Production of Prostaglandin E2 and I2 Is Coupled with Cyclooxygenase-2 in Human Follicular Dendritic Cells

ABSTRACT

BACKGROUND: Prostaglandins (PGs) play pathogenic and protective roles in inflammatory diseases. The novel concept of PGs as immune modulators is being documented by several investigators. By establishing an in vitro experimental model containing human follicular dendritic cell-like cells, HK cells, we reported that HK cells produce prostaglandin E2 (PGE2) and prostaglandin I2 (PGI2) and that these PGs regulate biological functions of T and B cells. METHODS: To investigate the respective contribution of cyclooxygenase-1 (COX-1) and COX-2 to PGE2 and PGI2 production in HK cells, we performed siRNA technology to knock down COX enzymes and examined the effect on PG production. RESULTS: Both PGE2 and PGI2 productions were almost completely inhibited by the depletion of COX-2. In contrast, COX-1 knockdown did not significantly affect PG production induced by lipopolysaccharide (LPS). CONCLUSION: The current results suggest that mPGES-1 and PGIS are coupled with COX-2 but not with COX-1 in human follicular dendritic cell (FDC) and may help understand the potential effects of selective COX inhibitors on the humoral immunity.