PrP(Sc) accumulation in placentas of ewes exposed to natural scrapie: influence of foetal PrP genotype and effect on ewe-to-lamb transmission.
Placentas from scrapie-affected ewes are known to be infectious. Nevertheless, placenta infectivity in such ewes is not systematic. Maternal transmission to lambs is highly suspected but contamination of the foetus in utero has not been demonstrated. Using ewes from a naturally scrapie-infected flock, it was demonstrated that abnormal prion protein (PrP(Sc)) accumulation in the placenta (i) is controlled by polymorphisms at codons 136, 154 and 171 of the foetal PrP gene and (ii) is restricted mainly to placentome foetal trophoblastic cells. In order to go deeper into the role of the placenta in scrapie transmission, the pattern of PrP(Sc) dissemination was established in susceptible lambs (genotype VRQ/VRQ) sampled from 140 days post-insemination to the age of 4 months from either VRQ/VRQ ewes with PrP(Sc)-positive placentas or ARR/VRQ ewes with PrP(Sc)-negative placentas. In both VRQ/VRQ lamb groups, PrP(Sc) spatial and temporal accumulation patterns were similar, suggesting post-natal rather than in utero contamination.
Andréoletti
Olivier
O
UMR 959 INRA-ENVT, Physiopathologie Infectieuse et Parasitaire des Ruminants, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, 31076 Toulouse Cedex 3, France1.
Lacroux
Caroline
C
UMR 959 INRA-ENVT, Physiopathologie Infectieuse et Parasitaire des Ruminants, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, 31076 Toulouse Cedex 3, France1.
Chabert
Armelle
A
UMR 959 INRA-ENVT, Physiopathologie Infectieuse et Parasitaire des Ruminants, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, 31076 Toulouse Cedex 3, France1.
Monnereau
Laurent
L
UMR 959 INRA-ENVT, Physiopathologie Infectieuse et Parasitaire des Ruminants, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, 31076 Toulouse Cedex 3, France1.
Tabouret
Guillaume
G
UMR 959 INRA-ENVT, Physiopathologie Infectieuse et Parasitaire des Ruminants, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, 31076 Toulouse Cedex 3, France1.
Lantier
Frédéric
F
INRA, Laboratoire de Pathologie Infectieuse et Immunologie, Nouzilly, France2.
Berthon
Patricia
P
INRA, Laboratoire de Pathologie Infectieuse et Immunologie, Nouzilly, France2.
Eychenne
Francis
F
INRA, Domaine de Langlade, Pompertuzat, France3.
Lafond-Benestad
Sylvie
S
NVI, Department of Pathology, Oslo, Norway4.
Elsen
Jean-Michel
JM
INRA, Station d'Amélioration Génétique des Animaux, Auzeville, France5.
Schelcher
François
F
UMR 959 INRA-ENVT, Physiopathologie Infectieuse et Parasitaire des Ruminants, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, 31076 Toulouse Cedex 3, France1.
D000818:Animals; D005260:Female; D005838:Genotype; D018445:Infectious Disease Transmission, Vertical; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D018620:PrPSc Proteins / Q000378:metabolism*; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D012608:Scrapie / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000635:transmission; D012756:Sheep
D018620:PrPSc Proteins; D011328:Prions