Fig. 4.

CD45 regulates membrane glycan clustering and cell death signaling activity of synthetic Gal3 oligomers. (A) Schematic presentation of membrane glycoconjugates that Gal3 can engage on Jurkat and J45.01 T cells. Membrane glycoprotein CD45 is distinguished from other membrane glycoconjugates, such as CD7, by its relatively larger size. Jurkat T cells are CD45⁺ and CD7⁺, whereas J45.01 T cells are CD45⁻ and CD7⁺. (B) Confocal microscopic images of Hexamer (green) and CD45 (magenta) following Hexamer treatment of Jurkat T cells and J45.01 T cells for 2 h. (C) Confocal microscopic images of Hexamer (green) and CD7 (magenta) following Hexamer treatment of Jurkat T cells and J45.01 T cells for 2 h. (D) Percentage of J45.01 T cell death after 18 h treatment with synthetic Gal3 oligomers or wild-type Gal3 (WT-Gal3), shown relative to the PBS-treated cells (untreated control). (E) Percentage of J45.01 T cells in the early apoptotic or late apoptotic population after 18 h treatment with synthetic Gal3 oligomers or WT-Gal3, shown relative to the untreated control. For D, n ≥ 3, mean ± SD, NS is no significant difference, and comparisons were made using one-way ANOVA with Tukey’s post hoc. For E, n ≥ 3, mean ± SD, ***P < 0.001, ****P < 0.0001, NS is no significant difference, and comparisons were made using unpaired two-tailed Student’s t test. All experiments were performed at an equimolar concentration of sfGFP or Gal3 = 5 µM (i.e., [WT-Gal3] = 5 µM, [Pentamer] = 1 µM, [Hexamer] = 0.83 µM).