From the mouth to the brain

TSEs typically exhibit a very long latency period between the time of infection and the clinical manifestation. Evidence suggests that during this time, prions undergo a first replication phase in peripheral lymphoid tissues before moving to the brain [Aguzzi, 2003]. During this process, little or no damage occurs to the brain, and thus it should be possible to design therapeutic strategies aimed to block the entry of prions, preventing neurodegeneration. This chapter discusses the state-of-the-art in the knowledge of the pathways and mechanisms implicated in the transport of prion infectious agent from the mouth to the brain (Figure 6.1).