneous nanoemulsion with small particle size (~ 105 nm), low viscosity (2.04 ± 0.24 cP at 20 °C), excellent stability (at least 24 months at 4 °C) and low toxicity. EAS-adjuvanted H3N2 swine influenza vaccine was administrated in mice subcutaneously to assess the adjuvant potency of EAS. The results demonstrated that in mice EAS-adjuvanted vaccine induced significantly higher titers of hemagglutination inhibition (HI) and IgG antibodies than water-in-oil (W/O) vaccines or antigen alone, respectively, at day 42 post vaccination (dpv) (P < 0.05). EAS-adjuvanted vaccine elicited significantly stronger IgG1 and IgG2a antibodies and higher concentrations of Th1 (IFN-γ and IL-2) cytokines compared to the W/O vaccine or antigen alone. Mice immunized with EAS-adjuvanted influenza vaccine conferred potent protection after homologous challenge.ConclusionThe O/W emulsion EAS developed in the present work induced potent humoral and cellular immune responses against inactivated swine influenza virus, conferred effective protection after homologous virus challenge and showed low toxicity in mice, indicating that EAS is as good as the commercial adjuvant MF59. The superiority of EAS to the conventional W/O formulation in adjuvant activity, safety and stability will make it a potential veterinary adjuvant.