Characterization of varicella zoster virus (VZV)–specific intra–ocular T cell response in patients with VZV–induced uveitis at the single cell level

Abstract

Abstract: : Purpose: VZV is a common cause of infectious uveitis. Beside the direct cytopathogenic effect of the virus, the intra–ocular T cell mediated response direct to VZV may play a pivotal role in its pathology. The aim of the study was to determine the presence and phenotype of VZV–specific T cells in intra–ocular fluid (IOF) samples of patients with VZV–induced uveitis. Methods: IOF–derived T cell lines (TCL) were generated by mitogenic stimulation of IOF samples obtained from 4 patients with VZV–induced uveitis. One patient with either herpes simplex virus– or Toxoplasma gondii–induced uveitis were included as disease controls. Characterization of individual T cells in the TCL was performed by stimulating the TCL with mock or VZV antigen pulsed autologous B cells and subsequent flow cytometric analyses. Virus–specificity, and characterization of the T cells were identified by simultaneous detection of intracellular IFN–γ and cell surface markers CD4, CD8 and T cell receptor (TCR) Vß gene (TCRBV) usage. Results: In contrast to the disease controls, the IOF–derived TCL from all 4 VZV/uveitis patients contained high numbers of VZV–specific T cells. Both CD4⁺ and CD8⁺ VZV–reactive T cells were identified. The majority of the TCL showed a restricted TCRBV usage. T cells expressing one or two TCRBV genes dominated the VZV reactivity in 2 out of 4 TCL analyzed. Conclusions:The data demonstrate that both CD4⁺ and CD8⁺ T cells participate in the VZV–specific T cell response in eyes of VZV/uveitis patients, and suggest the oligoclonality of this local VZV–specific T cell response

Keywords: uveitis–clinical/animal model • varicella zoster virus • inflammation