Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 1999 Oct 12;96(21):11860-5.

Inhibitory role of the host apoptogenic gene PKR in the establishment of persistent infection by encephalomyocarditis virus in U937 cells.

Author information

1
The Moses Grossman Infectious Diseases Laboratory, San Francisco General Hospital, San Francisco, CA 94110, USA.

Abstract

Persistent infections by viruses such as HIV-1 and hepatitis B virus can pose long-term health hazards. Because establishment of persistent infections involves close interactions and adjustments in both host and virus, it would be informative to establish a paradigm with which a normally cytolytic viral infection can be easily converted to persistent infection, so that the different stages in developing persistent infection can be examined. Such a model system is described in this paper. Highly cytolytic encephalomyocarditis virus (EMCV) infection was shifted to persistent infection as a result of repressed expression of the double-stranded RNA-dependent protein kinase (PKR) in the promonocytic U937 cells. Because of the apoptogenic potential of PKR, a deficiency of PKR resulted in a delay in virus-induced apoptosis in EMCV-infected U937 cells, allowing the eventual establishment of persistent EMCV infection in these cells (U9K-AV2). That this was a bona fide persistent infection was demonstrated by the ability of infected cells to propagate as long-term virus-shedding cultures; electron microscopy studies showing presence of intracellular EMCV virions and chromatin condensation; detection of virus-induced chromosomal DNA fragmentation and sustained expression of apoptogenic p53 and IL-1beta converting enzyme; and demonstration of active EMCV transcription by reverse transcription-PCR. In addition, a host-virus coevolution was observed in U9K-AV2 cultures over time: U9K-AV2 cells exhibited slower growth rates, resistance to viral super-infection, and cessation of IFN-alpha synthesis, whereas the infectivity of EMCV was drastically attenuated. Finally, data are presented on the suitability of this model to study establishment of persistent infection by other viruses such as Sendai virus and reovirus.

PMID:
10518541
PMCID:
PMC18377
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center