Role of phagocytes in experimental scrapie in hamsters

We studied the interactions between scrapie agent and hamster's phagocytic cells. Macrophages which have been in contact with the scrapie agent are able to carry the infectivity of this agent. We induced variations of different parameters involved on fixation and phagocytosis and we did not observe any modification. A depletion of phagocytic cells induced in hamster at the entry of scrapie increase the incubation time of the illness. Furthermore phagocytic cells cocultured with glial cells seem to be able to transfer infectivity to glial cells. So scrapie agent and hamster's reticulo-endothelial system probably interact at three levels: first at the entry, then during haematogenous diffusion of scrapie agent and finally nearly the central nervous system.