Retinal Pigment Epithelium (RPE) Can Either Promote or Inhibit the Activation of Uveitogenic T Cells In Vitro

Abstract

Abstract: : Purpose: RPE plays an important role in maintaining privileged status of the eye. In this study, we examined the outcomes of in vitro interactions between uveitogenic T cells and non- or activated-RPE. Methods: IRBP-reactive T cell lines and RPE were established. Expression of MHC class II molecules were determined on RPE activated by grade doses of IFN-γ by flow cytometry. Proliferation and cytokine production of IRBP-reactive T cells were measured after pre-exposure to the RPE activated by different doses of IFN-γ. Results: RPE expressed varying levels of MHC class II molecules depending on the concentrations of IFN-γ. IRBP-specific T cells could either be stimulated or inhibited by RPE. The dual effect of RPE is regulated via different levels of MHC class II molecules on RPE. Conclusion: Controlling immune activities of uveitogeneic T cells through varying levels of MHC class II expression on RPE might be one of the regulatory mechanisms by which RPE maintain immune privilege in the eye.

Keywords: retinal pigment epithelium • immunomodulation/immunoregulation • uveitis-clinical/animal model