Figure 4.

Fluorescence‐activated cell sorting (FACS) analysis of HLA expression in human telomerase‐immortalized corneal epithelial cells (HTCECs) of unstimulated and stimulated cell populations. (A): Histograms showing unstained population (control) and cell populations stained with HLA class I A, IB, and IC and Class II antibodies. (B): Median fluorescence index of HLA expression for control and stained populations without cytokine stimulation (n = 3). Mean median fluorescence index for class I was significantly different than for control but not for other class II molecules. (C): Representative FACS histograms out of three replicates showing HLA expression of class I and class II antigens in HTCECs after stimulation with IFN‐γ, TNF‐α, and combined stimulation of both (10 ng/ml, 3 days). Cells were stained with fluorescein isothiocyanate‐conjugated class I, HLA‐DR, HLA‐DQ antibodies, and HLA‐DP. Negative control for HLA‐DP was secondary IgG only. Gray, unstimulated cells; red, stimulated cells; yellow, IgG‐only stimulated cells. Abbreviations: HLA, human leukocyte antigen; IFN, interferon; TNF, tumor necrosis factor.