Epstein-Barr Virus Research Today is a free monthly online journal that collates and summarizes the latest research about Epstein-Barr Virus, including details on ebv, infectious mononucleosis, glandular fever, chronic fatigue. | ||||||||
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EBV latency III immortalization program sensitizes B cells to induction of CD95-mediated apoptosis via LMP1: role of NF-kappaB, STAT1, and p53.Le Clorennec C, Youlyouz-Marfak I, Adriaenssens E, Coll J, Bornkamm GW, Feuillard J Centre National de la Recherche Scientifique, Unité Mixte de Recherche (UMR) CNRS 6101, Faculté de Médecine de Limoges, Université de Limoges, Centre Hospitalier Universitaire (CHU) Dupuytren, Laboratoire d'Hématologie, Limoges, France. Epstein-Barr virus (EBV) induces CD95 expression and the CD95 gene (FAS) is regulated by NF-kappaB, STAT1, and/or p53. To understand the contribution of these factors in the regulation of CD95 by EBV in lymphoblastoid cell lines (LCLs), we cloned dominant-active IkappaBalpha, active (STAT1alpha) and inactive (STAT1beta) forms of STAT1, p53, a dominant-negative mutant of LMP1, and wild-type LMP1 into a novel double-inducible episomal vector, pRT-1. These plasmids were stably transfected either into wild-type LCLs or EREB2-5 cells, an LCL with an estrogen-regulatable EBNA2 protein. Inhibition of LMP1 signaling decreased expression of CD95, whereas overexpression of LMP1 markedly increased it. Induction of the latency III program in EREB2-5 cells correlated with activation of NF-kappaB, STAT1, and p53. CD95 expression was regulated by these 3 transcriptional systems. STAT1 and p53 activation were secondary to NF-kappaB activation. CD95 surface expression sensitized EBV-infected B cells to the induction of CD95-mediated apoptosis. In vitro inhibition of CD95-CD95 ligand interaction was found to reverse T-cell killing of EBV-infected B cells. Therefore, LMP1 activation of NF-kappaB sensitizes infected B cells to CD95-mediated apoptosis and renders EBV latency III-immortalized B cells susceptible to elimination by the immune system, contributing to the establishment of a host/virus equilibrium. Published 22 February 2006 in Blood, 107(5): 2070-8.
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