Objective: To evaluate the effects of doxycycline on the regulation of intercellular adhesion molecule-1 (ICAM-1, CD54), interleukin-1beta (IL-1beta), human leukocyte antigen DR (HLA-DR) and apoptosis in human conjunctival epithelial cells.
Methods: Human primary conjunctival epithelial cells were isolated and cultured from donors and identified by immunohistochemistry. Cultured epithelial cells were treated with either 0 U/ml IFN-gamma, 300 U/ml IFN-gamma, 300 U/ml IFN-gamma with 10 microg/ml doxycycline, 300 U/ml IFN-gamma with 20 microg/ml doxycycline, 300 U/ml IFN-gamma with 40 microg/ml doxycycline or 300 U/ml IFN-gamma with 100 microg/ml dexamethasone for 24 hours. The amount of CD54, HLA-DR and IL-1beta was measured by flow cytometry and western blot analysis. Apoptosis was evaluated by flow cytometry after the cultured epithelial cells were treated for 72 hours.
Results: Cultured conjunctival epithelial cells can express CD54 and IL-1beta. IFN-gamma increased the amount of CD54 and IL-1beta (P < 0.01). Doxycycline and dexamethasone inhibited the IFN-gamma induced increase of express of CD54 and IL-1beta of cultured conjunctival epithelial cells, and the inhibiting effect was dependent on the concentration of doxycycline (P < 0.01). Very little HLA-DR and apoptosis were detected before and after treatment with IFN-gamma.
Conclusion: Doxycycline can suppress the expression of inflammatory cytokine such as CD54 and IL-1beta, which suggests that doxycycline may be a potent drug for the treatment of ocular surface inflammatory disease.