The Pathogenic Role Of Bacterial Flagellin In Ulcerative Colitis

Background and ObjectiveInflammatory bowel diseases (IBD) includes Crohn's disease (CD) and ulcerative colitis (UC).At present, the etiology and pathogenesis of IBD is not clear. Most scholars consider the etiology and pathogenesis of IBD includes the immune factors of intestinal mucosa,the sustained of the intestinal infection,intestinal mucosal barrier damaged, genetic factors and environment factors. The enteric bacteria factors has being one of the reseach hotspot on the pathogenesis of IBD.The immunodeficiency animal models made by transgenosis and gene knockout will not develop enteric inflammation if there are not enteric bacteria;while if recover the enteric bacteria,the enteric inflammation will happen.So we can get that the enteric bacteria ingredients involve in the pathogenesis of IBD.Recent years, some foreign literatures think the flagellin is the important component part of bacteria surface complex,and it plays an important role in bacteria'adhesive capacity and vitality.In mammals,the toll-like receptor 5 (TLR5)can recognize the bacterial flagellin and then they can cause a series of inflammatory reactions. Now there is no correlational studies about this in domestic.Our experimental research is going to verify the express of bacterial flagellin in intestinal mucosa by immunohistochemistry and bacterial flagellin'antibody in seresum by enzyme-linked immuno sorbent assay in patients of ulcerative colitis (UC).What we can find the pathogenic role of bacterial flagellin in ulcerative colitis and it may give us a new idea about the etiology and pathogenesis of IBD.At the same time,We detect the positive rate of the antineutrophilic cytoplasmic antibodies(ANCA) in patient of ulcerative colitis (UC).The antineutrophilic cytoplasmic antibodies(ANCA) can help us to know the important role in diagnosis of Inflanunatory bowel diseases (IBD) and estimate the inflammation activity.Material and methods60 initially active UC patients has been chosen in the outpatiens and inpatiens of the First Affiliated Hospital of Zhengzhou University from Sep.2009 to Oct.2010. Among them,30 patients are moderate to severe ulcerative colitis (UC) group, and the other 30 patients are mild ulcerative colitis (UC) group. Their peripheral blood and colon mucosa were collected.We measured bacterial flagellin'antibodies in seresum by enzyme-linked immuno sorbent assay (ELISA), and counted bacterial flagellin positive intestinal epithelial cells in the colon mucosa by immunohistochemistry.30 healthy volunteers were in control group. And the 15 colon mucosa control group sample come from the colon stumps of the colon cancer patients. The positive rate of the antineutrophilic cytoplasmic antibodies(ANCA) in 60 patients of ulcerative colitis (UC) by indirect immnnofluotesent method. The statistics of results were treated by statistical software SPSS 16.0. All the measurement datas were expressed in mean±standard deviation (x±s), and compared the means of samples by single-factor variance analyse; compared all the fourfold table datas byχ- test. Test standardα=0.05 as the significent test standard.Results(1) ELISA:all these figures were obtained by automatic microplate reader. SNK has been used to do paired comparison,the results show that moderate to severe UC group and mild UC group had significant differences and moderate to severe UC group also had significant differences with healthy group.while the same to mild UC group and healthy group. (F=13.57, P<0.01)(2) Immunohistochemistry:By microscopic examination, scoring was evaluated by the positiveness of cells staining, positive cells counting≤25%:O point; 26%～50%:1 point; 51%～75%:2 points;>75%:3 points.Scoring was also evaluated by the degree of staining:mild staining counts 1 point, moderate staining counts 2 points and severe staining counts 3 points. The positiveness was identified by the sum of the two scores in each slide, it was assumed positive when the scores≥3 and negative when the scores<3. the bacterial flagellin positive cell rate of moderate to severe UC group is 73.33%(22/30).while the mild UC group is 56.67%(17/30) and the control group is 20%(3/15).The three groups' bacterial flagellin positive cell rate had significant differences. RχC sheet has been used to contrast the bacterial flagellin positive cell rate of the moderate to severe UC group,the mild UC group and the control group(test standardα=0.0167) and the results show significant differences in each other. (χ2=11.553, P=0.003)(3) Indirect immnnofluotesent method:fluorescence model has been used by microscope.The rate of ANCA of the UC patients were significantly higher than the health group, The data difference was statistically significance (P<0.05) (4) By using Spearman we find the bacterial flagellin antibodies and ANCA has positive relatives (r=0.428, P=0.000).Conclusion (1) The expression of the antibodies of bacterial flagellin in serum of periphery blood and the expression of bacterial flagellin in intestinal epithelium cells have positive correlation with the severity of UC.So bacterial flagellin can help us to realize the reason of the UC and can judge the severity. We can cure this disease in a new way.(2) The antineutrophilic cytoplasmic antibodies(ANCA) in ulcerative colitis' serum plays an important role in the diagnose and judgment the severity of the UC group.