Ginseng stem-leaf saponins (GSLS) and mineral oil act synergistically to enhance the immune responses to vaccination against foot-and-mouth disease in mice

Development of semisynthetic saponin immunostimulants

Many natural saponins demonstrate immunostimulatory adjuvant activities, but they also have some inherent drawbacks that limit their clinical use. To overcome these limitations, extensive structure-activity-relationship (SAR) studies have been conducted. The SAR studies of QS-21 and related saponins reveal that their respective fatty side chains are crucial for potentiating a strong cellular immune response. Replacing the hydrolytically unstable ester side chain in the C28 oligosaccharide domain with an amide side chain in the same domain or in the C3 branched trisaccharide domain is a viable approach for generating robust semisynthetic saponin immunostimulants. Given the striking resemblance of natural momordica saponins (MS) I and II to the deacylated Quillaja Saponaria (QS) saponins (e.g., QS-17, QS-18, and QS-21), incorporating an amide side chain into the more sustainable MS, instead of deacylated QS saponins, led to the discovery of MS-derived semisynthetic immunostimulatory adjuvants VSA-1 and VSA-2. This review focuses on the authors' previous work on SAR studies of QS and MS saponins.

Investigation on the immune effect of a chitosan-based particle-in-oil-in-water emulsion

Particle-in-oil-in-water (P/O/W) multiple emulsion adjuvants introduce particles into the internal water phase of a water-in-oil-in-water emulsion, combining the advantages of both particle and emulsion adjuvants to enhance humoral and cellular immune responses. In this study, we optimized P/O/W multiple emulsion adjuvants. Chitosan, poly (lactic-co-glycolic acid), and aluminum gel were used to prepare the particles, which were introduced into a water-in-oil-in-water emulsion to obtain three P/O/W multiple emulsion adjuvants. The immune enhancement effects and safety of the three adjuvants were compared, and it was proven that the adjuvant with chitosan nanoparticles in the internal water phase had good cellular and humoral immune effects. Simultaneously, the proportion of the internal water phase increased from 13% to 20%, reducing the antigen concentration required for embedding to one-third of the original concentration and expanding the application range of the composite adjuvant.

Immuno-Enhancing Effect of Ginsenoside Rh2 Liposomes on Foot-and-Mouth Disease Vaccine

The adjuvant is essential for vaccines because it can enhance or directly induce a strong immune response associated with vaccine antigens. Ginsenoside Rh2 (Rh2) had immunomodulatory effects but was limited by poor solubility and hemolysis. In this study, Rh2 liposomes (Rh2-L) were prepared by ethanol injection methods. The Rh2-L effectively dispersed in a double emulsion adjuvant system to form a Water-in-Oil-in-Water (W/O/W) emulsion and had no hemolysis. The physicochemical properties of the adjuvants were tested, and the immune activity and auxiliary effects indicated by the Foot-and-Mouth disease (FMDV) antigen were evaluated. Compared with the mice vaccinated with the FMD vaccine prepared with the double emulsion adjuvant alone, those with the FMD vaccine prepared with the double emulsion adjuvant containing Rh2-L had significantly higher neutralizing antibody titer and splenocyte proliferation rates and showed higher cellular and humoral immune responses. The results demonstrated that Rh2-L could further enhance the immune effect of the double emulsion adjuvant against Foot-and-Mouth Disease.

Adjuvant effect of saponin in an oil-based monovalent (serotype O) foot-and-mouth disease virus vaccine on the antibody response in guinea pigs and cattle

To enhance the potency of a foot-and-mouth disease (FMD) vaccine, saponin was included in the vaccine formula. In this study, the combined effect of Montanide ISA 50 and saponin was evaluated. Two experiments were performed in guinea pigs and one in cattle to determine the optimal antigen and saponin doses. Only serotype O of foot-and-mouth disease virus (O/PanAsia-2 of ME-SA topotype) was employed in preparation of the monovalent vaccine. All animals were immunized twice with a four-week interval, except for the negative controls. Blood was collected 10 days after the second booster, and the immune response was evaluated using a serum neutralization test. Oil-based FMD vaccines containing saponin induced higher neutralizing antibody levels than formulations lacking saponin. The addition of saponin to formulations with low antigen payload (2.5 µg of inactivated whole virus particles [146S particles] per dose) gave significantly higher neutralizing antibody levels (p < 0.005) than 5 µg of 146S without saponin, suggesting that it can be used to improve FMD vaccine potency in susceptible animals. No adverse effects were observed in vaccinated cattle or guinea pigs.

Efficacy of Rg1-Oil Adjuvant on Inducing Immune Responses against Bordetella bronchiseptica in Rabbits

Bordetella bronchiseptica (B. bronchiseptica) is an obligately aerobic, oxidase- and catalase-positive, nonfermentative Gram-negative coccobacillus. This study is aimed at examining the immune effects of Rg1, Rg1 plus oil, and other common adjuvants on inactivated B. bronchiseptica vaccine in rabbits. The mechanism underlying the adjuvant effect of Rg1 plus oil on the vaccine was also explored. Rg1 (100 μg) plus oil significantly improved the immune effect of B. bronchiseptica vaccine at both the humoral and cellular levels. Rg1-oil adjuvant increased the levels of IL-2 and IL-4 in rabbits after immunization. Rg1 (100 μg) plus oil also significantly increased TLR2 expression and downregulated NF-κB in splenocytes. Rg1-oil adjuvant may increase the levels of IL-2 and IL-4 via upregulating TLR2, thereby enhancing the immune effect of B. bronchiseptica vaccine. In conclusion, Rg1 plus oil could be used as a potential vaccine adjuvant for rabbit B. bronchiseptica vaccine.

Adaptogenic effects of Panax ginseng on modulation of immune functions

Traditional medicinal practices have used natural products such as adaptogens to treat inflammatory, autoimmune, neurodegenerative, bacterial, and viral diseases since the early days of civilization. Panax ginseng Myer is a common herb used in East Asian countries for millennia, especially in Korea, China, and Japan. Numerous studies indicate that ginseng can modulate the immune system and thereby prevent diseases. Although the human immune system comprises many different types of cells, multiple studies suggest that each type of immune cell can be controlled or stimulated by ginseng or its derivatives. Provisional lists of ginseng's potential for use against viruses, bacteria, and other microorganisms suggest it may prove to be a valuable pharmaceutical resource, particularly if higher-quality evidence can be found. Here, we reviewed the role of ginseng as an immune-modulating agent in attempt to provide a valuable starting point for future studies on the herb and the human immune system.

Ginseng Stem-Leaf Saponins in Combination with Selenium Promote the Immune Response in Neonatal Mice with Maternal Antibody

Neonates acquire from their mothers maternal antibody (MatAb) which results in poor immune response to vaccination. We previously demonstrated that ginseng stem-leaf saponins in combination with selenium (GSe) had adjuvant effect on the immune response to an attenuated pseudorabies virus (aPrV) vaccine. The present study was to evaluate GSe for its effect on the immune response to aPrV vaccine in neonatal mice with MatAb. Results showed that GSe had adjuvant effect on the immune response to aPrV vaccine in neonates. When GSe was co-administered with aPrV vaccine (aP-GSe), specific gB antibody, Th1 cytokines (IL-2, IL-12 and IFN-γ) and Th2 cytokines (IL-4, IL-6 and IL-10) responses were significantly increased in association with enhanced protection of vaccinated neonates against the lethal PrV challenge even though MatAb existed when compared to the neonates immunized with aPrV vaccine alone. GSe-enhanced immune response depended on its use in the primary immunization. The mechanisms underlying the adjuvant effect of GSe may be due to more innate immune related pathways activated by GSe. Transcriptome analysis of splenocytes from neonates immunized with aP-GSe, aPrV or saline solution showed that there were 3976 differentially expressed genes (DEGs) in aP-GSe group while 5959 DEGs in aPrV group when compared to the control. Gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) pathways analysis showed that innate immune responses and cytokine productions related terms or pathways were predominantly enriched in aP-GSe group, such as “NOD-like receptor signaling pathway”, “Natural killer cell mediated cytotoxicity”, “NF-κB signaling pathway”, “cytokine-cytokine receptor interaction”, and “Th1 and Th2 cell differentiation”. Considering the potent adjuvant effect of GSe on aPrV vaccine in neonatal mice with MatAb, it deserves further investigation in piglets.

Development of a water-in-oil-in-water adjuvant for foot-and-mouth disease vaccine based on ginseng stem-leaf saponins as an immune booster

There has been an increasing interest in finding new formulations that qualify as vaccine adjuvants, which must be safe, stable, and have the capacity to stimulate a strong immune response. In this study, a basic formulation of a water-in-oil-in-water (W/O/W) adjuvant CV13 was developed, and ginseng stem-leaf saponins (GSLS) were added as an immune booster into oil phase. The physicochemical properties of the adjuvant were tested. Furthermore, the immune activity and the adjuvant effects, as indicated by the foot-and-mouth disease virus (FMDV) antigen were evaluated. The results showed that CV13 was similar in appearance to ISA 206 and could package FMDV antigen into a stable W/O/W emulsion. The FMD vaccine prepared with CV13 alone or CV13 containing GSLS achieved pharmaceutical characteristics comparable to a vaccine prepared with ISA 206, moreover the structural stability of the CV 13 vaccine was found to be better. Mice that were immunized with the FMD vaccine prepared with CV13 containing GSLS presented a significantly higher LPBE antibody titer and splenocyte proliferation rate than those immunized with a vaccine prepared with CV13 alone (p < 0.05). In addition, there was no significant difference between the groups that were immunized with FMD vaccine prepared with CV13 containing GSLS and ISA206 in terms of cellular and humoral immune response. In this paper, CV13 containing GSLS shows excellent immunologic adjuvant effect in mice model, and this new adjuvant may provide a potential choice for FMD vaccine production in the future.

Biocompatible cationic solid lipid nanoparticles as adjuvants effectively improve humoral and T cell immune response of foot and mouth disease vaccines

In this work, we explored the potential of cationic solid lipid nanoparticles (cSLN) as efficient adjuvants for inactivated foot and mouth disease virus (iFMDV) vaccine. The cSLN were prepared by O/W emulsion method with Compritol 888 ATO as lipid matrix, and were modified by cationic lipid Didodecyldimethylammonium bromide (DDAB). The content of cationic lipid was optimized to produce cSLN with appropriate particle size, surface morphology, zeta potential, and polydispersity. Loading iFMDV onto cSLN by electrostatic attraction did not destruct iFMDV particle structure as measured by high performance size exclusion chromatography (HPSEC). Differential scanning fluorimetry (DSF) showed the transition temperature, T_m, related to iFMDV dissociation increased for 1.2 °C after loading on cSLN, indicating an enhanced stability of this unstable antigen. The cSLN loaded iFMDV enhanced in vitro antigen uptake and activation of bone-marrow-derived dendritic cells (BMDCs) with augmented expression of CD86, CD40, and MHC I. In animal trials, BALB/c mice were immunized with free iFMDV, antigen adjuvanted with the cSLN, and antigen adjuvanted with Montanide ISA 206 emulsion. Specific antibody titers showed cSLN could stimulate similar FMDV-specific IgG and IgG subclasses antibody level compared with the widely used ISA 206. In addition, cSLN significantly enhanced memory immune response including effector-memory T cells and central-memory T cells compared to free iFMDV antigen and antigen adjuvanted with ISA 206. Taken together the enhanced humoral and T cell immune responses and the antigen structure friendly properties, cSLN can be a potential adjuvant for iFMDV vaccines.

Panaxadiol saponins treatment caused the subtle variations in the global transcriptional state of Asiatic corn borer, Ostrinia furnacalis

Background

Methods

Results

Conclusion

A novel multiple emulsion enhanced immunity via its biomimetic delivery approach

A special emulsion with biomimetic structural dynamic properties was fabricated, inducing efficient vaccine–cell interaction and robust immunity.

Early IgG Response to Foot and Mouth Disease Vaccine Formulated with a Vegetable Oil Adjuvant

The present study evaluated soybean oil (SO) containing vitamin E (VE) and ginseng saponins (GS) (SO-VE-GS) for their adjuvant effect on foot-and-mouth disease (FMD) vaccine. Since mineral oil ISA 206 is a common adjuvant used in the FMD vaccine, it was used as a control adjuvant in this study. VE and GS were found to have a synergistic adjuvant effect. When mice were immunized with the FMD vaccine emulsified in SO with VE and GS, significantly higher serum IgG, IgG1, and IgG2a were found than VE and GS used alone. SO-VE-GS and ISA 206 behaved differently in adjuvant activities. When mice were immunized with the FMD vaccine adjuvanted with SO-VE-GS, significantly higher and earlier production of serum IgG was found than that adjuvanted with ISA 206. Although both adjuvants significantly increased the number of bone marrow plasma cells, a stimulation index of lymphocytes (SI) as well as the production of IL-4 and IL-6, SO-VE-GS promoted significantly higher SI and the ratio of CD4⁺/CD8⁺ T cells with production of increased IFN-γ and decreased TGF-β1 as compared with the ISA 206 group. The data suggested that SO-VE-GS activated Th1/Th2 immune responses. Transcriptome analysis of splenocytes showed that differentially expressed genes (DEGs), immune-related gene ontology (GO) terms, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly enriched in the SO-VE-GS group. Therefore, the potent adjuvant effect of SO-VE-GS on the FMD vaccine may be attributed to the immune-related gene profile expressed in lymphocytes. Due to its plant origin and due to being much cheaper than imported mineral oil ISA 206, SO-VE-GS deserves further study in relation to vaccines used in food animals.

Ginseng stem-leaf saponins in combination with selenium enhance immune responses to an attenuated pseudorabies virus vaccine

Pseudorabies, a herpesvirus infection, is mainly controlled by using attenuated live vaccines. In this study, the effect of ginseng stem and leaf saponins (GSLS) in combination with selenium (Se; in the form of sodium selenite) on vaccination against attenuated pseudorabies virus (aPrV) was evaluated. It was found that GSLS and Se have an adjuvant effect and that a combination of GSLS and Se stimulates significantly enhanced immune responses than does GSLS or Se alone. Following oral administration of GSLS, mice immunized with an attenuated PrV vaccine diluted in Se-containing physiological saline solution (PSS) provoked a significantly stronger gB-specific serum antibodies response (IgG, IgG1 and IgG2a), enhanced lymphocyte proliferation and cytolytic activity of NK cells, along with higher production of cytokines (IFN-γ, IL-12, IL-5 and IL-10) by splenocytes. Notably, the combination of GSLS and Se conferred a much higher resistance to fPrV challenge after immunization of the mice with aPrV vaccine. This study offers convincing experimental evidence that an injection of Se with oral GSLS is a promising adjuvant combination that improves the efficacy of vaccination against PrV and deserves further study regarding improvement of responses to other animal vaccines.

Screening and determination for potential acetylcholinesterase inhibitory constituents from ginseng stem-leaf saponins using ultrafiltration (UF)-LC-ESI-MS2

INTRODUCTION

Previous studies have demonstrated that several ginsenosides have remarkable inhibitory effect on acetylcholinesterase (AChE). In the present study, ginseng stem-leaf saponins (GSLS) can improve learning and memory of Alzheimer's disease patients. However, much comprehensive information regarding AChE inhibition of GSLS and its metabolites is yet unknown.

OBJECTIVE

The present study aims to screen and determine the potential of AChE inhibitors (AChEIs) from GSLS.

METHODOLOGY

The active fraction of the GSLS detected in vitro AChE inhibition assays was selected as a starting material for the screening of the potential of AChEIs using ultrafiltration liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (UF-LC-ESI-MS² ).

RESULTS

The results showed that 31 ginsenosides were identified with analysis using rapid resolution liquid chromatography with a diode array detector combined with electrospray ionisation tandem mass spectrometry (RRLC-DAD-ESI-MS² ) from the active fraction, and there are 27 compounds with AChE binding activity. Among them, 11 ginsenosides were evaluated and confirmed using in vitro enzymatic assay, and ginsenosides F₁ , Rd, Rk₃ , 20(S)-Rg₃ , F₂ and Rb₂ were found to possess strong AChE inhibitory activities.

CONCLUSION

The proposed UF-LC-ESI-MS² method was a powerful tool for the discovery of AChEIs from traditional Chinese medicine (TCM).

Soybean oil containing ginseng saponins as adjuvants promotes production of cytokines and enhances immune responses to foot-and-mouth disease vaccine

In the present study, the adjuvant effect of soybean oil containing ginseng root saponins (SO-GS-R) on the immune response to foot-and-mouth disease vaccine (FMDV) in mice was investigated. When immunized with FMDV antigen emulsified in an SO-GS-R formulation, mice generated remarkably higher serum antibody and cytokine responses than mice immunized with FMDV antigen alone. To elucidate the mechanisms underlying the adjuvant effect of SO-GS-R, we measured cytokines in serum and muscle tissue after intramuscular injection of SO-GS-R. The results showed that injection of SO-GS-R significantly increased the levels of IL-1β, IL-5, IL-6, G-CSF, KC, MCP-1, MIP-1α, and MIP-1β in both serum and muscle. These results suggested that SO-GS-R recruits neutrophils, eosinophils, T cells and macrophages, causing immune cell recruitment at the injection site, driving antigen-presenting cells to actively participate in the onset of immunity, and amplifying the immune responses. Considering its adjuvant activity and plant-derived properties, SO-GS-R should be further studied for its adjuvant effect on vaccines used in food animals.

Anti-inflammatory effects of water extract from bell pepper (Capsicum annuum L. var. grossum) leaves in vitro

Fruits and vegetables have been recognized as natural sources of various bioactive compounds. Peppers, one such natural source, are consumed worldwide as spice crops. They additionally have an important role in traditional medicine, as a result of their antioxidant bioactivity via radical scavenging. However, there are no reports regarding the bioactivity of the bell pepper (Capsicum annuum L. var. grossum), a commonly used edible vegetable. The present study aimed to evaluate the anti-inflammatory effect of water extract from bell pepper leaves on mouse spleen cells, and explore the potential mechanism underlying this effect. The extract was prepared through homogenization of bell pepper leaves in deionized water. The sterilized supernatant was added to a mouse spleen cell culture stimulated by concanavalin A. Following 72 h of culture, the levels of inflammatory cytokines in the culture supernatant were measured using a sandwich enzyme-linked immunosorbent assay system, and levels of inflammatory proteins were assessed using western blotting. The bell pepper leaf extract significantly inhibited inflammatory cytokine production, inhibited cell proliferation without producing cytotoxicity, and suppressed the expression of inflammatory proteins. These results suggest that components of the bell pepper leaf extract possess anti-inflammatory activity. The study of the anti-inflammatory mechanism of bell pepper leaf extract has provided useful information on its potential for therapeutic application.

Vaccine adjuvants: smart components to boost the immune system

Vaccination is an effective approach to prevent the consequences of infectious diseases. Vaccines strengthen immunity and make individuals resistant to infections with pathogens. Although conventional vaccines are highly immunogenic, they are associated with some safety issues. Subunit vaccines are safe, but they require adjuvants to stimulate the immune system because of their weaker immunogenicity. Adjuvants are entities incorporated into vaccines to increase the immunogenic responses of antigens. They play a crucial role in increasing the potency and efficacy of vaccines. Different adjuvants have different modes of action; therefore, a better understanding of their immunology could provide guidance for the development of novel adjuvants. Numerous studies have been conducted using different types of adjuvants to characterize their potency and safety; however, in practice, only few are used in human or animal vaccines. This review aims to introduce the different modes of action of adjuvants and give insight into the types of adjuvants that possess the greatest potential for adjuvanticity.

Adjuvants for Animal Vaccines

Vaccines are essential tools for the prevention and control of infectious diseases in animals. One of the most important steps in vaccine development is the selection of a suitable adjuvant. The focus of this review is the adjuvants used in vaccines for animals. We will discuss current commercial adjuvants and experimental formulations with attention to mineral salts, emulsions, bacterial-derived components, saponins, and several other immunoactive compounds. In addition, we will also examine the mechanisms of action for different adjuvants, examples of adjuvant combinations in one vaccine formulation, and challenges in the research and development of veterinary vaccine adjuvants.

Natural Vaccine Adjuvants and Immunopotentiators Derived From Plants, Fungi, Marine Organisms, and Insects

Immunopotentiators derived from different natural sources are under investigation with varying success. This chapter gives an overview of developments from plants, fungi, marine organisms, and insects. Plant-derived immune stimulators consist of a diverse range of small molecules or large polysaccharides. Notable examples that have been assessed in both preclinical and clinical trials include saponins, tomatine, and inulin. Similarly, fungi produce a range of potential candidate molecules, with β-glucans showing the most promise. Other complex molecules that have established adjuvant activity include α-galactosylceramide (originally obtained from a marine sponge), chitosan (commonly produced from chitin from shrimps), and peptides (found in bee venom). Some organisms, for example, endophytic fungi and bees, produce immunostimulants using compounds obtained from plants. The main challenges facing this type of research and tools being developed to overcome them are examined.

Effect of ginseng polysaccharides on the immunity and growth of piglets by dietary supplementation during late pregnancy and lactating sows

There are many reports that dietary supplementation with plant polysaccharides in pigs might promote their growth, but little is known about the maternal effect of ginseng polysaccharides (GPS) on piglets' growth by dietary supplementation to pregnant and lactating sows. In the current study, the effects of dietary supplementation with GPS on the immunity of sows and growth of their piglets were investigated. Results showed no significant difference among the four groups in the total number of piglets, live piglets, weak piglets and birth weight of piglets, indicating the GPS-treatment has no adverse effect on reproduction. Furthermore, the weaning weight of the GPS-treated groups was higher than that of control group (P < 0.05); among them, the addition of 200 mg/kg dose has the best effect. Interestingly, GPS increased the total immunoglobulin G concentration in milk and serum of sows (P < 0.05). The concentrations of interleukin (IL)-2, IL-6, tumor necrosis factor (TNF)-α, and interferon-γ in milk and serum of sows were also increased in the experimental groups relative to the control (P < 0.05). Meanwhile, maternal supplementation of GPS significantly increased IL-2 and TNF-α concentration in the piglets' serum of the experimental groups relative to control (P < 0.05). GPS (200 mg/kg) significantly increased the glutathione peroxidase activity in milk and serum (P < 0.05), while the concentrations of malondialdehyde were significantly reduced (P < 0.05). The present results indicated that GPS supplementation during late pregnancy and lactation improved immunity-related bio-molecular levels in sow serum and milk, which may be further beneficial to piglet health and growth through biological transmission effects.

QS-21 enhances the early antibody response to oil adjuvant foot-and-mouth disease vaccine in cattle

Purpose

One of the most important tools against foot-and-mouth disease, a highly contagious and variable viral disease of cloven-hoofed animals, is vaccination. However, the effectiveness of foot-and-mouth disease vaccines on slowing the spread of the disease is questionable. In contrast, high potency vaccines providing early protection may solve issues with the spread of the disease, escaping mutants, and persistency. To increase the potency of the vaccine, additives such as saponin and aluminium hydroxide are used. However, the use of saponin with an oil adjuvant is not common and is sometimes linked to toxicity. QS-21, which is less toxic than Quil A, has been presented as an alternative for use with saponin. In this study, the addition of QS-21 to a commercially available foot-and-mouth disease water-in-oil-in-water emulsion vaccine was evaluated in cattle.

Materials and Methods

After vaccination, serum samples were collected periodically over 3 months. Sera of the QS-21 and normal oil vaccine groups were compared via serum virus neutralization antibody titre and liquid phase blocking enzyme-linked immunosorbent assay antibody titre.

Results

The results showed that there was a significant early antibody increase in the QS-21 group.

Conclusion

Strong early virus neutralizing antibody response will be useful for emergency or ring vaccinations against foot-and-mouth disease in target animals.

Greater efficacy of the ECMS-oil adjuvant over other formulations on immune responses against Bordetella bronchiseptica in rabbits and the underlying mechanism

In this study, the adjuvant effects of the extract of Cochinchina momordica seed ECMS+oil, oil alone, ECMS alone, conventional alum adjuvant on inactivated Bordetella bronchiseptica (Bb) vaccine or control using antigen alone without adjuvant were evaluated along with the underlying mechanism. The results in experiment A demonstrated that antibody levels in Bb whole cell protein in the ECMS800μg+oil group were significantly higher than in the other adjuvant groups (p<0.05) on day 21. The agglutination antibody titer was also higher than the other groups (p<0.05) on day 37. The ECMS800μg+oil group improved cellular immune responses compared to other adjuvant groups, including control using antigen alone without adjuvant and the PBS group (p<0.05). After Bb challenge, the ECMS800μg+oil group showed the highest protection rate, which was significantly higher than ECMS alone or control using antigen alone without adjuvant and the PBS group (p<0.05 and p<0.01). IgA cells in the ECMS800μg+oil group differed significantly from the IgA cells of other groups in the lungs (p<0.01). The results of cell recruitment showed that the number of lymphocytes in the ECMS400μg+oil were higher than the number of cells for other groups except the ECMS(100μg/800μg)+oil groups (p<0.05). Intermediate cells in the ECMS(100μg/400μg)+oil groups were higher than the number of cells for other groups, including the control using antigen alone group (p<0.05). Neutrophils in the ECMS(100μg/400μg/800μg)+oil groups were significantly higher than the ECMS 800μg and control using antigen alone groups (p<0.05). White blood cells in the ECMS100μg+oil group were significantly higher than the oil, ECMS800μg and control using antigen alone groups (p<0.05). IL-2 expression in the ECMS800μg+oil group was significantly higher than other groups, except for the ECMS400μg+oil group (p<0.05). IL-4 expression in the ECMS800μg+oil group was significantly higher than other groups (p<0.05). GATA3 in the ECMS800μg+oil groups was significantly higher than the oil, ECMS800μg and control using antigen alone group (p<0.05). ECMS-oil adjuvant mixture could most effectively protect B. bronchiseptica immunized rabbits and, therefore, could be an alternative way of improving B. bronchiseptica vaccination in rabbits.

Improved immune response to an attenuated pseudorabies virus vaccine by ginseng stem-leaf saponins (GSLS) in combination with thimerosal (TS)

Vaccination using attenuated vaccines remains an important method to control animal infectious diseases. The present study evaluated ginseng stem-leaf saponins (GSLS) and thimerosal (TS) for their adjuvant effect on an attenuated pseudorabies virus (aPrV) vaccine in mice. Compared to the group immunized with aPrV alone, the co-inoculation of GSLS and/or TS induced a higher antibody response. Particularly, when administered together with GSLS-TS, the aPrV vaccine provoked a higher serum gB-specific antibody, IgG1 and IgG2a levels, lymphocyte proliferative responses, as well as production of cytokines (IFN-γ, IL-12, IL-5 and IL-10) from lymphocytes, and more importantly provided an enhanced cytotoxicity of NK cells and protection against virulent field pseudorabies virus challenge. Additionally, the increased expression of miR-132, miR-146a, miR-147 and miR-155 was found in murine macrophages cultured with GSLS and/or TS. These data suggest that GSLS-TS as adjuvant improve the efficacy of aPrV vaccine in mouse model and have potential for the development of attenuated viral vaccines.

Panax ginseng aqueous extract prevents pneumococcal sepsis in vivo by potentiating cell survival and diminishing inflammation

BACKGROUND

More than 50% of sepsis cases are caused by Streptococcus pneumoniae, and hospital mortality related to sepsis comprises 52% of all hospital deaths. Therefore, sepsis is a medical emergency, and any treatment against the agent that produces it, is welcome.

PURPOSE

The role of Panax ginseng C.A. Meyer (Araliaceae) aqueous extract in bacterial infection in vivo is not well understood. Here, the protective effect of Korean red ginseng (KRG) extract against pneumococcal infection and sepsis was elucidated.

STUDY DESIGN

In this study, mice were administrated KRG (25, 50, 100 mg/kg) for 15 days, and then infected with a lethal S. pneumoniae strain. Survival rate, body weight, and colonization were determined.

METHODS

The RAW 264.7 macrophage cells were infected with S. pneumoniae and cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inflammation was examined using an enzyme-linked immunosorbent assay (ELISA) and hematoxylin and eosin (HE) staining while gene expression was determined using western blotting.

RESULTS

KRG-pre-treated mice (100 mg/kg of KRG) had significantly higher survival rates and body weights than those of the non-treated controls; KRG-pre-treated mice had lower bacterial number and morbidity than those of the non-treated controls. 100 mg/kg of KRG administration decreased cytokine levels including tumor necrosis factor (TNF)-α (897 and 623 pg/ml, control and KRG groups, respectively, P < 0.05) and interleukin (IL)-1β (175 and 127 pg/ml, control and KRG groups, respectively, P = 0.051), nitric oxide level (149 and 81 nM, control and KRG groups, respectively, P < 0.05), and neutrophil infiltration 48 h post-infection, in vivo. In pneumococcal infection, KRG pre-treatment downregulated toll-like receptor (TLR) 4 and TNF-ɑ expressions in RAW 264.7 macrophage cells and increased cell survival by activating phosphoinositide 3-kinase (PI3K)/AKT signaling.

CONCLUSION

Taken together, 100 mg/kg of KRG appeared to protect host cells from lethal pneumococcal sepsis by inhibiting inflammation as well as by enhancing bacterial clearance thereby reinforcing cell survival against pneumococcal infection.

Human factor H (FH) impairs protective meningococcal anti-FHbp antibody responses and the antibodies enhance FH binding

The meningococcal 4CMenB vaccine (Bexsero; Novartis) contains four antigens that can elicit serum bactericidal activity, one of which is factor H (FH)-binding protein (FHbp). FHbp specifically binds human complement FH. When humans are immunized, FHbp is expected to form a complex with FH, which could affect immunogenicity and safety. Wild-type mice (whose FH does not bind to FHbp) and human FH transgenic mice were immunized with three doses of 4CMenB, and their responses were compared. There were no significant differences between the serum bactericidal responses of transgenic and wild-type mice to strains with all of the antigens mismatched for 4CMenB except PorA or NadA. In contrast, against a strain mismatched for all of the antigens except FHbp, the transgenic mice had 15-fold weaker serum bactericidal antibody responses (P = 0.0006). Binding of FH downregulates complement. One explanation for the lower anti-FHbp serum bactericidal activity in the transgenic mice is that their postimmunization serum samples enhanced the binding of FH to FHbp, whereas the serum samples from the wild-type mice inhibited FH binding. Control antiserum from transgenic mice immunized with a low-FH-binding mutant FHbp (R41S) vaccine inhibited FH binding. Two 4CMenB-vaccinated transgenic mice developed serum IgM autoantibodies to human FH. Thus, human FH impairs protective serum anti-FHbp antibody responses, in part by skewing the antibody repertoire to FHbp epitopes outside the FH binding site. FHbp vaccines that bind FH may elicit FH autoantibodies. Mutant FHbp antigens with low FH binding could improve protection and, potentially, vaccine safety in humans.

IMPORTANCE

Two serogroup B meningococcal vaccines contain a novel antigen called factor H (FH)-binding protein (FHbp). FHbp specifically binds human FH, a plasma protein that downregulates complement. One vaccine (4CMenB; Novartis) is licensed in Europe, Canada, and Australia. When humans are immunized, FHbp can complex with FH. We compared the immunogenicity of 4CMenB vaccine in wild-type mice, whose own FH does not bind to FHbp, and human FH transgenic mice. Transgenic mice had respective antibody responses similar to those of wild-type mice to 4CMenB antigens that do not bind FH. However, the protective antibody responses of the transgenic mice to FHbp were impaired, largely because the antibodies did not inhibit but rather enhanced the binding of FH to FHbp. Two transgenic mice developed serum IgM autoantibodies to FH. Mutant FHbp antigens with low FH binding likely will elicit greater protection in humans than FHbp vaccines that bind FH and have a lower risk of FH autoantibodies.

Enhanced immune responses of chickens to oral vaccination against infectious bursal disease by ginseng stem-leaf saponins

Infectious bursal disease (IBD), caused by infectious bursal disease virus (IBDV), is an immunosuppressive infectious disease of global economic importance in poultry. This study was designed to evaluate the effect of oral administration of ginseng stem-leaf saponins (GSLS) on humoral and gut mucosal immunity in chickens vaccinated with live IBDV vaccine, and furthermore, to test its protective efficacy against virulent IBDV challenge following vaccination. In experiment 1, chickens were orally administered with GSLS at 5 mg/kg of BW for 7 d, and then immunized with live IBDV vaccine via the oral route. Serum was sampled on 0, 1, 2, 3, 4, and 5 wk postvaccination for detecting antibody titers by ELISA, and intestinal tissues were collected on 0, 1, 3, and 5 wk postvaccination for measurement of IgA-positive cells and intestinal intraepithelial lymphocytes by immunohistochemical and hematoxylin-eosin staining, respectively. Result showed that antibody titers, IgA-positive cells and intestinal intraepithelial lymphocytes were significantly higher in chickens drinking GSLS than the control, suggesting an enhanced effect of GSLS on humoral and gut mucosal immune responses. In experiment 2, chickens were delivered with GSLS and then vaccinated in the same way as in experiment 1. The birds were challenged with virulent IBDV at wk 3 postvaccination. Then the birds were weighed, bled, and necropsied at d 3 postchallenge and the bursae were sampled for gross and histopathological examination. Results demonstrated that GSLS provided a better protection against virulent IBDV challenge following vaccination than the control. In conclusion, oral administration of GSLS enhances both humoral and gut mucosal immune responses to IBDV and offers a better protection against virulent IBDV challenge. Considering its immunomodulatory properties to IBDV vaccine, GSLS might be a promising oral adjuvant for vaccination against infectious diseases in poultry.

Adjuvant effects of L. acidophilus LW1 on immune responses to the foot-and-mouth disease virus DNA vaccine in mice

The adjuvant effects of Lactobacillus acidophilus on DNA vaccination are not fully understood. It has been hypothesized that swine-derived Lactobacillus acidophilus SW1 (LASW1) could function as an immune adjuvant to enhance antigen-specific immune responses after foot-and-mouth disease (FMD) DNA vaccination in mice. To evaluate the effect of oral LASW1 on the immune response to a DNA vaccine (pRC/CMV-vp1) harboring FMD VP1 gene, anti-FMDV antibody and its isotypes, T-cell proliferation, and cytokine detection were investigated. The results showed that LASW1 was able to enhance FMDV-specific antibody levels and FMDV-neutralizing antibodies. After a booster vaccine, the anti-FMDV antibody titers and FMDV-neutralizing antibodies levels induced by pRC/CMV-vp1 were higher in mice treated with LSAW1 than in the group immunized with pRC/CMV-vp1 alone (the control). Using T-cell proliferation, the stimulation index of the LASW1 group was significantly higher in response to ConA and 146S antigen (P<0.05) than in the control group. Importantly, higher concentrations of IFN-γ and IFN-γ-producing cells were also observed in splenocytes isolated from the experimental LASW1 mice, indicating that INF-γ secretion is important to the immune response to LASW1. The results indicate that LASW1 is a promising immune adjuvant in DNA vaccination against FMD when administrated orally.

Effects of radix ginseng on microbial infections: a narrative review

OBJECTIVE

To summarized the antimicrobial-like effects of Radix Ginseng, which provide important information to the relevant researchers and clinicians, and will benefit the clinical treatment of infectious diseases.

METHODS

PubMed and Google were used to search for and collect scientific publications related to Radix Ginseng and microbial infections. The authors read, classified, and discussed the associated scientific results or evidences, and summarized the corresponding results.

RESULTS

In this review, recent studies on the beneficial effects of Radix Ginseng extracts on microbial and biofilm infections were reviewed. The importance and significance of Radix Ginseng's beneficial effects are discussed. Evidence for the favorable effects of Radix Ginseng extracts on viral, bacterial, fungal, and parasitic infections and the possible underlying mechanisms are summarized.

CONCLUSION

Radix Ginseng might be a promising supplemental remedy for the prevention and treatment of infectious diseases.

Rapeseed oil and ginseng saponins work synergistically to enhance Th1 and Th2 immune responses induced by the foot-and-mouth disease vaccine

Previous investigations demonstrated that saponins isolated from the root of Panax ginseng C. A. Meyer (i.e., ginseng root saponin [GS-R]) had adjuvant activity. In the present study, the combined effects of rapeseed oil (RO) and GS-R on the immune responses elicited by foot-and-mouth disease (FMD) vaccine were investigated by measuring FMD virus (FMDV)-specific antibody levels, cytokine levels, lymphocyte proliferation, and long-lived IgG-secreting plasma cells from bone marrow in a mouse model. The results indicated that RO in combination with GS-R significantly enhanced serum IgG and isotype concentrations, gamma interferon (IFN-γ) and interleukin 5 (IL-5) levels, splenocyte proliferative responses to stimulations with concanavalin A (ConA), lipopolysaccharide (LPS), and FMDV antigen, and the numbers of IgG-secreting plasma cells in the bone marrow, suggesting that RO/GS-R enhanced both Th1 and Th2 immune responses. In addition, no significant difference was found between RO/GS-R and the commercial adjuvant oil ISA 206 in the promotion of FMD vaccine-induced immune responses. Considering the vegetable origin of RO and GS-R and the potent adjuvant activity, RO/GS-R should be studied further for the development of veterinary vaccines, especially for use in food animals in order to promote food safety.

Complete Genome Sequence of Neisseria meningitidis Serogroup A Strain NMA510612, Isolated from a Patient with Bacterial Meningitis in China

Serogroup A meningococcal strains have been involved in several pandemics and a series of epidemics worldwide in the past. Determination of the genome sequence of the prevalent genotype strain will help us understand the genetic background of the evolutionary and epidemiological properties of these bacteria. We sequenced the complete genome of Neisseria meningitidis NMA510612, a clinical isolate from a patient with meningococcal meningitis.

An interspecific Nicotiana hybrid as a useful and cost-effective platform for production of animal vaccines

The use of transgenic plants to produce novel products has great biotechnological potential as the relatively inexpensive inputs of light, water, and nutrients are utilised in return for potentially valuable bioactive metabolites, diagnostic proteins and vaccines. Extensive research is ongoing in this area internationally with the aim of producing plant-made vaccines of importance for both animals and humans. Vaccine purification is generally regarded as being integral to the preparation of safe and effective vaccines for use in humans. However, the use of crude plant extracts for animal immunisation may enable plant-made vaccines to become a cost-effective and efficacious approach to safely immunise large numbers of farm animals against diseases such as avian influenza. Since the technology associated with genetic transformation and large-scale propagation is very well established in Nicotiana, the genus has attributes well-suited for the production of plant-made vaccines. However the presence of potentially toxic alkaloids in Nicotiana extracts impedes their use as crude vaccine preparations. In the current study we describe a Nicotiana tabacum and N. glauca hybrid that expresses the HA glycoprotein of influenza A in its leaves but does not synthesize alkaloids. We demonstrate that injection with crude leaf extracts from these interspecific hybrid plants is a safe and effective approach for immunising mice. Moreover, this antigen-producing alkaloid-free, transgenic interspecific hybrid is vigorous, with a high capacity for vegetative shoot regeneration after harvesting. These plants are easily propagated by vegetative cuttings and have the added benefit of not producing viable pollen, thus reducing potential problems associated with bio-containment. Hence, these Nicotiana hybrids provide an advantageous production platform for partially purified, plant-made vaccines which may be particularly well suited for use in veterinary immunization programs.

Inhibitory effects of Ginsenoside Rb1 on apoptosis caused by HSV-1 in human glioma cells

To investigate the inhibitory effects of Ginsenoside Rb1 (GRb1) on apoptosis caused by Herpes Simplex Virus-1(HSV-1) in Human Glioma Cells (U251), U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRb1, GRb1+HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRb1 on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb1 and 400 μg/mL GRb1+HSV-1 groups, MTT values were higher than control group at all times (P<0. 05). Moreover, the apoptosis rate in the 400 μg/mL GRb1+HSV-1 group was lower than the HSV-1 group (P<0. 05). These results confirmed that, at appropriate concentrations, GRb1 could inhibit nerve cell apoptosis in HSV-1 infections.

Enhancement of humoral immune responses to inactivated Newcastle disease and avian influenza vaccines by oral administration of ginseng stem-and-leaf saponins in chickens

Newcastle disease (ND) and avian influenza (AI) are common in the poultry industry. The objective of this study was to evaluate the effect of oral administration of ginseng stem-and-leaf saponins (GSLS) on the humoral immune responses of chickens to inactivated ND and AI vaccines. In experiment 1, oral administration of GSLS at a dose of 5 mg/kg of BW for 7 d on the immune response in chickens intramuscularly injected with inactivated ND vaccine was evaluated. Results showed that GSLS significantly increased the antibody level against ND in the serum of chickens. In experiment 2, the same regimen of GSLS was administered to chickens inoculated with inactivated AI vaccines, and an enhanced serum antibody response to AI vaccination was also observed. Considering the safety of GSLS, because no adverse effect was found throughout the experiments, GSLS may be a promising oral adjuvant to improve immunization in poultry.

Effect of oral administration of ginseng stem-and-leaf saponins (GSLS) on the immune responses to Newcastle disease vaccine in chickens

This study was designed to evaluate the effect of oral administration of ginseng stem-and-leaf saponin (GSLS) on immune responses in chickens vaccinated with live Newcastle disease (ND) vaccines. In experiment 1, chickens were orally administered GSLS (2.5, 5, 10, and 20mg/kg) in drinking water for 3 days, and then intranasally vaccinated with ND vaccine. Hemagglutination inhibition (HI) test showed that the optimal dose of GSLS for enhancing HI titers was 5mg/kg. In experiment 2, chickens were fed with GSLS (5mg/kg) for 7, 5 or 3 days before vaccination. Result indicated that GSLS enhanced HI titers in a time-dependent manner. The order of the duration for drinking GSLS on increasing HI titers was 7 days>5 days>3 days. In experiment 3, chickens were fed with GSLS before or after immunization. Serum was sampled at a week interval for 5 weeks for HI test, splenic lymphocytes were prepared at weeks 2 and 4 after the booster immunization for lymphocyte proliferation test (LPT) and intestinal tissues were sampled at week 4 after the booster immunization for immunohistochemistry and histological examination. Results showed that HI titer, LPT, IgA+ cells and intestinal intraepithelial lymphocytes (iIELs) were significantly higher in chickens drinking GSLS before vaccination than those after vaccination. Therefore, oral administration of GSLS in drinking water at a dose of 5mg/kg for 7 days significantly increased systemic as well as gut mucosal immunity in chickens immunized with ND vaccine. Considering the immune potentiating effect of GSLS on ND vaccine, GSLS should be evaluated for its oral adjuvant effect on the immune response against other diseases such avian influenza and infectious bursal disease.

Florfenicol impairs the immune responses to vaccination against foot-and-mouth disease in mice

Florfenicol is a new type of broad-spectrum antibacterial that has been used in veterinary clinics. It showed immunosuppressive activity on the immune responses to vaccination against foot-and-mouth disease virus (FMDV) serotype O in mice. In the present study, BALB/c mice were immunized subcutaneously with FMDV serotype O antigen on days 1 and 14. Beginning on day 21, mice were treated with a single daily oral dose of florfenicol (50, 100, and 200 mg/kg) for seven consecutive days. On day 28, blood samples were collected to analyze FMDV-specific immunoglobulin G (IgG), IgG1, and IgG2b antibodies, and splenocytes were harvested to assess lymphocyte proliferation, CD3(+) T- and CD19(+) B-lymphocyte subsets. The results presented here demonstrated that florfenicol not only significantly suppressed concanavalin A-, lipopolysaccharide-induced splenocyte proliferation but also decreased the percentage of CD19(+) B-cells in a dose-dependent manner and suppressed CD3(+) T-cell at high doses. Moreover, FMDV-specific IgG, IgG1, and IgG2b antibody levels in FMDV-immunized mice were reduced by florfenicol. These results suggested that florfenicol could suppress humoral and cellular immune responses to vaccination against foot-and-mouth disease (FMD) in mice.

Ginsenoside Rg1 enhances immune response induced by recombinant Toxoplasma gondii SAG1 antigen

Ginsenoside, the most important component isolated from Panax ginseng, exhibits a variety of biological activities. Particularly, ginsenoside Rg1 is known to have immune-modulating activities such as increase of immune activity of T helper (Th) cells. In the present study, we evaluated the immunomodulatory potentials of the Rg1 at three dose levels on the cellular and humoral immune responses of ICR mice against T. gondii recombinant surface antigen 1 (rSAG1). ICR mice were immunized subcutaneously with 50 μg Rg1 alone, 100 μg rSAG1 alone or with 100 μg rSAG1 dissolved in saline containing ginsenoside Rg1 (10 μg, 50 μg or 100 μg). After immunization, we evaluated the immune response using lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged lethally. The results showed that the groups immunized with rSAG1 and Rg1 (50 μg, 100 μg) developed a high level of specific antibody responses against T. gondii rSAG1, a strong lymphoproliferative response, and significant levels of cytokine production, compared with the other groups. After lethal challenge, the mice immunized with the rSAG1 and Rg1 (50 μg, 100 μg) showed a significantly increased survival time compared with control mice which died within 6 days of challenge. Our data demonstrate that by addition of ginsenoside Rg1, the rSAG1 triggered a stronger humoral and cellular response against T. gondii, and that Rg1 is a promising vaccine adjuvant against toxoplasmosis, worth further development.