Interleukin 10 inhibits inflammatory cells infiltration in endotoxin-induced uveitis

Background: Endotoxin-induced uveitis (EIU) is a model for acute anterior uveitis associated with a variety of pro-inflammatory cytokines and nitric oxide production. Interleukin 10 (IL-10) down-regulates these inflammatory mediators. We report a study of the effect of systemic administration of IL-10 on the inflammatory parameters of EIU. Methods: Uveitis was induced in C3H/HeN mice by subcutaneous injection of 200 g lipopolysaccharide (LPS) per mouse. Intraocular inflammation was assessed by leukocyte count and measurement of the protein concentration in the aqueous humor (AH). Mouse recombinant IL-10 at 1000 U or its vehicle alone were administered by three intravenous injections given 4.0 h and 0.5 h before and 8.0 h after LPS injection. Results: The inflammatory cell infiltration in the eyes was significantly reduced in four of five experiments from 40% to 64% in the groups treated with IL-10 compared to the control groups (P<0.05). In contrast, the level of protein exudation in the anterior chamber (AC) was not significantly affected by IL-10 treatment. Conclusion: IL-10 reduces the cellular infiltration in the ocular inflammation produced by endotoxin. This result suggests potential usefulness for IL-10 in the treatment of severe anterior uveitis with a strong cellular component.