| Objective1. To investigate the dynamic changes of CD4+CD25+Foxp3+regulatory T cells (Tregs) in the mice model of disseminated trichosporonosis;2. To investigate the dynamic changes of cytokines interleukin-10(IL-10), transforming growth factor-β1 (TGF-β1) in the mice model of disseminated trichosporonosis;3. To analyze the relationship between CD4+CD25+Foxp3+regulatory T cells and cytokines IL-10, TGF-β1 level, Analyze the relationship between kidney fungal burden and CD4+CD25+Foxp3+regulatory T cells, cytokines IL-10, TGF-β1 level and further investigating the roles of regulatory T cells and IL-10, TGF-β1 in the in the immune response of disseminated trichosporonosis.Methods1. The mice model of disseminated trichosporonosis was established: 50 male BALB/c mice were randomly divided into experimental group and control group, each group with 25 mice, then they were injected with organisms of T. asahii or sterile saline via the tail vein.2. After 3,7,14,21 and 28 days infection, mice liver, spleen, kidney, heart, lungs and brain were aseptically removed and cultured respectively, then stained with HE and PAS to study fungal infection status and pathological damage degree.3. Fungal burdens of kidney were measured at different time points as an evaluation index to examine the serious degree of infection.4. After 3,7,14,21 and 28 days infection, CD4+CD25+Foxp3+Tregs in peripheral blood mononuclear cells were analyzed by flow cytometry.5. Foxp3, IL-10, TGF-β1 mRNA levels in spleen at different time points were determined by real-time fluorescent quantitative PCR.6. At different time points, serum levels of IL-10 and TGF-β1 of mice with disseminated trichosporonosis were determined by enzyme-linked immuno sorbent assay(ELISA) and compared with those from normal controls.7. By using the linear correlation analysis method, the correlation between the quantity of CD4+CD25+Foxp3+ regulatory T cells and IL-10, TGF-β1; kidney fungal burden and Regulatory T cells ratio, Foxp3 mRNA, IL-10 mRNA, TGF-β1 mRNA, IL-10, TGF-β1 were analyzed.Results1. Disseminated trichosporonosis mice model was established in our experiment using non-immunosuppressed mice, disseminated infection was established but not fatal.2. Mice splenic CD4+CD25+Foxp3+ regulatory T cells ratio increased gradually after infection, after 3 days infection, CD4+CD25+Foxp3+ regulatory T cells ratio were higher than that of the control group, but have no significant difference; after 7 days infection, CD4+CD25+Foxp3+ regulatory T cells ratio were significantly higher than that of the control group; after 14 days infection, CD4+CD25+Foxp3+regulatory T cells ratio reached the peak and gradually decreased, after 28 days post infection they have decreased to normal levels, and there was no statistically significant difference compared with the control group.3. After 3 days infection, Foxp3, IL-10, TGF-β1 mRNA levels were higher than those of the control group, but have no statistically significant difference; after 7 days infection, Foxp3, IL-10, TGF-β1 mRNA levels were significantly higher than those of the control group; 14 days post infection, Foxp3, IL-10, TGF-β1 mRNA levels reached the peak and gradually declined, after 28 days infection they have decreased to normal levels, compared with the control group, there was no statistically significant difference.4. After 3 days infection, IL-10, TGF-β1 mRNA levels were higher than those of the control group, but have no significant difference; after 7 days infection, IL-10, TGF-β1 levels were significantly higher than that of the control group; after 14 days infection, IL-10, TGF-β1 levels reached the peak and gradually declined, after 28 days infection they have decreased to normal levels, compared with the control group, there was no statistically significant difference.5. Serum IL-10, TGF-β1 and splenic IL-10, TGF-β1 mRNA levels of spleen in disseminated trichosporonosis correlate positively with CD4+CD25+Foxp3+ regulatory T cells.6. Regulatory T cells, Foxp3, IL-10, TGF-β1 mRNA levels of spleen and serum IL-10, TGF-β1 in disseminated trichosporonosis change follow infection progress: increased at first and then decreased to baseline. After 7,14,21 days infection, their levels correlate positively with fungal burden of kindey, but not after 3,28 days infection.Conclusions1. We demonstrated that Trichosporon asahii infection drove in vivo expansion of splenic CD4+CD25+Foxp3+ regulatory T cells population and serum IL-10, TGF-β1 levels. regulatory T cells and IL-10, TGF-β1 participate in the immune response of disseminated trichosporonosis infection.2. CD4+CD25+Foxp3+ regulatory T cells population correlated positively with IL-10, TGF-β1 levels, IL-10 and TGF-β1 could be considerable as a mechanism of Treg-cell-mediated suppression.3. High levels of Regulatory T cells、serum IL-10、TGF-β1 and splenic Foxp3, IL-10, TGF-β1 mRNA in disseminated trichosporonosis may reduces the body’s ability to remove T.asahii, and provide T.asahii a favorable condition of survival. |
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