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 β-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.

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.