Send to

Choose Destination
See comment in PubMed Commons below
PLoS Pathog. 2011 Sep;7(9):e1002230. doi: 10.1371/journal.ppat.1002230. Epub 2011 Sep 1.

Interferon regulatory factor-1 (IRF-1) shapes both innate and CD8(+) T cell immune responses against West Nile virus infection.

Author information

  • 1Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America.


Interferon regulatory factor (IRF)-1 is an immunomodulatory transcription factor that functions downstream of pathogen recognition receptor signaling and has been implicated as a regulator of type I interferon (IFN)-αβ expression and the immune response to virus infections. However, this role for IRF-1 remains controversial because altered type I IFN responses have not been systemically observed in IRF-1(-/-) mice. To evaluate the relationship of IRF-1 and immune regulation, we assessed West Nile virus (WNV) infectivity and the host response in IRF-1(-/-) cells and mice. IRF-1(-/-) mice were highly vulnerable to WNV infection with enhanced viral replication in peripheral tissues and rapid dissemination into the central nervous system. Ex vivo analysis revealed a cell-type specific antiviral role as IRF-1(-/-) macrophages supported enhanced WNV replication but infection was unaltered in IRF-1(-/-) fibroblasts. IRF-1 also had an independent and paradoxical effect on CD8(+) T cell expansion. Although markedly fewer CD8(+) T cells were observed in naïve animals as described previously, remarkably, IRF-1(-/-) mice rapidly expanded their pool of WNV-specific cytolytic CD8(+) T cells. Adoptive transfer and in vitro proliferation experiments established both cell-intrinsic and cell-extrinsic effects of IRF-1 on the expansion of CD8(+) T cells. Thus, IRF-1 restricts WNV infection by modulating the expression of innate antiviral effector molecules while shaping the antigen-specific CD8(+) T cell response.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Public Library of Science Icon for PubMed Central
    Loading ...
    Support Center