CD33rSiglec expression by resting and activated T cells. Adult peripheral blood or cord blood mononuclear cells were subjected to in vitro activation using soluble anti-CD3 and IL-2 for up to 7 days. Cells were split every 2–3 days. (a) Expression of Siglecs-3, –5, –6, –7, –8, –9, –10 was evaluated in the CD4 and CD8 T cell from multiple adult donors. (b) Representative plots and (c) summary for multiple adult donors (each dot represents an individual donor) of Siglec-5 expression within CD4 and CD8 T cells. (d) Summary for multiple cord blood donors of Siglec-5 expression within CD4 and CD8 T cells. (e) Summary for multiple cord blood donors (n = 3) for expression of Siglec-5 and PD-1 and (f) Siglec-5 and CTLA-4 within CD4 and CD8 T cells