Previous Article | Next Article ![]()
Journal of Virology, December 2007, p. 13092-13104, Vol. 81, No. 23
0022-538X/07/$08.00+0 doi:10.1128/JVI.01378-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
B Recruitment on Selected Cellular Promoters
GIGA-Research, Virology and Immunology Unit, GIGA B34, University of Liège, B-4000 Liège, Belgium
Received 25 June 2007/ Accepted 31 August 2007
Intercellular adhesion molecule 1 (ICAM-1) expression is down-regulated in the center of cutaneous varicella lesions despite the expression of proinflammatory cytokines such as gamma interferon and tumor necrosis factor alpha (TNF-
). To study the molecular basis of this down-regulation, the ICAM-1 induction of TNF-
was analyzed in varicella-zoster virus (VZV)-infected melanoma cells (MeWo), leading to the following observations: (i) VZV inhibits the stimulation of icam-1 mRNA synthesis; (ii) despite VZV-induced nuclear translocation of p65, p52, and c-Rel, p50 does not translocate in response to TNF-
; (iii) the nuclear p65 present in VZV-infected cells is no longer associated with p50 and is unable to bind the proximal NF-
B site of the icam-1 promoter, despite an increased acetylation and accessibility of the promoter in response to TNF-
; and (iv) VZV induces the nuclear accumulation of the NF-
B inhibitor p100. VZV also inhibits icam-1 stimulation of TNF-
by strongly reducing NF-
B nuclear translocation in MRC5 fibroblasts. Taken together, these data show that VZV interferes with several aspects of the immune response by inhibiting NF-
B binding and the expression of target genes. Targeting NF-
B activation, which plays a central role in innate and adaptive immune responses, leads to obvious advantages for the virus, particularly in melanocytes, which are a site of viral replication in the skin.
Published ahead of print on 12 September 2007.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»