Apoptosis of infiltrating cells in experimental autoimmune uveoretinitis

Objective To investigate the cellular phenotype and apoptosis of infiltrati ng cells involved in experimental autoimmune uveoretinitis (EAU). Methods Immunohistochemical staining and in situ apoptosis staining were pe rformed using monoclonal antibodies to monocytes and macrophages (ED1), maj or histocompatibility complex (MHC) class-II antigen (OX6), T lymphocytes ( R73) and TAGS 1 Klenow kit on both ocular sections and wholemounts from Lew is rats after immunization with interphotoreceptor retinoid-binding protein (IRBP). Results EAU was induced in 12 of 16 Lewis rats with a mean clinical inflamm ation score of 1.29 +/- 0.7. Influx of monocytes, lymphocytes and MHC class II-positive cells into the uvea and retina was noted after immunization wi th IRBP. Apoptosis of infiltrating cells was observed in the uvea and retin a, and more apoptotic cells were present in the iris and ciliary body compa red with those in the choroid and retina. Conclusion Apoptosis of infiltrating cells occurs at the early stage of EAU , which may greatly contribute to the rapid regression of the inflammation induced by IRBP.