Defensin Expression by the Cornea: Multiple Signalling Pathways Mediate IL-1β Stimulation of hBD-2 Expression by Human Corneal Epithelial Cells

Abstract

Human corneal epithelium expresses hBD-1 and -3. hBD-2 is not typically present, but its expression can be stimulated by proinflammatory cytokines such as IL-1beta, acting through mitogen-activated protein (MAP) kinase and nuclear factor (NF)-kappaB pathways. Because IL-1 is known to be increased at the ocular surface after injury, the current observations provide a mechanism to explain the previous finding that hBD-2 is upregulated in regenerating corneal epithelium. Cytokine stimulation of hBD-2 expression most likely provides additional protection against infection and raises the possibility that this defensin in particular may be involved in the wound-healing response, per se.