Suppression of Herpetic Stromal Disease by topical administration of Interleukin-10 Plasmid DNA
D. Bauer1, S. Wasmuth1, M. Lu2, M. Roggendorf2, K.-P. Steuhl1, A. Heiligenhaus1,3
Purpose: HSV-1 induced stromal keratitis (HSK) is an immune mediated disease of the cornea orchestrated by CD4+ Th1 lymphocytes. In this study we investigated whether the course of stromal keratitis could be altered by topical administration of interleukin-10 (IL-10) plasmid DNA.
Methods: BALB/c mice were corneally infected with 105 PFU of HSV-1 (KOS). IL-10 plasmid DNA constructs were prepared and used in vivo to transfect mouse corneas by particle-mediated gene transfer (gene gun) on day 7 p.i.. pcDNA3.1 vectors under control of the CMV-promotor were used for gene transfer studies in vivo and in vitro. In vitro, the DNA construct was transfected into cultured L929-cells with lipofectamine as a control for the production of IL-10. The development of HSV-1 keratitis was evaluated clinically and histologically.
Results: 80% of the HSV-1 infected control mice developed necrotizing stromal keratitis by day 14 p.i. After topical administration of IL-10 plasmid DNA, the incidence and severity of the stromal disease was significantly reduced and the corneal sections histologically had decreased inflammatory cell infiltration by day 14 p.i. compared to the control group that received only pcDNA3.1 vector. The gold particle-mediated gene transfer without HSV-1 infection was not associated with any corneal or ocular damage and did not induce any ocular irritation.
Conclusions: The results show that IL-10 is involved in the resolution of HSK. The corneal gene gun technique for the administration of DNA encoding protective cytokines may represent a therapeutic option for the management of inflammatory diseases in the future. The technique of gold particle-medited gene transfer may be a useful tool to study the effects of cytokines on the course of herpetic stromal keratitis.
1Dept. of Ophthalmology, University Essen, Germany; 2 Dept. of Virology, University Essen, Germany; 3 St Franziskus-Hospital, Muenster, Germany