OBJECTIVE: To explore the interaction of Mycoplasma pneumoniae (M. pneumoniae) capsular polysaccharide (CPS) with dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and its influence on the secretions of IL-10 and IL-12. METHODS: M. pneumoniae CPS and lipid-associated membrane proteins (LAMPs) were extracted and purified, and the specific binding of CPS and DC-SIGN was detected using indirect immunofluorescence staining. The expressions of IL-10 and IL-12 was tested by ELISA in immature DC after treated by CPS or/and LAMPs. RESULTS: Indirect immunofluorescence staining showed CPS could recognized and bind specifically to the DC, which could be blocked by the DC-SIGN-specific blocking antibody. ELISA revealed that the production of immunosuppressive cytokine IL-10 increased when immature DC were stimulated by CPS, and the effect was more obvious with the presence of LAMPs(P<0.05). But the production of IL-12 did not change significantly after stimulation of CPS or/and LAMPs. CONCLUSION: The CPS of M.pneumoniae can recognize and bind to the DC-SIGN specifically and promote the immature DC to secret IL-10.
OBJECTIVE: To explore the interaction of Mycoplasma pneumoniae (M. pneumoniae) capsular polysaccharide (CPS) with dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and its influence on the secretions of IL-10 and IL-12. METHODS: M. pneumoniae CPS and lipid-associated membrane proteins (LAMPs) were extracted and purified, and the specific binding of CPS and DC-SIGN was detected using indirect immunofluorescence staining. The expressions of IL-10 and IL-12 was tested by ELISA in immature DC after treated by CPS or/and LAMPs. RESULTS: Indirect immunofluorescence staining showed CPS could recognized and bind specifically to the DC, which could be blocked by the DC-SIGN-specific blocking antibody. ELISA revealed that the production of immunosuppressive cytokine IL-10 increased when immature DC were stimulated by CPS, and the effect was more obvious with the presence of LAMPs(P<0.05). But the production of IL-12 did not change significantly after stimulation of CPS or/and LAMPs. CONCLUSION: The CPS of M.pneumoniae can recognize and bind to the DC-SIGN specifically and promote the immature DC to secret IL-10.