Global Activation of CD8+ Cytotoxic T Lymphocytes Correlates with an Impairment in Regulatory T Cells in Patients with Generalized Vitiligo
Figure 4
Tregs suppress proliferation and cytokine production of autologous CD8+ T cells.
(A) Detection of Treg suppression for CD8+ T cells. CFSE-labeled CD8+ T cells were stimulated in the presence of CD4+ CD25+ Treg cells at the indicated ratios for 5 days. Cellular division was measured by flow cytometric analysis based on the intensity of CFSE signal. Representative CFSE profiles from a GV patient and a normal control are shown. Values given represent the percentage of CFSElow cells among CFSE+ T cells. (B) Treg cells are largely unresponsive to TCR stimulation. Unlabeled and CFSE labeled CD4+ CD25+ T cells were cultured with anti-CD3/CD28 Abs, under the same stimulatory conditions as above, but without autologous CD8+ T cells present. Values given are the percentage of CFSElow cells among CFSE+ Treg cells (Representative cases). (C) Dose-dependent suppression of CD8+ T cell proliferation by CD4+ CD25+ T cells. The suppressive capacity of CD4+ CD25+ Tregs was compared between GV patients (n = 6) and normal control subjects (n = 4). * = P<0.05; ** = P<0.01. The production of IFN-γ (D) and TNF-α (E) was determined. CD8+ T cells were cultured with Tregs at various ratios in the presence of anti-CD3/CD28 Ab stimulation for 48 hours. IFN-γ and TNF-α release into the supernatant was determined by an enzyme-linked immunosorbent assay. The data were from 6 progressive GV individuals and 4 healthy controls. * = P<0.05; ** = P<0.01.