Voie d'immunisation et séquence d'administration de l ... - TEL

tel-00827710, version 1 - 29 May 2013
Figure 10. Pathways leading to type I IFN production. Original design from J. Decalf.
4) Effects of type I IFN
As mentioned previously, type I IFN were first discovered for their antiviral properties; they
limit viral replication by inhibiting protein translation, viral polymerase activity and by
promoting RNA degradation and/or cell apoptosis. Importantly, these cytokines are also
known for their ability to modulate the function of immune cells. They can act directly, via
signaling through the IFN-alpha receptor (IFNAR), or indirectly by inducing the secretion of
chemokines that recruit cells to the site of immunization or cytokines that regulate cell
functions, or activate bystander cells.
(a) Signaling pathways activated by type I IFN
In spite of the high number of type I IFN isoforms, they bind to and signal through the same
IFNAR receptor, although they do appear to differ in the binding affinity for the receptor. The
receptor is composed of two subunits, IFNAR1 and IFNAR2, and is expressed in most
tissues. The main signaling pathway described downstream of IFNAR is the Janus Activated
Kinase /Signal Transducer and Activation of Transcription (JAK/STAT) pathway (Figure 11,
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