Abstract: Objective To study the effect and mechanism of soluble dendritic cell-specific intercellular adhesion molecule
3-grabbing nonintegrin (sDC-SIGN) on the phagocytosis of Staphylococcus aureus (S. aureus) by immature dendritic cells
(imDCs). Methods Flow cytometry was employed to examine the effect of sDC-SIGN on the phagocytosis of S. aureus by
imDCs. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the binging of sDC-SIGN to S. aureus, lipoteichoic
acid (LTA) and lipopolysaccharides (LPS) and investigate the effect of the ligands mannan and LTA and anti-DC-SIGN
antibodies 1C6 and 4H3 on the binging of sDC-SIGN to S. aureus. Results sDC-SIGN inhibited the phagocytosis of S. aureus by
imDCs. sDC-SIGN bound to S. aureus in a Ca2 +-dependent manner. sDC-SIGN concentration-dependently bound to LTA, but
not to LTA, and the binging of sDC-SIGN to S. aureus was blocked by mannan, LTA, 1C6 and 4H3. Conclusion sDC-SIGN
preferentially binds to the carbohydrate constituents on S. aureus to affect the binding between membrane-bound DC-SIGN
and S. aureus, thus suppressing the phagocytosis of S. aureus by imDCs.