The excretory-secretory products of Echinococcus granulosus protoscoleces stimulated IL-10 production in B cells via TLR-2 signaling.

BACKGROUND: Excretory-secretory products released by Echinococcus granulosus protoscoleces (EgPSC-ESPs) are well-known to regulate T cell responses. However, their direct influence on the differentiation of B cell subsets remains largely elusive. This study investigated the effects of EgPSC-ESPs on the differentiation of IL-10-producing B cells (B10), and explored the possible role of Toll-like receptor 2 (TLR-2) signaling in this process. RESULTS: In comparison to phosphate buffered saline (PBS), B cells exposed to the excretory-secretory products (ESPs) generated higher percentages of B10 cells, with higher expression of IL-10 mRNA, and larger amount of IL-10 production, which were in a dose dependent way. The mRNA and protein expression of TLR-2 in the ESPs-stimulated B cells were significantly higher than those in PBS, which was consistent to the results in B cells isolated from EgPSC infected mice. Moreover, TLR-2-/- B cells in response to ESPs stimulation expressed lower levels of IL-10 mRNA and produced undetectable IL-10 in comparison to those in normal B cells. In addition, Phosphatase and tensin homolog deleted on chromosome ten/AKT/Phosphatidylinositol-3 kinase (PTEN/AKT/PI3K) pathway was activated in ESPs-treated B cells, which was also dependent on TLR-2 signaling. Pam3CSK4, the agonist of TLR-2, could mock the effects of ESPs on the expression of PTEN, AKT and PI3K. CONCLUSION: Overall, this study revealed that TLR-2 signaling was required for B10 induction mediated by EgPSC-ESPs, which might be an immunomodulatory target against the parasite infection.

Polyene Phosphatidylcholine inhibited the inflammatory response in LPS-stimulated macrophages and ameliorated the adjuvant-induced rat arthritis.

This study sought to investigate the anti-inflammatory effect of Polyene Phosphatidylcholine (PPC), a clinical drug that is used to treat hepatopathy, on lipopolysaccharide (LPS)-stimulated macrophages and on bovine collagen II-induced arthritis (CIA) rats. In stimulated primary and Raw264.7 macrophages by LPS, PPC significantly down-regulated the relative expression of mRNA such as IL-6, TNF-α, TLR-2, TLR-4, MyD88, and NF-κB while up-regulated IL-10 and TGF-ß expression. Moreover, the concentration of IL-6, TNF-α, IL-10, and TGF-ß in the cultured supernatants showed the similar tendency with their mRNA alterations. In addition, PPC could significantly inhibit the LPS-induced expression of MyD88 and NF-κB p65 in both mRNA and protein levels. These results suggest that PPC could down-regulate the LPS-stimulated inflammation in macrophages through TLR-2/TLR-4/MyD88/NF-κB pathway in vitro. Furthermore, to explore its effects in vivo, PPC was administrated to CIA rats. In comparison to CIA group, PPC-treated rats showed decreased arthritis score and osteopenia. Besides, PPC exhibited its ability to alleviate the degree of synovial hyperplasia, inflammatory cell infiltration, and destruction of cartilage and bone, thus remarkably improving the condition of CIA rats. In short, this study demonstrated that PPC had the potential to be an anti-inflammatory drug to treat inflammatory disorders such as rheumatoid arthritis.

Genetic diversity and phylogenetic analysis of EG95 sequences of Echinococcus granulosus: Implications for EG95 vaccine application.

OBJECTIVE: To analyse the genetic variability of EG95 sequences and provide guidance for EG95 vaccine application against Echinococcus granulosus (E. granulosus). METHODS: We analysed EG95 polymorphism by collecting total 97 different E. granulosus isolates from 12 different host species that originated from 10 different countries. Multiple sequence alignments and the homology were performed by Lasergene 1 (DNASTAR Inc., Madison, WI), and the phylogenetic analysis was performed by using MEGA5.1 (CEMI, Tempe, AZ, USA). In addition, linear and conformational epitopes were analysed, including secondary structure, NXT/S glycosylation, fibronectin type III (FnIII) domain and glycosylphosphatidylinositol anchor signal (GPI-anchor). The secondary structure was predicted by PSIPRED method. RESULTS: Our results indicated that most isolates overall shared 72.6-100% identity in EG95 gene sequence with the published standard EG95 sequence, X90928. However, EG95 gene indeed has polymorphism in different isolates. Phylogenetic analysis showed that different isolates could be divided into three subgroups. Subgroup 1 contained 87 isolates while Subgroup 2 and Subgroup 3 consisted of 3 and 7 isolates, respectively. Four sequences cloned from oncosphere shared a high identity with the parental sequence of the current vaccine, X90928, and they belonged to Subgroup 1. However, in comparison to X90928, several amino acid mutations occurred in most isolates besides oncosphere, which potentially altered the immunodominant linear epitopes, glycosylation sites and secondary structures in EG95 genes. All these variations might change their previous antigenicity and thereby affecting the efficacy of current EG95 vaccine. CONCLUSIONS: This study reveals the genetic variability of EG95 sequences in different E. granulosus isolates, and proposed that more vaccination trials would be needed to test the effectiveness of current EG95 vaccine against distinct isolates in different countries.

The excretory-secretory products of Echinococcus granulosus protoscoleces directly regulate the differentiation of B10, B17 and Th17 cells.

BACKGROUND: Excretory-secretory products (ESPs) released by helminths are well-known to regulate T cell responses in the host. However, their direct influence in the differentiation of naïve T cells, and especially B cells, remains largely unknown. This study investigated the effects of Echinococcus granulosus protoscoleces ESPs (EgPSC-ESPs) on the differentiation of IL-10-producing B cells (B10), IL-17A-producing B cells (B17) and Th17 cells. METHODS: BALB/c mice injected with EgPSC were used to evaluate the in vivo profiles of B10, B17 and Th17 cells. In vitro purified CD19+ B and naïve CD4+ T cells were cultured in the presence of native, heat-inactivated or periodate-treated EgPSC-ESPs, and the differentiation of these cell subsets were compared. RESULTS: In contrast to the control group, infected mice showed higher frequencies of B10, B17 and Th17 cells, and higher levels of IL-10 and IL-17A in the sera. Interestingly, B17 cells were first identified to express CD19+CD1dhigh. In vitro, B cells cultured with native ESPs exhibited a higher percentage of B10 cells but lower percentage of B17 and Th17 cells compared to the PBS group. Moreover, the relative expression of IL-10 and IL-17A mRNA were consistent with the altered frequencies. However, ESPs subjected to heat-inactivation or periodate treatment exhibited an inverse effect on the induction of these cell subsets. CONCLUSIONS: Our findings indicate that ESPs released by EgPSC can directly regulate the differentiation of B10, B17 and Th17 cells, which appear to be heat-labile and carbohydrate-dependent.

Preservation properties of in situ modified CaCO3-chitosan composite coatings.

To improve the dispersibility, hydrophilia constraints of primitive particle size, and reduce the economic cost, in situ modified CaCO3-chitosan composite coatings were prepared by tape-casting with different modifiers. The coating structures were characterised, and the preservation properties of the coatings were evaluated by fresh indices of Sciaenops ocellatus. The results revealed that the coatings were homogeneous and compact when the in situ modifier was sodium stearate. Besides, the amide I group of chitosan disappeared and hydrogen bonds were formed between the nano-CaCO3 and the chitosan. Meanwhile, the preservation effects to S. ocellatus of the coatings modified in situ by sodium stearate and sodium citrate were better. This was because the coatings effectively prevented oxygen and bacteria from reaching S. ocellatus, and thus inhibited the degradation of the proteins and lipids. The in situ modified method is conducive to chitosan coating properties, which will be widely used in the food preservation field.

Preparation and antibacterial properties of titanium-doped ZnO from different zinc salts.

To research the relationship of micro-structures and antibacterial properties of the titanium-doped ZnO powders and probe their antibacterial mechanism, titanium-doped ZnO powders with different shapes and sizes were prepared from different zinc salts by alcohothermal method. The ZnO powders were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), and the antibacterial activities of titanium-doped ZnO powders on Escherichia coli and Staphylococcus aureus were evaluated. Furthermore, the tested strains were characterized by SEM, and the electrical conductance variation trend of the bacterial suspension was characterized. The results indicate that the morphologies of the powders are different due to preparation from different zinc salts. The XRD results manifest that the samples synthesized from zinc acetate, zinc nitrate, and zinc chloride are zincite ZnO, and the sample synthesized from zinc sulfate is the mixture of ZnO, ZnTiO3, and ZnSO4 · 3Zn (OH)2 crystal. UV-vis spectra show that the absorption edges of the titanium-doped ZnO powders are red shifted to more than 400 nm which are prepared from zinc acetate, zinc nitrate, and zinc chloride. The antibacterial activity of titanium-doped ZnO powders synthesized from zinc chloride is optimal, and its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) are lower than 0.25 g L-1. Likewise, when the bacteria are treated by ZnO powders synthesized from zinc chloride, the bacterial cells are damaged most seriously, and the electrical conductance increment of bacterial suspension is slightly high. It can be inferred that the antibacterial properties of the titanium-doped ZnO powders are relevant to the microstructure, particle size, and the crystal. The powders can damage the cell walls; thus, the electrolyte is leaked from cells.