Abstract
Purpose: :
In Behcet’s disease (BD), neutrophils increase in the blood and accumulate in hypopyon associated with iridocyclitis. However, the hypopyon resolves readily, even though additional intervention is not given. Experimental autoimmune uveoretinitis (EAU) is an animal model for non–infectious human uveitis including BD. In this present study, we examined whether neutrophil apoptosis is changed in the course of EAU development.
Methods: :
C57/BL6 mice were immunized with 200 µg human interphotoreceptor retinoid–binding protein (IRBP) peptide 1–20 emulsified in complete Freund's adjuvant. They were sacrificed at days 7, 14, 21 and 35 after immunization. The neutrophil fraction was positively selected from spleen cells using auto–MACS. Neutrophils were cultured for 12 hrs with or without LPS (0.1, 1, or 10 g/ml) stimulation, and the rate of apoptosis was assessed by annexin V assay. The severity of EAU was assessed by histopathological examination.
Results: :
After immunization with IRBP 1–20, EAU occurred on day 7, peaked on day 21, and gradually resolved. Neutrophil apoptosis was augmented in mice with EAU, with kinetics corresponding to the severity of EAU. Although LPS stimulation inhibited neutrophil to undergo apoptosis, neutrophil apoptosis augmented by the development of EAU was not affected.
Conclusions: :
Our results indicated that neutrophil apoptosis is augmented by EAU, which is not related to neutrophil activation. Study of the apoptotic factors is ongoing.
Keywords: uveitis-clinical/animal model • apoptosis/cell death • inflammation