登革病毒对人树突状细胞感染性的研究

探讨登革病毒对人树突状细胞(DC)的感染性。人外周新鲜血常规分离单核细胞,经细胞因子GMCSF、IL4诱导培养成DC,通过形态学特征、细胞表型和淋巴细胞刺激能力鉴定。用登革病毒2型(DV2)感染DC,于作用后6h、24h、48h、72h、96h分别收集上清液和细胞,甲基纤维素微量空斑试验测定病毒滴度,间接免疫荧光法检测细胞上病毒抗原表达,透射电镜观察病毒在细胞内的定位。病毒感染后6h即可在培养上清中测出病毒,病毒滴度在48h达到高峰,以后逐渐下降。间接免疫荧光法证明感染的DC胞浆及胞膜上携带病毒抗原。透射电镜下在病毒感染48h后DC胞浆内可见大量病毒颗粒。树突状细胞是登革病毒感染的靶细胞,病毒可感染DC并产生大量病毒颗粒,可能在其发病机制中起重要作用。

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.