The effects of signaling pathways activating DC-SIGN promoter on the activity of HIV-1 5'LTR

Abstract

Objective To explore the effects of signaling pathways inducing activation of DC-SIGN promoter on the activity of HIV-1 5'LTR.Methods The sequences of DC-SIGN promoter and HIV-1 5'LTR were amplified by PCR and then cloned into pGL-3/Basic plasmid to constructluciferase reporter plasmids for DC-SIGN promoter and HIV-1 5'LTR.Differentiated THP-1 cells stimulated by PMA (phorbol myristate acetate) were used as the in vitro model of DCs.The activaties of DC-SIGN promoter and HIV-1 5'LTR induced by IL-4 in differentiated THP-1 cells were studied using luciferase reporter plasmids.The signaling pathways were identified by using specific inhibitors.Results IL-4 induced signaling pathways could increase the activities of HIV-1 5'LTR and DC-SIGN promoter for more than two times in THP-1 cells transfected with luciferase reporter plasmids.However,the activity of HIV-1 5'LTR was weaker than that of DCSIGN promoter.ERK/JAK-STAT/NF-κB signal pathway blockers could inhibit the luciferase activity driven by DC-SIGN promoter,of which ERKI/2 blocker showed the strongest inhibitory effect that almost completely blocked IL-4 induction.NF-κB blocker had a significant inhibitory effect on HIV-1 5'LTR activity at a rate of 52.32％,followed by the ERK blocker at a rate of 43.31％.Conclusion This study suggested that IL-4-induced signaling pathways mediate the activation of DC-SIGN promoter and HIV-1 5'LTR through NFκB and ERK. Key words: DC-SIGN; HIV-1 latency; Signaling pathways; Dendritic cells; Reactivation