Document 0076
 DOCN  M9490076
 TI    Critical involvement of human T cell leukaemia virus type I virions in
       mediating the viral mitogenic effect.
 DT    9411
 AU    Casse H; Girerd Y; Gazzolo L; Duc Dodon M; Centre National de la
       Recherche Scientifique, Universite Claude; Bernard, Faculte de Medecine
       A. Carrel, Lyon, France.
 SO    J Gen Virol. 1994 Aug;75 ( Pt 8):1909-16. Unique Identifier : AIDSLINE
       MED/94321980
 AB    Human T cell leukaemia virus type I (HTLV-I) is a direct activator of
       human resting T lymphocytes. The present study was undertaken to
       delineate further the role of viral particles and to define the
       involvement of envelope glycoproteins in the induction of T cell
       mitogenic stimulation. Virus-producing cells treated with
       paraformaldehyde (PFA) were found to be unable to induce the formation
       of syncytia, but still able to trigger the proliferation of resting T
       cells. Likewise, PFA-treated virus particles were still mitogenic. These
       results suggest that the mitogenic event is triggered before the fusion
       of the envelope with the cell membrane. Furthermore, HTLV-I
       envelope-expressing cells obtained after infection of C8166/45 cells
       (HTLV-I-transformed, but defective in virion production) with an HTLV-I
       envelope recombinant vaccinia virus were unable to activate normal T
       cells. Human immuno-deficiency virus type 1 particles produced by
       C8166/45 cells were also devoid of mitogenic ability. However, when
       HTLV-I viral preparations were purified by chromatography, only the
       virion-containing fractions were found to be mitogenic for human resting
       T lymphocytes. This mitogenic activity was partially abolished by
       preincubating the purified virus with a monoclonal antibody directed to
       the surface envelope glycoprotein. Finally, treatment of
       HTLV-I-transformed cells by tunicamycin, an inhibitor of N-linked
       glycosylation, led to the production of virus particles with a decreased
       mitogenic activity. Collectively, these observations suggest that the
       HTLV-I mitogenic activity is triggered by the contact of HTLV-I virions
       with T cells.
 DE    Cell Division  Human  HTLV-I/*IMMUNOLOGY  *Lymphocyte Transformation
       Mitogens  Recombinant Proteins/IMMUNOLOGY  Support, Non-U.S. Gov't
       T-Lymphocytes/*IMMUNOLOGY  Viral Envelope Proteins/GENETICS/IMMUNOLOGY
       Virion/*IMMUNOLOGY  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).