Kaposi sarcoma herpesvirus-encoded vFLIP and vIRF1 regulate antigen presentation in lymphatic endothelial cells.
Blood
; 109(4): 1550-8, 2007 Feb 15.
Article
in En
| MEDLINE
| ID: mdl-17047149
ABSTRACT
Kaposi sarcoma-associated herpesvirus (KSHV) is etiologically linked to Kaposi sarcoma (KS), a tumor genetically akin to lymphatic endothelial cells (LECs). We obtained the immune transcriptional signature of KS and used KSHV-infected LECs (KLECs) as an in vitro model to determine the effects of KSHV on transcription and expression of genes involved in immunity. The antigen presentation, interferon (IFN) response, and cytokine transcriptomes of KLECs resemble those of KS. Transcription of genes involved in class I presentation is increased in KS and after infection of LECs, but MHC-I and ICAM-1 surface expression are down-regulated in KLECs. Inhibition of IFN induction of MHC-I transcription indicates that KSHV regulates MHC-I transcription. We show that MHC-I transcription is regulated by the KSHV-encoded viral FLICE inhibitory protein (vFLIP) and by viral IFN regulatory factor 1 (vIRF1). vFLIP up-regulates MHC-I and ICAM-1 through activation of NF-kappaB and stimulates T-cell proliferation, revealing a mechanism to prevent uncontrolled viral dissemination. In contrast, vIRF1 inhibits basal and IFN- and vFLIP-induced MHC-I transcription and surface expression through its interaction with the transcriptional coactivator p300, contributing to immune evasion. We propose that regulation of MHC-I by vFLIP and vIRF1 plays a crucial role in the host-pathogen equilibrium.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Viral Proteins
/
Endothelium, Lymphatic
/
Antigen Presentation
/
Herpesvirus 8, Human
/
Interferon Regulatory Factors
/
CASP8 and FADD-Like Apoptosis Regulating Protein
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Blood
Year:
2007
Document type:
Article
Affiliation country:
United kingdom