Research Progress of Polysaccharide-Gold Nanocomplexes in Drug Delivery.

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drug's effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Antigen cross-presentation in dendric cells: From bench to bedside.

Cross-presentation (XPT) is an adaptation of the cellular process in which dendritic cells (DCs) present exogenous antigens on major histocompatibility complex (MHC) class I molecules for recognition of the cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, resulting in immunity or tolerance. Recent advances in DCs have broadened our understanding of the underlying mechanisms of XPT and strengthened their application in tumor immunotherapy. In this review, we summarized the known mechanisms of XPT, including the receptor-mediated internalization of exogenous antigens, endosome escape, engagement of the other XPT-related proteins, and adjuvants, which significantly enhance the XPT capacity of DCs. Consequently, various strategies to enhance XPT can be adopted and optimized to improve outcomes of DC-based therapy.

Dendritic cell-based vaccine prepared with recombinant Lactococcus lactis enhances antigen cross-presentation and antitumor efficacy through ROS production.

Introduction: Lactococcus lactis (L.L) is safe and can be used as vehicle. In this study, the immunoregulatory effect of L.L on dendritic cell (DC) activation and mechanism were investigated. The immune responses and antigen cross-presentation mechanism of DC-based vaccine prepared with OVA recombinant L.L were explored. Methods: Confocal microscopy and flow cytometry were used to analyze the mechanism of L.L promoting DC maturation, phagosome membrane rupture and antigen presentation. The antitumor effect of DC vaccine prepared with L.L-OVA was assessed in the B16-OVA tumor mouse model. Results: L.L significantly promoted DC maturation, which was partially dependent on TLR2 and downstream MAPK and NF-κB signaling pathways. L.L was internalized into DCs by endocytosis and did not co-localized with lysosome. OVA recombinant L.L enhanced antigen cross-presentation of DCs through the phagosome-to-cytosol pathway in a reactive oxygen species (ROS)- and proteasome-dependent manner. In mouse experiments, L.L increased the migration of DCs to draining lymph node and DC vaccine prepared with OVA recombinant L.L induced strong antigen-specific Th1 and cytotoxic T lymphocyte responses, which significantly inhibited B16-OVA tumor growth. Conclusion: This study demonstrated that recombinant L.L as an antigen delivery system prepared DC vaccine can enhance the antigen cross-presentation and antitumor efficacy.

Evaluation and mechanism of immune enhancement effects of Pleurotus ferulae polysaccharides-gold nanoparticles.

We previously demonstrated that Pleurotus ferulae polysaccharide (PFPS) promoted dendritic cell (DC) maturation through the TLR4 signaling pathway. To improve PFPS activity and bioavailability, gold nanoparticles with PFPS (PFPS-Au NPs) were synthesized. Of note, although the polysaccharide content of PFPS-Au NPs was only one tenth of PFPS, PFPS-Au NPs enhanced the immunostimulatory activities of PFPS in the maturation and function of dendritic cells (DCs) by TLR4 and NLRP3 signaling pathways, evidenced by stronger activation of the down-stream MAPK and NF-κB pathways and NLRP3 inflammasome pathway. More importantly, PFPS-Au NPs enhanced DC migration and murine immunity, particularly in type 1 T-helper cell responses. Moreover, the half-life of PFPS-Au NPs (2.217 ± 0.187 h) was longer than that of PFPS (1.39 ± 0.257 h) in the blood and the distribution of PFPS-Au NPs (19.8 %) in the spleen was significantly increased compared with PFPS (13.3 %), indicating the improved bioavailability in vivo. PFPS-Au NPs as an adjuvant promoted antigen-specific cellular immune responses to an HPV DC-based vaccine, which significantly inhibited the growth of TC-1 tumors in mice. All results suggest that the prepared Au NPs could enhance PFPS-immunostimulatory activity, which will pave the way for PFPS-Au NPs to be applied in clinical trials.

Research progress in the application of CRISPR/Cas9 technology in the treatment of cervical cancer / 国际生物医学工程杂志

Cervical cancer is the fourth-ranked malignant tumor of female cancer in the world, and it seriously threatens women’s health. The main treatment options for patients with cervical cancer are surgery or concurrent chemoradiotherapy. With the development of medical research, researchers are committed to exploring more effective and specific treatment options in order to increase the treatment options for cervical cancer and improve the treatment effect. Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) technology is a method in which the Cas9 protein uses guide RNA (gRNA) to target the target gene and achieve precise editing of the target gene. At present, CRISPR/Cas9 technology has become a promising and powerful gene editing tool, a new and effective targeted therapy that has been applied in the treatment of various tumors. The research progress of CRISPR/Cas9 technology in the treatment of cervical cancer is mainly reviewed in terms of action targets, combination therapy strategies, and related drug resistance gene screening in order to provide new strategies for the treatment of cervical cancer.

In Vitro and In Vivo Dendritic Cell Immune Stimulation Effect of Low Molecular Weight Fucoidan from New Zealand Undaria pinnatifida.

Low molecular weight fucoidan (LMWF) has been reported to have immunomodulation effects through the increase of the activation and function of macrophages. In this study, the regulating effect of LMWF from Undaria pinnatifida grown in New Zealand on dendritic cells (DCs) was investigated. We discovered that LMWF could stimulate DCs' maturation and migration, as well as CD4+ and CD8+ T cells' proliferation in vitro. We proved that this immune promoting activity is activated through TLR4 and its downstream MAPK and NF-κB signaling pathways. Further in vivo (mouse model) investigation showed that LMWF has a strong immunological boosting effect, such as facilitating the proliferation of immune cells and increasing the index of immune organs. These findings suggest that LMWF has a positive immunomodulatory effect and is a promising candidate to supplement cancer immunotherapy.

Progress in microRNA/lncRNA regulating dendritic cell differentiation, maturation and function / 中华微生物学和免疫学杂志

Dendritic cells (DC) as professional antigen-presenting cells can activate na?ve T cells and play an important role in bridging innate immunity and acquired immunity. Therefore, the differentiation and maturation of DC and the mechanism in its function regulatory have attracted much attention. With the rapid development of high-throughput sequencing, noncoding RNAs (ncRNAs) have been gradually known. In recent years, increasing studies have reported that ncRNAs play an importantly role in regulating the differentiation and maturation of DC. In this paper, the regulatory effects of microRNAs and long ncRNAs on the differentiation, maturation and function of DC were reviewed.

Glycyrrhiza uralensis ethanol extract inhibits dendritic cell maturation and ameliorates asthma / 国际生物医学工程杂志

Objective:To investigate the immunoregulatory effects of Glycyrrhiza uralensis ethanol extract(GUEE) on the maturation of dendritic cells (DCs) and the adjuvant effect of GUEE on OVA in na?ve BALB/c mice and an ovalbumin (OVA)-induced asthma mouse model. Methods:GUEE was prepared, and the effects of different concentrations of GUEE on the maturation of DCs and the secreted cytokines as well as the effects of GUEE on bacterial lipopolysaccharide (LPS)-induced DC maturation were examined in vitro. The effect of GUEE on the morphology of mouse bone marrow derived DCs was observed using microscopy. Molecular expression levels on the surface of DCs were detected using flow cytometry. The levels of interleukin-1β (IL-1β), IL-6, IL-12, and tumor necrosis factor-α (TNF-α) in the supernatant of DCs cultures were measured by enzyme-linked immunosorbent assay (ELISA). The maturation status of DCs was detected by flow cytometry by injecting different concentrations of GUEE into the paws of mice and isolating the draining lymph nodes 24 h later. The naive BALB/c mice were co-immunized with OVA, and the changes in regulatory T cells (Treg) were detected by flow cytometry. An OVA-protein-induced mouse asthma model was established to investigate whether GUEE as a tolerogenic adjuvant has an antigen-specific therapeutic effect on asthmatic mice. Pulmonary pathological changes were analyzed by hematoxylin-eosin staining (HE) and PAS staining. OVA-specific antibodies in serum and the frequencies of Tregs, CD4 + IFN-γ + and CD4 + IL-4 + T cells in the spleen were detected by ELISA and flow cytometry, respectively. Results:GUEE suppressed DCs maturation induced by LPS both in vitro and in vivo (all P<0.05), and reduced proinflammatory cytokine production, including IL-1β, IL-6, IL-12 and TNF-α in the absence or presence of LPS (all P<0.05). Moreover, co-immunization with OVA and GUEE increased the amount of Tregs in na?ve BALB/c mice ( P<0.05). In OVA-induced asthmatic mice, OVA and GUEE co-immunization and GUEE alone treatment substantially ameliorated the inflammation of lung tissues, decreased the levels of IgG 1 and the amount of CD4 + IL-4 + T cells, and increased the amount of Tregs (all P<0.05). Conclusions:GUEE alone or as the tolerogenic adjuvant can ameliorate allergic diseases through inhibition of DC maturation and type 2 helper T cell responses and induction of Tregs.

Research progress in antitumor and immunoregulation of fucoidan / 国际生物医学工程杂志

Fucoidan is a kind of sulfated polysaccharide with various biological activities that mainly exists in the cell walls of brown algae. It is also found in marine invertebrates such as sea cucumbers and sea urchins. Fucoidan has received a lot of attention due to its tumor-killing and immune-boosting properties. Moreover, the combination of fucoidan with chemotherapeutic drugs not only improves antitumor efficacy but also reduces the side effects of these drugs. The function of fucoidan is closely correlated with its structure, molecular weight, degree of sulfation, monosaccharide component, algae source, and time of collection. In this review, the antitumor and immunomodulatory effects of fucoidan are reviewed from the aspects of promoting cell apoptosis, inducing cell cycle arrest, inhibiting angiogenesis and cell migration, and activating immune cells, to provide theoretical guidance for the development and clinical application of fucoidan.

Marchantia polymorpha L. ethanol extract induces apoptosis in hepatocellular carcinoma cells via intrinsic- and endoplasmic reticulum stress-associated pathways.

BACKGROUND: Marchantia polymorpha L. is a kind of Chinese herbal medicine and has various biological activities including antioxidant and antifungal. However, it is not clear about the antitumor effect and mechanism of M. polymorpha. We prepared M. polymorpha ethanol extract (MPEE) and investigated its antitumor effect on hepatocellular carcinoma cells both in vitro and in vivo. METHODS: The viability of hepatocellular carcinoma cells was detected by MTT assay. The distribution of cell cycle was analyzed by propidium iodide (PI) staining. The morphology of nuclei was observed by Hoechst 33258 staining. Apoptosis was detected by Annexin V/PI staining. JC-1 fluorescent probe and DCFH-DA were used to detect the mitochondrial membrane potential (ΔψM) and the level of reactive oxygen species (ROS), respectively. Caspase inhibitors were used to test the function of caspase in the induction of apoptosis. Quantitative real time polymerase chain reaction (qRT-PCR) and Western blot were used to evaluate the levels of mRNA and protein, respectively. Differentially expressed genes and signaling pathways were identified by transcriptome analysis. The H22 tumor mouse model was used to detect the antitumor effect of the extract. RESULTS: MPEE significantly suppressed the migration and growth of BEL-7404, HepG2 and H22 cells in a dose- and time-dependent manner through induction of apoptosis characterized by chromosomal condensation and cell cycle arrest at G0/G1 and G2/M phases. MPEE induced mitochondria-dependent apoptosis via upregulation of Bax and downregulation of Bcl-2 to reduce mitochondrial membrane potential and increase the release of cytochrome c. The levels of cleaved caspase-8 and -9 were significantly increased, which sequentially activated caspase-3 to cleave PARP. We further found that MPEE significantly increased ROS production and activated endoplasmic reticulum (ER) stress associated-apoptotic signaling pathway. Moreover, MPEE significantly inhibited H22 tumor growth in mouse model and improved the survival of tumor mice. CONCLUSION: These results suggested that MPEE suppressed hepatocellular carcinoma cell growth through induction of apoptosis via intrinsic- and ER stress-associated pathways.

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.

Preparation, Characterization, and Immuno-Enhancing Activity of Polysaccharides from Glycyrrhiza uralensis.

Glycyrrhiza uralensis is a Chinese herbal medicine with various bioactivities. Three fractions (GUPS-I, GUPS-II and GUPS-III) of G. uralensis polysaccharides (GUPS) were obtained with molecular weights of 1.06, 29.1, and 14.9 kDa, respectively. The monosaccharide compositions of GUPS-II and GUPS-III were similar, while that of GUPS-I was distinctively different. The results of scanning electron microscopy, FT-IR, and NMR suggested that GUPS-II and GUPS-III were flaky with a smooth surface and contained α- and ß-glycosidic linkages, while GUPS-I was granulated and contained only α-glycosidic linkages. Moreover, GUPS-II and GUPS-III exhibited better bioactivities on the maturation and cytokine production of dendritic cells (DCs) in vitro than that of GUPS-I. An in vivo experiment showed that only GUPS-II significantly enhanced the maturation of DCs. These results indicate that GUPS-II has the potential to be used in combination with cancer immunotherapy to enhance the therapeutic effect.

Cistanche tubulosa phenylethanoid glycosides induce apoptosis in Eca-109 cells via the mitochondria-dependent pathway.

Cistanche tubulosa has various biological functions. In the present study, the antitumor effect of water-soluble phenylethanoid glycosides of C. tubulosa (CTPG-W) on esophageal cancer was investigated. Eca-109 cells were treated with CTPG-W and the cell viability was measured by MTT assay. The apoptosis, cell cycle, mitochondrial membrane potential (Δψm) and reactive oxygen species were analyzed by flow cytometry. The levels of proteins in apoptotic pathways were detected by western blot analysis. It was determined that CTPG-W significantly reduced the viability of Eca-109 cells through the induction of apoptosis and cell cycle arrest. Following CTPG-W treatment, the Δψm of Eca-109 was notably decreased, which is associated with the upregulated levels of B-cell lymphoma-2 (Bcl-2)-associated X and downregulated levels of Bcl-2. Consequently, the levels of cytochrome c and c-Jun NH2-terminal kinase were increased, which upregulated the levels of cleaved-poly (ADP-ribose) polymerase and cleaved-caspase-3, -7 and -9, but not caspase-8. Correspondingly, the levels of reactive oxygen species in Eca-109 cells demonstrated notable changes. These results indicated that CTPG-W induced apoptosis of Eca-109 cells through a mitochondrial-dependent pathway.

Pleurotus ferulae polysaccharides improve the antitumor efficacy of therapeutic human papillomavirus dendritic cell-based vaccine.

We previously found that Pleurotus ferulae polysaccharides (PFPS) improved the maturation and function of dendritic cells (DCs). In this study, we investigated the effects of PFPS on the antitumor efficacy of therapeutic human papillomavirus (HPV) DC-based vaccine. PFPS stimulated DCs pulsed with HPV E6/E7 peptides were used to treat tumor mice on day 5 & 12 (HPV + PFPS-DCs early) and day 12 & 19 (HPV + PFPS-DCs late) after TC-1 cell injection. Compared to control group, both HPV + PFPS-DCs early and HPV + PFPS-DCs late strategies significantly inhibited tumor growth, which was significantly correlated with the increased activation status of both CD4+ and CD8+ T cells, the decreased frequencies of myeloid-derived suppressor cells, and the induction of HPV-specific CD8+ T cell responses. The survival of tumor mice was also greatly improved by HPV + PFPS-DCs early. Moreover, HPV + PFPS-DCs early completely inhibited the growth of second challenged TC-1 cells in tumor free mice. The results showed that PFPS improved the antitumor efficacy of therapeutic HPV DC-based vaccine, suggesting that PFPS might be a potential adjuvant for DC-based vaccines. This study provides a potential strategy for developing the therapeutic DC-based vaccine against cervical cancer.

Cistanche tubulosa phenylethanoid glycosides induce apoptosis in H22 hepatocellular carcinoma cells through both extrinsic and intrinsic signaling pathways.

BACKGROUND: Cistanche tubulosa (Schenk) R. Wight is a traditional Chinese medicine that parasitizes the roots of the Tamarix plant and has been used to treat male impotence, sterility, body weakness, and as a tonic. However, its antitumor effect on hepatocellular carcinoma is still elusive. Here, we investigated the antitumor effect of C. tubulosa phenylethanoid glycosides (CTPG) on H22 hepatocellular carcinoma cells both in vitro and in vivo and its mechanisms. METHODS: The morphology, viability, apoptosis, cell cycle and mitochondrial membrane potential (Δψm) of H22 cells were analyzed by inverted microscopy, MTT assay and flow cytometry, respectively. The expression and activation of proteins in apoptosis pathway were detected by Western blot. The in vivo antitumor effect was evaluated in tumor mouse model established using male Kunming mice. RESULTS: CTPG treatment significantly suppressed H22 cell growth in a dose- and time-dependent manner, which was correlated with the increased apoptosis and cell cycle arrest at G0/G1 and G2/M phases. Moreover, the chromosomal condensation was observed in CTPG-treated H22 cells. CTPG treatment significantly increased Bax/Bcl-2 ratio, reduced Δψm and enhanced the release of cytochrome c. The levels of cleaved caspase-8 and caspase-9 in both extrinsic and intrinsic signaling pathways were significantly increased that sequentially activated caspase-7 and -3 to cleave PARP. Finally, CTPG inhibited the growth of H22 cells in mice and improved the survival rate of tumor mice. CONCLUSIONS: These results suggested that CTPG suppressed H22 cell growth through both extrinsic and intrinsic apoptosis pathways.

N-Butanol Subfraction of Brassica Rapa L. Promotes Reactive Oxygen Species Production and Induces Apoptosis of A549 Lung Adenocarcinoma Cells via Mitochondria-Dependent Pathway.

Brassica rapa L., an edible and medical vegetable, has been traditionally used in Uyghur folk medicine to treat coughs and asthma in the Xinjiang Uygur Autonomous Region, China. In this study, we prepared an n-butanol subfraction of B. rapa L. (BRBS) and investigated the anti-tumor effect on A549 lung adenocarcinoma cells. The proliferation of A549 cells was significantly inhibited by BRBS treatment in a dose- and time-dependent manner. BRBS significantly induced cell cycle arrest and apoptosis in A549 cells through increased reactive oxygen species (ROS) production and mitochondrial dysfunction characterized by a reduction in mitochondrial membrane potential and the release of cytochrome c, which promoted caspase-3 and poly(ADP-ribose) polymerase processing. Moreover, BRBS significantly suppressed the migration of A549 cells in vitro. These results suggest that BRBS inhibited A549 cell proliferation through increased ROS production and the mitochondria-dependent apoptosis pathway. Consequently, BRBS might be a potential candidate for the treatment of lung cancer.

Enhanced contraception of canine zona pellucida 3 DNA vaccine via targeting DEC-205 in mice.

Zona pellucida 3 (ZP3) is a potential antigen for the development of contraceptive vaccines to control animal population. In this study, we designed a canine ZP3 (CZP3) DNA vaccine through targeting DEC-205 (named as pcD-scFv-CZP3c) and investigated its contraceptive effect in mice. Female BALB/c mice were intramuscularly immunized 3 times at 2 weeks intervals. After immunization, humoral and cellular immune responses were detected by ELISA and flow cytometry. The results showed that pcD-CZP3 and pcD-scFv-CZP3c induced CZP3-specific antibody (Ab) responses both in serum and vaginal secretions compared to pcDNA3.1. Additionally, compared to pcD-CZP3, pcD-scFv-CZP3c increased the levels of CZP3-specific Abs after a third immunization. Abs induced by these two DNA vaccines could bind with mice and dogs oocytes. Moreover, pcD-scFv-CZP3c enhanced the activation of CD4+ T cells characterized by the increased frequencies of CD4+CD44+ T cells. Finally, the contraceptive effect was evaluated in the immunized mice. These two DNA vaccines significantly decreased a mean litter size of mice compared to pcDNA3.1, but pcD-scFv-CZP3c group showed the smallest mean litter size. The mean litter size of pcD-scFv-CZP3 were 3.2 ±â€¯0.742 and 4.6 ±â€¯1.118 in two mating tests, which were significantly lower than pcDNA3.1(P < 0.001 and P < 0.05). Our results suggest that the CZP3 DNA vaccine targeted with DEC-205 may be a potential strategy for developing a contraceptive DNA vaccine.

Effects of crude extract of Capparis spinosa L. fruit alkaloids on the maturation of murine dendritic cells / 中华微生物学和免疫学杂志

Objective To investigate the effects of crude extract of Capparis spinosa L. fruit alka-loids (CSFA) on the maturation of murine bone marrow-derived dendritic cells (DCs). Methods CSFA was prepared and the contents were determined by high performance liquid chromatography. DCs were trea-ted with different doses (1, 2, 3 mg/ml) of CSFA. The viability of DCs, the expression of surface mole-cules and the ability of phagocytosis were detected by flow cytometry. The secretion of cytokines was meas-ured by ELISA. Western blot assay was performed to analyze the activation of key molecules in mitogen-acti-vated protein kinases ( MAPK) and nuclear factor-kappa B ( NF-κB) signaling pathways. Results The re-sults showed that CSFA alone had no significant influence on the expression of surface molecules and cyto-kines in DCs. However, it significantly decreased the expression of CD40, CD80, CD86 and MHC Ⅱ as well as the secretion of IL-12p40 and TNF-αthat were induced by lipopolysaccharides (LPS), but increased IL-10 secretion and the ability of phagocytosis after treating DCs with both CSFA and LPS. Further, the phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) and the nuclear translocation of NF-κBp65 induced by LPS were inhibited by CSFA. Conclusion CSFA could inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines induced by LPS while in-creasing the secretion of the anti-inflammatory cytokine IL-10 and the ability of phagocytosis, which might in-volve MAPK and NF-κB signaling pathways. This study suggests that CSFA could be used as a potential im-munosuppressant.

Purification, characterization and bioactivities of polysaccharides from Pleurotus ferulae.

Pleurotus ferulae is an edible mushroom and has been used in Uygur medicine for a long time. In this study, we purified polysaccharides from P. ferulae (PFPS) and investigated its structural characteristics. We obtained a homogeneous PFPS with a molecular weight of around 1600 kDa and prominent characteristic polysaccharide groups, which mainly contained glucose (97%), followed by mannose and galactose (3%). Both 1H and 13C NMR spectra indicated that PFPS contained both α- and ß-anomeric configurations. Atomic force microscopy and Congo red-staining data further suggested that PFPS belonged to a linear branched structure that existed in flexible single chains at low concentrations and could form aggregates such as a triple-helical structure at high concentrations. Moreover, PFPS promoted the maturation of dendritic cells through a TLR4 mediated signaling pathway, which is characterized by the increased expressions of CD40, CD86, IL-12 and TNF-α and the decreased endocytosis. The results suggest that PFPS has immunoregulatory activities.

λ-Carrageenan improves the antitumor effect of dendritic cellbased vaccine.

In this study, we investigated the effect of λ-carrageenan on the maturation and function of dendritic cells (DCs) and its adjuvant effect on DC-based vaccine. We found that λ-carrageenan dose-dependently decreased the endocytosis of DCs, promoted DC maturation and increased cytokine production through TLR4 mediated signaling pathway. λ-carrageenan treatment also enhanced the ability of DCs in the stimulating allogenic splenocyte proliferation. In TC-1 tumor mouse model, HPV peptides pulsed λ-carrageenan-DC (HPV-CGN-DC) significantly inhibited tumor growth compared with control group. The frequencies of CD4+ and CD8+ T cells in spleens of tumor mice and their activation status were significantly increased in HPV-CGN-DC group, but the frequencies of natural regulatory T cells and CD11b+Gr-1+ cells were significantly decreased. Further, HPV-CGN-DC induced strong CD8+ T cell responses, which are negatively correlated with tumor volumes. The results suggested that λ-carrageenan promoted DC maturation through TLR4 signaling pathway and could be used as the adjuvant in DC-based vaccines.