Distribution of MHC class II Positive Cells and Macrophages in the Iris and Ciliary Body in Endotoxin Induced Uveitis

ABSTRACT

Acute anterior uveitis was induced by footpad injection of bacterial lipopolysaccharide(LPS) in the Lewis rats. To evaluate the distribution and density of MHC class II positive cell, macrophages, B lymphocytes infiltration in the iris and ciliary body 24 hours after injection of bacterial LPS, immunohistochemical study was performed in the wholemount tissues with monoclonal antibodies. Quantitative analysis reveals that the density of MHC class II positive dendritic cells in the iris was 348.5+/-55cells/mm2 in the control group and 448.0+/-176cells/mm2 in the LPS injected group(p<0.05). The density of ED2 positive resident tissue macrophages was higher in the LPS injected group(761.9+/-82cells/mm2) than the control group(620.8+/-57cells/mm2)(p<0.05). ED1 positive macrophages infiltrated significantly in the LPS results in increased group(3225.0+/-522cells/mm2) than in the control group(590.5+/-52cells/mm2).OX33 positive cells were not observed in both control and LPS injected eyes. In conclusion, destruction of blood ocular barrier by infection of LPS results in increased infiltration of OX6 positive cells and macrophages, particularly massive influx of blood monocytes into the iris and ciliary body in acute phase of inflammation. This study confirmed that dendritic cells and macrophages play important roles in acute phase of endotoxin induced uveitis.