ABSTRACT
Objective:To investigate the effects of Ureaplasma urealyticum GrpE ( Uu-GrpE) on the maturation of dendritic cells and the polarization of T cells. Methods:Uu-GrpE was expressed and purified, and then identified by Western blot. The cytotoxicity of Uu-GrpE to mouse bone marrow-derived dendritic cells (BMDCs) was analyzed by LDH kit. After stimulating BMDCs with Uu-GrpE, the expression of costimulatory molecules, CD80, CD86 and major histocompatibility complex Ⅱ (MHCⅡ), on the surface of BMDCs was detected by flow cytometry, and ELISA was used to detect the cytokines such as IL-12p70, TNF-α, IL-1β and IL-6. CD4 + Na?ve T cells were isolated from mouse spleen tissues by magnetic beads. A co-culture system of BMDCs and Na?ve T cells was constructed to analyze the effects of GrpE-stimulated mature BMDCs (GrpE-BMDCs) on T cell proliferation and polarization towards Th1/Th2. Mice were immunized with GrpE-BMDCs through the tail vein, and the induced humoral and cellular immune responses were detected by ELISA and flow cytometry. Results:Uu-GrpE was successfully express and high purity BMDCs were isolated. Uu-GrpE could stimulate BMDCs to secrete cytokines such as IL-12p70, TNF-α, IL-1β and IL-6 without having cytotoxicity. Uu-GrpE significantly increased the expression of CD80 [mean flourscence indensity (MFI): (324.00±22.11) vs (91.03±10.95), P<0.01], CD86 [MFI: (1 176.00±51.39) vs (217.00±14.93), P<0.01] and MHCⅡ [MFI: (708.70±56.32) vs (185.70±16.77), P<0.01] on BMDCs. Compared to the GrpE-BMDCs only group and GrpE (boiled)-BMDCs+ T cell group, the GrpE-BMDCs+ T cell group showed significantly increased T cell proliferation [stimulation index: (7.25±0.21) vs(6.55±0.23) and (6.09±0.35), both P<0.05], and dramatically promoted T cell secretion of IL-2 and IFN-γ [IL-2: (145.60±14.67) pg/ml vs(55.92±3.12) pg/ml and (26.05±2.40) pg/ml, P<0.05 and P<0.01; IFN-γ: (267.20±37.80) pg/ml vs(146.70±20.65) pg/ml and(27.84±6.69) pg/ml, both P<0.05]. However, no significant change was observed in the expression of Th2-type cytokines. Moreover, the adoptive transfer of GrpE-BMDCs induced a Th1-type immune response. Conclusions:Uu-GrpE could stimulate the maturation and polarization of BMDCs. Moreover, it could induce Th1 immune response as a candidate protein vaccine for Ureaplasma urealyticum.
ABSTRACT
Objective To investigate the mocelualr mechanism of Cordycepin negative modulates LPSinduced cytokine production in murine macrophages.Methods The RAW264.7 murine macrophages were cultured in vitro and were pre-treated by different concentration of Cordycepin,and then stimulated by LPS for 8 h.Production of TNF-o,IL-6 and IL-12,and the content of p65 in the nuclear were detected by ELISA.Expression of heme oxygenase-1 (HO-1) and phosphorylation of IκB and p38 were measured by Western blot.Nuclear translocation of Nrf2 was detected by Immunofluorescence.Results 1 ～ 30 μg/mL of Cordycepin treatment significantly abrogated LPS-induced TNF-α,IL-6 and IL-12 production,p65 nuclear translocation and IκB phosphorylation.In addition,different concentration of Cordycepin could also induce RAW264.7 cells expression of HO-1,phosphorylation of p38 and nuclear translocation of Nrf2.Application of p38 inhibitor and small interfering RNA-mediated knock-down of Nrf-2 significantly inhibited surfactin-induced HO-1 expression.Treatment with a selective inhibitor of HO-1 reversed the Cordycepin mediated inhibition of pro-inflammatory cytokines.Conclusions Cordycepin induces antiinflammatory effects by inhibition of NF-κB and activation of Nrf-2 and p38 mediated HO-1 induction.
ABSTRACT
Late embryogenesis abundant (LEA) proteins are well associated with the desiccation tolerance in organisms. LEA proteins are categorized into at least seven groups by virtue of similarities in their deduced amino acid sequences. Most of the LEA proteins have the characteristics of high hydrophilicity and thermo-stability. The LEA proteins are in unstructured conformation in aqueous solution. However, they adopted amphiphilic alpha-helix structure during desiccation condition. LEA proteins are localized to the different organelles in the cells, i.e. cytoplasm, endoplasmic reticulum, mitochondria and nucleus. The multi-functional capacity of LEA proteins are suggested, as protein stabilization, protection of enzyme activity, membrane association and stabilization, antioxidant function, metal-ion binding or DNA protection, etc. Here, we review the structural and functional characteristics of LEA proteins to provide a reference platform to understand their protective mechanisms during the adaptive response to desiccation in organisms.