Generation of monoclonal antibody that distinguishes PrP super(S) super(c) from PrP super(C) and neutralizes prion infectivity

• Published in: Virology (New York, N.Y.) N.Y.), 2009-11, Vol.394 (2), p.200-207
• Main Authors: Horiuchi, M, Karino, A, Furuoka, H, Ishiguro, N, Kimura, K, Shinagawa, M
• Format: Article
• Language: English
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2009.08.025

To establish PrP super(S) super(c)-specific mAbs, we immunized Prnp super(-) super(/) super(-) mice with PrP super(S) super(c) purified from prion-infected mice. Using this approach, we obtained mAb 6H10, which reacted with PrP super(S) super(c) treated with proteinase K, but not with PrP super(S) super(c) pretreated with more than 3 M GdnHCl. In contrast, reactivity of pan-PrP mAbs increased with increasing concentrations of GdnHCl used for pretreatment of PrP super(S) super(c). In histoblot analysis, mAb 6H10 showed a positive reaction on a non-denatured histoblot but reactivity was lower when the histoblot was pretreated by autoclaving. Epitope analysis suggested that the extreme C-terminus of PrP is likely to be part of the epitope for mAb 6H10. MAb 6H10 immunoprecipitated PrP super(S) super(c) from brains of mice, sheep, and cattle infected with prions. Furthermore, pretreatment of purified PrP super(S) super(c) with mAb 6H10 reduced the infectious titer more than 1 log. Taken together, these results suggest that mAb 6H10 recognizes a conformational epitope on PrP super(S) super(c) that is related to prion infectivity.