[Study on dengue virus infection of human dendritic cells]

To study Dengue virus (DV) infection of human dendritic cells (DC). Monocyte isolated from healthy human peripheral blood were incubated in medium with GM-CSF and IL-4 for more than 7 days. DCs were then collected and identified by transmission electron microscope, immunohistochemistry and lymphocytes stimulatory ability. Dengue virus type II (DV-2) were infected with human dendritic cells(DC) in vitro, culture supernatants and cells were collected by different time postinfection (6h, 12h, 24h, 48h, 72h). Viral titers were evaluated by microplaque forming assay on C6/36 monolayer cells; DV antigen in human dendritic cells were demonstrated by an indirect immunofluorescent assay (IFA). Localization of DV in DC was observed under a transmission electron microscope. The viruses were detected in the culture supernatants as early as 6h after infection; the highest viral titers were obtained at 48h, and then declined to very low titers at 96h. DV-2 antigen was detected in infected DC by IFA. After infection for 48h, DV particles were obvious in cystic vesicle, vacuoles . Human dendritic cells are targets of dengue virus infection. DV could efficiently infect DC and produce virus particles, DC possibly plays a role in the pathogenesis of DV infection.