FIG. 3.

GXM, but not GalXM or MP, induces surface L-selectin loss from a CD4⁺ T-cell line, Jurkat. (A) Effects of PMA, GXM, GalXM, and MP on surface L-selectin expression on Jurkat cells. L-selectin on Jurkat cells was measured by direct immunofluorescence staining with flow cytometric analysis after the cells were incubated with the designated reagents at 37°C for 2 h. The values represent the mean ± SEM obtained from six individual experiments. (B) Quantification of soluble L-selectin levels in supernatants of Jurkat T cells after incubation with serum-free RPMI 1640 medium, PMA, GXM, GalXM, or MP at 37°C for 2 h. The supernatants were examined for soluble L-selectin with a commercial ELISA kit. The values represent the means ± SEMs obtained from quadruplicate determinations for each sample. The data are from one representative experiment of two. The concentration of GXM, GalXM, or MP used for treatment was 1 mg (dry weight)/ml.