Upregulated IL-21 and IL-21 receptor expression is involved in experimental autoimmune uveitis (EAU).
OBJECTIVE
Interleukin (IL)-21 has recently been shown to play a vital role in the development of many autoimmune diseases. Our study is designed to investigate the alteration and possible function of IL-21 in the development of an experimental autoimmune uveitis (EAU) model.


METHODS
EAU was induced in B10.RIII mice by subcutaneous injection of interphotoreceptor retinoid-binding protein (IRBP) 161-180 emulsified with complete Freund's adjuvant (CFA) and evaluated by clinical and histopathologic observation. IL-21 and IL-21R mRNA expressions in cells of draining lymph node (DLN) and spleen in EAU and control mice were determined by reverse transcription-PCR. The frequencies of interleukin-21 receptor positive cells were also examined using flow cytometry. IL-17 levels in the supernatant of the cell culture upon IL-21 stimulation were assayed by enzyme-linked immunosorbent assay.


RESULTS
Results showed that EAU was successfully induced by IRBP161-180. Expression of IL-21 mRNA was significantly increased in cells of DLN and spleen in EAU compared with recovery phase mice and normal controls. IL-21R was also found upregulated in DLN and spleen cells of EAU mice by reverse transcription-PCR and flow cytometry. Cells in EAU cultured with IL-21 combined with transforming growth factor-beta induced increased production of IL-17.


CONCLUSIONS
The findings revealed that increased IL-21 and IL-21R expression may be involved in the development of EAU, possibly by promoting IL-17 secretion.
Liu
Lan
L
Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, P.R. China. flowingblue@126.com
Xu
Yongfeng
Y
Wang
Jianyong
J
Li
Huiyan
H
D000818:Animals; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000150:complications* / Q000235:genetics* / Q000473:pathology; D002452:Cell Count; D004195:Disease Models, Animal; D006801:Humans; D020381:Interleukin-17 / Q000378:metabolism; D007378:Interleukins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D008198:Lymph Nodes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D053655:Receptors, Interleukin-21 / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000187:drug effects / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*; D014605:Uveitis / Q000139:chemically induced / Q000150:complications* / Q000235:genetics* / Q000473:pathology; D000098546:Interleukin-21
D020381:Interleukin-17; D007378:Interleukins; D053655:Receptors, Interleukin-21; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D000098546:Interleukin-21