Triggering of DC migration by dengue virus stimulation of COX‐2‐dependent signaling cascades in vitro highlights the significance of these cascades beyond inflammation

A term “bone‐breaking fever” is used in Chinese medicine to describe the symptoms of patients infected with dengue virus (DV). We examined the significance of the COX‐prostaglandin pathway in human DC infected by DV. We show that DV infection induced the expression of COX‐2 and the production of prostaglandin E₂ (PGE₂) in DC, and stimulated the DNA binding of NF‐κB and the kinase activity of both IκBα kinase (IKK) α and β. DV infection also activated MAPK and AP‐1 signaling. Both IκBα kinase‐NF‐κB and MAPK‐AP‐1 were upstream of COX‐2 activation. Our investigation into the significance of COX‐2‐PGE₂ pathway also revealed that DV infection enhances DC migration by inducing CC chemokine receptor 7 (CCR7) expression, and that blocking COX‐2 or MAPK activity suppresses DV‐induced DC migration. Our data also suggest that PGE₂ can induce CCR7 expression on DC and that antagonists of the PGE₂ receptors EP2 and EP4 suppress DV‐induced DC migration. We further show that the increased CCR7 expression was observed in both DV‐infected and bystander DC, suggesting the presence of secondary effects in inducing CCR7 expression. Collectively, this study reveals not only the pathways involved in COX‐2 synthesis in DV‐infected DC but also the autocrine action of PGE₂ on the migration of DV‐infected DC.