B7+ iris pigment epithelium induce CD8+ T regulatory cells; both suppress CTLA-4+ T cells.

Cells T + Regulatory Cells; Both Suppress Ctla-4 T + Iris Pigment Epithelium Induce Cd8 + B7

B7+ iris pigment epithelial cells convert T cells into CTLA-4+, B7-expressing CD8+ regulatory T cells.

PURPOSE To determine whether iris PE (IPE) promotes the generation of regulatory T-cells (Tregs) with cell contact via B7-2/CTLA-4 interactions. METHODS T cells were cocultured with IPE cells obtained from eyes of normal and B7-deficient mice, x-irradiated, and used as regulators. IPE T regulator cells (IPE Tregs) of normal and CD28- or CTLA-4-deficient mice were established. Target bystander...

CTLA-4+CD8+ T cells that encounter B7-2+ iris pigment epithelial cells express their own B7-2 to achieve global suppression of T cell activation.

Pigment epithelial (PE) cells cultured from the eye possess the novel property of suppressing TCR-dependent activation of T cells in vitro. Iris PE (IPE) cells accomplish this suppression by a direct cell contact mechanism in which B7-2 expressed by the PE cells interacts with CTLA-4 on responding T cells. Because CTLA-4 expression is constitutively expressed on a very small proportion of naive...

Iris Pigment Epithelium Expressing CD86 (B7-2) Directly Suppresses T Cell Activation In Vitro via Binding to Cytotoxic T Lymphocyte–associated Antigen 4

A monolayer of pigment epithelium (PE) lines the iris PE (IPE), ciliary body PE, and retina PE of the inner eye, an immune-privileged site. These neural crest-derived epithelial cells participate in ocular immune privilege through poorly defined molecular mechanisms. Murine PE cells cultured from different ocular tissues suppress T cell activation by differing mechanisms. In particular, IPE cel...

Role of thrombospondin-1 in T cell response to ocular pigment epithelial cells.

Ocular pigment epithelium (PE) cells promote the generation of T regulators (PE-induced Treg cells). Moreover, T cells exposed to PE acquire the capacity to suppress the activation of bystander T cells via TGFbeta. Membrane-bound TGFbeta on iris PE cells interacts with TGFbeta receptors on T cells, leading to the conversion of T cells to CD8(+) Treg cells via a cell contact-dependent mechanism....