Fucoidan and sulfatide inhibited SDF-1–induced CXCR4 internalization. (A) Jurkat cells were prelabeled with anti-CXCR4 antibody. Cells were then washed and incubated with SDF-1 (500 ng/mL) plus fucoidan or sulfatide (100 μg/mL) for 1 hour at 37°C. CXCR4 that was originally expressed and still remaining on cell surface was detected by PE-conjugated sheep antimouse antibody and flow cytometry. Representative histograms from 1 of 3 similar experiments are shown. (B) Jurkat cells were prelabeled with ¹²⁵I-SDF-1. CXCR4 internalization was induced by incubation at 37°C with or without L-selectin stimulation and quantitated by a gamma counter.