Effect Of Faecalibacterium Prausnitzii Combined With Kuikeling On Treg Cell And Cytokines In Colitis Of Mice

Background:It has been widely accepted that Faecalibacterium prausnitzii(F.prausnitzii)induce the differentiation of Treg cells.KuiKeLing(KKL)is also involved in the differ entiation of Treg cells.Aims:To investigate the effect of F.prausnitzii combined with KKL on colitis of mice by regulating Treg cells and cytokines.Methods:A total of fifty C57BL/6J mice were randomly divided into five groups,whic hnamed normal group,colitis model group,F.prausnitzii treatment group,KKL treatment group,and F.prausnitzii combined with KKL treatment group,respectively(n=10 in eac h group).The normal group drunk water normally,colitis were induced by drinking 2.5%DSS solution in other groups.The treatment groups were injected F.prausnitzii,KKL and F.prausnitzii combined with KKL through stomach,respectively.General condition and histology of colon were observed in each group.Percentages of Treg cells in perip heral blood,spleen and mesenteric lymph nodes(MLN)were analyzed by flow cytomet ry.Serum levels of TGF-?1 and IL-10 were measured by ELISA,and the mRNA level of Foxp3,TGF-?1 and IL-10 in colonic tissue was detected by real time PCR.Results:Compared to the colitis model group and F.prausnitzii treatment group,the col onic histological score of F.prausnitzii combined with KKL treatment group was lower(p<0.05),but the colonic histological score of the KKL treatment group was no difference with the F.prausnitzii combined with KKL treatment group(p>0.05).Percentages of Treg cells of F.prausnitzii combined with KKL treatment group in peripheral blood,spleen a nd mesenteric lymph nodes(MLN)were higher than that in corresponding colitis group(p<0.05).Compared to F.prausnitzii treatment group and KKL treatment group,percentages of Treg cells of F.prausnitzii combined with KKL treatment group in spleen were high er(p<0.05),but were no difference in peripheral blood and mesenteric lymph nodes(p>0.05).Serum levels of TGF-?1 and IL-10 of F.prausnitzii combined with KKL treatment gr oup were higher than that of colitis group(p<0.05)and the levels of expression of Fox p3 mRNA and TGF-?1 mRNA in colonic tissue were increasing than that in correspond ing colitisgroup(p<0.05),but expression of IL-10 mRNA in colonic tissue were no differ ence than that in corresponding colitis group(p>0.05).Compared to F.prausnitzii treatmen t group andKKL treatment group,serum levels of TGF-?1 of F.prausnitzii combined wit h KKL treatment group were higher and the levels of expression of Foxp3 mRNA and TGF-?1 mRNA in colonic tissue were increasing(p<0.05),but expression of IL-10 mRN A were no difference(p>0.05).Conclusions:The F.prausnitzii combined with KKL is involved in the functional regulat ion of Treg cells,including up-regulating Treg cells to secrete anti-inflammatory cytokin es,such as TGF-?1 and IL-10 and increasing the expression of Foxp3 mRNA andTGF-?1 mRNA in colonic tissue.The therapeutic efficacy of Treg cells on colitis treated by F.prausnitzii combined with KKL was higher than that in F.prausnitzii treatment group an d KKL treatment group,which may be related to promoting the function and cytokines secretion of Treg cells by F.prausnitzii combined with KKL.