T-cell profiling of glaucoma patients

Abstract

Purpose : Accumulating evidence suggests an involvement of adaptive immune responses in the pathophysiology of glaucoma. The purpose of this study was to determine if differences in the T-cell populations exist between patients with primary open angle glaucoma (POAG) and age-matched controls.

Methods : Peripheral blood mononuclear cells (PBMC) were obtained from POAG patients (n=60) and age matched controls (n=40). T-cells were then profiled by fluorescence assisted cell sorting (FACS) using a panel of 29 cell surface markers. In a second experiment, PBMC were stimulated with phorbol myristate acetate (PMA) and ionomycin and analyzed using a panel of 18 cytokine markers. Data were collected on a Cytek® Aurora equipped with five lasers and 64 detectors and analyzed with SpectroFlo and FlowJo software. Data are given as frequencies of total cell number in each sample.

Results : Few differences between POAG and control samples were detected among unstimulated T cell populations. However, there is a significant increase of naïve CD4 T cells in POAG patients (POAG: 4114%; controls: 3415%; P=0.036). However, upon ex vivo stimulation several significant differences in CD4 cell populations are apparent. These include increased frequencies in POAG samples of CD4 T cells expressing CD154 (POAG: 6511%; controls: 537%; P=0.017), naïve CD4 T cells numbers expressing IFN (POAG:10.5%; controls: 0.40.1%; P=0.001), and TNF (POAG: 136%; controls: 73%; P=0.003). Likewise, there was a significant increase in IL-17A expressing central memory cells (POAG: 0.6 controls 0.4 P=0.049). In contrast, a significant decrease in IL-21 (POAG:2 ctrls:5P=0.0002) and IL-17 (POAG: 0.2 controls: 0.4P=0.011) effector memory cells was detected in the POAG cohort. No differences in the CD8 T cells population between POAG and control samples were observed.

Conclusions : Our data suggest that trafficking of central memory cells and/or effector CD4 memory cells is altered in POAG patients. Additionally, the T cell activation threshold is reduced in POAG patients. These findings indicate that T cells in POAG patients are more likely to actively contribute to pro-inflammatory signaling than those of controls.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.