Differential Effects of Low- and High-dose Glucocorticoids on the Innate Immunity of Corneal Epithelium in Vitro

Abstract

Purpose: To evaluate the effect of glucocorticoids on the innate immunity of corneal epithelial cells.

Methods: Human corneal epithelial cell lines (HCEC) were co-cultured with LPS and hydrocortisone to determine whether hydrocortisone modulates the expression and function of TLR2, 4. The release of IL-6, 8 from cultured HCEC was measured in the presence and absence of specific blocking antibodies to TLR2, 4. The proteins of TLR2, 4 were also compared by Western blot.

Results: Incubation of HCEC with LPS upregulated the expression of TLR2, 4 and increased the release of IL-6, 8. This upregulation was enhanced by low-concentration hydrocortisone, but inhibited by high-concentration hydrocortisone. The concentration of IL-6, 8 was also enhanced by low-concentration hydrocortisone and inhibited by high-concentration hydrocortisone.

Conclusions: Low-concentration hydrocortisone enhances the expression and function of TLRs in HCEC and provides evidence for a novel function of glucocorticoids in innate immunity.

Keywords::

• corneal epithelial cell
• cytokines
• hydrocortisone
• innate immunity
• Toll-like receptors

ACKNOWLEDGMENT

We thank Zan Pan (New York University, USA) for providing us with the HCEC. This work was sponsored by a project supported by the National Natural Science Foundation of China (Grant No.81070705), the Zhejiang Provincial Natural Science Foundation of China (Y2090193), and Zhejiang Provincial Health Bureau Foundation of China (N20080731).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.