Adjuvant Effect Research Articles

The effect of carbohydrate adjuvants in the composition of the experimental hantavirus vaccine on the dynamics of neutralizing antibodies in the blood sera of guinea pigs

Introduction. Vaccination could be the most effective means of preventing hemorrhagic fever with renal syndrome (HFRS), which is one of the leading zoonoses and a major cause of natural disease in humans. Therefore, research to develop an effective vaccine and the search for new non-toxic and effective adjuvants that can enhance and prolong the immune response, reduce the antigen concentration and reduce the frequency of dose administration is an urgent task. The aim of the study was to determine the dependence of the immunogenic activity of an experimental hantavirus vaccine based on Puumala virus (HV) on the antigen dose both in native form and in combination with carbohydrate adjuvants. Materials and methods. The immunoadjuvant effect of Ac3-LPS S. sonnei and S. flexneri 1B and emulsions of nanoemulsified squalene Sepivac SWE (SWE) as part of HV at the optimal and minimal doses was investigated by induction of neutralising antibodies after 3-fold immunisation (day 0, 14, 182) of guinea pigs (Cavia porcellus). Differences in the immunogenic activity of HV were assessed in the neutralisation reaction by 50% suppression of focal units in Vero E6 cell cultures. Results. A statistically significant increase in neutralising antibodies levels was observed after immunization both with HV at the optimal dose and for its combination with adjuvants. Ac3-LPS S. sonnei and SWE showed the most pronounced immunoadjuvant effect at concentrations of 50 and 100 μg/dose, respectively. The immunoadjuvant effect of the combination of the hantavirus vaccine with Ac3-LPS S. sonnei and SWE contributed to both an enhanced immune response and its duration. The tenfold reduction of the antigen dose in the presence of SWE allows optimization of the immune response to the vaccine. Conclusion. The results of this study show the prospects of using Ac3-LPS S. sonnei and Sepivac SWE in the vaccine for the prevention of HFRS.

The synergistic effect and mechanism of different adjuvants on pinoxaden efficacy against Lolium multiflorum Lam

Adjuvants play a crucial role in optimizing and improving the efficacy of herbicides. Therefore, adding appropriate adjuvants to herbicides is an important part of weed control. The aim of this study was to investigate the synergistic effect and underlying mechanism of action of three commercial adjuvants (Hasuteng, Penwubao, and Zhenxiao IV) in conjunction with pinoxaden for controlling Lolium multiflorum Lam. The results of synergic effect, which were determined by dose‒response assay showed that the addition of Hasuteng and Penwubao could significantly enhance the efficacy of pinoxaden and decrease the ED50 (the herbicide dose resulting in 50% weed control) on L. multiforum while being safe to wheat. Hasuteng and Penwubao were further selected to investigate the underlying mechanisms by which adjuvants enhanced the efficacy of pinoxaden. The results indicated that the addition of Hasuteng and Penwubao significantly reduced the surface tension and shortened the drying time of the pinoxaden solution; moreover, it significantly increased both expanded diameter and maximum retention. Additionally, ultra high performance liquid chromatography-tandem mass spectrometry (UPLC‒MS/MS) analysis was used to evaluate the recovery rate, absorption level, and rainfastness. These two adjuvants could improve the absorption and metabolism levels of L. multiforum to pinoxaden. However, Hasuteng and Penwubao did not improve the rainfastness of pinoxaden. In summary, Hasuteng and Penwubao enhance the efficacy of pinoxaden by improving its physical properties and absorption level. The studies present a novel approach for enhancing the utilization rate of pinoxaden and provide theoretical guidance toward effectively reducing herbicide application in wheat fields.

Development of α-Tocopherol Loaded PLGA Nanoparticles and Its Evaluation as a Novel Immune Adjuvant.

With the continuous development of preventive and therapeutic vaccines, traditional adjuvants cannot provide sufficient immune efficacy and it is of high necessity to develop safe and effective novel nanoparticle-based vaccine adjuvants. α-Tocopherol (TOC) is commonly used in oil-emulsion adjuvant systems as an immune enhancer, yet its bioavailability is limited by poor water solubility. This study aims to develop TOC-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TOC-PLGA NPs) to explore the potential of TOC-PLGA NPs as a novel nanoparticle-immune adjuvant. TOC-PLGA NPs are prepared by a nanoprecipitation method and their physicochemical properties are characterized. It is shown that TOC-PLGA NPs are 110.8nm, polydispersity indexvalue of 0.042, and Zeta potential of -13.26mV. The encapsulation efficiency and drug loading of NPs are 82.57% and 11.80%, respectively, and the cumulative release after 35days of in vitro testing reaches 47%. Furthermore, TOC-PLGA NPs demonstrate a superior promotion effect on RAW 264.7 cell proliferation compared to PLGA NPs, being well phagocytosed and also promoting antigen uptake by macrophages. TOC-PLGA NPs can strongly upregulate the expression of co-stimulatory surface molecules and the secretion of cytokines. In conclusion, TOC-PLGA NPs can be a novel vaccine adjuvant with excellent biocompatibility and significant immune-enhancing activity.

Antimicrobial Therapy in Dentistry: An Evidence-based Review of Pomegranate Fruit Properties

Background: Phytotherapy is characterized by the use of medicinal plants in their different dosage forms. Currently, the use of this alternative medicine has increased. The raw material of herbal medicines consists of organs from medicinal plants (leaves, stems, fruits, peels, flowers and roots) with pharmacological, food, technical or cosmetic adjuvant effects. In addition, the side effects of its use appear to be reduced compared to synthetic and conventional medication. Objective: The aim of this mini-review is to present the scientific evidence involving the properties of the pomegranate fruit for future antimicrobial applications in dentistry. Methods: Literature searches included randomized clinical trials and in vitro studies [2000-2023] filtered mainly by the following terms [Punica granatum L.], [Pomegranate], [Dentistry], [Antimicrobial activity] and [Candida albicans]. Results: Studies have shown that Punica granatum Linn. has considerable antimicrobial activity, in addition to other pharmacological effects such as anti-cancer, antioxidant and antiinflammatory action. The use of herbal medicines, as potent antimicrobial agents against oral pathogens, has been widely reported. Conclusion: The use of P. granatum has proven its effectiveness, as a potent antimicrobial agent against oral pathogens, especially against the fungus Candida albicans, future studies need to focus on the development of a biocompatible formulation directed to the treatment of patients with oral candidiasis.

Role of Adjuvant Mitomycin C in The Endoscopic Treatment of Laryngotracheal Stenosis (Meta-Analytic Study)

Abstract Background Laryngotracheal stenosis is a life-threatening restriction in pulmonary ventilation. It is an umbrella term, including luminal compromise at the level of the larynx, subglottis, or trachea. Etiology of laryngotracheal stenosis is multifactorial. In adults and adolescents it is mostly acquired, where in children it may be acquired or congenital. Acquired laryngotracheal stenosis can result from previous intubation or tracheostomy, systemic disease, trauma, infection, or idiopathic causes. Historically, infectious etiology was common. Currently, laryngotracheal stenosis most frequently results from prolonged intubation or trauma from intubation itself. Objective To evaluate the effectiveness of topical Mitomycin C as an adjuvant treatment with the endoscopic management of laryngotreacheal stenosis. Patients and Methods The total number of patients in all the included studies was 454, 379 patients in MMC group and 75 patients in non-MMC group. Results This meta-analysis study showed that resolution (success) rate in MMC group was (68.7%) and there was a significant increase in resolution (success) rate in MMC compared to non- MMC group (p = 0.011) with the odds of being 5 times higher in MMC group (OR = 5.04). The Complications rate in MMC using patients was (4%). The result of this meta-analysis study showed that Mitomycin C is an effective and safe adjuvant in the endoscopic treatment of laryngotracheal stenosis. However, this study included limitations. We recommend the need of more high quality prospective randomized controlled trials, two armed studies and further studies in the future to achieve stronger results. Conclusion We suggest that that Mitomycin C is an effective and safe adjuvant in the endoscopic treatment of laryngotracheal stenosis. However, this study included limitations. We recommend the need of more high quality prospective randomized controlled trials, two armed studies and further studies in the future to achieve stronger results.

Dexmedetomidine versus Dexamethasone as Adjuvant to Bupivacaine in Fascia Iliaca Block in Knee Arthroscopy for Postoperative Pain

Abstract Background Knee arthroscopy is one of the most frequently performed interventions in orthopedic surgery that is commonly performed on a day-case basis. It allows the diagnosis and management of a wide range of knee problems without making a large incision, thus decreasing soft tissue trauma. However, postoperative pain is a common upsetting symptom following arthroscopic knee surgery that if inadequately treated, leads to prolonged duration of the functional rehabilitation of the knee, recovery time and the length of hospital stay thus a significant increase in the medical care costs. Aim of the Work To compare the adjuvant effect of adding dexmedetomidine and/or dexamethasone to bupivacaine while using facsia iliaca block for knee arthroscopy and their efficacy in achieving postoperative analgesia. Patients and Methods The type of study was a prospective double – blinded randomized controlled Trial conducted in Ain Shams University hospitals, Cairo, Egypt at 6 months. Patients aged 20 to 60 years scheduled for elective knee arthroscopy under spinal anesthesia were included to receive FICB. Results In general, there was no significant difference between the three study groups regarding general patient characteristics as well as operative time. That ensured proper randomization conducted between our study groups. Additionally, that should nullify any bias that may have skewed the results in favor of one group rather than another one. There was statistically significant difference between groups according to heart rate from after 2hrs to after 24hrs this was also observed while measuring the systolic blood pressure and diastolic blood pressure but there was no significant difference between group B and C. Conclusion Our study shows that adding Dexmedetomidine and/or Dexamethasone (8mg) to Bupivacaine for FICB significantly prolonged the duration of block and decreased the requirement of rescue analgesics as compared to patients who received Bupivacaine alone. FICB is relatively easy and safe to perform. In our study we did not encounter any complication while doing the procedures and also by adding dexmedetomidine and/or dexamethasone (8mg).

Action Programmed Nanoantibiotics with pH-Induced Collapse and Negative-Charged-Surface-Induced Deformation against Antibiotic-Resistant Bacterial Peritonitis.

The incorporation of well-designed antibiotic nanocarriers, along with an antibiotic adjuvant effect, in combination with various antibiotics, offers an opportunity to combat drug-resistant strains. However, precise control over morphology and encapsulated payload release can significantly impact their antibacterial efficacy and synergistic effects when used alongside antibiotics. Here, this study focuses on developing lipopeptide-based nanoantibiotics, which demonstrate an antibiotic adjuvant effect by inducing pH-induced collapse and negative-charged-surface-induced deformation. This enhances the disruption of the bacterial outer membrane and facilitates drug penetration, effectively boosting the antimicrobial activity against drug-resistant strains. The modulation regulations of the lipopeptide nanocarriers with modular design are governed by the authors. The nanoantibiotics, made from lipopeptide and ciprofloxacin (Cip), have a drug loading efficiency of over 80%. The combination with Cip results in a significantly low fractional inhibitory concentration index of 0.375 and a remarkable reduction in the minimum inhibitory concentration of Cip against multidrug-resistant (MDR) Escherichia coli (clinical isolated strains) by up to 32-fold. The survival rate of MDR E. coli peritonitis treated with nanoantibiotics is significantly higher, reaching over 87%, compared to only 25% for Cip and no survival for the control group. Meanwhile, the nanoantibiotic shows no obvious toxicity to major organs.

Ultrasound Guided Erector Spinae Block Using Bupivacaine – Magnesium Sulphate versus Bupivacaine – Dexmedetomidine for Postoperative Analgesia in Lumbar Spine Surgeries

Abstract Purpose Lumbar spine surgeries are associated with significant postoperative pain. Erector Spinae Plain Block (ESPB) is a new ultra-sound guided block technique for such surgeries . We aimed to explore the analgesic effect of adding dexmedetomidine and magnesium sulfate as adjuvants to bupivacaine in ESP. Patients and Methods Fifty two patients scheduled for lumbar spine surgery were randomly allocated into two groups to receive an ESP block., A total volume of 25 ml, [10 mL 0.5% bupivacaine diluted in normal saline (NS) and 2 mg/kg MgSO4 in group (MG group) and 10 mL 0.5% bupivacaine in NS with 2 μg/kg dexmedetomidine in group (DEX group)] were injected. The block was administered preoperatively before anesthesia induction. Postoperatively, hemodynamics, visual analog scale scores, the first request for analgesia, total analgesic consumption, and side effects were observed for 12 hours. Results The demographic data including age, gender, height, weight and BMI showed no difference between both groups, also, ASA classification and duration of surgeries done showed no difference between the studied groups (P > 0.05). There were no recorded complications in both groups (P > 0.05). There was no significant difference among both groups regarding basal, and follow up period at 15 min values of heart rate, and basal value of mean arterial pressure (P > 0.05), but for the intraoperative hemodynamic parameters including MAP and HR, both parameters decreased significantly in the group which received dexmedetomidine in comparison to the other group except follow up values at 180 and 210 min, as no significant differences were recorded among both groups (P > 0.05). Regarding postoperative pain, the visual analogue score (VAS) was used to record it postoperatively every 2 hours while we found a statistically significant difference regarding the VAS from 4 to 6 hours postoperatively as P < 0.005, but, we found no difference regarding the postoperative total consumption of nalbuphine (P < 0.005) . As for patient satisfaction in the studied groups, an anaesthesia satisfaction questionnaire was developed, validated (Kappa coefficient). Dexmedetomidine group was associated with a significant increase in satisfaction compared to MG group (P < 0.05). Conclusion Magnesium sulphate and dexmedetomidine seem to be both effective adjuvants to bupivacaine in ESP blocks for postoperative analgesia in patients undergoing lumbar spine surgeries, with slightly better analgesia provided by dexmedetomidine.

Tank-Mix Adjuvants Enhance Pesticide Efficacy by Improving Physicochemical Properties and Spraying Characteristics for Application to Cotton with Unmanned Aerial Vehicles.

Tank-mix adjuvants have been used to reduce spray drift and facilitate the efficacy of pesticides applied with unmanned aerial vehicles (UAVs). However, the effects of specific adjuvants on pesticide characteristics and the mechanism of action remain unclear. Herein, we analyzed the effects of three different types of tank-mix adjuvants (plant oil; mineral oil; and mixture of alcohol and ester) on the surface tension (ST), contact angle, wetting, permeation, evaporation, spray performance, and aphid-control effects of two types of pesticides. The mineral oil adjuvant Weichi (WCH) was highly effective in reducing the pesticide solution ST, improving the wetting and penetration ability, increasing droplet size, and promoting droplet deposition. The mixed alcohol and ester adjuvant Quanrun (QR) showed excellent wetting and antievaporation properties and promoted droplet deposition. A plant oil adjuvant (Beidatong) moderately improved wetting and penetration ability and reduced droplet drift. Field tests showed that the control efficiencies (CEs) of two pesticides were increased after the addition of adjuvants, even with 20% reductions in pesticide application. When the UAV was operated at 1.5 m, the CEs of two pesticides were increased from 65.39 and 66.63% to 73.11-76.52% and 77.91-88.31%, respectively. When operated at 2.5 m, the CEs were increased from 51.24 and 68.60% to 65.06-75.70% and 77.57-92.59%, respectively. Especially, the CEs of pesticides with WCH and QR increased obviously. Importantly, neither WCH nor QR inhibited hatching of the critical insect natural enemy ladybird beetle at concentrations used in the field. This study provides a framework for assessment of tank-mix adjuvants in aerial sprays and directly demonstrates the value of specific adjuvants in improving pesticide bioavailability and minimizing associated environmental pollution.

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

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. 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. 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. 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. 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.

Evaluation of varying doses of magnesium as an adjuvant to ropivacaine in supraclavicular brachial plexus block

Background: Peripheral nerve blockade is a crucial component of comprehensive anesthetic care, providing effective analgesia with fewer side effects than opioids and other oral analgesics. Aims and Objectives: This study investigated the effectiveness of a magnesium adjuvant in an ultrasound-guided supraclavicular brachial plexus block to determine the minimum dose required for the desired effects. Materials and Methods: This prospective, double-blind, and randomized controlled study included 90 patients scheduled for elective upper limb orthosurgery at GTMCH. The 90 patients were divided into three groups: A, B, and C. Each group received 21.5 mL of the test drug, with A receiving ropivacaine and normal saline, B receiving ropivacaine and magnesium, and C receiving ropivacaine and magnesium. Results: There was a significant difference in Group A between the onset of sensory and motor blockade in Groups B and C. There was a significant difference in Group A between the duration of sensory and motor blockade in Groups B and C, but no significant difference was observed between Groups B and C. The visual analog scale score varied from 0 to 6 in Group A and from 0 to 5 in Groups B and C. It was found to be significant only from the 7th to 10th h. There was a significant difference in Group A between Groups B and C in 1st rescue analgesia post-operatively and the number of rescue injections in the first 24 h, but no significant differences was observed between Groups B and C. Conclusion: Both 100 and 150 mg magnesium sulfate with 0.5% ropivacaine in supraclavicular blocks prolonged the blockade duration and reduced analgesic needs.

The Analgesic and Anti-inflammatory Properties of Caffeine Co-administration with Nefopam in Mice

This study aimed to evaluate the analgesic properties of nefopam and the adjuvant effects of caffeine. It also investigated the anti-inflammatory effect of co-administering nefopam and caffeine on Prostaglandin E2 level (PGE2). The study involved 56 female albino mice (Mus musculus), divided into seven groups, eight mice per each group. Group A which served as the control group received distilled water; Group B received 30 mg/kg BW of nefopam orally; Group C received 28.5 mg/BW of nefopam and 5 mg/BW of caffeine orally; Group D received 27 mg/BW of nefopam and 10 mg/BW of caffeine orally; Group E received 25.5 mg/BW of nefopam and 15 mg/BW of caffeine orally; Group F received 24 mg/BW of nefopam and 20 mg/BW of caffeine orally; Group G received 22.5 mg/BW of nefopam and 25 mg/BW of caffeine orally. The nociceptive response was assessed using the formalin test, showing a significant (P<0.05) reduction in pain response (accumulative time of flinching and licking) was the first phase (0-5 minutes) in Group E as well as, a significant (P<0.05) decrease in nociceptive response in flinching and licking in second phase (20-60 minutes) was observed in Group D. However, the Prostaglandin level was significantly (P<0.05) lower in Group C. The study concluded that adding low dosages of caffeine to analgesics can boost pain relief in smaller quantities. Caffeine co-administration with nefopam may exert

Unveiling the critical roles of cellular metabolism suppression in antibiotic tolerance

Metabolic inhibitors are known to exhibit complex interactions with antibiotics in bacteria, potentially acting as antagonists by inducing cell dormancy and promoting cell survival. However, the specific synergistic or antagonistic effects of these inhibitors depend on factors like their mechanisms of action, concentrations, and treatment timings, which require further investigation. In our study, we systematically explored the synergistic interactions of various metabolic inhibitors—such as chloramphenicol (a translation inhibitor), rifampicin (a transcription inhibitor), arsenate (an ATP production inhibitor), and thioridazine (a PMF inhibitor)—in combination with ofloxacin. We conducted this investigation under pre-, co-, and post-treatment conditions, employing a wide concentration range and utilizing four distinct synergy models. Chloramphenicol, rifampicin, and arsenate consistently showed minimal synergy scores, indicating a notable antagonistic relationship with ofloxacin across all models and conditions. In contrast, thioridazine consistently demonstrated elevated synergy scores, especially in pre- and co-treatment scenarios, albeit its synergy decreased during post-treatment conditions. When multivariable linear regression analyses were used for all drugs and conditions examined, a correlation between the synergy of thioridazine and its ability to suppress cellular energy metabolism became evident, underscoring the potential utility of certain metabolic inhibitors as effective anti-persistence adjuvants.

Tadalafil versus pentoxifylline in the management of diabetic kidney disease: a randomized clinical trial

AimsTo investigate the efficacy and safety of tadalafil (TAD) versus pentoxifylline (PTX) in the management of diabetic kidney disease (DKD). Some animal studies and clinical trials reported that tadalafil and pentoxifylline have a reducing effect on different blood glucose parameters and lipid profiles which contribute to progress the patients with diabetes mellitus (DM) to DKD.MethodsFrom February 2022 to March 2023, 90 patients with type 2 DM and DKD (micro-albuminuria) were enrolled in this randomized-controlled study. The patients were randomized into three equal groups: control group, TAD group, and PTX group. The three groups received traditional blood glucose lowering therapy + ramipril 10 mg PO. The TAD group also received tadalafil 20 mg PO every other day. The PTX group also received pentoxifylline 400 mg PO twice daily.ResultsBoth TAD and PTX groups produced statistically significant improvement in the primary outcomes by a significant reduction in Urinary albumin/creatinine ratio (UACR) which was pronounced by a reduction percentage of—47.47%, −53.73% respectively. In addition to a significant decrease in Hemoglobin A1C (HbA1c) (mmol/mol), Fasting blood glucose (FBG), 2-h postprandial blood glucose (2-h PPG) (p < 0.001). Only the PTX group showed a significant increase in Cr Cl and a significant decrease in S. Cr (p < 0.001). Only the TAD group showed a significant increase in high-density lipoprotein—cholesterol (HDL-C) (p < 0.001), while the PTX group showed a significant decrease in low-density lipoprotein—cholesterol (LDL-C) (p-value 0.011), and triglyceride (p-value 0.002). Both TAD and PTX groups showed a decrease in tumor necrosis factor-α (TNF-α) which was significant only in the PTX group (p < 0.001). There was a significant increase in malondialdehyde (MDA) (p < 0.001), and an increase in urinary neutrophil gelatinase-associated Lipocalin (uNGAL) (p-value 0.850, 0.014 respectively) which was significant only in the PTX group.ConclusionsThe use of tadalafil or pentoxifylline may serve as an effective adjuvant therapy for patients with diabetic kidney disease.Trial Registration: ClinicalTrials.gov identifier NCT05487755, July 25, 2022.

GFPBW1, a β-glucan from Grifola frondosa as vaccine adjuvant: APCs activation and maturation.

Adjuvants for vaccines with characteristics of improving adaptive immunity particularly via leverage of antigen presenting cells (APCs) are currently lacking. In a previous work we obtained a new soluble 300 kDa homogeneous β-glucan named GFPBW1 from the fruit bodies of Granola frondosa. GFPBW1 could activate macrophages by targeting dendritic cell associated C-type lectin 1 (Dectin-1)/Syk/NF-κB signaling to achieve antitumour effects. In this study the adjuvant effects of GFPBW1 were explored with OVA-antigen and B16-OVA tumor model. We showed that GFPBW1 (5, 50, 500 μg/mL) dose-dependently promoted activation and maturation of APCs in vitro by increasing CD80, CD86 and MHC II expression. We immunized female mice with OVA in combination with GFPBW1 (50 or 300 μg) twice with an interval of two weeks. GFPBW1 markedly and dose-dependently increased OVA-specific antibody titers of different subtypes including IgG1, IgG2a, IgG2b and IgG3, suggesting that it could serve as an adjuvant for both Th1 and Th2 type immune responses. Furthermore, GFPBW1 in combination with aluminum significantly increased the titers of OVA-specific IgG2a and IgG2b, but not those of IgG1, suggesting that GFPBW1 could be used as a co-adjuvant of aluminum to compensate for Th1 deficiency. For mice immunized with OVA plus GFPBW1, no obvious pathological injury was observed in either major organs or injection sites, and no abnormalities were noted for any of the hematological parameters. When GFPBW1 served as an adjuvant in the B16-OVA cancer vaccine models, it could accomplish entire tumor suppression with preventive vaccines, and enhance antitumour efficacy with therapeutic vaccines. Differentially expressed genes were found to be enriched in antigen processing process, specifically increased tumor infiltration of DCs, B1 cells and plasma cells in the OVA plus GFPBW1 group, in accordance with its activation and maturation function of APCs. Collectively, this study systematically describes the properties of GFPBW1 as a novel potent and safe adjuvant and highlights its great potential in vaccine development.

Flagellin Enhances the Immunogenicity of Pasteurella multocida Lipoprotein E Subunit Vaccine.

Fowl cholera, caused by Pasteurella multocida infection, poses challenges for prevention because of its many serotypes. Bacterins are currently widely used for vaccination against fowl cholera, but protection is limited to homologous strains. Live attenuated vaccines of P. multocida provide some heterologous protection, but side effects are considerable. More recently, protein-based antigens are promising subunit vaccines when their low immunogenicity has been addressed with effective adjuvants. Bacterial flagellin has been widely considered a promising adjuvant for vaccines. In this study, we tested the adjutancy of flagellin in a subunit vaccine against P. multocida in a mice and chicken models. For vaccine formulation, the antigen fPlpE (P. multocida liporotein E) was combined with fFliC (Salmonella Typhimurium flagellin). The recombinant proteins of fPlpE and fFliC were successfully expressed using the Escherichia coli system as the expected sizes of 55 kDa and 70 kDa, respectively. The fFliC elicited strong expression levels of proinflammatory cytokine (IL-1β, IL-8, and IL-6) when stimulated in native chicken peripheral blood mononuclear cells. Immunization of mice and chickens with the subunit vaccines containing fFliC accelerated the antibody response. In the challenge tests, fFliC increased vaccine protective efficacy against the heterologous strain P. multocida A1 and highly virulent strain Chu01 in mice and chickens, respectively. These data indicated potential possibilities of using fFliC as an immunostimulant adjuvant in developing a subunit vaccine against fowl cholera.

Lipid Nanoparticle with 1,2-Di-O-octadecenyl-3-trimethylammonium-propane as a Component Lipid Confers Potent Responses of Th1 Cells and Antibody against Vaccine Antigen.

Adjuvants are effective tools to enhance vaccine efficacy and control the type of immune responses such as antibody and T helper 1 (Th1)- or Th2-type responses. Several studies suggest that interferon (IFN)-γ-producing Th1 cells play a significant role against infections caused by intracellular bacteria and viruses; however, only a few adjuvants can induce a strong Th1-type immune response. Recently, several studies have shown that lipid nanoparticles (LNPs) can be used as vaccine adjuvants and that each LNP has a different adjuvant activity. In this study, we screened LNPs to develop an adjuvant that can induce Th1 cells and antibodies using a conventional influenza split vaccine (SV) as an antigen in mice. We observed that LNP with 1,2-di-O-octadecenyl-3-trimethylammonium-propane (DOTMA) as a component lipid (DOTMA-LNP) elicited robust SV-specific IgG1 and IgG2 responses compared with SV alone in mice and was as efficient as SV adjuvanted with other adjuvants in mice. Furthermore, DOTMA-LNPs induced robust IFN-γ-producing Th1 cells without inflammatory responses compared to those of other adjuvants, which conferred strong cross-protection in mice. We also demonstrated the high versatility of DOTMA-LNP as a Th1 cell-inducing vaccine adjuvant using vaccine antigens derived from severe acute respiratory syndrome coronavirus 2 and Streptococcus pneumoniae. Our findings suggest the potential of DOTMA-LNP as a safe and effective Th1 cell-inducing adjuvant and show that LNP formulations are potentially potent adjuvants to enhance the effectiveness of other subunit vaccines.

Interleukin-1 beta (IL-1β) as adjuvant enhances the immune effects of Aeromonas veronii inactivated vaccine in largemouth bass (Micropterus salmoides)

Largemouth bass (Micropterus salmoides) has emerged as a significant economic fish species, with a rise in Aeromonas veronii infections in farming. However, research on adjuvants for vaccines against A. veronii in largemouth bass remains scarce. In present study, recombinant largemouth bass IL-1β (LbIL-1β) was expressed to explore its adjuvant effect on the A. veronii inactivated vaccine. Following vaccination with recombinant LbIL-1β (rLbIL-1β) and the inactivated A. veronii, higher serum SOD levels and lysozyme activities were observed in largemouth bass from inactivated A. veronii + rLbIL-1β vaccinated group. Furthermore, it was discovered that rLbIL-1β was able to boost the serum-specific antibody levels induced by the inactivated A. veronii. The qRT-PCR analysis revealed that rLbIL-1β also enhanced the expression of IgM, CD4, and MHC II in largemouth bass triggered by the inactivated A. veronii. After challenged with live A. veronii, the outcomes demonstrated that the relative percentage survival (RPS) for largemouth bass resulting from the inactivated A. veronii in combination with rLbIL-1β was 76.67 %, surpassing the RPS of 60 % in the inactivated A. veronii group. Collectively, these findings indicate that rLbIL-1β enhances the protective effect of the A. veronii inactivated vaccine on largemouth bass, showcasing potential as an adjuvant for further development.

Design and Synthesis of Polyphenolic Imidazo[4,5-c]quinoline Derivatives to Modulate Toll Like Receptor-7 Agonistic Activity and Adjuvanticity.

TLR-7/8 agonists are a well-known class of vaccine adjuvants, with a leading example now included in Covaxin, a licensed human COVID-19 vaccine. This thereby provides the opportunity to develop newer, more potent adjuvants based on structure-function studies of these classes of compounds. Imidazoquinoline-based TLR7/8 agonists are the most potent, but when used as a vaccine adjuvant side effects can arise due to diffusion from the injection site into a systemic circulation. In this work, we sought to address this issue through structural modifications in the agonists to enhance their adsorption capacity to the classic adjuvant alum. We selected a potent TLR7-selective agonist, BBIQ (EC50 = 0.85 μM), and synthesized polyphenolic derivatives to assess their TLR7 agonistic activity and adjuvant potential alone or in combination with alum. Most of the phenolic derivatives were more active than BBIQ and, except for 12b, all were TLR7 specific. Although the synthesized compounds were less active than resiquimod, the immunization data on combination with alum, specifically the IgG1, IgG2b and IgG2c responses, were superior in comparison to BBIQ as well as the reference standard resiquimod. Compound 12b was 5-fold more potent (EC50 = 0.15 μM in TLR7) than BBIQ and induced double the IgG response to SARS-CoV-2 and hepatitis antigens. Similarly, compound 12c (EC50 = 0.31 μM in TLR7) was about 3-fold more potent than BBIQ and doubled the IgG levels. Even though compound 12d exhibited low TLR7 activity (EC50 = 5.13 μM in TLR7), it demonstrated superior adjuvant results, which may be attributed to its enhanced alum adsorption capability as compared with BBIQ and resiquimod. Alum-adsorbed polyphenolic TLR7 agonists thereby represent promising combination adjuvants resulting in a balanced Th1/Th2 immune response.

Structural characterization and adjuvant activity of a water soluble polysaccharide from Poria cocos

Adjuvants, as the essential component of vaccines, are crucial in enhancing the magnitude, breadth and durability of immune responses. Unfortunately, commonly used Alum adjuvants predominantly provoke humoral immune response, but fail to evoke cellular immune response, which is crucial for the prevention of various chronic infectious diseases and cancers. Thus, it is necessary to develop effective adjuvants to simultaneously induce humoral and cellular immune response. In this work, we obtained a water soluble polysaccharide isolated and purified from Poria cocos, named as PCP, and explored the possibility of PCP as a vaccine adjuvant. The PCP, with Mw of 20.112 kDa, primarily consisted of →6)-α-D-Galp-(1→, with a small amount of →3)-β-D-Glcp-(1 → and →4)-β-D-Glcp-(1→. Our results demonstrated that the PCP promoted the activation of dendritic cells (DCs) and macrophages in vitro. As the adjuvant to ovalbumin, the PCP facilitated the activation of DCs in lymph nodes, and evoked strong antibody response with a combination of Th1 and Th2 immune responses. Moreover, compared to Alum adjuvant, the PCP markedly induced a potent cellular response, especially the cytotoxic T lymphocytes response. Therefore, we confirmed that the PCP has great potential to be an available adjuvant for simultaneously inducing humoral and cellular immune responses.