A new pathway that helps cells to recognize viruses is described in a report published online by Nature this week. The research suggests that multiple dendritic cell types can initiate immune responses in answer to certain viral infections.
It has long been argued that a unique subtype of dendritic cell - the plasmacytoid cell - has the potential to produce vast amounts of type I interferons; chemicals that play a key role in raising immunity to infections. Caetano Reis e Sousa and colleagues treated conventional non-plasmacytoid mouse dendritic cells with double-stranded RNA to mimic viral infection. They found that these cells were able to produce just as much interferon as plasmacytoid cells.
For the response to occur, the RNA must make it through the cell membrane and into the cytosol. Rather than looking at the inside of the cell, most previous research has focussed on cell surface receptors that recognize extracellular signs of infection. The new research hints that intracellular recognition of infection can be critical for some cell types, and highlights the role of an enzyme, protein kinase R, in this process.
Caetano Reis e Sousa
London Research Institute
Cancer Research UK
Tel: +44 20 7269 2832
Also available online.
(C) Nature press release.
Message posted by: Trevor M. D'Souza