Interaction between mouse retinal astrocyte and antigen specific Th1 and Th17 Cells

Abstract

Background C57BL/6 and B10R Ⅲ are routine murine species used in experimental autoimmune uveitis (EAU).The inflammation is light for mouse after immunization whereas it is prominent for B10R Ⅲ. Objective This study was to observe the killing effect of interphotoreceptor retinoid binding protein (IRBP) 1-20-specific T cells on mouse retinal astrocyte.Th1 and Th17 cells effect in the EAU mechanism was discussed.Methods B10RllⅢ mice and C57BL/6 mice were immunized with IRBP 161-180 and IRBP 1-20 in complete Freund adjuvant (CFA).The infiltrating cells of diseased B10R Ⅲ eyes were analyzed by flow cytometry.IRBP 1-20-specific T cells were isolated from the drainage lymph node and spleen and cultured in IL-2 or IL-23 for Th1 and Th17 cells polarization,respectively.Th1 and Th17 cells cultured for 5 days were seeded on the mouse retinal astrocyte monolayer pretreated with gamma interferon.Cell interaction was observed and the quantity of TNF-α was tested by ELISA.Every test was repeated 6 times and the mean was calculated.The maintenance of experimental animals complied with the Statement of ARVO. Results There were lots of infiltrating cells in the eyes of B10Rm mice after immunization,including 9.5％ IFNγ+ cells,5.1％ IL-17+cells and 41.4％ CD45+ cells.Six days after IRBP1-20 stimulation and cultured by IL-2 and IL-23,44.0％ and 8.0％ cells were IFNγ+,and 1.0％ and 26.0％ cells were IL17+.Twentyfour hours after the interaction between Th1 or Th17 and retinal astrocyte,retinal astrocyte died and detached.The killing effect of Th17 was stronger than Th1.48 hours after co-culture of Th1 or Th17T cells with astrocytes,the concentrations of TNF-α were ( 500± 10 ) and ( 801 ±24 μg/L) μg/L,respectively,with a significant statistical difference (t =-20.36,P =0.00). Conclusions Both Th1 and Th17 can kill retinal astrocyte,but Th17 plays a key role in the EAU pathogenesis process.The killing effect is caused by intercellular contact and interaction under the induction of cytokines. Key words: Experimental autoimmune uveitis; Antigen specificity; Astrocyte; T cell