Studies on the entry ports for the scrapie agent (prion)

点击翻译按钮获取中文摘要

Major cause of infection in animal prion diseases is thought to be consumption of prion-contaminated stuff orally. There is evidence that the enteric nerve system (ENS) and lymphoid tissues, especially gut-associated lymphoid tissues (GATL) is involved in the infection of prion via alimentary tract. To elucidate the initial entry port for prion, we inoculated prion to alympholasia (aly) mice that show a deficiency in the systemic lymph nodes and Peyer's patches with various route. The aly/aly mice was susceptible to prion by intra-cranial inoculation, however, they showed reduced susceptibility with intra-peritoneal inoculation. The aly/aly mice were completely resistant to with per os administration, while C57BL/6J mice, the wild type mice for aly/aly mice, were sensitive to per os administration as they got the terminal stage of disease 307±7 days post inoculation. The prion infectivities were detected in the intestine and spleen of prion-inoculated C57BL/6J mice even after the early stage of exposure, whereas no infectivity was detected from those tissues of prion-inoculated aly/aly mice. PrPSc also detected in the intestine and spleen only of C57BL/6 mice, however PrPSc was not detected in the spleen and intestine of aly/aly mice that was affected by scrapie with the intra-peritoneal inoculation. No apparent difference in the organization of enteric nerve system was found between wild type and aly/aly mice. These results indicate that not ENS but GALT acts as a primary entry port for prion after the oral exposure.