The effects of transforming growth factor β2 and prostaglandin E2 secreted by murine corneal stroma cells on maturating procedure of dendritic cells / 中华实验眼科杂志

ABSTRACT

Background Researches demonstrated that dendritic cells(DCs) are uniformly immature in the central cornea but mature in the peripheral region of cornea.So an important question is which factor impact the maturation of DCs,especially in terms of corneal transplant rejection and the known roles of DCs in the development and persistence of some corneal diseases.Objective This study aimed to examine whether corneal stroma cells (CSCs) inhibit DCs maturation through secreting transforming growth factor beta 2 (TGF-β2) and prostaglandin E2 (PGE2).Methods DCs,T cells and CSCs were isolated and cultured from clean BALB/c and C57BL/6 mice.The level of PGE2 and TGF-β2in CSCs culture supernatant and the fresh RPMI 1640 medium were then analyzed by enzyme linked immunosorbent assay (ELISA).During the DCs maturation stage,the neutralizing TGF-β2 antibody and the EP2 receptor antagonist AH6809 were added in the CSCs culture supernatant respectively.According to the different treatment,cultured cells were assigned to different groups as followscontrol group,CSCs culture supernatant group,AH6809 group,TGF-β2 antibody group,AH6809 +TGF-β2 antibody group.Subsequently,the cellular surface markers for DCs,including CD11c,CD80,CD86,and MHC- Ⅱ,were analyzed by flow cytometry.The capability of stimulating the proliferation of T lymphocytes was evaluated by allogeneic mixed lymphocyte reactions,and the function of endocytosis was assessed by fluorescein isothiocyanate-dextran(FITC) uptake.Results The data of ELISA showed a higher concentration of TGF-β2 and PGE2 in murine CSCs culture supernatant than in the fresh RPMI 1640 medium.Compared with the CSCs culture supernatant group,the expression of CD80,CD86,and MHC- Ⅱ was up-regulated ( P ＜ 0.05 ),the expression of dextran was down-regulated ( P ＜ 0.05 ),and the stimulate index was increased( P＜ 0.05 ) in the TGF-β2 antibody group; the expression of CD86,and MHC-Ⅱ was up-regulated (P＜0.05),the expression of dextran was down-regulated ( F =13.740,P =0.006 ),and the stimulate index was increased(P＜0.05) in the AH6809 group;the expression of MHC-Ⅱ was up-regulated and the stimulate index was increased with statistical difference in interaction(P＜0.05 ) in the AH6809+TGF-β2 antibody group.Compared with the control group,the expression of CD80 and CD86,and the stimulate index was still lower(P＜0.05 ).Conclusions TGF-β2 and PGE2 contribute to the inhibitory effects on DCs maturation mediated by murine CSCs in vitro and further have additive effect on the immunosuppression of DCs.