Prion cell tropism significantly varies among animal species, depending on both the agent strain and host-specific factors. For example, prions show high lymphotropism in scrapie infected sheep and in vCJD, but little, if any, in sCJD or BSE. In particular, the BSE strain is associated with significant PrP-res accumulation in tonsils, spleen and appendix in humans, whereas, it is largely confined to the nervous system in infected cattle. So, it appears that, at least in the case of BSE and vCJD, host properties can influence the accumulation of the infectious agent in lymphoid organs.

Given that the normal cellular prion protein (PrPc), is sine qua non for PrP-res formation and the development of TSE, it appears reasonable to hypothesize that tissue-specific PrPc properties may represent one of the host factors influencing the cell tropism of the infectious agent in human or bovine.

0

20

40

60

80

100

Human Cerebellum

Bovine Cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7

n = 4 P value <5%

0

20

40

60

80

100

Human Cerebellum

Bovine Cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7

n = 4

0

20

40

60

80

100

Human Cerebellum

Bovine Cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7

n = 4 P value <5%P value <5%

0

20

40

60

80

100

Human medullaBovine medulla

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7

n = 8 P value <5%

0

20

40

60

80

100

Human medullaBovine medulla

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7

n = 8

0

20

40

60

80

100

Human medullaBovine medulla

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7

n = 8 P value <5%P value <5%

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

Full Length 20 KDafragment

18 KDafragment

%

n = 8n = 4 P value <5%

P value <10%

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

Full Length 20 KDafragment

18 KDafragment

%

n = 8n = 4 P value <5%

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

Full Length 20 KDafragment

18 KDafragment

%

n = 8n = 4 P value <5%

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

Full Length 20 KDafragment

18 KDafragment

%

n = 8n = 4

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

Full Length 20 KDafragment

18 KDafragment

%

n = 8n = 4 P value <5%P value <5%

P value <10%

78,42 %

66,10 %

Full length

28,10 %11,81 %Bovine medulla

15,28 %6,31 %Bovine cerebellum

18 kDa frag.20 kDa frag.PrPc

78,42 %

66,10 %

Full length

28,10 %11,81 %Bovine medulla

15,28 %6,31 %Bovine cerebellum

18 kDa frag.20 kDa frag.PrPc

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 8

n = 4 P value <5%

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 8

n = 4 P value <5%

0

20

40

60

80

100

Bovine medulla

Bovine cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 8

n = 4 P value <5%P value <5%

73,79 %

66,62 %

Diglycos.

16,62 %16,76 %Bovine medulla

10,76 %15,45 %Bovine cerebellum

Unglycos.Monoglycos.PrPc

73,79 %

66,62 %

Diglycos.

16,62 %16,76 %Bovine medulla

10,76 %15,45 %Bovine cerebellum

Unglycos.Monoglycos.PrPc

0

20

40

60

80

100

Human medulla

Human cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7n = 7

P value <5%

0

20

40

60

80

100

Human medulla

Human cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7n = 7

0

20

40

60

80

100

Human medulla

Human cerebellum

DiglycosylatedPrPc

MonoglycosylatedPrPc

UnglycosylatedPrPc

%

n = 7n = 7

P value <5%P value <5%

62,08 %

59, 02 %

Diglycos.

18,59 %22,38 %Humanmedulla

11,60 %26,32 %Humancerebellum

Unglycos.Monoglycos.PrPc

62,08 %

59, 02 %

Diglycos.

18,59 %22,38 %Humanmedulla

11,60 %26,32 %Humancerebellum

Unglycos.Monoglycos.PrPc

Characterization of bovine and human cellular prion protein expressed Characterization of bovine and human cellular prion protein expressed in the central nervous system and in lymphoid organsin the central nervous system and in lymphoid organs

V. Defaweux1, S. Capellari2, S. Stramiello2, N. Antoine3, G. Dorban1, C. Demonceau1, O. Jolois1, E. Heinen1 and P. Parchi2. 1Dpt of Morphology and Immunology, Institute of Human Histology, Faculty of Medecine, University of Liège, Belgium–www.ulg.ac.be/histohum.

2Department of Neurological Sciences, Faculty of Medicine, University of Bologna, Italy.3Laboratoy of Animal Histology, Department of Morphology and Pathology, Faculty of Veterinary Medecine, University of Liège, Belgium.

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231SAF32

+ +-++-PNGaseF - -

Med S6381 Cer S6381 Med S6380 Cer S6380

32KDa

26KDa

18KDa

+ +-++-PNGaseF - -

Med S6381 Cer S6381 Med S6380 Cer S6380

+ +-++-PNGaseF - -+ +-++-PNGaseF - -

Med S6381 Cer S6381 Med S6380 Cer S6380

32KDa

26KDa

18KDa

32KDa

26KDa

18KDa

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231SAF60

PrPc glycoform ratios are significantly different between cerebellum and medulla in bovine and human. Only the unglycosylated PrPc is distributed like wise in medulla and in the cerebellum of bovine and human.

Western blot analysis to compare the ratio of PrPc glycoforms expressed in the CNS of bovine and human

Western blot analysis of truncated PrPc forms expressed in bovine

CNS

Cer s6375

PNGaseF +-

Cer s6375

PNGaseF +-

The expression of truncated forms of PrPc (i.e. 21 and 18 kDa PrPc) is also significantly heterogenous according to the brain region investigated.

Western blot analysis to compare the PrPc glycoform ratios and the truncated PrPc forms expressed in bovine lymphoid tissues in bovine lymhpoid cells

Spleen Fo To

Fo IPP

Fo JPP

Fo MLN

- --PNGaseF - -

32KDa

26KDa

Spleen Fo To

Fo IPP

Fo JPP

Fo MLN

- --PNGaseF - -Spleen Fo

ToFo IPP

Fo JPP

Fo MLN

- --PNGaseF - -

32KDa

26KDa

32KDa

26KDa

32KDa

26KDa

32KDa

26KDa

FoMLN

Spleen FoTo

Medul MedulPNGaseF + + + +-

FoMLN

Spleen FoTo

Medul MedulPNGaseF + + + +-

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231SAF32

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231SAF60

FoToMedullar Spleen

FoMln

PNGase F + + + +--

32KDa

26KDa

18KDa

FoToMedullar Spleen

FoMln

PNGase F + + + +--

FoToMedullar Spleen

FoMln

PNGase F + + + +--

FoToMedullar Spleen

FoMln

PNGase F + + + +--

32KDa

26KDa

18KDa

32KDa

26KDa

18KDa

32KDa

26KDa

LymphocytesTotal Spleen

PNGaseF + +-

32KDa

26KDa

32KDa

26KDa

LymphocytesTotal Spleen

PNGaseF + +-

LymphocytesTotal Spleen

PNGaseF + +-

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231SAF32

Isolation of PrPc expressing follicular dendritic cells (FDC)

FDC ultrastructure SAF32+ FDC

Mesenteric lymph nodes

32KDa

26KDa

Lymphocytes Follicular dendritic cells

+ +- -

Mesenteric lymph nodes

32KDa

26KDa

Lymphocytes Follicular dendritic cells

+ +- -

32KDa

26KDa

32KDa

26KDa

Lymphocytes Follicular dendritic cells

+ +- -

Lymphocytes Follicular dendritic cells

+ +- -

PNGaseF

LymphocytesFollicularDendritic cells

Jejunal Peyer’s Patches

+ +- -

LymphocytesFollicularDendritic cellsFo

- - -+ +

32KDa

26KDa

Tonsils

PNGaseF

LymphocytesFollicularDendritic cells

Jejunal Peyer’s Patches

+ +- -

LymphocytesFollicularDendritic cellsFo

- - -+ +

32KDa

26KDa

PNGaseF

LymphocytesFollicularDendritic cells

Jejunal Peyer’s Patches

+ +- -

LymphocytesFollicularDendritic cells

Jejunal Peyer’s Patches

+ +- -

LymphocytesFollicularDendritic cellsFo

- - -+ +

LymphocytesFollicularDendritic cellsFo

- - -+ +

32KDa

26KDa

32KDa

26KDa

Tonsils

PrPc is highly glycosylated in spleen and in lymphoid follicles isolated from bovine lymphoid tissues as well as in their FDC and lymphocytes. After deglycosylation, a novel PrPc truncated form with a relative molecular mass of about 25 kDa was detected in bovine lymphoid organs beside the typical 18 and 21 kDa forms.

Western blot analysis to compare the PrPc glycoform ratios and the truncated PrPc forms expressed in human lymphoid tissues

Human spleenHuman Tonsil

PNGaseF + +- ++ - --

Follicles Lymphocytes FollicularDendritic

Cells

32KDa

26KDa

Human spleenHuman Tonsil

PNGaseF + +- ++ - --

Follicles Lymphocytes FollicularDendritic

Cells

32KDa

26KDa

PNGaseF + +- ++ - --

Follicles Lymphocytes FollicularDendritic

Cells

32KDa

26KDa

32KDa

26KDa

Our results highlight variation in the profile expression of PrPc in peripheral and central tissues of bovine and human. Such differences may have an implication for PrPc function and may represent critical factors influencing the accumulation of the infectious agent in these areas.

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231

(-C) (21kDa)

(α-C) (19kDa)

FL (Full length, N-C) (27kDa)

α

23 231SAF32

No difference in WB PrPc profile was seen in follicles, lymphocytes and FDC of human tissues Immune PrPc is highly glycosylated and, after deglycosylation, the 25 kDa is also expressed in human lymphoid tissues and cells. Supported by the EU contract QLG3-CT-2002-81030