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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #147377
Title: FAILURE TO DETECT PRION PROTEIN (PRPRES) BY IMMUNOHISTOCHEMISTRY IN STRIATED MUSCLE TISSUES OF ANIMALS EXPERIMENTALLY INOCULATED WITH AGENTS OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY

Author
item Hamir, Amirali
item Miller, Janice
item Cutlip, Randall

Submitted to: Veterinary Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/2003
Publication Date: 1/1/2004
Citation: Hamir, A.N., Miller, J.M., Cutlip, R.C. 2004. Failure to detect prion protein (PrPres) by immunohistochemistry in striated muscle tissues of animals experimentally inoculated with agents of transmissible spongiform encephalopathy. Veterinary Pathology. 41(1):78-81.

Interpretive Summary: Transmissible spongiform encephalopathies (TSEs) are fatal, neurologic diseases. Infection by the causative agent, a prion, induces accumulations of an abnormal form of prion protein (PrPres) in tissues of affected animals. Presence of characteristic lesions and detection of protease-resistant PrPres in tissues are the basis of currently available methods for diagnosis of TSEs. In this study, samples of muscle tissues (tongue, heart, diaphragm and masseter muscle) from 20 animals (cattle, sheep, elk, and raccoons) were examined for PrPres. All of the animals had developed TSE after experimental inoculation with scrapie, chronic wasting disease, or transmissible mink encephalopathy agents. PrPres was found in the brains, but not in muscle tissues of all examined animals. These results are contradictory to recently published data in laboratory animals with TSEs, which may indicate that laboratory-adapted TSE strains have acquired the capacity to amplify in muscles during propagation in laboratory animals. Although further testing of muscle tissues is needed to confirm findings of the present study, meat consumers may be relieved to know that at present no PrPres can be detected in muscle tissues of experimental animals with TSEs.

Technical Abstract: Transmissible spongiform encephalopathies (TSEs) are fatal, neurologic diseases. Infection by the causative agent, a prion, induces accumulations of an abnormal form of prion protein (PrPres) in tissues of nervous and lymphoid systems. Presence of characteristic histopathological changes (spongiform encephalopathy) and detection of protease-resistant PrPres in neural and lymphoid tissues are the basis of currently available methods for diagnosis of TSEs. In this study, samples of striated muscle tissues (tongue, heart, diaphragm and masseter muscle) from 20 animals (cattle, sheep, elk, and raccoons) were examined for PrPres by immunohistochemistry. All of the animals had developed TSE after experimental inoculation with scrapie, chronic wasting disease, or transmissible mink encephalopathy. PrPres was found in the brains, but not in muscle tissues of all examined animals. These results are contradictory to recently published data in laboratory animals with TSEs, which may indicate that laboratory-adapted TSE strains have acquired the capacity to amplify in muscles during propagation in laboratory animals. Further testing of muscle tissues is needed to confirm findings of the present study.