A new mechanism regulates type I interferon production in white blood cells

The plasmacytoid dendritic cell (pDC) is a type of white blood cell. The primary function of this cell type is to produce type I interferon when the body is infected by a virus. The pDC has special surface receptors that can detect many types of viruses. Type I interferon is thus very important for the clearance of a viral infection.

"Working with mice, we have identified a mechanism that regulates the amount of interferon that is produced by pDCs, explains Dr. Makrigiannis. That mechanism is a protein-protein interaction between surface receptor Ly49Q and the class I major histocompatibility complex (MHC) molecule."

It is known that viruses often cause a decrease of class I MHC molecules on cells. The team of scientists believes that the reason for this may be to stop interferon production by the pDCs. Thus, class I MHC recognition by Ly49Q on pDCs is necessary for the optimal activation of innate immune responses in vivo.

The discovery of this molecular strategy will very likely have a great impact in virology, and could eventually help physicians develop better therapeutic strategies to fight the infectious diseases afflicting their patients.

The online version of this article is available at: http://jem.rupress … N_THIS_ISSUE

Source: Institut de recherches cliniques de Montreal