Murine ciliary body pigment epithelial cells inhibit activation of T cells

PURPOSE: Pigment epithelial(PE) cells cultured from the eye possess the novel property of suppressing T cells in vitro. Although cultured iris PE (IPE) and retinal PE (RPE) achieve suppression, the function of ciliary body PE (CBPE) is still unknown. We investigated whether CBPE can suppress the activation of T cells in vitro. METHODS: CBPE, IPE and RPE cells(controls) were established from normal C57BL/6 mice. T-cell activation was assessed by proliferative response and cytokine production, by ELISA. The expression of candidate genes on ocular PE was evaluated with on oligonucleotide microarray, and PE proliferation and PE morphology were also evaluated. RESULTS: CBPE significantly suppressed T cell activation in vitro. Cell division of CBPE was much greater than in other PE, and the cells were confluent from on early phase. Microarray analysis showed that the expression of candidate genes in CBPE is similar to the expression in other PE cells. CONCLUSIONS: CBPE fully suppress T cell activation. Thus, ocular pigment epithelial cells display inhibitory function in the immune privileged site.