Open AccessTest for Detection of Disease-Associated Prion Aggregate in the Blood of Infected but Asymptomatic Animals
Author(s) -
Binggong Chang,
Xin Cheng,
Shaoman Yin,
Tao Pan,
Hongtao Zhang,
Poki Wong,
Shin Chung Kang,
Fan Xiao,
Huimin Yan,
Chaoyang Li,
Lisa L. Wolfe,
Michael W. Miller,
Thomas Wısnıewskı,
Mark I. Greene,
Man Sun Sy
Publication year - 2007
Publication title -
clinical and vaccine immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.649
H-Index - 77
eISSN - 1556-6811
pISSN - 1556-679X
DOI - 10.1128/cvi.00341-06
Subject(s) - chronic wasting disease , asymptomatic , virology , disease , in vitro , biology , prion protein , medicine , pathology , biochemistry , scrapie
We have developed a sensitive in vitro assay for detecting disease-associated prion aggregates by combining an aggregation-specific enzyme-linked immunosorbent assay (AS-ELISA) with the fluorescent amplification catalyzed by T7 RNA polymerase technique (FACTT). The new assay, named aggregation-specific FACTT (AS-FACTT), is much more sensitive than AS-ELISA and could detect prion aggregates in the brain of mice as early as 7 days after an intraperitoneal inoculation of PrPSc . However, AS-FACTT was still unable to detect prion aggregates in blood of infected mice. To further improve the detection limit of AS-FACTT, we added an additional prion amplification step (Am) and developed a third-generation assay, termed Am-A-FACTT. Am-A-FACTT has 100% sensitivity and specificity in detecting disease-associated prion aggregates in blood of infected mice at late but still asymptomatic stages of disease. At a very early stage, Am-A-FACTT had a sensitivity of 50% and a specificity of 100%. Most importantly, Am-A-FACTT also detects prion aggregates in blood of mule deer infected with the agent causing a naturally occurring prion disease, chronic wasting disease. Application of this assay to cattle, sheep, and humans could safeguard food supplies and prevent human contagion.