The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform

Mariano Esteban - One of the best experts on this subject based on the ideXlab platform.

Dolores Rodríguez - One of the best experts on this subject based on the ideXlab platform.

J C Gluckman - One of the best experts on this subject based on the ideXlab platform.

  • Extensive C-terminal deletion in human immunodeficiency virus type 1 Env Glycoprotein arising after long-term culture of chronically infected cells.
    The Journal of general virology, 1994
    Co-Authors: V Zaides, E. Fenouillet, M Yagello, T Veselovskaya, D Schmitt, L Rykova, J C Gluckman
    Abstract:

    Human immunodeficiency virus type 1 (HIV-1) chronically infected (CI) cell lines were established from HIV-1HIB/LAI-infected MT-4 cells that survived acute infection. The HIV env gene expressed in the two long-term cultured cell lines differed from that of the lines cultured for shorter periods, by coding for a Glycoprotein Gp 160 that had the C terminus deleted. One long-term cultured cell line, CI-17, was studied in detail. An insertion of a premature stop codon in the env gene caused about 90% of Gp160 molecules to be truncated (Gp160x), lacking both cytoplasmic and transmembrane domains; these species were secreted into the cell medium, and could form oligomers with other truncated Gp160 molecules as well as with their normal counterparts. CI-17 cells constantly yielded high levels of viral protein and relatively low quantities of infectious virus, without cytopathicity. However, acute infection of fresh MT-4 cells with CI-17-derived virus led to cytopathicity, the rate of which as well as the Env Glycoprotein pattern depended on multiplicity: (i) using an infection dose of 10(-4) ID50/cell, cells died 7 to 8 days post-infection with normal Gp160 synthesis predominating; (ii) with 10(-2) ID50, Gp160x was produced as early as 48 h post-infection and cell death was delayed. Predominant Gp160x formation occurred again when new CI cell lines were obtained with CI-17-derived virus. Thus, two human immunodeficiency virus variants, a normal and a defective one, are persistently expressed in CI-17 cells. The other long-term cultured CI cell line also expressed Gp160 with a similar (albeit slightly longer) deletion of a C-terminal region in most molecules, but the cell lines that were cultured for shorter periods did not. These results suggest that the emergence of HIV variants with a C-terminal deletion in the Env Glycoprotein, which coexist with normal virus, may play a role in maintaining the long-term growth capacity and viability of CI cells.

J R Rodriguez - One of the best experts on this subject based on the ideXlab platform.

E. Fenouillet - One of the best experts on this subject based on the ideXlab platform.

  • Extensive C-terminal deletion in human immunodeficiency virus type 1 Env Glycoprotein arising after long-term culture of chronically infected cells.
    The Journal of general virology, 1994
    Co-Authors: V Zaides, E. Fenouillet, M Yagello, T Veselovskaya, D Schmitt, L Rykova, J C Gluckman
    Abstract:

    Human immunodeficiency virus type 1 (HIV-1) chronically infected (CI) cell lines were established from HIV-1HIB/LAI-infected MT-4 cells that survived acute infection. The HIV env gene expressed in the two long-term cultured cell lines differed from that of the lines cultured for shorter periods, by coding for a Glycoprotein Gp 160 that had the C terminus deleted. One long-term cultured cell line, CI-17, was studied in detail. An insertion of a premature stop codon in the env gene caused about 90% of Gp160 molecules to be truncated (Gp160x), lacking both cytoplasmic and transmembrane domains; these species were secreted into the cell medium, and could form oligomers with other truncated Gp160 molecules as well as with their normal counterparts. CI-17 cells constantly yielded high levels of viral protein and relatively low quantities of infectious virus, without cytopathicity. However, acute infection of fresh MT-4 cells with CI-17-derived virus led to cytopathicity, the rate of which as well as the Env Glycoprotein pattern depended on multiplicity: (i) using an infection dose of 10(-4) ID50/cell, cells died 7 to 8 days post-infection with normal Gp160 synthesis predominating; (ii) with 10(-2) ID50, Gp160x was produced as early as 48 h post-infection and cell death was delayed. Predominant Gp160x formation occurred again when new CI cell lines were obtained with CI-17-derived virus. Thus, two human immunodeficiency virus variants, a normal and a defective one, are persistently expressed in CI-17 cells. The other long-term cultured CI cell line also expressed Gp160 with a similar (albeit slightly longer) deletion of a C-terminal region in most molecules, but the cell lines that were cultured for shorter periods did not. These results suggest that the emergence of HIV variants with a C-terminal deletion in the Env Glycoprotein, which coexist with normal virus, may play a role in maintaining the long-term growth capacity and viability of CI cells.

  • Conglutinin Binds The HIV-1 Envelope Glycoprotein Gpl60 and Inhibits its Interaction with Cell Membrane CD4
    Scandinavian journal of immunology, 1991
    Co-Authors: O. Andersen, A.‐m. Sørensen, S.‐e. Svehag, E. Fenouillet
    Abstract:

    The highly glycosylated envelope Glycoprotein (Gp 160) of human immunodeficiency virus (HIV) interacts with the CD4 molecule present on the membrane of CD4+ cells and is involved in the pathobiology of HIV infection. Lectins bind Glycoproteins through non-covalent interactions with specific hexose residues. The mammalian C-type lectin bovine conglutinin was examined for its ability to interact with recombinant Gp160 (rGp160) produced in vaccinia virus-infected BHK21 cells. Specific binding of conglutinin to rGp160 was demonstrated by ELISA. The interaction of bovine conglutinin with rGp160 was calcium-dependent, which is characteristic of the binding of a C-type lectin to its ligand, and the binding was inhibited in a dose-dependent manner with N-acetyl-D-glucosamine. Deglycosylation of rGp160 abrogated the conglutinin binding. In addition, conglutinin exerted a dose-dependent inhibition of the binding of rGp160 to the CD4 receptor on CEM 13 cells, as demonstrated by FACS analyses. These results indicate that conglutinin may inhibit the infection with HIV-1 through its interaction with the viral envelope Glycoprotein.