Yeast Shells Encapsulating Adjuvant AS04 as an Antigen Delivery System for a Novel Vaccine against Toxoplasma Gondii.

Toxoplasma gondii (T. gondii) infection causes severe zoonotic toxoplasmosis, which threatens the safety of almost one-third of the human population globally. However, there is no effective protective vaccine against human toxoplasmosis. This necessitates anti-T. gondii vaccine development, which is a main priority of public health. In this study, we optimized the adjuvant system 04 (AS04), a vaccine adjuvant constituted by 3-O-desacyl-4'-monophosphoryl lipid A (a TLR4 agonist) and aluminum salts, by packing it within natural extracts of ß-glucan particles (GPs) from Saccharomyces cerevisiae to form a GP-AS04 hybrid adjuvant system. Through a simple mixing procedure, we loaded GP-AS04 particles with the total extract (TE) of T. gondii lysate, forming a novel anti-T. gondii vaccine GP-AS04-TE. Results indicated that the hybrid adjuvant can efficiently and stably load antigens, mediate antigen delivery, facilitate the dendritic uptake of antigens, boost dendritic cell maturation and stimulation, and increase the secretion of pro-inflammatory cytokines. In the mouse inoculation model, GP-AS04-TE significantly stimulated the function of dendritic cells, induced a very strong TE-specific humoral and cellular immune response, and finally showed a strong and effective protection against toxoplasma chronic and acute infections. This work proves the potential of GP-AS04 for exploitation as a vaccine against a range of pathogens.

Structural elucidation, antioxidant and immunomodulatory activities of a novel heteropolysaccharide from cultured Paecilomyces cicadae (Miquel.) Samson.

The fine structure and chain conformation of a heteropolysaccharide (PCIPS3) from mycelium of Paecilomyces cicadae were investigated via the analysis of HPLC, IR, methylation, NMR spectroscopy and multiangle light scattering. It was determined to be a 2.23 × 104 g/mol heteropolysaccharide primarily composed of glucose, galactose and mannose in a molar ratio of 23.8:2.1:1.0. The PCIPS3 backbone consisted of 1,4-linked α-d-Glcp and 1,4-linked 6-O-Me-α-d-Glcp residues, which were occasionally interrupted by branched ß-Galf residues through 1,6-linkage. Moreover, the α (0.60) from Mark-Houwink-Sakurada (MHS) equation suggested that PCIPS3 adopted a flexible chain conformation in 0.1 mol/L NaNO3 at 25 °C. The worm-like chains model parameters for PCIPS3 were estimated as following: ML = 437 nm-1, q = 0.46 nm and 0.79 nm, which were further evidenced by AFM. Furthermore, PCIPS3 showed excellent scavenging capacities of 2,2-diphenyl-1-picrylhydrazyl radical, superoxide radical, hydroxyl radical, ORAC radical and moderate immunomodulatory activity.

Safety Assessment of Microbial Polysaccharide Gums as Used in Cosmetics.

The Cosmetic Ingredient Review Expert Panel assessed the safety of 34 microbial polysaccharide gums for use in cosmetics, finding that these ingredients are safe in cosmetic formulations in the present practices of use and concentration. The microbial polysaccharide gums named in this report have a variety of reported functions in cosmetics, including emulsion stabilizer, film former, binder, viscosity-increasing agent, and skin-conditioning agent. The Panel reviewed available animal and clinical data in making its determination of safety.

Toxicology and immunology of Ganoderma lucidum polysaccharides in Kunming mice and Wistar rats.

In the present work, the toxicology and immunology of polysaccharides from fruiting body of Ganoderma lucidum (GPs) were investigated. No abnormal clinical-symptoms or deaths and no significant difference in body weight and food in-taking rate were found in Wistar rats during the 30-day feeding administration. No significant differences were found in each hematology value, clinical chemistry value and organ/body weight ratio, either. It had no mutagenicity due to the negative experimental results of Ames test, micronucleus test of polychromatic erythrocyte, sperm abnormality test, and chromosome aberration test in Kunming mice, respectively. The immune experiments indicated that high-dose GPs had immune effects in increasing the degree of toe swelling and enhancing the primary immune response to SRBC (P<0.01). But no-significant influence of GPs on the phagocytic function of mononuclear macrophages (MΦ) could be obtained.

A polysaccharide virulence factor of a human fungal pathogen induces neutrophil apoptosis via NK cells.

Aspergillus fumigatus is an opportunistic human fungal pathogen that sheds galactosaminogalactan (GG) into the environment. Polymorphonuclear neutrophils (PMNs) and NK cells are both part of the first line of defense against pathogens. We recently reported that GG induces PMN apoptosis. In this study, we show that PMN apoptosis occurs via a new NK cell-dependent mechanism. Reactive oxygen species, induced by the presence of GG, play an indispensable role in this apoptotic effect by increasing MHC class I chain-related molecule A expression at the PMN surface. This increased expression enables interaction between MHC class I chain-related molecule A and NKG2D, leading to NK cell activation, which in turn generates a Fas-dependent apoptosis-promoting signal in PMNs. Taken together, our results demonstrate that the crosstalk between PMNs and NK cells is essential to GG-induced PMN apoptosis. NK cells might thus play a role in the induction of PMN apoptosis in situations such as unexplained neutropenia or autoimmune diseases.

Toxicological evaluation of Antrodia cinnamomea in BALB/c mice.

Antrodia cinnamomea is a natural component of some herbal medicines used for treatment of abdominal pain, hypertension and hepatocellular carcinoma in Taiwan and other countries. Subchronic oral toxicity studies of A. cinnamomea extracts in male and female BALB/c mice were performed to evaluate its safety. Three different concentrations of A. cinnamomea (16.67, 833.3 and 1666.67 mg/kg/day) were given orally to groups of mice (10 mice/dose) for 90 consecutive days. All animals survived to the end of the study, and there were no significant differences in body weight among the control and treatment groups. No significant differences were found in hematological and serum biochemical parameters among the control and treatment groups. No abnormalities of internal organs were observed in the treated groups.

Anti-tumor activity of the regenerated triple-helical polysaccharide from Dictyophora indusiata.

A triple helical polysaccharide (PD3) was isolated from Dictyophora indusiata. After denaturation in dilute NaOH solution (0.3 M) and renaturation by sequential dialysis, regenerated polysaccharide (RPD3) was obtained. The physico-chemical properties of RPD3 including intrinsic viscosity [η], molecular weight (Mw) and optical rotation were similar to those of PD3, which suggested that RPD3 also had a triple helical structure after denaturation-renaturation. However, different intrinsic viscosity dependence on the concentration of NaOH solution was noted in PD3 and RPD3, which indicated that RPD3 had lower chain tightness compared with PD3. The anti-tumor activity of this polysaccharide after denaturation-renaturation treatment was further investigated. Both PD3 and RPD3 showed no direct cytotoxicity against S-180 cells in vitro but behaved anti-tumor activity in vivo. Meanwhile, RPD3 in high-dose group showed much higher anti-tumor activity than that of PD3, suggesting that the denaturation-renaturation treatment improved the bioactivity of the polysaccharide from D. indusiata.

Evaluation of in vitro antioxidant potency of exopolysaccharide from endophytic Fusarium solani SD5.

A potent endophytic fungus, Fusarium solani SD5 was used for exopolysaccharide (EPS) production. The isolated EPS were purified and major EPS fraction (PS-I); rhamno galactan was used to evaluate anti oxidant activities in vitro. EPS (PS-I) showed significant free radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl) and scavenging potency is indicated by IC(50) value 578.541 ± 33.256 µg/ml. EPS (PS-I) significantly induced antioxidant parameters of peritoneal macrophage cells at a concentration dependent manner and at 500 µg/ml it showed maximum protective effect against free radicals [malondialdehyde (MDA) 0.178 ± 0.015; super oxide dismutase (SOD) 41.287 ± 1.051; glutathione peroxidase (GPx) 30.182 ± 1.237; reduced glutathione (GSH) 56.892 ± 1.272; oxidized glutathione (GSSG) 8.458 ± 0.768]. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide] cytotoxicity assay indicated that EPS (PS-I) had no significant cytotoxic effect (concentration up to 500 µg/ml) on macrophage cells. Present findings suggested that the EPS (PS-I) may become a potential nontoxic exogenous antioxidant.