Vaccinia virus lacking the Bcl-2-like protein N1 induces a stronger natural killer cell response to infection

J Gen Virol. 2008 Nov;89(Pt 11):2877-2881. doi: 10.1099/vir.0.2008/004119-0.


The vaccinia virus (VACV) N1 protein is an intracellular virulence factor that has a Bcl-2-like structure and inhibits both apoptosis and signalling from the interleukin 1 receptor, leading to nuclear factor kappa B activation. Here, we investigated the immune response to intranasal infection with a virus lacking the N1L gene (vDeltaN1L) compared with control viruses expressing N1L. Data presented show that deletion of N1L did not affect the proportion of CD4+ and CD8+ T cells infiltrating the lungs or the cytotoxic T-cell activity of these cells. However, vDeltaN1L induced an increased local natural killer cell activity between days 4 and 6 post-infection. In addition, in the absence of N1 the host inflammatory infiltrate was characterized by a reduced proportion of lymphocytes bearing the early activation marker CD69. Notably, there was a good correlation between the level of CD69 expression and weight loss. The implications of these findings are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Genes, bcl-2
  • Humans
  • Infections / immunology*
  • Killer Cells, Natural / immunology*
  • Lung / immunology
  • Lung / virology
  • Mice
  • Mice, Inbred BALB C
  • NF-kappa B / physiology
  • Proto-Oncogene Proteins c-bcl-2 / deficiency*
  • Proto-Oncogene Proteins c-bcl-2 / immunology
  • Smallpox / immunology*
  • Vaccinia virus / genetics
  • Vaccinia virus / immunology*
  • Viral Plaque Assay


  • NF-kappa B
  • Proto-Oncogene Proteins c-bcl-2