RESUMO
Objective To investigate the regulation of Treg/Th17 axis by mannan-binding lectin (MBL) in mice with Candida albicans ( C. albicans ) infection. -ethods MBL gene-knockdown (MBL-/-) C57BL/6 mice and wild-type (WT) C57BL/6 mice were divided into four groups. C. albicans strains (2×107 CFU) were injected intraperitoneally into the mice of infection groups. Paraffin sections of mouse liver and kidney tissues were prepared on 3 d. Histopathological changes were observed with hematox-ylin and eosin ( HE) and Periodic acid-Schiff ( PAS) staining. Flow cytometry was performed to analyze Th17 and Treg cells in mice on 7 d. The levels of IL-10 and IL-17A were measured by ELISA. CD4+T cells were obtained from spleen cells by magnetic sorting. Expression of Foxp3 and RORγt at mRNA and protein levels were detected by qRT-PCR and Western blot, respectively. Results The mouse model of C. albicans infection was established successfully. After infection, the MBL-/- mice had higher percentages of Th17 cells, but lower percentages of Treg cells than the WT mice. ELISA results showed that compared with the WT mice with C. albicans infection, the MBL-/- mice had significantly increased IL-17A and decreased IL-10 after infection. Moreover, the expression of RORγt at both mRNA and protein levels was up-regula-ted, while that of Foxp3 was down-regulated in the MBL-/- mice than in the WT mice following infection. Conclusions MBL regulates the immune balance of Treg/Th17 cells in mice infected with C. albicans through promoting the differentiation of CD4+ T cells into Treg cell subsets and inhibiting the differentiation into Th17 cell subsets.
RESUMO
Objective To investigate the effects of mannan-binding lectin ( MBL) on the differen-tiation of Th17 cells (T helper cell 17, Th17). Methods CD4+T cells were separated in vitro from fresh human cord blood by MACS ( magnetic-activated cell sorting ) separator. Anti-CD3 monoclonal antibody ( McAb) and anti-CD28 McAb were used to stimulate CD4+T cells with IL-6 and TGF-β1 as inducers. Then, these cells were treated with ( MBL group) or without ( control group) different concentrations of MBL. Percentages of Th17 cells in different groups were detected by fluorescence-activated cell sorting( FACS) after 72 hours of culturing. Quantitative real-time PCR ( Q-PCR) was used to analyze the expres-sion of RORγt ( retinoid-related orphan receptor-γ-t) at mRNA level in both control and MBL groups. En-zyme-linked immunosorbent assay (ELISA) was performed to detect the levels of IL-17A in supernatants of cell culture from different groups. FACS was used to detect the percentages of Th17 cells in MBL-/-and wild type ( WT) mice. Results MBL could significantly reduce the percentage of Th17 cells after 72 hours of culturing as compared with the control group. Moreover, MBL could significantly down-regulate the expres-sion of RORγt at mRNA level and decrease the expression of IL-17A. Results of animal experiments showed that the percentages of CD4+RORγt+Th17 cells in MBL-/- mice were significantly higher than those in WT mice. Conclusion MBL can inhibit the differentiation of CD4+T cells to Th17 cells, which is induced by IL-6 and TGF-β1.
RESUMO
Objective To investigate the effects of mannan-binding lectin ( MBL) on the differen-tiation of Th17 cells (T helper cell 17, Th17). Methods CD4+T cells were separated in vitro from fresh human cord blood by MACS ( magnetic-activated cell sorting ) separator. Anti-CD3 monoclonal antibody ( McAb) and anti-CD28 McAb were used to stimulate CD4+T cells with IL-6 and TGF-β1 as inducers. Then, these cells were treated with ( MBL group) or without ( control group) different concentrations of MBL. Percentages of Th17 cells in different groups were detected by fluorescence-activated cell sorting( FACS) after 72 hours of culturing. Quantitative real-time PCR ( Q-PCR) was used to analyze the expres-sion of RORγt ( retinoid-related orphan receptor-γ-t) at mRNA level in both control and MBL groups. En-zyme-linked immunosorbent assay (ELISA) was performed to detect the levels of IL-17A in supernatants of cell culture from different groups. FACS was used to detect the percentages of Th17 cells in MBL-/-and wild type ( WT) mice. Results MBL could significantly reduce the percentage of Th17 cells after 72 hours of culturing as compared with the control group. Moreover, MBL could significantly down-regulate the expres-sion of RORγt at mRNA level and decrease the expression of IL-17A. Results of animal experiments showed that the percentages of CD4+RORγt+Th17 cells in MBL-/- mice were significantly higher than those in WT mice. Conclusion MBL can inhibit the differentiation of CD4+T cells to Th17 cells, which is induced by IL-6 and TGF-β1.