Generation of antibodies against bovine recombinant prion protein in various strains of mice.

Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, belong to a group of neurodegenerative disorders affecting humans and animals. To date, definite diagnosis of prion disease can only be made by analysis of tissue samples for the presence of protease-resistant misfolded prion protein (PrP(Sc)). Monoclonal antibodies (MAbs) to the prion protein provide valuable tools for TSE diagnosis, as well as for basic research on these diseases. In this communication, the development of antibodies against recombinant bovine prion protein (brecPrP) in four strains of mice (BALB/c, ND4, SJL, and NZB/NZW F(1)) is described. Immunization of autoimmunity-prone NZB/NZW F(1) and SJL mice with brecPrP was applied to overcome self-tolerance against the prion protein. ND4 and SJL mice did not develop an immune response to brecPrP. BALB/c mice produced antibody titers of 1:1,000 to 1:1,500 in an enzyme-linked immunosorbent assay (ELISA), while NZB/NZW F(1) mice responded with titers of 1:7,000 to 1:11,000. A panel of 71 anti-brecPrP MAbs recognizing continuous and discontinuous epitopes was established from BALB/c and NZB/NZW F(1) mice. Seven anti-brecPrP MAbs reacted with both the cellular form of PrP and protease K-resistant PrP(Sc) from sheep brain in Western blot assays. The epitope specificity of these MAbs was determined, and applicability to immunohistochemical detection of prions was studied. The MAbs generated will be useful tools in the development of TSE immunochemical diagnosis and for research. This is the first report of the development of anti-PrP MAbs by use of autoimmune NZB/NZW F(1) mice as an alternative approach for the generation of PrP-specific MAbs.