ABSTRACT
Objective To investigate the effect of different concentrations of Echinococcus multilocularis secretion antigen (Em-sAg) on the phenotype and function of mouse bone marrow-derived dendritic cells (BMDCs) induced by lipopolysaccharide (LPS). Methods The bone marrow precursor cells isolated from the mouse bone marrow cavity were stimulated by mouse recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) to form BMDCs, and then cell morphology was observed under an inverted microscope. After the purity of BMDCs was identified by flow cytometry, BMDCs were divided into control group, positive control group (LPS 1 μg/ml), LPS+3 mg/ml Em-sAg group, LPS+1.5 mg/ml Em-sAg group, LPS+0.75 mg/ml Em-sAg group, and LPS+0.375 mg/ml Em-sAg group. Flow cytometry was used to measure the expression of BMDC surface molecules (CD80, CD86, and MHC-Ⅱ molecules) in each group, and ELISA was used to measure the expression level of the cytokine IL-12p70. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups. Results Observation under an inverted microscope showed that after 8-10 days of culture, the cells had burr-like protrusions and were in a state of complete suspension. Flow cytometry showed that the positive rate of CD11c was above 70% and most of the cultured cells were identified as BMDCs based on this. Flow cytometry further showed that compared with the control group, the LPS group had significant increases in the cell molecules CD80, CD86, and MHC-Ⅱ on surface (all P 0.05). ELISA showed that there was a significant difference in the level of IL-12 p70 between groups ( F =73.140, P < 0.05); compared with the control group, the LPS group had a significant increase in the expression level of IL-12p70 after stimulation ( P < 0.05); compared with the positive control group, the LPS+3 mg/ml Em-sAg group, the LPS+1.5 mg/ml Em-sAg group, the LPS+0.75 mg/ml Em-sAg group, and the LPS+0.375 mg/ml Em-sAg group had a significant reduction in the expression level of IL-12p70 ( P < 0.05), and the degree of reduction in the pro-inflammatory factor IL-12p70 increased with the increase in the concentration of Em-sAg. Conclusion Different concentrations of Em-sAg can inhibit LPS-induced maturity of BMDCs and the expression of the pro-inflammatory cytokine IL-12p70.
ABSTRACT
Dendritic cells (DCs), a type of antigen-presenting cells (APC), are recognized as an important regulator of immune response and immune tolerance, and play a critical role in the host innate immunity and adaptive immunity. Previous studies have shown that the long-term parasization of Echinococcus in the host is strongly associated with the host immune tolerance induced by DCs. This review summarizes the research progress of the role of DCs in host immune tolerance caused Echinococcus infection, aiming to provide the theoretical basis and insights into the management and immunotherapy of Echinococcus infections.
ABSTRACT
Gambogic acid (GA), the main active ingredient in gamboge, has been reported to have good anti-tumor activity with excellent selectivity. However, its clinical application is limited by the poor water solubility. GA nanosuspensions were designed in this study in order to solve this problem. GA nanosuspensions were prepared by microprecipitation method based on pH adjustment. Suitable stabilizer was screened according to the size and polydispersity index (PDI) of the resultant nanosuspensions. Dynamic light scattering method was used to measure the particle size and transmission electron microscopy was used to observe the morphology. The stability was studied in different medium. The drug release was evaluated using a dialysis method. MTT assay was used to assess their cytotoxicity in vitro against cancer cell line. Anti-tumor effect in vivo was investigated on H22-bearing mice. In result, Poloxamer (P188) was found to be a good stabilizer. The resultant GA nanosuspensions (GA-NSps) were 135.9 ±5.1 nm in diameter, with PDI value being 0.26 ±0.01 and the zeta potential being −35.1 ±1.36) mV. GA-NSps were nearly spherical. They were quite stable in various physiological media. GA-NSps exhibited a sustained drug release pattern, with the cumulative release reaching 90.26% within 312 h. In MTT assay, GA-NSps had a stronger cytotoxicity against HepG2 cells than the free drug (IC50, 0.851 8 μg·mL−1 vs 2.104 μg·mL−1, P vs 66.80%, P < 0.01). In summary, we prepared GA-NSps with high drug loading capacity, small particle size and good stability, and provided a solid basis for the effective dosage form of gambogic acid.
ABSTRACT
Honokiol (HK) have extensive pharmacological activities, but its poor solubility and instability restricted its clinical application and efficacy exertion. HK nanosuspensions (HK-NSps) were designed in this study in order to solve the problems. HK-NSps were prepared by antisolvent precipitation method, using poly-vinylpyrrolidone (PVP) and bovine serum albumin (BSA) as a combined stabilizer. The particle size was measured using dynamic light scattering method, the morphology was observed by transmission electron microscopy. The size change and drug content of HK-NSps in various physiological media during the storage at ambient temperature was examined to evaluate their storage stability. Dialysis method was used to study their drug release in vitro. MTT assay was used to assess their in vitro cytotoxicity against 4T1 breast cancer cell line. Anti-tumor effect in vivo was also investigated in 4T1 tumor-bearing mice. HK-NSps were prepared with high drug loading content of 48.62%, nearly spherical shape and good storage stability. The average particle size was (83.40 ±1.042) nm, the polydispersity index (PDI) value was 0.223 ±0.011, the zeta potential was (-42.2 ±1.2) mV. HK-NSps showed sustained in vitro drug release and enhanced cytotoxicity in contrast to free HK against 4T1 cells (IC50, 8.36 μg·mL-1 vs 37.58 μg·mL-1, Pin vivo study on 4T1 tumor-bearing mice demonstrated that HK-NSps showed good dose-dependent tumor inhibition rate (TIR). In contrast to 4 mg·kg-1 of PTX injection (TIR, 47.9%), medium and high dose of HK-NSps displayed improved therapeutic efficacy (TIR, 55.67% for 40 mg·kg-1, 67.28% for 60 mg·kg-1, P-1) had TIR of only 54.13% even administrated every day. In conclusion, HK-NSps were prepared with small size, high drug-loading capacity, and good stability. The improved in vitro and in vivo antitumor efficacy demonstrated that HK can be a promising antitumor drug in combination with nanosuspensions technology.