P076 Specific mRNA Expression Profile in Inflamed Colonic Mucosa Derived from Patients with Inflammatory Bowel Disease
T. Velikova*1, Z. Spassova2, D. Kyurkchiev1, I. Altankova3, S. Stanilova4
1University Hospital St. Ivan Rilski, Department of Clinical laboratory and clinical immunology, Sofia, Bulgaria, 2University Hospital St. Ivan Rilski, Clinic of gastroenterology, Sofia, Bulgaria, 3University Hospital Lozenets, Clinical Immunology, Sofia, Bulgaria, 4Medical Faculty -Trakia University , Department of Molecular Biology, Immunology and Medical genetics , Stara Zagora, Bulgaria
Recent studies indicated that the dynamic interplay between Th17 cells and FoxP3+ T regulatory cells is essential for gut homeostasis maintaining. Cytokines related to these T cells subsets are crucial mediators of tissue damage closely connected to the intestinal inflammation in Inflammatory Bowel Disease (IBD).
The aim of this study was to investigate expression of IL-17A, TGF β 1, IL-6, IL-23, IL-10 and transcription factor FoxP3 in mucosal samples from IBD patients in order to specify the cytokine milieu in the inflamed tissue.
We examined mRNA relative quantities of these parameters in inflamed and adjacent normal colonic mucosa samples derived from 37 IBD patients (23 with ulcerative colitis - UC and 14 with Crohn`s disease - CD) and in normal mucosa from 12 non-IBD persons by performing qRT-PCR assay. We further investigated IL-17A, TGF β 1, IL-6, IL-10 serum and tissue protein levels by enzyme immunoassay.
Our Results showed that gene expression of FoxP3 and IL-6 were significantly higher in inflamed mucosal tissue of the IBD patients than in the adjacent normal mucosa (p=0.035, p=0.03 respectively), borderline significance for IL-10 (p=0.05), and no significance for IL-17A, IL-23 and TGFbeta. Overall all investigated genes are upregulated according to RQ value in inflamed mucosa in the following order: IL-6>FoxP3>TGFbeta>IL-23>IL-17A>IL-10. We also observed significant differences between higher gene expression of FoxP3 and IL-6 in inflamed tissue in UC (p=0.011, p=0.000 respectively) and CD (p=0.008, p=0.000 respectively) compared to normal mucosa of non-IBD persons and increased TGFbeta in CD patients alone (p=0.041). Moreover IL-6 and TGFbeta were overexpressed (RQ>10) in non-inflamed mucosa from IBD patients in comparison with normal mucosa from the controls. We found also increased levels of IL-17A, IL-6, IL-10 and decreased level of TGF β 1 in inflamed tissue compared to serum levels of patients with IBD. We did not define significant correlation between gene and protein expression of the target cytokines within the IBD patients group. The serum and tissue levels of IL-17A and IL-6 were lower in the non-IBD patients compared to IBD ones. None surprisingly, tissue level of IL-10 and serum level of TGF β 1 in IBD patients were similar to these obtained in non-IBD controls.
Our Results demonstrated significant differences in the expression of some mRNA-encoded effector and regulatory cytokines in IBD. Specific expression profile obtained in mucosa of IBD patients including IL-6, TGF β 1 and IL-10 cytokines simultaneously with the transcription factor FoxP3 may represent a transcriptional hallmark for IBD.