CD4⁺CD25⁺ regulatory T cells suppress allograft rejection mediated by memory CD8⁺ T cells via a CD30-dependent mechanism
J. Clin. Invest. Zhenhua Dai, et al. 113:310 doi:10.1172/JCI19727 [Go to this article.]

Figure 5
Treg cells promote the apoptosis of memory CD8⁺ T cells in vitro in a contact-dependent manner. (a) Purified memory CD8⁺ T cells (CD8⁺CD44^high) were cultured with Treg cells at a ratio of 1:2 (Treg/M) in 24-well plates in the presence of irradiated BALB/c spleen cells (APCs) for 48 hours. Intracellular expression of IFN-γ is shown in histograms after gating on CD8⁺CD44^high cells. The shaded histogram shows isotype control, and the dotted, gray, and black lines represent memory cells (M) alone, M plus naive Treg cells, and M plus DST Treg cells, respectively. (b) Memory CD8⁺ T cells were incubated as described above. Their proliferation was measured by [³H]-TdR uptakes. Results are presented as the mean of triplicate cultures. (c) Memory CD8⁺ T cells were cultured with Treg cells (1:2, Treg/memory) in 24-well plates and transwell in the presence of APCs and the indicated agents (5 μg/ml anti-FasL) for 48 hours. Cells were then stained for surface markers, fixed, permeabilized, and measured for apoptosis by the TUNEL method. One of three experiments is presented; data are expressed as percentage of apoptotic CD8⁺CD44^high cells.