Fig. 1
Extracellular cholesterol import is required for T-cell proliferation and is decreased in T cells from CLL patients. A PBMCs from healthy donors (HD) and chronic lymphocytic leukemia (CLL) patients were labeled with cell-trace violet (CTV) and stimulated with αCD3/αCD28 antibodies for 5 days under complete serum conditions, lipid deprivation (lipoprotein-deficient serum, LPDS) and LPDS supplemented with LDL. Proliferation of CD4+ T cells was measured as percentage divided cells (left) and division index (average number of cell divisions that a cell in the original population has undergone; right). Representative CTV histograms are shown (complete serum: black, LPDS: blue, and LPDS+ LDL: purple). B Expression of CD25, CD71 and IL-2 (intracellularly, after 4 h of Brefeldin treatment) was measured on CD4+ HD and CLL T cells after 2 days of stimulation in the same experimental conditions as in (A). C PBMCs from HD and CLL patients were stimulated with αCD3/αCD28 antibodies for 5 days in the presence or absence of the NPC1 inhibitor U18666A (10 µM). Proliferation of CD4+ T cells is shown as percentage divided cells (left) and division index (right). Representative CTV histograms are shown (αCD3/αCD28 only: black, αCD3/αCD28 + U1866A: orange). D Expression of CD25 was measured after 2 days of stimulation in the same experimental conditions as in (C). E Expression of LDLR was measured on CD4+ HD and CLL T cells after a 2-day stimulation with αCD3/αCD28 antibodies in total CD4+ T cells (left) and within CD4+ CD25high T cells (right). F expression of LDLR was measured on CD4+ HD and CLL T cells in the same experimental conditions as in (B). G LDLR expression was measured on day 2 and day 5 upon PBMC stimulation in the presence or absence of the NPC1 inhibitor U18666A (10 µM) on CD4+ T cells (left) and within CD4+ CD25high T cells (right). Data are presented as mean ± SEM and differences were analyzed with two-way repeated measures ANOVA with Tukey’s/Šidák’s multiple comparison test (A–E (left), F, G) or t-test (E (right)). **** = p < 0.0001; *** = p < 0.001; ** = p < 0.01; * = p < 0.05
