[Expression of co-stimulators in ulcerative colitis and its pathologic significance].
OBJECTIVE
To study the expression and localization of co-stimulators in the mucosa of patients with ulcerative colitis (UC), and to explore its role in the pathogenesis of UC.


METHODS
Expression of co-stimulators CD86 and inducible co-stimulator (ICOS) was studied by immunohistochemistry on paraffin-embedded mucosal tissue from patients with active UC (64 cases), inactive UC (51 cases) and normal controls (20 cases). Immunostaining for CD28 was also carried out on frozen fresh mucosal tissue sampled from patients with active UC (7 cases), inactive UC (2 cases) and normal controls (5 cases). In addition, expression of CD4, CD8 and CD20 were also examined.


RESULTS
In active UC, increased expression of CD86 was not only observed in lamina propria mononuclear cells but also in the intestinal epithelial cells, as compared with inactive UC and the normal controls (P < 0.01). Increased ICOS expression in lamina propria mononuclear cells was detected in active UC, as compared with inactive UC and the normal controls (P < 0.01). Increased ICOS expression in intestinal epithelial cells was also seen in active UC, as compared with that of inactive UC (P < 0.01). The expression of CD86 was higher in inactive UC than in the normal controls (P < 0.05 or P < 0.01). However, the expression of ICOS showed no statistically significant difference between inactive UC and normal controls. Increased expression of CD28 in active UC, compared with that in inactive UC and normal controls, was also noticed (P < 0.05 or P < 0.01). The number of CD4 or CD8-positive intraepithelial lymphocytes and lymphocytes infiltrating in the lamina propria and small vessel walls was much higher in active UC than in inactive UC and normal controls (P < 0.01). Moreover, the ratio of CD4/CD8 was highest in active UC (P < 0.01). The number of CD20-positive B lymphocytes in lamina propria was also higher in active UC than in inactive UC and normal controls (P < 0.01).


CONCLUSIONS
In active UC, CD86 and ICOS were over-expressed in the intestinal epithelial cells and lamina propria mononuclear cells. The phenomenon suggests that abnormal expression of co-stimulators may contribute to the deregulation of acquired immune responses in UC.
Li
Fang
F
Department of Pathology, Peking University School of Basic Medical Science, Beijing, China.
Chen
A-jing
AJ
Du
Juan
J
Zhang
Yan
Y
Gong
En-cong
EC
Shi
Xue-ying
XY
D000328:Adult; D000368:Aged; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D051940:B7-2 Antigen / Q000378:metabolism*; D018106:CD28 Antigens / Q000378:metabolism; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000378:metabolism* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D060889:Inducible T-Cell Co-Stimulator Protein; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
D000945:Antigens, Differentiation, T-Lymphocyte; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497964:CD86 protein, human; C556692:ICOS protein, human; D060889:Inducible T-Cell Co-Stimulator Protein