| Trametes versicolor Polysaccharopeptide (PSP) is a polysaccharide-protein conjugated. It is derived from the deep-layer cultivated Trametes versicolor mycelia Cov-1 strain, and now is a national type II medicine in China. PSP was applied for cancer patients to antagonise the side-effect of radio- and chemo-therapy, and to restore their immunity. PSP also used to enhance the immunity of sub-health population. But the effects and mechanism of PSP on excessive-immune were still not clearly.In this study, mouse macrophage Raw 264.7 cells were stimulated by lipopolysaccharide (LPS) to create an inflammation model, and then analysed the effects of PSP on normal and LPS stimulated cells.ELISA results showed that PSP (25,100?g/ml) alone promoted the expression of IL-1β(0.76+1.07 and 2.73+1.29pg/ml) compared with control (0.76+0.21pg/m), but was not significance. In LPS model, the expression of IL-1β?were markedly increased (8.20+0.43pg/ml, p<0.05). Whereas PSP (25,100?g/ml) inhibated the elevated expression of IL-1βstimulated by LPS (6.36+0.86 and 7.12+3.21pg/ml).ELISA results showed that PSP (25,100?g/ml) were not significantly induced the production of PGE2 compared with control (95.01+14.70pg/ml), and concentrations of PGE2 were 114.11+17.67pg/ml and 200.25+76.00pg/ml induced by PSP (25,100?g/ml) alone (p>0.05). In LPS model, the secretion level of PGE2 was markedly augmented to 419.78+75.70pg/ml (p<0.05). However, co-inbubated cells with PSP (25,100?g/ml) and LPS (1βg/ml) down-regulated the production of PGE2 to 146.97+15.20 and 154.96+58.73pg/ml compared with model.Western blot results showed that incubated with PSP (25,100?g/ml) alone did not significantly alter the expression of COX-2 (main rate-limiting enzyme of PGE2) compared with control, but the expression of COX-2 was dramatically elevated in LPS group. Whereas, treated cells with PSP and LPS attenuated the high expression of COX-2 compared with LPS model. (p<0.05)The data of Immunofluorescence and Western blot showed that PSP alone slightly induced the translocation of NF-κB into nucleus and consequently decreased NF-κB cytoplasmic level. But in LPS model, the level of NF-κB in cytoplasm was the least, this means LPS markedly activated NF-κB to translocate into nucleus. However, PSP co-incubated cells with LPS elevated the level of NF-κB in cytoplasm.Flow cytometry was applied to detect the interference effect of PSP to the binding of LPS-FITC with macrophage. The results revealed that PSP could disturb the binding of LPS-FITC to the macrophages, and consequently reduced the mean fluorescent intensity from 2.07+0.42 (LPS Model) to 1.20+0.25(PSP and LPS-FITC co-incubated cells). These results showed that, PSP can activate normal macrophages, and weakly increased the production of IL-1βand PGE2. However, when cells were over-stimulated, PSP inhibited the high expression of IL-1β? PGE2 and COX-2 induced by LPS. The down-regulated effects associated with PSP could block NF-?κB nuclear translocation and interfere with LPS binding to cells. Therefore, the effect of PSP on macrophages is a two-way modulation, PSP is a bidirectional immunomodulator.
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