Role of the CD8+ dendritic cell subset in transmission of prions.

Controversial results have been observed in mouse models regarding the role of lymphoid tissues in prion pathogenesis. To investigate the role of dendritic cells (DC), we used a transgenic mouse model. In this model (CD11c-N17Rac1), a significant reduction of CD8+ CD11c(hi) DC has been described, and the remaining CD8+ DC demonstrate a reduced capacity for the uptake of apoptotic cells. After intraperitoneal prion infection, significantly longer incubation times were observed in CD11c-N17Rac1 mice than in controls, indicating that a defect in CD8+ CD11c(hi) DC significantly impedes neuroinvasion after intraperitoneal infection. In contrast, no distinct differences were observed between CD11c-N17Rac1 mice and controls after oral infection. This provides evidence that oral and intraperitoneal prion infections differ in lymphoreticular requirements.