Fig. 4.

CTLA-4 blockade partially restores T cell proliferation in the presence of dexamethasone. a Flow cytometry analysis of CTLA-4 surface expression on CD4 (left) or CD8 (right) T cells stimulated with αCD3/αCD28 microbeads. Unstimulated (dashed line), stimulated in presence of vehicle (solid line), and stimulated in presence of dexamethasone (filled red line) are shown (left) and median fluorescence intensity (MFI) of CTLA-4-expressing T cells is quantified (right). Data are representative of four independent experiments. b Expression of CTLA-4 by qPCR of T cells stimulated in the presence of vehicle or dexamethasone. Data are representative of four independent experiments. c Healthy donor T cells stimulated for four days in the presence of vehicle or dexamethasone and with or without ipilimumab F(ab’)₂ antibody. Proliferation analysis of CD4 T cells (top) and CD8 T cells (bottom) was performed, and the ratio of cells stimulated with dexamethasone relative to vehicle control are shown for Precursor Frequency (PF), Expansion Index (EI), and Proliferation Index (PI). All samples were plated in duplicate and the ratios were analyzed with an unpaired, two-tailed T test. Data are representative of 7 healthy donors. d Cells were cultured as in (c). The number of T cells in each differentiation group were quantified by flow cytometry and analyzed by SPICE. e Expression of the indicated cytokines was determined by qPCR. Five healthy donors were assayed for each condition. Each data point represents and average of triplicate wells. Data were analysed with a paired, two-tailed T test