Figure 7.

Expression of activation markers and inhibitory cell surface molecules on isolated primary humanT lymphocytes. T cells were loaded with citrate-coated superparamagnetic iron oxide nanoparticles (SPION^Citrate) at an iron concentration of 75 µg/mL for 24 h. After purification, they were stimulated with CD3/CD28/CD2 activator mix and recombinant human interleukin-2. 0, 72 and 120 h after stimulation, T cells were stained with anti-CD4 and anti-CD8 antibodies as well as antibodies against the inhibitory cell surface molecules programmed cell death 1 (PD-1), lymphocyte activation gene 3 (LAG-3), T cell immunoglobulin and mucin domain containing 3 (Tim-3), and the T cell activation markers CD25 and CD69 and analyzed in flow cytometry. Results for CD4⁺ T cells are displayed in (a) and CD8⁺ T cells in (b). The experiments were performed with four different donors. Significance between the mean values of all donors of loaded cells and control at the respective points of time is indicated as follows: not significant (n.s.), p > 0.05, * p < 0.05, ** p < 0.005. Abbreviations: LAG-3: lymphocyte activation gene 3, MFI: median fluorescence intensity, PD-1: programmed cell death 1, SPION^Citrate: citrate-coated superparamagnetic iron oxide nanoparticles, Tim-3: T cell immunoglobulin and mucin domain containing 3.