Immunohistochemical localization of 14.3.3 zeta protein in amyloid plaques in human spongiform encephalopathies.

The localization of 14.3.3 proteins was studied in different subtypes of brain amyloid plaques. We examined paraffin-embedded brain sections of sporadic MV2 Creutzfeldt-Jakob disease (sCJD) with Kuru plaques, sporadic VV2 CJD with plaque-like PrP(sc) (the abnornal form of prion protein) deposits, variant CJD (vCJD) with florid plaques, Gerstmann-Straüssler-Scheinker (GSS) with multicentric plaques and of Alzheimer's disease (AD) with senile plaques. Adjacent immunostaining revealed PrP(sc) and 14.3.3 zeta deposits in the same amyloid plaques in all cases of sporadic CJD and vCJD, whereas 14.3.3 zeta was not seen in amyloid plaques of GSS with A117V, P102L and D202N mutations. The same immunostaining method using anti-betaA4 and anti-14.3.3 zeta antibodies revealed no colocalization in patients with AD. Our data suggest that 14.3.3 zeta protein could interact either with PrP or with other components of PrP(sc) deposits in CJD.