Comparative analysis of normal prion protein expression on human, rodent, and ruminant blood cells by using a panel of prion antibodies.
BACKGROUND
It is not known whether variant CJD can be transmitted within the human population by blood transfusion. The expression of normal cellular prion protein (PrPC) by different blood cell types may permit selective uptake and dissemination of infectivity.


METHODS
The normal distribution of PrPC on the major blood cell types of species known to be susceptible to natural or experimental transmissible spongiform encephalopathies was studied. Blood from healthy humans, mice, hamsters, cattle, and sheep was examined by flow cytometry by using a large panel of antibodies with different prion protein (PrP) epitope specificities to maximize the detection of PrP variants across species and cell type.


RESULTS
PrP was detected on all major human blood cells types except eosinophils, but was not detected as ubiquitously or uniformly on major blood cell types of different animal species.


CONCLUSIONS
Different animal species have unique patterns of expression of PrPC on blood cell types, with none equivalent to the human pattern. This needs to be considered when extrapolating from animal models of blood-borne transmissible spongiform encephalopathy infectivity, particularly in regard to the risk assessment of potential variant CJD spread within the human population. The relationship between PrP distribution and infectivity distribution in blood needs further investigation.
Barclay
G Robin
GR
Scottish National Blood Transfusion Service Cell Therapy Group, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom. robin.barclay@ed.ac.uk
Houston
E Fiona
EF
Halliday
Sue I
SI
Farquhar
Christine F
CF
Turner
Marc L
ML
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001773:Blood Cells / Q000737:chemistry*; D002417:Cattle / Q000097:blood*; D006224:Cricetinae; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008647:Mesocricetus / Q000097:blood*; D051379:Mice / Q000097:blood*; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D018621:PrPC Proteins / Q000097:blood* / Q000276:immunology; D011817:Rabbits; D012756:Sheep / Q000097:blood*; D013045:Species Specificity
D000911:Antibodies, Monoclonal; D018621:PrPC Proteins