cis-presentation by glycosaminoglycans is important for D6 function. (A) Flow cytometry using antibodies against the N-terminal HA tag demonstrates equivalent D6 expression in the CHO-K1/hD6 and CHO-745/hD6 clones selected for analysis. Red lines, isotype control profile; blue lines, anti-HA immunoreactivity profile. (B) FACS profiles demonstrating uptake of Alexa-CCL2 by D6-transfected CHO cells (CHO-K1/hD6) but not untransfected controls (CHO-K1). Alexa-CCL2 uptake is seen as a “right-shift” in the FACS profiles. (C) Alexa-CCL2 uptake by CHO-K1/hD6 (hD6 K1) and CHO-745/hD6 (hD6 745) transfectants at 20 minutes, 1 hour, and 2 hours as assessed by FACS.