Astragalus polysaccharides enhance immune responses of HBV DNA vaccination via promoting the dendritic cell maturation and suppressing Treg frequency in mice

Induction of Regulatory T Cells After Virus Infection and Vaccination

Vaccines have been proven to be one of the safest and most effective ways to prevent and combat diseases. However, the main focus has been on the evaluation of the potency of effector mechanisms and the lack of adverse effects of vaccine candidates. Recently, the importance of induced regulatory mechanisms of the immune system after vaccination has come to light. With the increase in our knowledge about these regulatory mechanisms including the regulatory T cells (Tregs), we have come to understand the significance of this arm of the immune system in controlling immunopathology and/or diminishing the effectiveness of vaccines, especially viral vaccines. Tregs play a dual role during infectious diseases by limiting immune-mediated pathology and also contributing to chronic pathogen persistence by decreasing effector immunity and clearance of infection. Tregs may also affect immune responses after vaccination primarily by inhibiting antigen presenting cell function such as cytokine secretion and co-stimulatory molecule expression as well as effector T (Teff) and B cell function. In this article, we review the current knowledge on the induction of Tregs after several life-threatening virus infections and their available vaccines to bring them to the spotlight and emphasise that studying viral-induced antigen-specific Tregs will help us improve the effectiveness and decrease the immunopathology or side effects of viral vaccines. Trial Registration: ClinicalTrials.gov identifier: NCT04357444.

Astragalus polysaccharide inhibits infectious hematopoietic necrosis virus damage to rainbow trout (Oncorhynchus mykiss) spleen by promoting the efficacy of inactivated vaccine

Pandemic infectious hematopoietic necrosis (IHN) caused by severe acute IHN virus (IHNV) threatens rainbow trout aquaculture in China. Therefore, it is crucial to develop effective vaccines and elucidate their mechanisms of action. Here, we revealed the mechanism of immune response of Astragalus polysaccharide (APS) combined with IHNV inactivated vaccine on rainbow trout spleen by serum enzyme activity assay, histopathological analysis, RNA-seq and viral load measurement. Histopathology and TUNEL showed that the APS combination vaccine significantly inhibited spleen damage and apoptosis by IHNV. Also, APS increased serum SOD, CAT, T-AOC, AKP and ACP activities by enhancing vaccine efficacy. Transcriptome analysis of the spleen showed that immune-related pathways were significantly enriched in the APS + vaccine group. The PPI network identified hub genes including IgM, IRF7, IgT, IgD, TLR7, CD4, CD8, IL-1β, and the APS + vaccine induced expression of these genes in the spleen. Notably, the APS combination vaccine significantly inhibited IHNV replication in the spleen. Overall, APS enhanced IHNV inactivated vaccine efficacy through stronger immune stimulation. These results indicate that the combined use of inactivated vaccine and APS can stimulate strong immunity in rainbow trout spleen, which provides valuable reference data to study the mechanism of aquatic vaccine immunoprophylaxis.

Application prospect of polysaccharide in the development of vaccine adjuvants

Vaccination is an effective strategy for preventing infectious diseases. Subunit vaccines offer more precise targeting and safer protection compared with traditional inactivated virus vaccines. However, due to their poor immunogenicity, subunit vaccines necessitate the use of adjuvants to stimulate the immune system. Adjuvants have long been incorporated into vaccines to enhance the body's immune response, allowing for reduced dosage and lower production costs. Despite the development of numerous vaccine adjuvants, few exhibit the necessary potency and low toxicity for clinical use, often due to limited efficacy or adverse side effects. This underscores the urgent need for novel human vaccine adjuvants that are safe, effective, and cost-efficient. Recent studies have identified certain natural polysaccharides as promising human vaccine adjuvants due to their immunostimulatory properties, low toxicity, and high safety profiles, which enhance both humoral and cellular immunity. These natural polysaccharides are primarily derived from traditional Chinese medicine (TCM) plants, bacteria, and yeast. This review comprehensively analyzes several promising polysaccharide adjuvants, discussing their clinical applications, market potential, and immunoregulatory activities. In summary, the future prospects of polysaccharides provide valuable insights for the application and development of vaccine adjuvants.

Enhancement of HPV therapeutic peptide-based vaccine efficacy through combination therapies and improved delivery strategies: A review

Human papillomavirus (HPV) has been linked to the development of various cancers, including head and neck, cervical, vaginal, penile, and anal cancers. The development of therapeutic vaccines against HPV-positive tumors is crucial for protecting individuals already infected with HPV, preventing tumor progression, and effectively treating the disease. The HPV therapeutic peptide-based vaccines demonstrate specificity and safety advantages by targeting specific epitopes while minimizing the risk of allergic or autoimmune reactions. However, HPV therapeutic peptide-based vaccines typically lack immunogenicity and frequently fail to induce effective immune responses. Therefore, there is a need for more effective approaches to improve the immunogenicity of HPV peptide-based vaccines. Here, we review relevant research and possible uses for increasing the immunogenicity and therapeutic efficacy of HPV peptide-based vaccines through combined therapy and improved delivery strategies. Additional research is necessary to validate the application of combination therapy and delivery strategy modifications as standard treatment approaches for HPV therapeutic peptide-based vaccines.

Progress and prospect of polysaccharides as adjuvants in vaccine development

Vaccines are an effective approach to confer immunity against infectious diseases. Modern subunit vaccines offer more precise target and safe protection compared to traditional whole-pathogen vaccines. However, subunit vaccines require adjuvants to stimulate the immune system due to the less immunogenicity. Adjuvants strengthen immunogenicity by enhancing, modulating, and prolonging the immune response. Unfortunately, few adjuvants have sufficient potency and low enough toxicity for clinical use, highlighting the urgent need for new vaccine adjuvants with the characteristics of safety, efficacy, and cost-effectiveness. Notably, some natural polysaccharides have been approved as adjuvants in human vaccines, owing to their intrinsic immunomodulation, low toxicity, and high safety. Natural polysaccharides are mainly derived from plants, bacteria, and yeast. Partly owing to the difficulty of obtaining them, synthetic polysaccharides emerged in clinical trials. The immune mechanisms of both natural and synthetic polysaccharides remain incompletely understood, hindering the rational development of polysaccharide adjuvants. This comprehensive review primarily focused on several promising polysaccharide adjuvants, discussing their recent applications in vaccines and highlighting their immune-modulatory effects. Furthermore, the future perspectives of polysaccharides offer insightful guidance to adjuvant development and application.

Recent efficacy and long-term survival of Astragalus polysaccharide combined with gemcitabine and S-1 in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly malignant tumor with a rapid progression rate and a high susceptibility to infiltration and metastasis. Astragalus polysaccharide (APS), a pure Chinese medicine preparation primarily made from the traditional Chinese herb Astragalus, plays a positive role in the treatment of many malignant tumors.

AIM

To explore the recent efficacy of APS combined with gemcitabine plus tegafur gimeracil oteracil potassium capsule (S-1) (GS) regimen in the treatment of pancreatic cancer and assess its effect on the immune function and long-term survival of patients.

METHODS

A total of 97 patients who were diagnosed with pancreatic cancer and received GS chemotherapy at The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine) from March 2021 to December 2021 were included in the retrospective analysis. Among them, 41 patients received APS combined with GS chemotherapy, and 56 patients received GS chemotherapy only. The recent efficacy, immune function, adverse reactions, and long-term survival were compared among these patients.

RESULTS

After 4 cycles of treatment, the objective response rate of patients receiving the combined therapy of APS and GS was 51.22%, and the disease control rate (DCR) was 56.10%, higher than those of patients receiving the monotherapy with GS alone (30.36% and 35.71%, respectively). Besides, the percentages of CD3+ T cells (50.18% ± 9.57%) and CD4+ T cells (31.52% ± 5.33%) in the peripheral blood of patients receiving the combined therapy of APS and GS were higher compared with those treated with GS regimen alone [(44.06% ± 8.55%) and (26.01% ± 7.83%), respectively]. Additionally, the incidences of leukopenia, thrombocytopenia, and fatigue in patients receiving the combined therapy of APS and GS were significantly lower than those in patients receiving the monotherapy of GS alone (17.07%, 9.76%, 31.71% vs 37.50%, 28.57%, 60.71%). Moreover, the median survival time of patients receiving the combined therapy of APS and GS was 394 days, significantly longer than that of patients receiving the monotherapy of GS alone (339 days) (hazard ratio: 0.66; 95%CI: 0.45-0.99; P = 0.036). All these differences were statistically significant (P < 0.05).

CONCLUSION

The combined therapy of APS and GS improved the recent efficacy and long-term survival of patients with pancreatic cancer and alleviated chemotherapy-induced immune suppression and adverse reactions.

Purified Astragalus Polysaccharide Combined with Inactivated Vaccine Markedly Prevents Infectious Haematopoietic Necrosis Virus Infection in Rainbow Trout (Oncorhynchus mykiss)

Rainbow trout (Oncorhynchus mykiss) is experiencing a catastrophic pandemic. In recent years, infectious hematopoietic necrosis virus (IHNV) has spread nationwide, resulting in significant mortality. Currently, there are no available treatments or vaccines for IHNV in China. Here, the Astragalus extract was purified and characterized. Then, we developed an inactivated IHNV vaccine with purified Astragalus polysaccharide (P-APS) as an adjuvant. Safety assays showed that IHNV was successfully inactivated. After a serious IHNV challenge, the cumulative mortality rates were 76.0, 38.0, and 22.1% in control, vaccine, and P-APS + vaccine groups, respectively. P-APS + vaccine was effective at reducing head kidney damage and apoptosis after IHNV challenge by histopathological and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analyses. The P-APS + vaccine group showed better results in enhancing specific antibodies (IgM) and immune enzyme activities (C3, LZM, GOT, and GPT). RNA-seq revealed that many immune-related pathways were significantly enriched. TLR2, TLR7, C3, IFN-γ, IgM, MHC1, MHC2, MX1, and VIG1 were identified as core genes based on RNA-seq and PPI networks. Mechanistic investigations showed that P-APS + vaccine activates the immune pathway by upregulating the expression of these genes. P-ASP+vaccine induced effective innate and adaptive immune responses that were stronger than single vaccines after vaccination and IHNV challenged. Our findings will provide a promising vaccine candidate against IHNV.

Astragalus Polysaccharide improves immunogenicity of influenza vaccine as well as modulate gut microbiota in BALB/c mice

BACKGROUND

Vaccination is the best way to prevent influenza virus infection, and insufficient antibodies make it difficult to resist influenza virus invasion. Astragalus Polysaccharide (APS) has a boosting effect on immunity, so we evaluate the effect of APS as an immune adjuvant for H1N1 influenza vaccines in this study.

METHODS

The mice were immunized twice with influenza A (H1N1) vaccine and APS. Subsequently, the serum antibody levels were assessed using enzyme-linked immunosorbent assay (ELISA). The frequency of peripheral immune T cells was determined by flow cytometry. Following this, the immunized mice were exposed to a lethal dose of the virus, and changes in body weight and survival rates were recorded. Hematoxylin-eosin staining was employed to observe pathological alterations in lung and intestinal tissues. Western blot analysis was conducted to detect the expression of intestinal barrier function proteins (Occludin and Claudin-1). ELISA was utilized to measure the expression level of serum inflammatory cytokine TNF-α. Fresh mouse feces were collected after the initial immunization as well as after viral infection for 16S rRNA analysis aimed at detecting alterations in gut microbiota.

RESULTS

Compared to the Hemagglutinin (HA) group, the APS group demonstrated higher levels of immunoglobulin G (IgG), IgG1, and IgG3, as well as neutralizing antibody levels. Additionally, it increased the frequency of CD8+ cells to enhance resistance against lethal infection. On day 14 post-infection, the high-dose APS group exhibited a higher survival rate (71.40 %) compared to the HA group (14.28 %), along with faster weight recovery. Furthermore, APS was found to ameliorate alveolar damage in lung tissue and rectify intestinal structural disorder. It also upregulated the expression levels of tight junction proteins Occludin and Claudin-1 in intestinal tissue while reducing serum TNF-α expression levels. In addition, populations of Colidextribacter, Peptococcaceae, and Ruminococcaceae were the dominant gut microbiota in the APS group after viral infection.

CONCLUSION

APS has an immune-enhancing effect and is expected to be a novel adjuvant in the H1N1 influenza vaccine.

Astragalus polysaccharide enhances antitumoral effects of chimeric antigen receptor- engineered (CAR) T cells by increasing CD122+CXCR3+PD-1- memory T cells

Chimeric antigen receptor-engineered T (CAR-T) cell therapy of cancer has been a hotspot and promising. However, due to rapid exhaustion, CAR-T cells are less effective in solid tumors than in hematological ones. CD122+CXCR3+ memory T cells are characterized with longevity, self-renewal and great antitumoral capacity. Thus, it's compelling to induce memory CAR-T cells to enhance their efficacy on solid tumors. Astragalus polysaccharide (APS) has reportedly exhibited antitumoral effects. However, it's unclear if APS has an impact on CD8+ memory T cell generation or persistence. Using two human cancer cell lines, here we found that APS significantly improved the persistence of GPC3-targeted CAR-T cells and enhanced their suppression of tumor growth in both Huh7 and HepG2 xenograft models of hepatocellular carcinoma. APS increased CD122+/CXCR3+ memory T cells, but decreased their PD-1+ subset within CD8+ CAR-T cells in tumor-bearing mice, while these effects of APS were also confirmed with in vitro experiments. Moreover, APS augmented the expression of chemokines CXCL9/CXCL10 by the tumor in vivo and in vitro. It also enhanced the proliferation and chemotaxis/migration of CAR-T cells in vitro. Finally, APS promoted the phosphorylation of STAT5 in CD8+ CAR-T cells, whereas inhibition of STAT5 activation reversed these in vitro effects of APS. Therefore, APS enhanced the antitumoral effects of CD8+ CAR-T cells by promoting formation/persistence of CD122+/CXCR3+/PD-1- memory T cells and their migration to the tumor.

Activates B lymphocytes and enhanced immune response: A promising adjuvant based on PLGA nanoparticle to improve the sensitivity of ZEN monoclonal antibody

In preparing monoclonal antibodies by hybridoma cell technology, the quality of B lymphocytes used for cell fusion directly affects the sensitivity of monoclonal antibodies. To obtain B-lymphocytes producing high-quality specific antibodies for cell fusion during the immunization phase of the antigen, we prepared a TH2-Cell stimulatory delivery system as a novel adjuvant. Astragalus polysaccharide has a good ability to enhance antigenic immune response, and it was encapsulated in biocompatible materials PLGA as an immunostimulatory factor to form the delivery system (APS-PLGA). The preparation conditions of APSP were optimized using RSM to attain the highest utilization of APS. Immunization against ZEN-BSA antigen using APSP as an adjuvant to obtain B lymphocytes producing ZEN-specific antibodies for cell fusion. As results present, APSP could induce a stronger TH2 immune response through differentiating CD4 T cells and promoting IL-4 and IL-6 cytokines. Moreover, it could slow down the release efficiency of ZEN-BSA and enhance the targeting of ZEN-BSA to lymph nodes in vivo experiments. Ultimately, the sensitivity of mouse serum ZEN-specific antibodies was enhanced upon completion of immunization, indicating a significant upregulation of high-quality B lymphocyte expression. In the preparation of monoclonal antibodies, the proportion of positive wells for the first screening was 60%, and the inhibition rates of the antibodies were all similar (>50%). Then we obtained the ZEN monoclonal antibody with IC50 of 0.049 ng/mL, which was more sensitive than most antibodies prepared under conventional adjuvants. Finally, a TRFIAS strip assay was preliminarily established with a LOD value of 0.246 ng/mL.

Advances in research on the anti-tumor mechanism of Astragalus polysaccharides

The dry root of the soybean plant Astragalus membranaceus (Fisch) Bge. var. mongholicus (Bge) Hsiao or A. membranaceus (Fisch) Bge, Astragali Radix (AR) has a long medicinal history. Astragalus polysaccharide (APS), the natural macromolecule that exhibits immune regulatory, anti-inflammatory, anti-tumor, and other pharmacological activities, is an important active ingredient extracted from AR. Recently, APS has been increasingly used in cancer therapy owing to its anti-tumor ability as it prevents the progression of prostate, liver, cervical, ovarian, and non-small-cell lung cancer by suppressing tumor cell growth and invasion and enhancing apoptosis. In addition, APS enhances the sensitivity of tumors to antineoplastic agents and improves the body's immunity. This macromolecule has prospects for broad application in tumor therapy through various pathways. In this article, we present the latest progress in the research on the anti-tumor effects of APS and its underlying mechanisms, aiming to provide novel theoretical support and reference for its use in cancer therapy.

Astragalus polysaccharide ameliorates insulin resistance in HepG2 cells through activating the STAT5/IGF-1 pathway

BACKGROUND

Insulin resistance (IR) is considered as a major factor initiating type 2 diabetes mellitus and can lead to a reduction in glucose uptake that mainly occurs in the liver. Astragalus polysaccharide (APC), extracted from the traditional Chinese medicine, has been recorded to suppress IR. However, the underlying mechanism remains inadequately explored.

METHODS

IR was induced in HepG2 cells which further underwent APC treatment. Cell viability was determined by cell counting kit-8 assay. Pretreatment with AG490, an inhibitor of signal transducer and activator of transcription 5 (STAT5) signaling, was performed for investigating the influence of STAT5 on APC. Glucose uptake level was reflected by 2-deoxyglucose-6-phosphate content determined through colorimetric assay. Expression levels of insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), phosphorylated-STAT5/STAT5, and p-protein kinase B (AKT)/AKT in the cells were assessed by Western blot. Radioimmunoassay (RIA) was used to detect IGF-1 secretion in the cells.

RESULTS

APC at doses of 10 and 20 mg increased the viability of HepG2 cells with/without IR induction, and abrogated IR-induced inhibition of glucose intake. Meanwhile, APC (10 mg) offset IR-induced inhibition on the expressions of IGF-1R and IGF-1, the activation of AKT and STAT5, and the secretion of IGF-1 in HepG2 cells. More importantly, the reversal effect of APC on IR-induced alterations in HepG2 cells was counteracted by AG490.

CONCLUSION

APC ameliorates IR in HepG2 cells through activating the STAT5/IGF-1 pathway.

The Mechanisms of Polysaccharides from Tonic Chinese Herbal Medicine on the Enhancement Immune Function: A Review

Tonic Chinese herbal medicine is a type of traditional Chinese medicine, and its primary function is to restore the body's lost nutrients, improve activity levels, increase disease resistance, and alleviate physical exhaustion. The body's immunity can be strengthened by its polysaccharide components, which also have a potent immune-system-protecting effect. Several studies have demonstrated that tonic Chinese herbal medicine polysaccharides can improve the body's immune response to tumor cells, viruses, bacteria, and other harmful substances. However, the regulatory mechanisms by which various polysaccharides used in tonic Chinese herbal medicine enhance immune function vary. This study examines the regulatory effects of different tonic Chinese herbal medicine polysaccharides on immune organs, immune cells, and immune-related cytokines. It explores the immune response mechanism to understand the similarities and differences in the effects of tonic Chinese herbal medicine polysaccharides on immune function and to lay the foundation for the future development of tonic Chinese herbal medicine polysaccharide products.

Synergist for antitumor therapy: Astragalus polysaccharides acting on immune microenvironment

Various new treatments are emerging constantly in anti-tumor therapies, including chemotherapy, immunotherapy, and targeted therapy. However, the efficacy is still not satisfactory. Astragalus polysaccharide is an important bioactive component derived from the dry root of Radix astragali. Studies found that astragalus polysaccharides have gained great significance in increasing the sensitivity of anti-tumor treatment, reducing the side effects of anti-tumor treatment, reversing the drug resistance of anti-tumor drugs, etc. In this review, we focused on the role of astragalus polysaccharides in tumor immune microenvironment. We reviewed the immunomodulatory effect of astragalus polysaccharides on macrophages, dendritic cells, natural killer cells, T lymphocytes, and B lymphocytes. We found that astragalus polysaccharides can promote the activities of macrophages, dendritic cells, natural killer cells, T lymphocytes, and B lymphocytes and induce the expression of a variety of cytokines and chemokines. Furthermore, we summarized the clinical applications of astragalus polysaccharides in patients with digestive tract tumors. We summarized the effective mechanism of astragalus polysaccharides on digestive tract tumors, including apoptosis induction, proliferation inhibition, immunoactivity regulation, enhancement of the anticancer effect and chemosensitivity. Therefore, in view of the multiple functions of astragalus polysaccharides in tumor immune microenvironment and its clinical efficacy, the combination of astragalus polysaccharides with antitumor therapy such as immunotherapy may provide new sparks to the bottleneck of current treatment methods.

An arabinogalactan extracted with alkali from Portulaca oleracea L. used as an immunopotentiator and a vaccine carrier in its conjugate to BSA

A neutral polysaccharide (POPAN) from Portulaca oleracea L. was isolated with alkali and purified to obtain. HPLC analysis suggested POPAN (40.9 kDa) was mainly composed of Ara and Gal with traces of Glc and Man. GC-MS and 1D/2D NMR analysis confirmed POPAN was an arabinogalactan possessing a backbone mainly composing of (1 → 3)-α-l-Araf-linked arabinan and (1 → 4)-β-d-Galp-linked galactan, which was different from structure characterization of typical arabinogalactan reported previously. Importantly, we conjugated POPAN to BSA (POPAN-BSA), and detected the potential and mechanism of POPAN as an adjuvant in POPAN-BSA. The results indicated, in contrast to BSA, POPAN-BSA induced the robust and persistent humoral response in addition to the cellular response with Th2-biased immunity response in mice. Further investigations of mechanism revealed effects of POPAN-BSA were a result of POPAN as the adjuvant to: 1) significantly activate DCs in vitro or in vivo including the upgraded expressions of costimulators, MHCs and cytokines; 2) greatly facilitated the capture of BSA. Overall, present studies demonstrated POPAN can be a potential adjuvant as an immunopotentiator and an antigen delivery vehicle in its conjugate to recombinant protein vaccines.

Biosynthesis and Pharmacological Activities of Flavonoids, Triterpene Saponins and Polysaccharides Derived from Astragalus membranaceus

Astragalus membranaceus (A. membranaceus), a well-known traditional herbal medicine, has been widely used in ailments for more than 2000 years. The main bioactive compounds including flavonoids, triterpene saponins and polysaccharides obtained from A. membranaceus have shown a wide range of biological activities and pharmacological effects. These bioactive compounds have a significant role in protecting the liver, immunomodulation, anticancer, antidiabetic, antiviral, antiinflammatory, antioxidant and anti-cardiovascular activities. The flavonoids are initially synthesized through the phenylpropanoid pathway, followed by catalysis with corresponding enzymes, while the triterpenoid saponins, especially astragalosides, are synthesized through the universal upstream pathways of mevalonate (MVA) and methylerythritol phosphate (MEP), and the downstream pathway of triterpenoid skeleton formation and modification. Moreover, the Astragalus polysaccharide (APS) possesses multiple pharmacological activities. In this review, we comprehensively discussed the biosynthesis pathway of flavonoids and triterpenoid saponins, and the structural features of polysaccharides in A. membranaceus. We further systematically summarized the pharmacological effects of bioactive ingredients in A. membranaceus, which laid the foundation for the development of clinical candidate agents. Finally, we proposed potential strategies of heterologous biosynthesis to improve the industrialized production and sustainable supply of natural products with pharmacological activities from A. membranaceus, thereby providing an important guide for their future development trend.

Bidirectional and persistent immunomodulation of Astragalus polysaccharide as an adjuvant of influenza and recombinant SARS-CoV-2 vaccine

Respiratory viral infections, such as coronavirus disease of 2019 (COVID-19) and influenza, cause significant morbidity and mortality and have become a worldwide public health concern with tremendous economic and societal burdens. Vaccination is a major strategy for preventing infections. However, some new vaccines have an unmet need for impairing responses in certain individuals, especially COVID-19 vaccines, despite ongoing vaccine and adjuvant research. Here, we evaluated the effectiveness of Astragalus polysaccharide (APS), a bioactive polysaccharide extracted from the traditional Chinese herb Astragalus membranaceus as an immune adjuvant to regulate the efficacy of influenza split vaccine (ISV) and recombinant severe acute respiratory syndrome (SARS)-Cov-2 vaccine in mice. Our data indicated that APS as an adjuvant can facilitate the induction of high levels of hemagglutination inhibition (HAI) titer and specific antibody immunoglobulin G (IgG) and confer protection against the lethal challenge of influenza A viruses, including increased survival and amelioration of weight loss in mice immunized with the ISV. RNA sequencing (RNA-seq) analysis revealed that the NF-κB and Fc gamma R-mediated phagocytosis signaling pathways are essential for the immune response of mice immunized with the recombinant SARS-Cov-2 vaccine (RSV). Another important finding was that bidirectional immunomodulation of APS on cellular and humoral immunity was observed, and APS-adjuvant-induced antibodies persisted at a high level for at least 20 weeks. These findings suggest that APS is a potent adjuvant for influenza and COVID-19 vaccines, and has the advantages of bidirectional immunoregulation and persistent immunity.

Astragalus polysaccharides combined with simvastatin as an immunostimulant enhances the immune adjuvanticity of oil-in-water emulsion and immune responses in mice

Oil-in-water emulsion-based adjuvants have demonstrated acceptable safety in many disease indications, while their adjuvant activities for vaccines still need to be improved. Recently, the strategy of combining adjuvants with multiple types of immunostimulants has been shown to enhance immune responses. In this study, astragalus polysaccharides were combined with simvastatin as an immunostimulant to construct a compound O/W emulsion adjuvant. The formulations were optimized according to the OVA-specific antibody responses induced in mice. For this reason, high (5 mg/mL), medium (2.5 mg/mL), and low (1.25 mg/mL) concentrations of astragalus polysaccharides and high (10 mg/mL), medium (1 mg/mL), and low (0.1 mg/mL) concentrations of simvastatin were selected. The final optimal formulation of the immunostimulant was a high concentration of astragalus polysaccharides combined with a medium concentration of simvastatin. The optimal compound O/W emulsion adjuvant could induce effective humoral and cellular immune responses that were stronger and more stable than those induced by aluminum adjuvant and Freund's adjuvant. The OVA/HAPS-MSim-OE induced dramatically strong and persistent IgG expressions and Th1-polarized immune responses. What's more, the highest CD4⁺/CD8⁺lymphocyte ratios were observed in OVA/HAPS-MSim-OE group. In addition, compound O/W emulsion adjuvant groups significantly promoted the secretion of IFN-γ and IL-6, which also indicated that the compound O/W emulsion adjuvants could induce both enhanced Th1 and Th2-mediated immune responses but prefer the Th1-mediated ones. This study would contribute to an interesting and promising direction in the development of emulsion-based adjuvants.

Immune-enhancing effects of Astragalus polysaccharides and Ganoderma lucidum polysaccharides on Vibrio harveyi flgJ DNA vaccine in grouper

Astragalus polysaccharides (APS) and Ganoderma lucidum polysaccharides (GLP) have been shown to possess strong immunoregulatory properties in aquatic animals. In this study, the fragment containing Vibrio harveyi flgJ gene was ligated into pcDNA3.1(+) vector and pcDNA3.1(+)-flgJ was constructed as DNA vaccine. APS and GLP were used as DNA vaccine adjuvants to evaluate the immunoregulatory effect by intramuscular injection to pearl gentian grouper (♀Epinephelus fuscoguttatus × ♂E. lanceolatus). The results showed that pcDNA3.1(+)-flgJ combined with APS or GLP could significantly up-regulate the innate and adaptive immune response in fish, including serum-specific antibody titres, catalase and lysozyme activities. At the same time, DNA vaccine combined with APS or GLP significantly up-regulated the expression levels of CD8α, IgM, IL-1β, MHC-Iα, MyD88 and TLR3 genes in thymus, head kidney, spleen and liver of pearl gentian grouper in comparison with those of the pFlgJ group. After 42 days post-vaccination, V. harveyi was used to challenge pearl gentian grouper by intraperitoneal injection. The relative percentage of survival (RPS) of pFlgJ, pFlgJ +APS, pFlgJ +GLP and pFlgJ+APS+GLP groups were 69%, 81%, 77% and 88%, respectively. These results suggested APS and GLP were potential adjuvants for DNA vaccine against V. harveyi infection in pearl gentian grouper.

Immunologically effective biomaterials-enhanced vaccines against infection of pathogenic microorganisms

Infectious diseases are severe public health events that threaten global health. Prophylactic vaccines have been considered as the most effective strategy to train the immune system to recognize and clear pathogenic infections. However, the existing vaccines against infectious diseases have several limitations, such as difficulties in mass manufacturing and storage, weak immunogenicity, and low efficiency of available adjuvants. Biomaterials, especially functional polymers, are expected to break through these bottlenecks based on the advantages of biocompatibility, degradability, controlled synthesis, easy modification, precise targeting, and immune modulation, which are excellent carriers and adjuvants of vaccines. This review mainly summarizes the application of immunologically effective polymers-enhanced vaccines against viruses- and bacteria-related infectious diseases and predicted their potential improvements.

Polysaccharides from Astragalus membranaceus elicit T cell immunity by activation of human peripheral blood dendritic cells

Astragalus membranaceus is a widely used herbal medicine in Asia. It has been recognized as possessing various biological properties, however, studies on the activity of the A. membranaceus polysaccharide (AMP), a major component of A. membranaceus, on human peripheral blood dendritic cells (PBDCs) have not been thoroughly investigated. In this study, we found that AMP induced changes in dendritic morphology and the upregulation of activation marker expression and inflammatory cytokine production in human blood monocyte-derived dendritic cells (MDDCs). The AMP promoted the activation of both blood dendritic cell antigen 1⁺ (BDCA1⁺) and BDCA3⁺ PBDCs. AMP-induced secretion of cytokines in the peripheral blood mononuclear cells (PBMCs) was mainly due to PBDCs. Finally, activated BDCA1⁺ and BDCA3⁺ PBDCs by AMP elicited proliferation and activation of autologous T cells, respectively. Hence, these data demonstrated that AMPs could activate dendritic and T cells in human blood, and may provide a new direction for the application of AMPs in the regulation of human immunity.

Effects of compound small peptides of Chinese medicine on intestinal immunity and cecal intestinal flora in CTX immunosuppressed mice

The study was designed to explore the improvement effect of CSPCM (compound small peptide of Chinese medicine) on intestinal immunity and microflora through the treatment of different doses of CSPCM. A total of 100 male Kunming mice were weighed and divided into five groups, namely, group A (control group), group B (model group), group C (0.1 g/kg·bw CSPCM), group D (0.2 g/kg·bw CSPCM), and group E (0.4 g/kg·bw CSPCM). The use of CTX (cyclophosphamide) caused a series of negative effects: the secretion of IL-2, IL-22, TNF-α, sIgA, length of the villi, and the area of Pey's node were significantly reduced (P < 0.05); the depth of crypt and the percent of CD3⁺ and CD4⁺ cells were significantly increased (P < 0.05); the cecal flora taxa decreased; the abundance of Firmicutes and Lactobacillus increased; and the abundance of Bacteroidetes, Deferribacteres, Proteobacteria, Mucispirillum, Bacteroides, and Flexisprra decreased. The addition of CSPCM improved the secretion of cytokines and the development of intestinal villi, crypts, and Pey's node. The number of CD3⁺ and CD4⁺ cells in groups C, D, and E was significantly higher than that in group B (P < 0.05). Compared with group B, the abundance of Firmicutes in groups C, D, and E was decreased, and the Bacteroidetes, Deferribacteres, and Proteobacteria increased. The abundance of Lactobacillus decreased, while that of Mucispirillum, Bacteroides, and Flexisprra increased. It is concluded that cyclophosphamide is extremely destructive to the intestinal area and has a great negative impact on the development of the small intestine, the intestinal immune system, and the intestinal flora. The CSPCM can improve the negative effects of CTX.

Astragalus polysaccharide: a review of its immunomodulatory effect

The Astragalus polysaccharide is an important bioactive component derived from the dry root of Astragalus membranaceus. This review aims to provide a comprehensive overview of the research progress on the immunomodulatory effect of Astragalus polysaccharide and provide valuable reference information. We review the immunomodulatory effect of Astragalus polysaccharide on central and peripheral immune organs, including bone marrow, thymus, lymph nodes, spleen, and mucosal tissues. Furthermore, the immunomodulatory effect of Astragalus polysaccharide on a variety of immune cells is summarized. Studies have shown that Astragalus polysaccharide can promote the activities of macrophages, natural killer cells, dendritic cells, T lymphocytes, B lymphocytes and microglia and induce the expression of a variety of cytokines and chemokines. The immunomodulatory effect of Astragalus polysaccharide makes it promising for the treatment of many diseases, including cancer, infection, type 1 diabetes, asthma, and autoimmune disease. Among them, the anticancer effect is the most prominent. In short, Astragalus polysaccharide is a valuable immunomodulatory medicine, but further high-quality studies are warranted to corroborate its clinical efficacy.

Antiviral Compounds Based on Natural ASTRAGALUS POLYSACCHARIDE (APS): Researches and Foresight in the Strategies for Combating SARS-CoV-2 (COVID-19)

Today, finding natural polymers with desirable properties for use in various industries is one of the critical axes of research in the world. Polysaccharides are a group of natural polymers that have various applications in the pharmaceutical industry. The attachment of monosaccharides forms polysaccharides through glycosidic bonds that are widely found in various sources, including plants. Genus Astragalus belongs to the Fabaceae family. Plants belonging to this genus have different polysaccharides. Astragalus polysaccharides (APS) have attracted a great deal of attention among natural polymers because they are non-toxic, biodegradable, and biocompatible. Currently, APS has great drug potential for curing or treating various diseases. Due to the different biological activities of polysaccharides, including Astragalus, this study has investigated the chemical structure of APS, research report on antiviral, anti-inflammatory, and stimulation of cytokine secretion by these polysaccharides. Also, in this study, the pharmaceutical approaches of APS compounds, as a natural, new and inexpensive source, have been discussed as suitable candidates for use in pharmaceutical formulations and preparation of new drugs to control COVID-19 infection.

Polysaccharides derived from Chinese medicinal herbs: A promising choice of vaccine adjuvants

Adjuvants have been used in vaccines for a long time to promote the body's immune response, reducing vaccine dosage and production costs. Although many vaccine adjuvants are developed, the use in human vaccines is limited because of either limited action or side effects. Therefore, the development of new vaccine adjuvants is required. Many studies have found that natural polysaccharides derived from Traditional Chinese medicine (TCM) possess good immune promoting effects and simultaneously improve humoral, cellular and mucosal immunity. Recently polysaccharide adjuvants have attracted much attention in vaccine preparation because of their intrinsic characteristics: immunomodulation, biocompatibility, biodegradability, low toxicity and safety. This review article systematically analysed the literature on polysaccharides possessing vaccine adjuvant activity from TCM plants, such as Astragalus polysaccharide (APS), Rehmannia glutinosa polysaccharide (RGP), Isatis indigotica root polysaccharides (IRPS), etc. and their derivatives. We believe that polysaccharide adjuvants can be used to prepare the vaccines for clinical use provided their mechanisms of action are studied in detail.

Increased expression of co-stimulatory molecules and enhancement of the IgG response in rats orally administered with a polyherbal formulation

Background

Link Samahan® (LS) is a standardized modern formulation of a polyherbal preparation used in the indigenous system of medicine in Sri Lanka.

Objective

Evaluation of the immunostimulatory activity of LS and the molecular mechanisms that modulate the humoral immune response.

Material and methods

Immunostimulatory activity of LS was tested in rats following oral administration on days 1-5 and 15-19 and immunization with bovine serum albumin (BSA) on day 1 and 15. Anti-BSA IgM and IgG response in rats treated with LS, water and sugar (as controls) were compared on days 0-35, using ELISA. The expression of co-stimulatory molecules on lymphocytes was assessed on days 0-8 and days 14-22 using RT-qPCR.

Results

IgM and IgG levels of LS-treated rats were increased significantly by day 7 and 21 respectively compared to controls (p < 0.05). IgG response of LS-treated group reached a higher magnitude compared to its IgM response. Gene expression of CD28 and CD40L on T cells (4.9-5.1 fold) and CD80, CD86 and CD40 on APCs (2.4-3.1 fold) were induced significantly by day 2 compared to their expression on day 0 (p < 0.05). The expression levels of CD28 and CD40L on day 2-4 and 16-18 were similar while the expression of CD80, CD86 and CD40 on day 16-18 was higher (3.7-5.1 folds) compared to their levels on day 2-4 (2.4-3.2).

Conclusions

These findings support an adjuvant effect of LS contributing to its immunostimulatory activity and increased expression of co-stimulatory molecules that contribute to boosting immune response.

A Seasonal Change of Active Ingredients and Mineral Elements in Root of Astragalus membranaceus in the Qinghai-Tibet Plateau

Astragalus membranaceus is an important traditional Chinese herb whose roots have been used for medicinal purposes for more than 2000 years. Because of excessive exploitation, the wild resources are currently almost exhausted, and therefore, artificial planting of Astragalus membranaceus has been increasingly important. But to date, few studies have focused on the active ingredients and mineral element of Astragalus membranaceus in the Qinghai-Tibet Plateau.In this study, five density gradients (M1: 10 cm × 25 cm, M2: 15 cm × 25 cm, M3: 20 cm × 25 cm, M4: 25 cm × 25 cm and M5: 30 cm × 25 cm) were assessed to evaluate the effects of various planting densities on the mineral element and secondary metabolite content of Astragalus membranaceus roots in different months. It was found that the content of calycosin-7-O-β-D-glucoside and astragaloside IV reached its highest in October. Ononin content increased month by month, while formononetin content decreased during months. Calycosin content did not show significant changes during seasons. Taken together, these results suggest that the optimal planting density is 15 cm × 25 cm (D2) and the optimal harvest period is October. According to the results, the Cu content in all samples did not exceed the limit (20 mg/kg). Principal component analysis (PCA) revealed that Na, P, K Al, Ba, Ca, Fe, Li, and Mn were selected as characteristic elements of Astragalus membranaceus. The results also showed a high correlation between elements and active ingredients. Ba and Co had extremely significant associations with astragaloside IV.

Polysaccharides from traditional Asian food source and their antitumor activity

Polysaccharides extracted from Asian traditional food source have been demonstrated to possess different antitumor activities mostly without side effect. In this paper, we reviewed many kinds of polysaccharides from different Asian food source and their antitumor activities. Some are common food such as different mushroom with more research. Some are special e.g., Ginseng, Salvia, Astragalus, Lycium barbarum etc. with relatively fewer research. This review mainly focused on their structure, derivatives, antitumor activities and their mechanism of action in the last decades. It aimed to bridge traditional Asian ingredients with tumor and cancer curation in order to avoid side effect of traditional treatment. PRACTICAL APPLICATIONS: There are abundant resources of Asian food. And polysaccharides from these resources have been showed good antitumor activities and immunopotentiating activity. This review introduced the advance of the polysaccharides and their antitumor activities, which will promote the development antitumor medicine derived from Asian food source, or their applications as Adjuvant therapy of traditional chemotherapy and radiotherapy. Due to their multiple antitumor activities, enhancing immunity potential, and non-toxic side-effects, it might be utilized for the treatment of multiple tumors and improve the health and the life quality of patients whether as anti-tumor drugs or as adjuvant therapy method. Furthermore, traditional Asian food source is rich. In the near future, more and more efficient polysaccharides with antitumor activities of Asian food source will be discovered. There will be broad application market for the polysaccharides.

Immunomodulatory effects of polysaccharides enzymatic hydrolysis from Hericium erinaceus on the MODE-K/DCs co-culture model

The aim of this study was to explore the indirect immunomodulatory activities and its mechanism of enzymatic hydrolysis of Hericium erinaceus polysaccharides (EHEP) in the MODE-K/DCs co-culture model. According to the TEER value, transmission of phenol red and AKP activity of MODE-K cells, single model was established in order to evaluate the eligibility of MODE-K cells monolayer. Then the MODE-K/DCs co-culture model was set up and HEP and EHEP were added into the apical chamber, DCs were obtained for the expression of key surface markers, the ability of phagocytosis, the morphology, the secretion of cytokines and the production of target proteins. We found that after 21 d of culture, the MODE-K cells monolayer became intact and dense, which can be used for the MODE-K/DCs co-culture model. Under the treatment of HEP and EHEP, immature DCs become into mature DCs with the high expression of CD86 and MHCII, the low antigens up-taking, the typical morphology, the more content of IL-12 and TNF-α and the high level of TLR4, MyD88 and NF-κB proteins. However, compared with HEP, EHEP showed the better immunomodulatory activities. These findings indicated that EHEP could indirectly affect the immune function of DCs in the MODE-K/DCs co-culture model.

Standardized astragalus extract for attenuation of the immunosuppression induced by strenuous physical exercise: randomized controlled trial

Background

This paper aimed to verify how a supplementation of rower’s diet with Astragalus Membranaceus Root (AMR) modulated their immune system response to maximal physical exertion.

Methods

The double-blind study included 18 members of the Polish Rowing Team assigned to the supplemented group (n = 10), and the placebo group (n = 8). The participants performed a 2000 m test on a rowing ergometer at the beginning and at the end of the six-week of intensive training camp during which the supplemented group received 500 mg of AMR. Blood samples were obtained prior to, 1 min after completing, and 24 h after the exertion test. The levels of interleukin 2 (IL2), interleukin 4 (IL4), interleukin 10 (IL10), interferon ɤ (IFN-ɣ), and lactic acid were determined. Subpopulations of T regulatory lymphocytes [CD4+/CD25+/CD127−] (Treg), cytotoxic lymphocytes [CD8+/TCRαβ+] (CTL), natural killer cells [CD3−/CD16+/CD56+] (NK), and TCRδγ-positive cells (Tδγ) were determined with flow cytometry.

Results

After the camp, the initial NK and Treg levels sustained at the baseline, while Tδγ counts increased relative to the levels in the placebo group. In the supplemented subgroup, a decrease in IL2 level in reaction to maximal exertion clearly deepened while the change in IL-2/IL-10 level induced by the recovery after this exertion clearly increased, relative to the changes in the placebo group.

Conclusions

AMR restored the immunological balance in strenuously trained athlets through a stabilization of NK and Treg cells with a positive trend in Tδγ towards Th1 response during restitution by cytokine IL2 modulation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12970-021-00425-5.

Astragalus membranaceus polysaccharides potentiate the growth-inhibitory activity of immune checkpoint inhibitors against pulmonary metastatic melanoma in mice

Astragalus membranaceus (A. membranaceus) is commonly used in various herbal formulations to treat several human and animal diseases. Polysaccharides, which are the major bioactive components in the A. membranaceus, exhibit various bioactive properties. However, the ability of A. membranaceus polysaccharides (APS) to activate the mucosal immune response has not been examined. We examined the effect of intranasal administration of APS on mucosal immune cell activation and the growth-inhibitory activity against pulmonary metastatic melanoma in mice by combination treatment with immune checkpoint blockade. The intranasal treatment of APS increased the number of lineage-CD11c+ dendritic cell (DCs) in the mesenteric lymph nodes (mLN) through the upregulation of CC-chemokine receptor 7 expression. Moreover, intranasal treatment of APS activated DCs, which further stimulated natural killer (NK) and T cells in the mLN. The APS/anti-PD-L1 antibody combination inhibited the pulmonary infiltration of B16 melanoma cells. The depletion of NK cells and CD8 T cells in mice mitigated the anti-cancer effect of this combination, thereby highlighting the critical role of NK cells and CD8 T cells in mediating anti-cancer immunity. These findings demonstrated that APS could be used as a topical mucosal adjuvant to enhance the immune check point inhibitor anti-cancer effect.

Natural Polysaccharides and Their Derivates: A Promising Natural Adjuvant for Tumor Immunotherapy

The treatment process of tumor is advanced with the development of immunotherapy. In clinical experience, immunotherapy has achieved very significant results. However, the application of immunotherapy is limited by a variety of immune microenvironment. For a long time in the past, polysaccharides such as lentinan and Ganoderma lucidum glycopeptide have been used in clinic as adjuvant drugs to widely improve the immunity of the body. However, their mechanism in tumor immunotherapy has not been deeply discussed. Studies have shown that natural polysaccharides can stimulate innate immunity by activating upstream immune cells so as to regulate adaptive immune pathways such as T cells and improve the effect of immunotherapy, suggesting that polysaccharides also have a promising future in cancer therapy. This review systematically discusses that polysaccharides can directly or indirectly activate macrophages, dendritic cells, natural killer cells etc., binding to their surface receptors, inducing PI3K/Akt, mitogen-activated protein kinase, Notch and other pathways, promote their proliferation and differentiation, increasing the secretion of cytokines, and improve the state of immune suppression. These results provide relevant basis for guiding polysaccharide to be used as adjuvants of cancer immunotherapy.

Evidence-Based Immunotherapeutic Effects of Herbal Compounds on Humoral Immunity: Ancient and New Approaches

The human immune system represents a dynamic multiscale system with high complexity in biology. Humoral immunity, as the main branch of adaptive immunity, is characterized by differentiated stages of the B lymphocytes, producing the final product of antibodies that has a diversity of the tuning mechanisms within genetic and epigenetic levels in confrontation with environmental exposures. Disorders because of disturbed humoral immunity are linked with dysregulation of feedback-regulated signaling and the dynamic of immune components that determine the overall response. Food products, mainly herbal components have a significant role in tailoring the immune system micro-ecosystem which can diversify the adaptive nature of humoral immunity. Herein, we review the current evidence-based approaches for the impact of medicinal herbs on humoral immunity signaling and antibody production with a focus on immunotherapeutic applications.

Structural Characterization and Immune Activity Screening of Polysaccharides With Different Molecular Weights From Astragali Radix

Saccharides are the most abundant substance with the strongest immunological activity in Astragali Radix (AR). However, systematic structure study and immunoactivity screening of polysaccharides with different molecular weights (Mw) in AR have yet to be conducted. In this study, Astragalus polysaccharides (APSs) were divided into three fragments of different Mw values, >2,000 kDa (APS-Ⅰ), about 10 kDa (APS-Ⅱ), and about 300 Da (APS-Ⅲ), by using ultrafiltration for the first time. The structural differences of the three products were determined on the basis of monosaccharide composition, FT-IR spectrum, linkage analysis, and nuclear magnetic resonance analysis. Cellular immune activity experiments in vitro and cyclophosphamide immunosuppression animal model experiments in vivo for nonspecific and specific immunoactivity screening were applied to identify the most immunogenic fragment in APSs. Linkage analysis results showed that APS-Ⅰ, APS-Ⅱ, and APS-Ⅲ have different attachment sites of monosaccharide residues. Immune screening experiments indicated that the Mw of the APSs influenced their activity, and APS-Ⅱ had the strongest immunoenhancing activity among the products. This research may serve as a reference for further study on APSs with different structures and immune activities, and as a guidance for the quality control of APSs and the development of new APS products.

Polysaccharide from Astragalus membranaceus promotes the activation of human peripheral blood and mouse spleen dendritic cells

Astragalus membranaceus (A. membranaceus) is a widely used traditional herb in China and Korea. A. membranaceus polysaccharides (AMP), which make up a major part of the root extract, have been shown to modulate immune modulations, especially activation of bone marrow-derived dendritic cells (BMDCs) and T cells. However, the immune stimulatory effect of AMP in the mouse in vivo and human peripheral blood DCs (PBDCs) has not been well investigated. In this study, we found that intravenous (i.v.) injection of AMP in C57BL/6 mice induced remarkable elevations in co-stimulatory and MHC class I and II molecule levels in the splenic DCs and its subsets. The stimulatory effect of DCs by AMP was elevated 6 h after treatment, which rapidly decreased 18 h after injection. Furthermore, AMP promoted intracellular production of pro-inflammatory cytokines in spleen DC subsets, which contributed elevation of serum cytokine levels. Finally, the AMP promoted PBDC activation. Thus, these results demonstrate that AMP can be used as an immune stimulatory molecules in human and mouse.

Application prospect of polysaccharides in the development of anti-novel coronavirus drugs and vaccines

Since the outbreak of the novel coronavirus disease COVID-19, caused by the SARS-CoV-2 virus, it has spread rapidly worldwide and poses a great threat to public health. This is the third serious coronavirus outbreak in <20 years, following SARS in 2002-2003 and MERS in 2012. So far, there are almost no specific clinically effective drugs and vaccines available for COVID-19. Polysaccharides with good safety, immune regulation and antiviral activity have broad application prospects in anti-virus, especially in anti-coronavirus applications. Here, we reviewed the antiviral mechanisms of some polysaccharides, such as glycosaminoglycans, marine polysaccharides, traditional Chinese medicine polysaccharides, and their application progress in anti-coronavirus. In particular, the application prospects of polysaccharide-based vaccine adjuvants, nanomaterials and drug delivery systems in the fight against novel coronavirus were also analyzed and summarized. Additionally, we speculate the possible mechanisms of polysaccharides anti-SARS-CoV-2, and propose the strategy of loading S or N protein from coronavirus onto polysaccharide capped gold nanoparticles vaccine for COVID-19 treatment. This review may provide a new approach for the development of COVID-19 therapeutic agents and vaccines.

Integrated metabolomics and network pharmacology approach to reveal immunomodulatory mechanisms of Yupingfeng granules

Systems biology is an approach that employs modern biological techniques and methods to combine the overall regulation of the body by Chinese herbal formulas with systems analysis at the molecular level. In this study, the underlying immunomodulatory mechanisms of yupingfeng granules (YPFG) were investigated based on the integration of metabolomics and network pharmacology methods. Selected routine peripheral blood indicators, body weight, and organ indices related to immunity were firstly measured in order to evaluate the effects of YPFG in cyclophosphamide-induced immunocompromised rats. Plasma metabolomics analyses were carried out by UPLC-Q-TOF-MS combined with a multivariate data analysis. Our study indicates that the potential regulatory mechanism was related to bile acid and glycerophospholipid metabolism, involving the regulation of 11 metabolites, including 8 bile acids, 1 phosphatidylserine, and 2 phosphatidylethanolamines. By means of network pharmacology, the compound-target network between potential active components of YPFG and immune dysregulation was constructed, which releated to estrogen receptor, PPAR, MAPK, PI3K-Akt, JNK signaling pathways, and ubiquitin-mediated protein degradation. The immunomodulatory effect of YPFG may be exerted through regulating lipid metabolism, then bile acid metabolism and inflammation were affected. Biological verification was also performed on cyclophosphamide-induced immunocompromised BALB/c mice. Flavonoid and saponin, two types of compounds in YPFG, were found to be the major active ingredients in the immunomodulatory effects of YPFG, and these components may regulate the abnormal metabolism of bile acids by enhancing the expression of FXR and LXRα. This work elucidated active ingredients, potential biomarkers, and mechanisms of action in the immunoregulatory effects of YPFG from the perspective of systems biology, which provides a scientific basis for its precise clinical medication.

Plant-Derived Nutraceuticals and Immune System Modulation: An Evidence-Based Overview

Immunomodulators are agents able to affect the immune system, by boosting the immune defences to improve the body reaction against infectious or exogenous injuries, or suppressing the abnormal immune response occurring in immune disorders. Moreover, immunoadjuvants can support immune system acting on nonimmune targets, thus improving the immune response. The modulation of inflammatory pathways and microbiome can also contribute to control the immune function. Some plant-based nutraceuticals have been studied as possible immunomodulating agents due to their multiple and pleiotropic effects. Being usually more tolerable than pharmacological treatments, their adjuvant contribution is approached as a desirable nutraceutical strategy. In the present review, the up to date knowledge about the immunomodulating properties of polysaccharides, fatty acids and labdane diterpenes have been analyzed, in order to give scientific basic and clinical evidence to support their practical use. Since promising evidence in preclinical studies, limited and sometimes confusing results have been highlighted in clinical trials, likely due to low methodological quality and lacking standardization. More investigations of high quality and specificity are required to describe in depth the usefulness of these plant-derived nutraceuticals in the immune system modulation, for health promoting and disease preventing purposes.

Astragali Radix (Huangqi): A promising edible immunomodulatory herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Astragali Radix (AR, Huangqi in Chinese), the dried root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao or A. membranaceus (Fisch.) Bge., possesses diverse therapeutic effects against fatigue, dyspepsia, diarrhea, heart diseases, hepatitis, and anemia. In recent years, increasing evidence has indicated the multiple immunomodulatory activities of AR in preclinical and clinical studies.

AIM OF THE REVIEW

This review attempts to elaborate the immunomodulatory effects of AR and its potential application in the treatment of immune related diseases.

MATERIALS AND METHODS

A comprehensive literature search AR was carried out using multiple internationally recognized databases (including Web of Science, Google Scholar, PubMed, ScienceDirect, Wiley, ACS, Springer, Taylor & Francis, and CNKI).

RESULTS

The immunomodulatory effects of AR are closely attributed to its active constituents such as polysaccharides, saponins, and flavonoids. We also demonstrate that AR can be used as a potential therapeutic intervention for immune related diseases through regulating immune organs, mucosal immune, and immune system (innate immunity and acquired immunity).

CONCLUSION

AR promotes the development of immune organs, enhances mucosal immune function, increases the quantity and phagocytic capacity of innate immunity, promotes the maturation and differentiation of acquired immunity cells, and improves the expression of antibodies in acquired immunity. We believe that AR has a broad research space in the adjuvant treatment of immune related diseases, which could be a breakthrough point to improve the application value of AR.

Overall quality control of the chemical and bioactive consistency of ShengMai Formula

ShengMai Formula (SMF), a famous traditional Chinese medicine (TCM) formula, has been extensively used for treating the diseases caused by Qi-Yin deficiency for almost 1000 years. However, few studies are elucidated about its batch-to-batch quality control system and the quality control markers remain largely unrevealed, which have hindered the development and utilization of SMF. In this study, we aimed to screen the optimal quality control markers to evaluate the overall quality consistency of SMF. High-performance liquid chromatography (HPLC) fingerprint coupled with similarity analysis (SA), principal components analysis (PCA) and hierarchical cluster analysis (HCA) was firstly established to hunt for the discriminant components that resulting in the chemical inconsistence among different batches of SMF. Subsequently, different batches of samples were selected to explore their immunomodulatory activities by neutral red method, Cell Counting Kit-8 (CCK-8) assay and enzyme-linked immunosorbent assay (ELISA). Finally, the fingerprint-efficacy relationships were further illuminated to discover the major bioactive compositions using grey relational analysis (GRA), partial least squares regression (PLSR) analysis and artificial neural network (ANN) analysis. As a result, schisandrol A, schisandrol B, methylophiopogonanone A, schisandrin B, ginsenoside Rf, ginsenoside Rb1, ginsenoside Rg2 and ginsenoside Rb2 were selected as the quality control markers and thus their simultaneous quantification was performed to both evaluate the batch-to-batch chemical and bioactive consistency among different batches of SMF. Our investigation not only stresses the necessity of consistency in efficacy besides chemical consistency, but also provides a comprehensive and powerful quality assessment approach, which is promising to monitor the overall quality consistency of SMF.

A New Method for Screening Natural Products to Stimulate IFN-γ Production in Jurkat Human T Lymphocytes

Interferon-γ (IFN-γ) is a critical cytokine in the defense against viral and bacterial infection. It is mainly produced by natural killer cells and activated T cells. Given its regulatory role in coordinating cellular and humoral immune responses, IFN-γ is considered to be an effective therapeutic agent in the treatment of viral infection. Here we established a fluorescence-based high-content screening model to find small molecules that can stimulate the production of IFN-γ in human Jurkat cells. After a primary screening of 267 natural products, two hits, Astragalus polyphenols and 6-shogaol, were identified to promote the activity of the IFN-γ promoter and subsequently validated by the flow cytometry assay. Obviously, both Astragalus polyphenols and 6-shogaol exhibited potential to induce the transcription and expression of IFN-γ in a dose-dependent manner. These results indicated that our high-content screening model could be a credible and useful platform to contribute to the discovery of novel molecules to promote the expression of IFN-γ and provide leading compounds for the treatment of viral infectious diseases.

A Potential Herbal Adjuvant Combined With a Peptide-Based Vaccine Acts Against HPV-Related Tumors Through Enhancing Effector and Memory T-Cell Immune Responses

Viral infection is associated with many types of tumorigenesis, including human papillomavirus (HPV)-induced cervical cancer. The induction of a specific T-cell response against virus-infected cells is desired to develop an efficient therapeutic approach for virus-associated cancer. Chinese herbal medicine (CHM) has a long history in the treatment of cancer patients in Asian countries. Hedyotis diffusa Willd (Bai Hua She She Cao, BHSSC) is frequently used clinically and has been shown to inhibit tumor growth in vitro. However, in vivo data demonstrating the antitumor efficacy of BHSSC are still lacking. We showed that BHSSC induces murine and human antigen-presenting cell (APC) activation via the MAPK signaling pathway and enhances antigen presentation in bone marrow-derived dendritic cells (BMDCs) in vitro. Furthermore, we identified that treatment with BHSSC leads to improved specific effector and memory T-cell responses in vivo. Variant peptide-based vaccines combined with BHSSC improved antitumor activity in preventive, therapeutic, and recurrent HPV-related tumor models. Furthermore, we showed that rutin, one of the ingredients in BHSSC, induces a strong specific immune response against HPV-related tumors in vivo. In summary, we demonstrated that BHSSC extract and its active compound, rutin, can be used as adjuvants in peptide-based vaccines to increase immunogenicity and to bypass the requirement of a conditional adjuvant.

Immune effect of Vibrio harveyi formalin-killed cells vaccine combined with chitosan oligosaccharide and astragalus polysaccharides in ♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus

Vibrio harveyi is the pathogen causing vibriosis in marine-cultured animals, leading to massive deaths in farmed grouper around the world. It is urgent to develop an effective vaccine to prevent vibriosis. In the previous study, we developed a V. harveyi formalin-killed cells vaccine (FKC), and sought an effective adjuvant for enhancing the immune efficacy of vaccine. In this study, we aimed to evaluate the immune responses and protective effect of FKC combined with chitosan oligosaccharide (COS) or Astragalus polysaccharides (APS) in the pearl gentian grouper♀Epinephelus fuscoguttatus × ♂E. lanceolatus. The results indicated the vaccine triggered a remarkably higher expression levels of IL-1β, IL-16, TNF-α, MHC-Iα and IgM in the kidney and spleen of groupers post-vaccination. Antibody titers, lysozyme, catalase, superoxide dismutase and total protein were significantly elevated in the vaccinated fish compared with those in the control. The experimental groupers were challenged intraperitoneally by V. harveyi at 35 d post-vaccination, and the relative percentage of survival (RPS) of group FKC + COS, FKC + APS, COS, APS and FKC were 80%, 72%, 52%, 47% and 55%, respectively. These results demonstrated COS and APS was the potential adjuvants for FKC against V. harveyi in aquaculture.

The immunostimulatory activity of polysaccharides from Glycyrrhiza uralensis

Background

The enhancement of immunity is very important for immunocompromised patients such as cancer patients with radiotherapy or chemotherapy. Glycyrrhiza uralensis has been used as food and medicine for a long history. G. uralensis polysaccharides (GUPS) were prepared and its immunostimulatory effects were investigated.

Methods

Human monocyte-derived dendritic cells (DCs) and murine bone marrow-derived DCs were treated with different concentrations of GUPS. The DCs maturation and cytokine production were analyzed by flow cytometry and ELISA, respectively. Inhibitors and Western blot were used to study the mechanism of GUPS. The immunostimulatory effects of GUPS were further evaluated by naïve mouse model and immunosuppressive mouse model induced by cyclophosphamide.

Results

GUPS significantly promoted the maturation and cytokine secretion of human monocyte-derived DCs and murine bone marrow-derived DCs through TLR4 and down-stream p38, JNK and NF-κB signaling pathways. Interestingly, the migration of GUPS treated-DCs to lymph node was increased. In the mouse model, GUPS increased IL-12 production in sera but not for TNF-α. Moreover, GUPS ameliorated the side effect of cyclophosphamide and improved the immunity of immunosuppressive mice induced by cyclophosphamide. These results suggested that GUPS might be used for cancer therapy to ameliorate the side effect of chemotherapy and enhance the immunity.

Effects of the stems and leaves of Astragalus membranaceus on growth performance, immunological parameters, antioxidant status, and intestinal bacteria of quail

This study was designed to evaluate the potential application of the stems and leaves of Astragalus membranaceus (AMSL) in the poultry industry. Quails were divided into four groups and fed daily with an AMSL-free diet (control) or with 1%, 3%, or 5% (w/w) AMSL-incorporated diets for 35 days. The results showed that supplementing AMSL in the diet, especially at a concentration of 3%, increased daily gain and feed intake during the entire experiment (p < 0.05). The immune organ development of the thymus and bursa of Fabricius was promoted, and the immune system was enhanced by increasing the quantities of IgA and complements C3 and C4 (p < 0.05). The total antioxidant capacity and the activities of glutathione peroxidase and catalase were increased (p < 0.05). Moreover, the 3%-5% AMSL groups regulated the intestinal flora by promoting the proliferation of lactic acid bacteria and inhibiting the growth of coliform bacteria (p < 0.05). In conclusion, feeding incorporated diets with appropriate AMSL levels significantly increased growth performance, strengthened the immune system, improved antioxidative status, and regulated the intestinal microflora of quails, suggesting that AMSL has the potential to serve as a feed additive in the poultry industry.