FIGURE 7.

Inhibition of tyrosine phosphatase activity cannot overcome the block to galectin-1 death in T cells expressing high levels of α2,6-linked sialic acid. A, tyrosine phosphatase inhibitor bpV(phen) increases galectin-1 death of PhaR2.1 and PhaR ST3 cells, but does not affect PhaR ST6 cells. Phar2.1, PhaR ST6, and PhaR ST3 cells were treated with 20 μm bpV(phen) or buffer control for 3 h, then incubated with 20 μm galectin-1 or buffer control for an additional 4.5 h. Data are mean ± S.D. of triplicate samples. B, treatment with bpV(phen) does not increase galectin-1-induced death in SP thymocytes. Total thymocytes were incubated with 10 μm bpV(phen) and followed by 20 μm galectin-1 as above. Cells were stained with 7-AAD, anti-CD4, and anti-CD8, and gated for DP, CD4, and CD8 populations. Data are mean ± S.D. of triplicate samples from two independent experiments.