Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Tetherin does not significantly restrict dendritic cell-mediated HIV-1 transmission and its expression is upregulated by newly synthesized HIV-1 Nef. | Coleman et al. Retrovirology 2011 8 26 http content 8 1 26 RETROVIROLOGY RESEARCH Open Access Tetherin does not significantly restrict dendritic cell-mediated HIV-1 transmission and its expression is upregulated by newly synthesized HlV-1 Nef Christopher M Coleman1 Paul Spearman2 and Li Wu1 Abstract Background Dendritic cells DCs are among the first cells to encounter HIV-1 and play important roles in viral transmission and pathogenesis. Immature DCs allow productive HIV-1 replication and long-term viral dissemination. The pro-inflammatory factor lipopolysaccharide LPS induces DC maturation and enhances the efficiency of DC-mediated HIV-1 transmission. Type I interferon IFN partially inhibits HIV-1 replication and cell-cell transmission in CD4 T cells and macrophages. Tetherin is a type I IFN-inducible restriction factor that blocks HIV-1 release and modulates CD4 T cell-mediated cell-to-cell transmission of HIV-1. However the role of type I IFN and tetherin in HIV-1 infection of DCs and DC-mediated viral transmission remains unknown. Results We demonstrated that IFN-alpha IFNa -induced mature DCs restricted HIV-1 replication and transinfection of CD4 T cells. Tetherin expression in monocyte-derived immature DCs was undetectable or very low. High levels of tetherin were transiently expressed in LPS- and IFNa-induced mature DCs while HIV-1 localized into distinct patches in these DCs. Knockdown of induced tetherin in LPS- or IFNa-matured DCs modestly enhanced HIV-1 transmission to CD4 T cells but had no significant effect on wild-type HIV-1 replication in mature DCs. Intriguingly we found that HIV-1 replication in immature DCs induced significant tetherin expression in a Nef-dependent manner. Conclusions The restriction of HIV-1 replication and transmission in IFNa-induced mature DCs indicates a potent anti-HIV-1 response however high levels of tetherin induced in mature DCs cannot significantly restrict wild-type HIV-1 release and DC-mediated