Methods: Twenty-two patients with OLP were enrolled in this study, together with 12 matched healthy volunteers served as control group. The scores of OLP disease activity were assessed according to REU scoring system. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation. The expression of B7-H1 and PD-1 on T cells in PBMCs were tested by two-colour flow cytometry. The lymphocyte cells of OLP patients and healthy adults were mixed for culture with anti-B7-H1 mAbs, then the proliferation of lymphocyte cells were detected through XTT method.
Results: Significant differences were found among OLP patients and healthy controls in the expression of B7-H1 and PD-1 on T cells (p<0.05). The expression of B7-H1 on T cells in OLP positively associated with the disease activity score (p<0.05). However, no correlation was found between the expression of PD-1 and the disease activity score in OLP (p>0.05). When blocking B7-H1/PD-1 pathway with anti-B7-H1 mAbs, the proliferation of T cells had no significant difference between the OLP group and the control group after mixed lymphocyte cell cultures.
Conclusions: The results indicated that B7-H1/PD-1 might play important roles in the pathogenesis of OLP. B7-H1 in T cells may relate with the progression of OLP. (This work was supported by National Nature Science Foundation of China Grants No.30973311).