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120. Follicular dendritic cell involvement in ovine scrapie
44
Abstracts.
Wednesday
27th
underway to make available a sterilisation process that can be applied to laboratory or surgical instruments. The effect of such treatments on infectivity dried on to the surface of surgical
March
2002
stainless steel instruments is not known, hence a range of combinations of heat and hydroxide need to be tested for effectiveness.
Room C. 12.15-12.30 120.
Follicular
dendritic
EATON, Institute
For Animal
Health,
cell involvement
in ovine
S.L.,*:” FOSTER, J.D., HUNTER,
Neuropathogenesis
Unit,
Ogston
Transmissible spongiform encephalopathies (TSE’S) are a group of neurological diseases that involve the lymphoreticular system for the developing pathogenesis. Follicular dendritic cells (FDCs) present in the secondary follicles of lymphatic tissue play a crucial role in the accumulation of the normal prion protein form (PrPC), and presentation to phagocytic cells within the follicle via their dendritic extensions. Using the sensitive Immunocytochemistry (ICC) techniquevisualisation of the abnormal formof prionprotein
Building,
West
scrapie
N. Mains
Road,
Edinburgh
EH9
3JF
(PrP”“) is detected in germinal centres of scrapie infected sheep. However, it would be useful to compare the FDC localisation and PrPS” accumulation within the same lymphatic tissue of scrapie infected sheep by using double labelling ICC or fluorescent techniques. Due to the delicate FDC network, particularly aggressive pre-treatments cannot be included in the same run required for detection of PrP”“. Therefore a new detection system for comparison of PrPSC accumulation and FDC location was introduced.
Room C. 12.30-12.45 121.
Morphological
studies
of the spleen following MCGOVERN,
‘VLA
Lasswade,
Pentlands Science Park, Institute for Animal
antigenic
stimulation
in uninfected
and scrapie
infected
mice
G.,*“’ BROWN, K.,I JEFFREY, M.’ Penicuik, Midlothian, Health, West Mains
The peripheral lymphoid system plays a major role in the pathogenesis of many natural and experimental TSEs. Previous research has shown that follicular dendritic cells (FDCs) of the lymphoreticular system are necessary for peripheral replication of murine scrapie. Disease specific prion protein (PrP) and the normal cellular form of this protein are associated with these cells. Following scrapie infection, disease specific PrP accumulates on the FDC plasmalemma and in the adjacent extracellular space, as well as in the lysosomes of tingible body macrophages. Other
Scotland, EH26 Road, Edinburgh,
OPZ; EH9
‘Neuropathogenesis 3JF
Unit,
pathological changes also occur within secondary follicles such as extension and complex folding of FDC dendrites and apoptosis. In this study, we compare the morphology of the secondary follicles of the spleen of scrapie infected mice and normal mice following immunological challenge with sheep red blood cells. Spleens were taken at 10 weeks post scrapie infection and at an early clinical stage of disease, and studied ultrastucturally for changes associated with immune system stimulation. These observations will be presented and discussed.
Room C. 124-13.00 122.
Differential MARTIN,
‘VLA
Lasswade
diagnosis
of BSE agent and scrapie
S.,:+’ GONZALEZ, Veterinary
Laboratory,
infection
L.,’ JEFFREY, M.,2 BELLWORTHY, EH26
The possibility that some UK sheep may be infected with the BSE agent is of human and animal health concern. Immunohistochemistry was used to identify specific prion protein (PrP) peptide sequences in specific cell types of the brain and lymphoreticular system (LRS) of natural scrapie infected sheep of various breed and genotype combinations. The same antibody panels were then used to immuno-label tissues of BSE-agentinfected Suffolk and Romney sheep. Clinically affected and some pre-clinical BSE agent infected sheep could be differentiated
OPZ
and ‘VLA
Weybridge,
of sheep S.J.’ KT1.5
3NB
from scrapie by the lesser amount of labelling of PrP containing the 84-105 amino-acid peptide sequences in phagocytic cells of the LRS and brain. Additionallv, BSE-agent-infected sheeo could be differentiated from natural&eep sc;apie by the higher levels of intra-neuronal PrP accumulation in brain detected by labelling for a range of PrP peptide sequences. These results suggest that there is strain dependent processing of PrP in specific cell types within the nervous system and LRS which can be used to differentiate between BSE agent and other scrapie strain infections of sheep.
Abstracts.
Wednesday
27th
underway to make available a sterilisation process that can be applied to laboratory or surgical instruments. The effect of such treatments on infectivity dried on to the surface of surgical
March
2002
stainless steel instruments is not known, hence a range of combinations of heat and hydroxide need to be tested for effectiveness.
Room C. 12.15-12.30 120.
Follicular
dendritic
EATON, Institute
For Animal
Health,
cell involvement
in ovine
S.L.,*:” FOSTER, J.D., HUNTER,
Neuropathogenesis
Unit,
Ogston
Transmissible spongiform encephalopathies (TSE’S) are a group of neurological diseases that involve the lymphoreticular system for the developing pathogenesis. Follicular dendritic cells (FDCs) present in the secondary follicles of lymphatic tissue play a crucial role in the accumulation of the normal prion protein form (PrPC), and presentation to phagocytic cells within the follicle via their dendritic extensions. Using the sensitive Immunocytochemistry (ICC) techniquevisualisation of the abnormal formof prionprotein
Building,
West
scrapie
N. Mains
Road,
Edinburgh
EH9
3JF
(PrP”“) is detected in germinal centres of scrapie infected sheep. However, it would be useful to compare the FDC localisation and PrPS” accumulation within the same lymphatic tissue of scrapie infected sheep by using double labelling ICC or fluorescent techniques. Due to the delicate FDC network, particularly aggressive pre-treatments cannot be included in the same run required for detection of PrP”“. Therefore a new detection system for comparison of PrPSC accumulation and FDC location was introduced.
Room C. 12.30-12.45 121.
Morphological
studies
of the spleen following MCGOVERN,
‘VLA
Lasswade,
Pentlands Science Park, Institute for Animal
antigenic
stimulation
in uninfected
and scrapie
infected
mice
G.,*“’ BROWN, K.,I JEFFREY, M.’ Penicuik, Midlothian, Health, West Mains
The peripheral lymphoid system plays a major role in the pathogenesis of many natural and experimental TSEs. Previous research has shown that follicular dendritic cells (FDCs) of the lymphoreticular system are necessary for peripheral replication of murine scrapie. Disease specific prion protein (PrP) and the normal cellular form of this protein are associated with these cells. Following scrapie infection, disease specific PrP accumulates on the FDC plasmalemma and in the adjacent extracellular space, as well as in the lysosomes of tingible body macrophages. Other
Scotland, EH26 Road, Edinburgh,
OPZ; EH9
‘Neuropathogenesis 3JF
Unit,
pathological changes also occur within secondary follicles such as extension and complex folding of FDC dendrites and apoptosis. In this study, we compare the morphology of the secondary follicles of the spleen of scrapie infected mice and normal mice following immunological challenge with sheep red blood cells. Spleens were taken at 10 weeks post scrapie infection and at an early clinical stage of disease, and studied ultrastucturally for changes associated with immune system stimulation. These observations will be presented and discussed.
Room C. 124-13.00 122.
Differential MARTIN,
‘VLA
Lasswade
diagnosis
of BSE agent and scrapie
S.,:+’ GONZALEZ, Veterinary
Laboratory,
infection
L.,’ JEFFREY, M.,2 BELLWORTHY, EH26
The possibility that some UK sheep may be infected with the BSE agent is of human and animal health concern. Immunohistochemistry was used to identify specific prion protein (PrP) peptide sequences in specific cell types of the brain and lymphoreticular system (LRS) of natural scrapie infected sheep of various breed and genotype combinations. The same antibody panels were then used to immuno-label tissues of BSE-agentinfected Suffolk and Romney sheep. Clinically affected and some pre-clinical BSE agent infected sheep could be differentiated
OPZ
and ‘VLA
Weybridge,
of sheep S.J.’ KT1.5
3NB
from scrapie by the lesser amount of labelling of PrP containing the 84-105 amino-acid peptide sequences in phagocytic cells of the LRS and brain. Additionallv, BSE-agent-infected sheeo could be differentiated from natural&eep sc;apie by the higher levels of intra-neuronal PrP accumulation in brain detected by labelling for a range of PrP peptide sequences. These results suggest that there is strain dependent processing of PrP in specific cell types within the nervous system and LRS which can be used to differentiate between BSE agent and other scrapie strain infections of sheep.