Figure 1.

Generation of L-selectin–expressing cell lines. (A) Structure of L-selectin and the L-selectin–GyrB (L-Gb) fusion protein containing the entire L-selectin protein in-frame with the NH₂-terminal 24-kD subdomain of the B subunit of bacterial DNA gyrase (GyrB). Domains: EGF, epidermal growth factor–like; SCR, short consensus repeat; TM, transmembrane; Cyto, cytoplasmic. (B) Cell-surface expression of wild-type L-selectin or L-Gb in stably-transfected 300.19 cells and wild-type L-selectin expression by human blood lymphocytes. Cells were isolated and stained with FITC-conjugated LAM1-116 mAb specific for L-selectin (solid line) or an isotype-matched, nonbinding control mAb (dashed line) as previously described (16). Fluorescence histograms from flow cytometry analysis are on a three-decade log scale and are representative of results from at least five experiments.