ABSTRACT
The use of streptomycin in the PrP(sc) detection procedures represents a new and attractive way to detect more PrP(sc), the best marker for the transmissible spongiform encephalopathies (TSEs). Actually, the streptomycin PrP(sc) aggregating property reported recently was established as beneficial in PrP(sc) detection using immunohistochemistry in diagnostic as well as in experimental conditions. The present study reports in details how to use advantageously this original streptomycin property in PrP(res) biochemical extraction and detection. Using TSE diagnostic brain material, specificity and increased sensitivity using streptomycin-treated samples were substantiated. Then an early sequential brain and spleen sampling (from 7 to 49 days post-inoculation) from C57Bl/6 mice inoculated intra-cerebrally or intra-peritoneally with C506M3 scrapie strain was analysed using streptomycin versus ultracentrifugation PrP(res) extraction. Whatever the inoculation route, streptomycin allowed earlier PrP(res) detection in spleen (7 d.p.i.), then in brain suggesting a stronger affinity of the infectious agent for the lymphoid compartment.
Subject(s)
Prion Diseases/diagnosis , Prions/analysis , Streptomycin/chemistry , Animals , Brain Chemistry , Cattle , Chemical Precipitation , Female , Kinetics , Methods , Mice , Mice, Inbred C57BL , Prions/chemistry , Spleen/chemistryABSTRACT
To investigate the amplifying potentialities of streptomycin sulfate in the immunohistochemical (IHC) detection of the abnormal prion protein (PrPsc), we used a sequential brain sampling from C506M3 scrapie strain inoculated C57Bl/6 mice. The weekly removed brains, from 7 to 63 days post intra-cranial inoculation were analysed using PrPsc IHC. The introduction of streptomycin sulfate, a technique developed for accurate cellular and regional mapping of PrPsc deposition in several animal TSEs, revealed a substantial amplifying effect and a clear specific PrPsc detection as early as 28 days post inoculation. The location of the first detected PrPsc deposits suggests a possible involvement of the cerebrospinal fluid in the early dissemination of the infectious agent. The meaning of these newly accessible PrPsc deposits is discussed in relation to a possible nascent form of PrPsc molecules detected in situ for the first time. Altogether, these findings argue that this method can be highly useful to study the early stages after infection with prion agents.
Subject(s)
Brain/metabolism , PrPSc Proteins/analysis , Scrapie/metabolism , Streptomycin/chemistry , Animals , Brain/pathology , Early Diagnosis , Female , Immunohistochemistry/methods , Mice , Mice, Inbred C57BL , PrPSc Proteins/cerebrospinal fluid , PrPSc Proteins/chemistry , Scrapie/diagnosisABSTRACT
The ability of streptomycin to form multimolecular aggregates with pathogenic prion proteins and their recovery by precipitation via a low-speed centrifugation step has been demonstrated; these novel properties of streptomycin make it a useful substance that increases the sensitivity of laboratory diagnostic techniques for prion infections in man and animals.
