title: A novel anti-prion protein monoclonal antibody and its single-chain fragment variable derivative with ability to inhibit abnormal prion protein accumulation in cultured cells.
abstract: mAbs T1 and T2 were established by immunizing PrP gene ablated mice with recombinant MoPrP of residues 121-231. Both mAbs were cross-reactive with PrP from hamster, sheep, cattle and deer. A linear epitope of mAb T1 was identified at residues 137-143 of MoPrP and buried in PrP(C) expressed on the cell surface. mAb T1 showed no inhibitory effect on accumulation of PrP(Sc) in cultured scrapie-infected neuroblastoma (ScN2a) cells. In contrast, mAb T2 recognized a discontinuous epitope ranged on, or structured by, residues 132-217 and this epitope was exposed on the cell surface PrP(C). mAb T2 showed an excellent inhibitory effect on PrP(Sc) accumulation in vitro at a 50% inhibitory concentration of 0.02 microg/ml (0.14 nM). The scFv form of mAb T2 (scFv T2) was secreted in neuroblastoma (N2a58) cell cultures by transfection through eukaryotic secretion vector. Coculturing of ScN2a cells with scFv T2-producing N2a58 cells induced a clear inhibitory effect on PrP(Sc) accumulation, suggesting that scFv T2 could potentially be an immunotherapeutic tool for prion diseases by inhibition of PrP(Sc) accumulation.
authors.affiliation: Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kaku-Ushiki
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Iwamaru
authors.forename: Tamaki
authors.initials: T
authors.lastname: Muramoto
authors.forename: Tetsuyuki
authors.initials: T
authors.lastname: Kitamoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Shirou
authors.initials: S
authors.lastname: Mohri
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tagawa
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D006224:Cricetinae; D003670:Deer; D051379:Mice; D017096:Prion Diseases / Q000188:drug therapy / Q000378:metabolism / Q000662:veterinary*; D011328:Prions / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy / Q000378:metabolism*; D057127:Single-Chain Antibodies / Q000494:pharmacology*
chemical_list: D000911:Antibodies, Monoclonal; D011328:Prions; D057127:Single-Chain Antibodies