NR AQMS
AU Melot,F.; Thielen,C.; Labiet,T.; Eisher,S.; Jolois,O.; Heinen,E.; Antoine,N.
TI Do bovine lymphocytes express a peculiar prion protein?
QU Developmental Immunology 2002 Dec; 9(4): 245-52
PT journal article
AB The cellular prion protein (PrPc) is a glycolipid-anchored cell surface protein that usually exhibits three glycosylation states. Its post-translationally modified isoform, PrPsc, is involved in the pathogenesis of various transmissible spongiform encephalopathies (TSEs). In bovine species, BSE infectivity appears to be restricted to the central nervous system; few or no detectable infectivity is found in lymphoid tissues in contrast to scrapie or variant CJD. Since expression of PrPc is a prerequisite for prion replication, we have investigated PrPc expression by bovine immune cells. Lymphocytes from blood and five different lymph organs were isolated from the same animal to assess intra- and interindividual variability of PrPc expression, considering six individuals. As shown by flow cytometry, this expression is absent or weak on granulocytes but is measurable on monocytes, B and T cells from blood and lymph organs. The activation of the bovine cells produces an upregulation of PrPc. The results of our in vitro study of PrPc biosynthesis are consistent with previous studies in other species. Interestingly, western blotting experiments showed only one form of the protein, the diglycosylated band. We propose that the glycosylation state could explain the lack of infectivity of the bovine immune cells.
IN
Das normale Prionprotein PrPc wird beim Rind in Granulozyten höchstens schwach, aber meßbar auf Monozyten, B- und T-Zellen aus Blut und lymphatischen Organen exprimiert. Eine Aktivierung dieser Zellen bewirkt auch eine Verstärkung der Expression des Prionproteins.
Interessanterweise meinen die Autoren, bei BSE seien die Immunzellen deshalb so wenig infektiös, weil bei BSE das PrPsc (fast) nur in der diglykosilierten Form vorkomme. Ganz so extrem ist es zwar in Wirklichkeit nicht, aber es besteht gerade in dieser Hinsicht ein deutlicher Unterschied zwischen der klassischen BSE-Normalform und einigen BSE-Fällen mit deutlich abweichenden molekularen Signaturen.
MH Animals; Blotting, Western; Cattle/*immunology; Cells, Cultured; Encephalopathy, Bovine Spongiform/immunology; Flow Cytometry; Glycosylation; Lymphocyte Activation; Lymphocyte Subsets/*metabolism; Lymphoid Tissue/*metabolism; PrPc Proteins/*metabolism; Protein Isoforms/*metabolism; Support, Non-U.S. Gov't
AD Laboratory of Human Histology (Professor Ernst Heinen), Centre de recherche prion, University of Liege, 20, rue de Pitteurs, B-4020, Liege, Belgium.
SP englisch
PO England
ZF kritische Zusammenfassung von Roland Heynkes