Interferon-α plays an important role in the control of many viral infections, but its cellular source and the mechanisms by which it is produced remain unclear. In February 18 Journal of Experimental Medicine, Winfried Barchet and colleagues from European Molecular Biology Laboratory (EMBL) station in Monterotondo, Italy, show that virus induced interferon-α can be produced in vivo by a specific subset of dendritic cells in the absence of feedback signaling.
Barchet et al. studied mice infected with the vesicular stomatitis virus (VSV). They found that a number of cells located in the marginal zone of the spleen (which, unlike other dendritic cells, are CD11cintCD11b-GR-1+) produce IFN-α irrespective of whether they were isolated from VSV-infected IFN receptor-competent or -deficient mice (J Exp Med 2002, 195:507-516).
These results indicate for the first time a less stringently regulated IFN-α expression in highly specialized dendritic cells. A better understanding of the role of interferon ...