Species differences in the blood content of the normal cellular isoform of prion protein, PrPc, measured by time‐resolved fluoroimmunoassay

Abstract

The concern that variant Creutzfeldt-Jakob disease could be transmitted via blood transfusion has prompted studies of blood infectivity in animal models. As normal prion protein acts as a substrate for conversion to the abnormal form associated with infectivity, we have quantified its distribution in mice and hamsters, the most commonly used animal models. A time-resolved fluoroimmunoassay was used to measure normal prion protein in hamster and mouse tissues, including blood. Levels of prion protein in hamster blood were remarkably low compared with human blood. In contrast, levels in mouse blood were quite similar to human blood; however, there were differences in the distribution of normal prion between cellular and cell-free fractions. Differences between levels of normal prion in blood of animal models and humans should be considered as a possible contributor to infectivity study outcomes in these models.