Interference with intraepithelial TNF-α signaling inhibits CD8(+) T-cell-mediated lung injury in influenza infection

Viral Immunol. 2010 Dec;23(6):639-45. doi: 10.1089/vim.2010.0076.

Abstract

CD8(+) T-cell-mediated pulmonary immunopathology in respiratory virus infection is mediated in large part by antigen-specific TNF-α expression by antiviral effector T cells, which results in epithelial chemokine expression and inflammatory infiltration of the lung. To further define the signaling events leading to lung epithelial chemokine production in response to CD8(+) T-cell antigen recognition, we expressed the adenoviral 14.7K protein, a putative inhibitor of TNF-α signaling, in the distal lung epithelium, and analyzed the functional consequences. Distal airway epithelial expression of 14.7K resulted in a significant reduction in lung injury resulting from severe influenza pneumonia. In vitro analysis demonstrated a significant reduction in the expression of an important mediator of injury, CCL2, in response to CD8(+) T-cell recognition, or to TNF-α. The inhibitory effect of 14.7K on CCL2 expression resulted from attenuation of NF-κB activity, which was independent of Iκ-Bα degradation or nuclear translocation of the p65 subunit. Furthermore, epithelial 14.7K expression inhibited serine phosphorylation of Akt, GSK-3β, and the p65 subunit of NF-κB, as well as recruitment of NF-κB for DNA binding in vivo. These results provide insight into the mechanism of 14.7K inhibition of NF-κB activity, as well as further elucidate the mechanisms involved in the induction of T-cell-mediated immunopathology in respiratory virus infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenovirus E3 Proteins / immunology
  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • Chemokine CCL2 / immunology
  • Chemokines / immunology
  • Influenza A virus / immunology
  • Lung Injury / immunology
  • Lung Injury / pathology*
  • Mice
  • Mice, Inbred BALB C
  • NF-kappa B / immunology
  • Orthomyxoviridae Infections / immunology*
  • Respiratory Mucosa / immunology*
  • Signal Transduction / immunology*
  • T-Lymphocytes, Cytotoxic / immunology*
  • Tumor Necrosis Factor-alpha / immunology*

Substances

  • Adenovirus E3 Proteins
  • Chemokine CCL2
  • Chemokines
  • E3 14.7K protein, Adenovirus
  • NF-kappa B
  • Tumor Necrosis Factor-alpha