tailieunhanh - Báo cáo y học: "The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells"

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: The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells. | Liu and Eiden Retrovirology 2011 8 53 http content 8 1 53 RETR0VIR0L0GY RESEARCH Open Access The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells Meihong Liu and Maribeth V Eiden Abstract Background Over the last several decades it has been noted using a variety of different methods that cells infected by a specific gammaretrovirus are resistant to infection by other retroviruses that employ the same receptor a phenomenon termed receptor interference. Receptor masking is thought to provide an earlier means of blocking superinfection whereas receptor down regulation is generally considered to occur in chronically infected cells. Results We used replication-competent GFP-expressing viruses containing either an amphotropic murine leukemia virus A-MLV or the gibbon ape leukemia virus GALV envelope. We also constructed similar viruses containing fluorescence-labeled Gag proteins for the detection of viral particles. Using this repertoire of reagents together with a wide range of antibodies we were able to determine the presence and availability of viral receptors and detect viral envelope proteins and particles presence on the cell surface of chronically infected cells. Conclusions A-MLV or GALV receptors remain on the surface of chronically infected cells and are detectable by respective antibodies indicating that these receptors are not downregulated in these infected cells as previously proposed. We were also able to detect viral envelope proteins on the infected cell surface and infected cells are unable to bind soluble A-MLV or GALV envelopes indicating that receptor binding sites are masked by endogenously expressed A-MLV or GALV viral envelope. However receptor masking does not completely prevent A-MLV or GALV superinfection. Background Rubin and co-workers discovered many years ago that chicken embryos productively infected with Rous Sarcoma Virus RSV were .