NR ATRC
AU Vranac,T.; Curin Serbec,V.; Popovic,M.
TI A single synthetic peptide can elicit a panel of mAbs against different conformations of PrP
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Structure of PrP and molecular determinants of infectivity STRCT-18
PT Konferenz-Poster
AB
In theory, the lack of response of the immune system to PrP could be overcome by immunisation with short peptide parts of PrP bound to a carrier molecule. In this case, short peptides are able to undertake a variety of conformations. We hypothesised that it should be possible to obtain antibodies specific for conformations that are not present in the native protein. Based on published articles, we inferred which parts of PrP might differ in conformation between PrPc and PrPsc. We expected to obtain different mAbs that would bind to different isoforms of PrP and that some of them would be PrPsc-specific.
To test our hypothesis, we immunised BALB/c mice (expressing the unmodified PrP) with three 13-amino acid peptides from human PrP, named P1, P2 and P3, covalently linked to haemocyanin (KLH). The humoral immune response was determined by indirect ELISA and immunohistochemistry (IHC) on brain samples of a sporadic Creutzfeldt-Jakob disease (sCJD) patient. From mice immunised with P1-KLH, a panel of mAbs specific for different isoforms of PrP was obtained. Among these, C7/5 (a mAb specific for denatured PrPc), C1/1 (a mAb that reacts with PrPsc and denatured PrPc) and E9/5 (a mAb specific for PrPsc) were characterised in detail with ELISA, dot blot, Western blot and IHC. Minimal epitopes of selected mAbs were determined using the SPOT method.
Our results confirm that the P1 peptide (PrP 214-226) can be present in various conformations. The presence of PrPc in mice restricts the formation of Abs only to those conformations of P1 that are not present in the native PrPc. Based on our results, we can also presume that the C-terminal part of PrP (in which the P1 peptide is found) probably undergoes significant conformational changes during the transition from PrPc to PrPsc. The obtained PrP conformation-specific mAbs could be useful for development of TSE diagnostics as well as for further research.
AD Tanja Vranac, Vladka Curin Serbec, Blood Transfusion Centre of Slovenia, Slovenia; Mara Popovic, School of Medicine, Institute of Pathology, Ljubljana, Slovenia
SP englisch
PO Deutschland