Abstract
Purpose :
CD4+ T cell subsets (Th1, Th17) play an important immunopathogenic role in experimental autoimmune uveitis (EAU). The aim of this study was to investigate in vivo and in vitro whether the T cell subset (Th1/17) contributes to the inflammatory process within the retina.
Methods :
Female C57Bl/6 mice (aged 6-8 weeks; n=10 mice per group) were immunized with interphotoreceptor retinoid-binding protein emulsified in complete Freunds’ adjuvant sc and pertussis ip. Mice were clinically scored by retinal fundoscopy (days 14, 18, and 20) and harvested at peak disease (usually days 19-21 post immunization). Histological scores were also performed. Retinal flow cytometry and immunostaining for T cell subsets were analyzed. For in vitro migration assays, draining lymph node (dLN) cells from peak EAU mice were harvested and co-cultured in 3um Transwell inserts with confluent monolayers of primary mouse brain endothelial cells (MBECs) isolated from 3-4 week old C57Bl/6 mice (n=10). After 18 hours, the non-migrated, adherent and migrated T cells were immunophenotyped by flow cytometry (LSR Fortessa, BD).
Results :
EAU mice had detectable levels of Th1, Th17 and Th1/17 cells infiltrating the vitreous and retinal layers. Increased percentages of retinal Th17 (63.4 ± 5.8%; P < 0.0001) and Th1/17 (29.4 ± 7.4%; P < 0.0001) cells were detected relative to Th1 (2.4 ± 2.2%). In an in vitro migration assay, unlike Th1 and Th17, Th1/17 cells were significantly increased in the migrated population (15.6 ± 9.5; P = 0.0014) relative to non-migrated cells (1.9 ± 1.5%).
Conclusions :
Th1/17 cells were observed in the retinal tissues during peak EAU, and demonstrated significantly increased migratory function. The immunopathogenic role of these cells is currently under investigation.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.