Abstract
Purpose :
Recently human cytomegalovirus (HCMV) has been recognized as the pathogen of corneal endotheliitis. However its pathogenesis is unknown, to examine whether HCMV-infected corneal endothelial cells may activate cytotoxic T lymphocyte (CTL) activity of CD8+ T cells from patients of corneal endotheliitis.
Methods :
Immortalized human corneal endothelial cells (HCEn) were infected with HCMV (TB40E strain), and examined for expression of viral proteins (immediate early 1: IE1 and phosphoprotein65: pp65) using confocal microscopy. HCEn cells (HLA-A*2402) were co-cultured with CD8+ T cells from 7 patients of HCMV corneal endotheliitis (A*2402) or 5 HCMV seropositive donors (A*2402). HCMV-specific CD8+ T cell proliferation by infected HCEn cells was examined using BrdU uptake. CTL activity of epitope-targeted CD8+ T cells was measured by ELISA of released interferon-γ and granzyme B.
Results :
HCMV infection induced prompt expression of IE1 and pp65 in HCEn cells. HCMV-infected HCEn cells strongly stimulated proliferation of allogeneic CD8+ T cell from endotheliitis patients and HCMV-seropositive normal subjects. Next, in vitro stimulated HCMV-specific CD8+ T cells were examined for cytotoxic activity against HCEn cells using measurement of interferon-γ and granzyme B.
When the HCMV-expanded CD8+ T cells were co-cultured with IE1 or pp65 epitope stimulated-HCEn cells, seropositive donor-derived CD8+ T cells promptly released interferon-γ and granzyme B in a MHC class I-restricted manner. In endotheliitis patients-derived CD8+ T cells, interferon-γ release stimulated by IE1 or pp65 epitope was significantly impaired.
Conclusions :
Impairment of corneal endothelial cell-induced CTL activity may contribute to immunopathogenesis of corneal endotheliitis.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.