Chemically injured keratocytes induce cytokine release by human peripheral mononuclear cells

Abstract

PurposeTo establish an in vitro model to study the role of keratocytes in corneal chemical burns and to investigate the interaction between chemically injured keratocytes and human peripheral blood mononuclear cells (PBMCs). MethodsHuman keratocytes, epithelial cells, and PBMCs were cultured. The PBMC stimulation assay was then performed using cultured human keratocytes, epithelial cells, and NaOH-treated keratocytes. Matrix metalloprotease-9 (MMP-9), transforming growth factor-beta 1 (TGF-β1), and macrophage migration inhibitory factor (MIF) secretion profiles of activated PBMCs stimulated by NaOH-treated keratocytes were determined by ELISA. ResultsHuman keratocytes stimulated PBMC proliferation (p=0.016), and keratocytes treated with various concentrations of NaOH further stimulated PBMC proliferation compared to control cells in a dose-dependent manner (p=0.028 and 0.009). MMP-9 and MIF levels were higher than in the negative controls, while TGF-β1 levels did not differ from those of the negative controls. ConclusionOur results suggest that PBMCs are stimulated by chemically injured keratocytes, and produce inflammatory cytokines in response. This may be a major mechanism underlying the process causing corneal chemical burn injuries. This model can be used as an in vitro model for further studies on corneal chemical burns.