SATURDAY, JANUARY 29, 2011
Atypical L-Type Bovine Spongiform Encephalopathy (L-BSE) Transmission to Cynomolgus Macaques, a Non-Human Primate
Jpn. J. Infect. Dis., 64 (1), 81-84, 2011
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Short Communication
Atypical L-Type Bovine Spongiform Encephalopathy (L-BSE) Transmission to Cynomolgus Macaques, a Non-Human Primate
Fumiko Ono, Naomi Tase1, Asuka Kurosawa3, Akio Hiyaoka, Atsushi Ohyama, Yukio Tezuka, Naomi Wada2, Yuko Sato3, Minoru Tobiume3, Ken'ichi Hagiwara4, Yoshio Yamakawa4*, Keiji Terao1, and Tetsutaro Sata3
The Corporation for Production and Research of Laboratory Primates, Tsukuba 305-0843; 1Tsukuba Primate Research Center, National Institute of Biomedical Innovation, Tsukuba 305-0843; 2Department of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515; and 3Department of Pathology and 4Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
(Received December 9, 2010. Accepted December 22, 2010)
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*Corresponding author: Mailing address: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan. Tel: +81-3-5285-1111 ext. 2127, Fax: +81-3-5285-1157, E-mail: yamakawa@nih.go.jp
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SUMMARY: A low molecular weight type of atypical bovine spongiform encephalopathy (L-BSE) was transmitted to two cynomolgus macaques by intracerebral inoculation of a brain homogenate of cattle with atypical BSE detected in Japan. They developed neurological signs and symptoms at 19 or 20 months post-inoculation and were euthanized 6 months after the onset of total paralysis. Both the incubation period and duration of the disease were shorter than those for experimental transmission of classical BSE (C-BSE) into macaques. Although the clinical manifestations, such as tremor, myoclonic jerking, and paralysis, were similar to those induced upon C-BSE transmission, no premonitory symptoms, such as hyperekplexia and depression, were evident. Most of the abnormal prion protein (PrPSc) was confined to the tissues of the central nervous system, as determined by immunohistochemistry and Western blotting. The PrPSc glycoform that accumulated in the monkey brain showed a similar profile to that of L-BSE and consistent with that in the cattle brain used as the inoculant. PrPSc staining in the cerebral cortex showed a diffuse synaptic pattern by immunohistochemistry, whereas it accumulated as fine and coarse granules and/or small plaques in the cerebellar cortex and brain stem. Severe spongiosis spread widely in the cerebral cortex, whereas florid plaques, a hallmark of variant Creutzfeldt-Jakob disease in humans, were observed in macaques inoculated with C-BSE but not in those inoculated with L-BSE.
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To date, 27 cases of L-BSE and 24 cases of H-BSE have been reported worldwide (16), thus meaning that the prevalence of atypical BSE is considerably lower than that of C-BSE. However, recent studies showed that L-BSE is easily transmissible to transgenic mice expressing human (17,18) or bovine (19,20) prion protein, as well as to non-human primates (21), with shorter incubation periods than for the transmission of C-BSE to these animals. The virulent nature of L-BSE has stimulated new concern for human public health since the transmission of C-BSE to humans resulted in variant Creutzfeldt-Jakob disease (vCJD) (4-7), a new emergent prion disease.
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Two macaques simultaneously developed neurological signs and symptoms 19-20 months post-inoculation (mpi) with the brain homogenate of BSEI JP24. The monkeys entered the terminal stage of the disease (total paralysis) at 24-25 mpi, Both the onset and duration of the disease were shorter than those reported for the transmission of C-BSE to macaques by us and other groups (27,28). The clinical manifestations such as tremor, myoclonic jerking, and paralysis were similar to those observed during the transmission of C-BSE to ma- caques, whereas the premonitory abnormal behaviors, such as hyperekplexia and depression, seen upon transmission of C-BSE to macaques were not evident (27).
Histopathological analysis and IHC, performed as described previously (29), showed that severe spongiform changes and the accumulation of Prpsc with various patterns were detectable in the brains of both monkeys (Fig. 1). Vacuolization was profound throughout the cerebral cortex, from the frontal to the occipital lobes (Fig. la). Likewise, synaptic-type Prpsc precipitation (30) was observed in the whole cerebral cortex and basal ganglia by IHC (Figs. Ib and c). Dense precipitates and plaques of Prpsc, which had been observed in cattle (JP24) brain (13), were not detected in the cerebrum of the monkeys. Prpsc, in the form of small plaques or coarse granules, was, however, detected in the molecular layer of the cerebellum (Fig. Ie). Despite the severe spongiosis in the cerebral cortex, florid plaques, which are large Prpsc plaques surrounded by vacuoles, a hallmark ofvCJD (4-7,30) and C-BSE transmission to macaques (27,28), were not observed. The histopathology of the brain was therefore similar to that reported for the brain of L-BSE (BASE)-transmitted macaques (21).
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see full text ;
Monday, September 13, 2010
atypical BSE strains and sporadic CJD strains, is there a connection and why shouldn't there be $
Monday, September 13, 2010
atypical BSE strains and sporadic CJD strains, is there a connection and why shouldn't there be $ A Surprisingly High Number of the Plaque-Like VV sCJD Subtype Among the Polish sCJD-is There a Connection with BASE?
PPo4-15:
A Surprisingly High Number of the Plaque-Like VV sCJD Subtype Among the Polish sCJD—is There a Connection with BASE?
Beata Sikorska and Pawel P. Liberski Department of Molecular Pathology and Neuropathology; Medical University of Lodz; Lodz, Poland
Recently described bovine amyloidotic spongiform encephalopathy (BASE) or L type BSE—was is overrepresented in Poland (15% of all cases of BSE). Moreover, the number of BASE cases in Poland per million bovines is the highest in Europe. A potential human risk from BASE is evident from experimental transmission to “humanized” transgenic animals and primates. Taking into consideration that non-human primate inoculated with BASE had a shorter incubation period than monkeys infected with classical BSE, and that humanized Tg mice have been found to be highly susceptible to infection with atypical form of BSE, it seems probable that BASE may be more pathogenic for humans than BSE, but the transmitted disease may differ from BSE-derived vCJD. Among 47 cases which have been diagnosed as definite in our laboratory, in 19 cases complete histopathological examination and codon 129 status were available. On the basis of the histological pattern and codon 129 status the cases of sCJD were divided into subtypes according to the Parchi&Gambetti classification. The results are as follows: type 1 (MMorMV)- 42%, type 2 (VV)-32%, type 3 (MV)-10.5%, type 4c (MM)- 10.5% and type 5 (VV)-5 %. Although the number of cases is too low to conclude a significantly different distribution of sCJD subtypes in Polish population those data show surprisingly high number of the plaque-like VV sCJD subtype. Interestingly, it was shown before that Tg mice inoculated with BASE showed granular and plaque-like aggregates or PrPSc in brains resembling those observed in VV2 subtype of sCJD.
PPo2-26:
Transmission of Classical and Atypical (L-type) Bovine Spongiform Encephalopathy (BSE) Prions to Cynomolgus macaques
Fumiko Ono,1 Yoshio Yamakawa,2 Minoru Tobiume,3 Yuko Sato,3 Harutaka Katano,3 Kenichi Hagiwara,2 Iori Itagaki,1 Akio Hiyaoka,1 Katuhiko Komatuzaki,1 Yasunori Emoto,1 Hiroaki Shibata,4 Yuichi Murayama,5 Keiji Terao,4 Yasuhiro Yasutomi4 and Tetsutaro Sata3
1The Corporation for Production and Research of Laboratory Primates; Tsukuba City, Japan; 2Departments of Cell Biology and Biochemistry; and 3Pathology; National Institute of Infectious Diseases; Tokyo, Japan; 4Tsukuba Primate Research Center; National Institute of Biomedical Innovation; Tsukuba City, Japan; 5Prion Disease Research Team; National Institute of Animal Health; Tsukuba City, Japan
Key words: L-type BSE, cBSE, cynomolgus macaques, transmission
BSE prion derived from classical BSE (cBSE) or L-type BSE was characterized by inoculation into the brain of cynomolgus macaques. The neurologic manifestation was developed in all cynomolgus macaques at 27–43 months after intracerebral inoculation of brain homogenate from cBSE-affected cattle (BSE JP/6). Second transmission of cBSE from macaque to macaque shortened incubation period to 13–18 months. cBSE-affected macaques showed the similar clinical signs including hyperekplexia, tremor and paralysis in both primary and second transmission.
Two macaques were intracerebrally inoculated brain homogenate from the L-type BSE-affected cattle (BSE JP/24). The incubation periods were 19–20 months in primary transmission.
The clinical course of the L-type BSE-affected macaques differed from that in cBSE-affected macaques in the points of severe myoclonus without hyperekplexia. The glycoform profile of PrPSc detected in macaque CNS was consistent with original pattern of either cBSE or L-typeBSE PrPSc, respectively. Although severe spongiform change in the brain was remarkable in all BSE-affected macaques, severe spongiform spread widely in cerebral cortex in L-type BSE-affected macaques. Heavy accumulation of PrPSc surrounded by vacuola formed florid plaques in cerebral cortex of cBSE-affected macaques. Deposit of PrPSc in L-type BSE-affected macaque was weak and diffuse synaptic pattern in cerebrum, but large PrPSc plaques were evident at cerebellum. MRI analysis, T2, T1, DW and flair sequences, at the time of autopsy revealed that brain atrophy and dilatation of cerebral ventricles were significantly severe in L-type BSE-affected macaques. These results suggest that L-type BSE is more virulent strain to primates comparing to cBSE.
SP1-4:
Evidence from Molecular Strain Typing
Gianluigi Zanusso Department of Neurological and Visual Sciences; Section of Clinical Neurology; University of Verona; Verona, Italy
Key words: molecular analysis, strain typing, atypical BSE, CJD
In 2001, active surveillance for bovine spongiform encephalopathy (BSE) led to the discovery of atypical BSE phenotypes in aged cattle distinct from classical BSE (C-type). These atypical BSE cases had been classified as low L-type (BASE) or high H-type BSE based on the molecular mass and the degree of glycosylation of of the pathological prion protein (PrPSc). Transmission studies in TgBov mice showed that H-type BSE, C-type BSE and BASE behave as distinct prion strains with different incubation periods, PrPSc molecular patterns and pathological phenotypes. A still unclear issue concerns the potential transmissibility and phenotypes of atypical BSEs in humans. We previously indicated that BASE was similar to a distinct subgroup of sporadic form of Creutzfeldt-Jakob disease (sCJD) MV2, based on molecular similarities and on neuropathological pattern of PrP deposition. To investigate a possible link between BASE and sCJD, Kong et al. and Comoy et al. experimentally inoculated TgHu mice (129MM) and a non-human primate respectively, showing in both models that BASE was more virulent compare to BSE. Further, non-human primate reproduced a clinical phenotype resembling to that of sCJD subtype MM2. Here, we presented a comparative analysis of the biochemical fingerprints of PrPSc between the different sCJD subtypes and animal TSEs and after experimental transmission to animals.
Opinion of the Scientific Steering Committee on the GEOGRAPHICAL RISK OF BOVINE SPONGIFORM ENCEPHALOPATHY (GBR) in POLAND Adopted on 30/03/2001
It is concluded that it is likely but not confirmed that one or several cattle that are (pre-clinically or clinically) infected with the BSE agent are currently present in the domestic herd of Poland (GBR III).
Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate
Emmanuel E. Comoy1*, Cristina Casalone2, Nathalie Lescoutra-Etchegaray1, Gianluigi Zanusso3, Sophie Freire1, Dominique Marcé1, Frédéric Auvré1, Marie-Magdeleine Ruchoux1, Sergio Ferrari3, Salvatore Monaco3, Nicole Salès4, Maria Caramelli2, Philippe Leboulch1,5, Paul Brown1, Corinne I. Lasmézas4, Jean-Philippe Deslys1
1 Institute of Emerging Diseases and Innovative Therapies, CEA, Fontenay-aux-Roses, France, 2 Istituto Zooprofilattico Sperimentale del Piemonte, Turin, Italy, 3 Policlinico G.B. Rossi, Verona, Italy, 4 Scripps Florida, Jupiter, Florida, United States of America, 5 Genetics Division, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
Abstract Top Background Human variant Creutzfeldt-Jakob Disease (vCJD) results from foodborne transmission of prions from slaughtered cattle with classical Bovine Spongiform Encephalopathy (cBSE). Atypical forms of BSE, which remain mostly asymptomatic in aging cattle, were recently identified at slaughterhouses throughout Europe and North America, raising a question about human susceptibility to these new prion strains.
Methodology/Principal Findings Brain homogenates from cattle with classical BSE and atypical (BASE) infections were inoculated intracerebrally into cynomolgus monkeys (Macacca fascicularis), a non-human primate model previously demonstrated to be susceptible to the original strain of cBSE. The resulting diseases were compared in terms of clinical signs, histology and biochemistry of the abnormal prion protein (PrPres). The single monkey infected with BASE had a shorter survival, and a different clinical evolution, histopathology, and prion protein (PrPres) pattern than was observed for either classical BSE or vCJD-inoculated animals. Also, the biochemical signature of PrPres in the BASE-inoculated animal was found to have a higher proteinase K sensitivity of the octa-repeat region. We found the same biochemical signature in three of four human patients with sporadic CJD and an MM type 2 PrP genotype who lived in the same country as the infected bovine.
Conclusion/Significance Our results point to a possibly higher degree of pathogenicity of BASE than classical BSE in primates and also raise a question about a possible link to one uncommon subset of cases of apparently sporadic CJD. Thus, despite the waning epidemic of classical BSE, the occurrence of atypical strains should temper the urge to relax measures currently in place to protect public health from accidental contamination by BSE-contaminated products.
Citation: Comoy EE, Casalone C, Lescoutra-Etchegaray N, Zanusso G, Freire S, et al. (2008) Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate. PLoS ONE 3(8): e3017. doi:10.1371/journal.pone.0003017
Editor: Neil Mabbott, University of Edinburgh, United Kingdom
Received: April 24, 2008; Accepted: August 1, 2008; Published: August 20, 2008
Copyright: © 2008 Comoy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work has been supported by the Network of Excellence NeuroPrion.
Competing interests: CEA owns a patent covering the BSE diagnostic tests commercialized by the company Bio-Rad.
* E-mail: emmanuel.comoy@cea.fr
Session I - Prions: Structure, Strain and Detection (II)
Searching for BASE Strain Signature in Sporadic Creutzfedlt-Jakob Disease
Gianluigi Zanusso
Department of Neurological and Visual Sciences, Section of Clinical Neurology University of Verona, Verona, Italy.
Bovine amyloidotic spongiform encephalopathy (BASE) is a newly recognized form of bovine prion disease, which was originally detected in Italy in 2004 as an effect of active surveillance. BASE or BSE L-type (L is referred to the lower electrophoretic PrPSc migration than classical BSE) has now been reported in several countries, including Japan. All field cases of BASE were older than 8 years and neurologically normal at the time of slaughtered. By experimental transmission, we defined the disease phenotype of cattle BASE, which is quite distinct from that seen in typical BSE and characterized by mental dullness and amyotrophy. Surprisingly, following intraspecies and interspecies transmission the incubation period of BASE was shorter than BSE. The relatively easy transmission of BASE isolate as well as the molecular similarity with sporadic Creutzfeldt-Jakob disease (sCJD) have raised concern regarding its potential passage to humans. Tg humanized mice Met/Met at codon 129 challenged with both BSE and BASE isolates, showed a resistance to BSE but a susceptibility to BASE at a 60% rate; in addition, BASE-inoculated Cynomolgus (129 Met/Met) had shorter incubation periods than BSE-inoculated primates. In this study we compared the biochemical properties of PrPSc in Cynomolgus and in TgHu Met/Met mice challenged with BSE and BASE strains, by conventional SDS-PAGE analysis and 2D separation. The results obtained disclose distinct conformational changes in PrPSc, which are dependent on the inoculated host but not on the codon 129 genotype.
This work was supported by Neuroprion contract n. FOOD CT 2004 -506579 (NOE)
SEE OTHER YEARS OF PRION CONFERENCE ABSTRACTS
P02.35
Molecular Features of the Protease-resistant Prion Protein (PrPres) in H-type BSE
Biacabe, A-G1; Jacobs, JG2; Gavier-Widén, D3; Vulin, J1; Langeveld, JPM2; Baron, TGM1 1AFSSA, France; 2CIDC-Lelystad, Netherlands; 3SVA, Sweden
Western blot analyses of PrPres accumulating in the brain of BSE-infected cattle have demonstrated 3 different molecular phenotypes regarding to the apparent molecular masses and glycoform ratios of PrPres bands. We initially described isolates (H-type BSE) essentially characterized by higher PrPres molecular mass and decreased levels of the diglycosylated PrPres band, in contrast to the classical type of BSE. This type is also distinct from another BSE phenotype named L-type BSE, or also BASE (for Bovine Amyloid Spongiform Encephalopathy), mainly characterized by a low representation of the diglycosylated PrPres band as well as a lower PrPres molecular mass. Retrospective molecular studies in France of all available BSE cases older than 8 years old and of part of the other cases identified since the beginning of the exhaustive surveillance of the disease in 20001 allowed to identify 7 H-type BSE cases, among 594 BSE cases that could be classified as classical, L- or H-type BSE. By Western blot analysis of H-type PrPres, we described a remarkable specific feature with antibodies raised against the C-terminal region of PrP that demonstrated the existence of a more C-terminal cleaved form of PrPres (named PrPres#2 ), in addition to the usual PrPres form (PrPres #1). In the unglycosylated form, PrPres #2 migrates at about 14 kDa, compared to 20 kDa for PrPres #1. The proportion of the PrPres#2 in cattle seems to by higher compared to the PrPres#1. Furthermore another PK-resistant fragment at about 7 kDa was detected by some more N-terminal antibodies and presumed to be the result of cleavages of both N- and C-terminal parts of PrP. These singular features were maintained after transmission of the disease to C57Bl/6 mice. The identification of these two additional PrPres fragments (PrPres #2 and 7kDa band) reminds features reported respectively in sporadic Creutzfeldt-Jakob disease and in Gerstmann-Sträussler-Scheinker (GSS) syndrome in humans.
Thursday, October 07, 2010
Experimental Transmission of H-type Bovine Spongiform Encephalopathy to Bovinized Transgenic Mice
Thursday, October 07, 2010 Experimental Transmission of H-type Bovine Spongiform Encephalopathy to Bovinized Transgenic Mice
Vet Pathol 0300985810382672, first published on October 4, 2010
Experimental Transmission of H-type Bovine Spongiform Encephalopathy to Bovinized Transgenic Mice
H. Okada okadahi@affrc.go.jp Prion Disease Research Center, National Institute of Animal Health, Tsukuba, K. Masujin Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Y. Imamaru Prion Disease Research Center, National Institute of Animal Health, Tsukuba, M. Imamura Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Y. Matsuura Prion Disease Research Center, National Institute of Animal Health, Tsukuba, S. Mohri Prion Disease Research Center, National Institute of Animal Health, Tsukuba, S. Czub Animal Disease Research Institute, Canadian Food Inspection Agency, T. Yokoyama Prion Disease Research Center, National Institute of Animal Health, Tsukuba,
Abstract
To characterize the biological and biochemical properties of H-type bovine spongiform encephalopathy (BSE), a transmission study with a Canadian H-type isolate was performed with bovinized transgenic mice (TgBoPrP), which were inoculated intracerebrally with brain homogenate from cattle with H-type BSE. All mice exhibited characteristic neurologic signs, and the subsequent passage showed a shortened incubation period. The distribution of disease-associated prion protein (PrPSc) was determined by immunohistochemistry, Western blot, and paraffin-embedded tissue (PET) blot. Biochemical properties and higher molecular weight of the glycoform pattern were well conserved within mice. Immunolabeled granular PrPSc, aggregates, and/or plaque-like deposits were mainly detected in the following brain locations: septal nuclei, subcallosal regions, hypothalamus, paraventricular nucleus of the thalamus, interstitial nucleus of the stria terminalis, and the reticular formation of the midbrain. Weak reactivity was detected by immunohistochemistry and PET blot in the cerebral cortex, most thalamic nuclei, the hippocampus, medulla oblongata, and cerebellum. These findings indicate that the H-type BSE prion has biological and biochemical properties distinct from those of C-type and L-type BSE in TgBoPrP mice, which suggests that TgBoPrP mice constitute a useful animal model to distinguish isolates from BSE-infected cattle.
© 2010 Sage Publications, Inc.
Evaluation of the Human Transmission Risk of an Atypical Bovine Spongiform Encephalopathy Prion Strain▿ Qingzhong Kong1,*, Mengjie Zheng1, Cristina Casalone2, Liuting Qing1, Shenghai Huang1,†, Bikram Chakraborty1, Ping Wang1, Fusong Chen1, Ignazio Cali1, Cristiano Corona2, Francesca Martucci2, Barbara Iulini2, Pierluigi Acutis2, Lan Wang1, Jingjing Liang1, Meiling Wang1, Xinyi Li1, Salvatore Monaco3, Gianluigi Zanusso3, Wen-Quan Zou1, Maria Caramelli2 and Pierluigi Gambetti1,* + Author Affiliations
1Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106 2CEA, Istituto Zooprofilattico Sperimentale, 10154 Torino, Italy 3Department of Neurological and Visual Sciences, University of Verona, 37134 Verona, Italy ABSTRACT
Bovine spongiform encephalopathy (BSE), the prion disease in cattle, was widely believed to be caused by only one strain, BSE-C. BSE-C causes the fatal prion disease named new variant Creutzfeldt-Jacob disease in humans. Two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H, have been discovered in several countries since 2004; their transmissibility and phenotypes in humans are unknown. We investigated the infectivity and human phenotype of BASE strains by inoculating transgenic (Tg) mice expressing the human prion protein with brain homogenates from two BASE strain-infected cattle. Sixty percent of the inoculated Tg mice became infected after 20 to 22 months of incubation, a transmission rate higher than those reported for BSE-C. A quarter of BASE strain-infected Tg mice, but none of the Tg mice infected with prions causing a sporadic human prion disease, showed the presence of pathogenic prion protein isoforms in the spleen, indicating that the BASE prion is intrinsically lymphotropic. The pathological prion protein isoforms in BASE strain-infected humanized Tg mouse brains are different from those from the original cattle BASE or sporadic human prion disease. Minimal brain spongiosis and long incubation times are observed for the BASE strain-infected Tg mice. These results suggest that in humans, the BASE strain is a more virulent BSE strain and likely lymphotropic.
SNIP...
DISCUSSION We have shown that 60% of our Tg40 mice (in an inbred FVB background) that express normal levels of human PrP-129M became infected 20 to 22 months after i.c. inoculation with 0.3 mg of brain tissue from the two BASE isolates, suggesting a titer of approximately 3 50% infective dose units per milligram of brain tissue in the Tg40 line. An approximately 20% attack rate has been reported for the Tg650 line (in a mixed 129/Sv × C57BL/6 background) after i.c. inoculation with 2 mg brain tissues from BSE-C-infected cattle (2). It is noteworthy that the Tg650 mice express human PrP-129M at five to eight times the normal level, and high PrP levels are known to increase prion transmissibility (9, 17, 22). Inefficient BSE-C transmissions (0 to 30%) in Tg mouse lines of other genetic backgrounds expressing human PrP-129M at one or two times the normal level have also been reported by different groups (1, 4). Although it is difficult to compare results from different mouse lines, these findings suggest that the BASE strain has higher transmissibility than BSE-C does for humanized Tg mice with PrP-129M and possibly for humans with PrP-129MM. The BASE strain also appears to be more virulent than BSE-C in bovinized Tg mice, since the incubation time for the BASE strain is 185 ± 12 days, whereas that for BSE-C is 230 ± 7 days (7). Nevertheless, compared with the 100% attack rate and incubation times of ∼9 months for sCJDMM1 and sCJDMM2 in the Tg40 line (Table 1), the 60% attack rate and unusually long incubation times (20 to 22 months) for the BASE strain in the same Tg line suggest that the transmission barrier from the BASE strain to humans with PrP-129MM is still quite significant.
PK-resistant PrPSc was also detected in the spleen in 4 out of 18 BASE strain-infected Tg40 mice. In contrast, no spleen involvement could be demonstrated for the Tg40 mice following i.c. inoculation with human PrPSc from sCJDMM1. This is the first report of the presence of PrPSc in the spleens of humanized Tg mice after i.c. inoculation with a BSE strain, suggesting that the BASE strain, like BSE-C, where at least in vCJD-infected subjects PrPSc and prion infectivity have been detected in spleens and tonsils (6, 11), is intrinsically lymphotropic. Therefore, lymphoid tissues of BASE strain-infected individuals might also carry prion infectivity.
The gel mobility of the PK-resistant PrPSc recovered from the BASE strain-inoculated Tg40 mice was consistently slightly faster than the mobility of BSE-C, as originally reported for the BASE strain (8). The computed difference in gel mobilities between BASE and BSE-C PrPSc is 0.29 ± 0.12 kDa, corresponding to 2 to 4 amino acid residues. In contrast, the gel mobilities of the PK-resistant PrPSc species from the BASE strain, BASE strain-infected Tg40 mice, and sCJDMM2, which was used as representative of human PrPSc of type 2, were indistinguishable. This finding suggests that the PK-resistant PrPSc electrophoretic heterogeneity between the BASE strain and BSE-C falls well within the 7-amino-acid variability of the N terminus (positions 92 to 99) that is consistently found in PK-resistant PrPSc of type 2 (16). Therefore, despite their minor but distinct variability in gel mobility, both the BASE strain and BSE-C PrPSc species appear to belong to the PrPSc of type 2. However, the PrPSc glycoform ratios of BASE strain-infected Tg40 mice and the BASE strain inocula display a small but statistically significant difference (Fig. 1). Therefore, PrPSc in BASE strain-infected human subjects may be expected to display a different glycoform ratio from that of the BASE strain. It is worth noting that the electrophoretic characteristics of the PK-resistant PrPSc of some human prion strains has been faithfully reproduced by our Tg40 line as well as by other humanized mouse lines (10, 13, 21).
Two distinct histopathological and PrP immunohistochemical phenotypes have been reported following BSE-C inoculation: one reproduced the distinctive features of vCJD with the “florid” plaques that intensely immunostained for PrP, and the other was reminiscent of sCJDMM1, with prominent spongiform degeneration and no plaque PrP immunostaining (1, 23). The brain histopathology, the PrPSc distribution, and the PrP immunostaining pattern of BASE strain-inoculated Tg40 mice were definitely distinct from such features described above (1, 23), further supporting the notion that BASE and classical BSE are associated with two distinct prion strains (8).
The relatively easy transmission of BASE to humanized Tg mice indicates that effective cattle prion surveillance should be maintained until the extent and origin of this and other atypical forms of BSE are fully understood.
Previous Section Next Section ACKNOWLEDGMENTS
Tuesday, December 14, 2010
Infection control of CJD, vCJD and other human prion diseases in healthcare and community settings part 4, Annex A1, Annex J, UPDATE DECEMBER 2010
Saturday, June 13, 2009
Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States 2003 revisited 2009
Saturday, January 2, 2010
Human Prion Diseases in the United States January 1, 2010 ***FINAL***
14th ICID International Scientific Exchange Brochure -
Final Abstract Number: ISE.114
Session: International Scientific Exchange
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America
update October 2009
T. Singeltary
Bacliff, TX, USA
Background:
An update on atypical BSE and other TSE in North America. Please remember, the typical U.K. c-BSE, the atypical l-BSE (BASE), and h-BSE have all been documented in North America, along with the typical scrapie's, and atypical Nor-98 Scrapie, and to date, 2 different strains of CWD, and also TME. All these TSE in different species have been rendered and fed to food producing animals for humans and animals in North America (TSE in cats and dogs ?), and that the trading of these TSEs via animals and products via the USA and Canada has been immense over the years, decades.
Methods:
12 years independent research of available data
Results:
I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2009. With all the science to date refuting it, to continue to validate this old myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, medical i.e., surgical, blood, dental, endoscopy, optical, nutritional supplements, cosmetics etc.
Conclusion:
I would like to submit a review of past CJD surveillance in the USA, and the urgent need to make all human TSE in the USA a reportable disease, in every state, of every age group, and to make this mandatory immediately without further delay. The ramifications of not doing so will only allow this agent to spread further in the medical, dental, surgical arena's. Restricting the reporting of CJD and or any human TSE is NOT scientific. Iatrogenic CJD knows NO age group, TSE knows no boundaries. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Gajdusek, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route.
Tuesday, December 14, 2010
Infection control of CJD, vCJD and other human prion diseases in healthcare and community settings part 4, Annex A1, Annex J, UPDATE DECEMBER 2010