CHST1 and CHST2 sulfotransferase expression by vascular endothelial cells regulates shear-resistant leukocyte rolling via L-selectin.

Sulfation is an essential component of the selectin ligands, potentially mediated by members of a new family of carbohydrate sulfotransferases. In this study, we assessed the contributions of CHST1, CHST2, CHST3, and CHST4 in producing functional L-selectin ligands. Human umbilical vein endothelial cells predominantly expressed CHST1 and CHST2 transcripts with low levels of CHST3 mRNA, while cytokine activation up-regulated CHST2 expression and induced low-level CHST4 expression. A human umbilical vein endothelial cell line, EA.hy926, displayed functional L-selectin ligands that correlated with CHST1 and CHST2 expression in the absence of CHST4 expression. Increased CHST1 or CHST2 expression by a cell line expressing low-level L-selectin ligand activity during in vitro flow chamber assays increased rolling leukocyte numbers, reduced rolling velocities, and enhanced leukocyte rolling under higher shear stresses. These results suggest that CHST1 and CHST2 contribute to the generation of optimal L-selectin ligands in vascular endothelial cells at sites of inflammation.