***2018***

Cervid to human prion transmission

Kong, Qingzhong

Case Western Reserve University, Cleveland, OH, United States

Abstract

Prion disease is transmissible and invariably fatal. Chronic wasting disease (CWD) is the prion disease affecting deer, elk and moose, and it is a widespread and expanding epidemic affecting 22 US States and 2 Canadian provinces so far. CWD poses the most serious zoonotic prion transmission risks in North America because of huge venison consumption (>6 million deer/elk hunted and consumed annually in the USA alone), significant prion infectivity in muscles and other tissues/fluids from CWD-affected cervids, and usually high levels of individual exposure to CWD resulting from consumption of the affected animal among often just family and friends. However, we still do not know whether CWD prions can infect humans in the brain or peripheral tissues or whether clinical/asymptomatic CWD zoonosis has already occurred, and we have no essays to reliably detect CWD infection in humans.

We hypothesize that:

(1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues;

(2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence;

(3) Reliable essays can be established to detect CWD infection in humans; and

(4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.

Aim 1 will prove that the classical CWD strain may infect humans in brain or peripheral lymphoid tissues at low levels by conducting systemic bioassays in a set of humanized Tg mouse lines expressing common human PrP variants using a number of CWD isolates at varying doses and routes. Experimental human CWD samples will also be generated for Aim 3.

Aim 2 will test the hypothesis that the cervid-to-human prion transmission barrier is dependent on prion strain and influenced by the host (human) PrP sequence by examining and comparing the transmission efficiency and phenotypes of several atypical/unusual CWD isolates/strains as well as a few prion strains from other species that have adapted to cervid PrP sequence, utilizing the same panel of humanized Tg mouse lines as in Aim 1.

Aim 3 will establish reliable essays for detection and surveillance of CWD infection in humans by examining in details the clinical, pathological, biochemical and in vitro seeding properties of existing and future experimental human CWD samples generated from Aims 1-2 and compare them with those of common sporadic human Creutzfeldt-Jakob disease (sCJD) prions.

Aim 4 will attempt to detect clinical CWD-affected human cases by examining a significant number of brain samples from prion-affected human subjects in the USA and Canada who have consumed venison from CWD-endemic areas utilizing the criteria and essays established in Aim 3. The findings from this proposal will greatly advance our understandings on the potential and characteristics of cervid prion transmission in humans, establish reliable essays for CWD zoonosis and potentially discover the first case(s) of CWD infection in humans.

Public Health Relevance

There are significant and increasing human exposure to cervid prions because chronic wasting disease (CWD, a widespread and highly infectious prion disease among deer and elk in North America) continues spreading and consumption of venison remains popular, but our understanding on cervid-to-human prion transmission is still very limited, raising public health concerns. This proposal aims to define the zoonotic risks of cervid prions and set up and apply essays to detect CWD zoonosis using mouse models and in vitro methods. The findings will greatly expand our knowledge on the potentials and characteristics of cervid prion transmission in humans, establish reliable essays for such infections and may discover the first case(s) of CWD infection in humans.

NIH 2015 R01 NS Cervid to human prion transmission Kong, Qingzhong / Case Western Reserve University $337,507

http://grantome.com/grant/NIH/R01-NS088604-04

ZOONOTIC CHRONIC WASTING DISEASE CWD TSE PRION UPDATE

here is the latest;

PRION 2018 CONFERENCE

Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice

Hermann M. Schatzl, Samia Hannaoui, Yo-Ching Cheng, Sabine Gilch (Calgary Prion Research Unit, University of Calgary, Calgary, Canada) Michael Beekes (RKI Berlin), Walter Schulz-Schaeffer (University of Homburg/Saar, Germany), Christiane Stahl-Hennig (German Primate Center) & Stefanie Czub (CFIA Lethbridge). To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years.

After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were detected in spinal cord and brain of some euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and pre-clinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles.

Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate.

The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.

Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP.

The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD..

***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***

https://prion2018.org/

READING OVER THE PRION 2018 ABSTRACT BOOK, LOOKS LIKE THEY FOUND THAT from this study ;

P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States

Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1) (1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA..

SEEMS THAT THEY FOUND Highly endemic states had a higher rate of prion disease mortality compared to non-CWD states.

AND ANOTHER STUDY;

P172 Peripheral Neuropathy in Patients with Prion Disease

Wang H(1), Cohen M(1), Appleby BS(1,2) (1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio..

IN THIS STUDY, THERE WERE autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017,

AND

included 104 patients. SEEMS THEY FOUND THAT The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%),

AND

THAT The Majority of cases were male (60%), AND half of them had exposure to wild game.

snip...see more on Prion 2017 Macaque study from Prion 2017 Conference and other updated science on cwd tse prion zoonosis below...terry

https://prion2018.org/wp-content/upl...05/program.pdf

https://prion2018.org/

Cervid to human prion transmission 5R01NS088604-04 Update

National Institute of Health (NIH)

http://chronic-wasting-disease.blogs...nsmission.html

MONDAY, NOVEMBER 26, 2018

***> The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP

https://chronic-wasting-disease.blog...g-disease.html

SATURDAY, NOVEMBER 10, 2018

cwd, bse, scrapie, cjd, tse prion updated November 10 2018

https://chronic-wasting-disease.blog...n-updated.html

THURSDAY, OCTOBER 25, 2018

***> Norway New additional requirements for imports of hay and straw for animal feed from countries outside the EEA due to CWD TSE Prion

https://chronic-wasting-disease.blog...ments-for.html

***> cwd scrapie pigs oral routes

***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***

>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <***


***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).

***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period.

***> This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease.

***> Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.

>>>> The successful transmission of pig-passaged CWD to Tg40 mice reported here suggests that passage of the CWD agent through pigs results in a change of the transmission characteristics which reduces the transmission barrier of Tg40 mice to the CWD agent. If this biological behavior is recapitulated in the original host species, passage of the CWD agent through pigs could potentially lead to increased pathogenicity of the CWD agent in humans.

https://www.ars.usda.gov/research/pu...eqNo115=353091

https://www.ars.usda.gov/research/pr...432011&fy=2017

https://www.ars.usda.gov/research/pu...eqNo115=337105

prepare for the storm...

THURSDAY, OCTOBER 04, 2018

Cervid to human prion transmission 5R01NS088604-04 Update

http://chronic-wasting-disease.blogs...nsmission.html

FRIDAY, NOVEMBER 30, 2018

The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSEs) in 2017
published November 2018 (see CWD TSE Prion)

https://transmissiblespongiformencep...report-on.html


terry