title: Protective effect of scFv-DAF fusion protein on the complement attack to acetylcholine receptor: a possible option for treatment of myasthenia gravis.
abstract: BACKGROUND
  Autoantibody-induced complement activation, which causes disruption of the postsynaptic membrane, is recognized as a key pathogenic factor in myasthenia gravis (MG). Therefore, specific targeting of complement inhibitors to the site of complement activation is a potential therapeutic strategy for treatment of MG.
  
  
  METHODS
  We assessed expression of single-chain antibody fragment-decay accelerating factor (scFv-DAF), comprising a single-chain fragment scFv1956 based on the rat complement inhibitor DAF in prokaryotic systems, and studied its inhibitory effect on complement deposition in vitro.
  
  
  RESULTS
  The recombinant conjugate scFv-DAF completely retained the wild-type binding activity of scFv1956 to AChR and inhibited complement activation of DAF in vitro.
  
  
  CONCLUSIONS
  We found that scFv-DAF could bind specifically to TE671 cells, and it is significantly more potent at inhibiting complement deposition than the untargeted parent molecule DAF. scFv-DAF may be a candidate for in vivo protection of the AChR in MG.
authors.affiliation: Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Song
authors.affiliation: Department of Microbiology, Fourth Military Medical University, Xi'an, China.
authors.forename: Zhikai
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Jianting
authors.initials: J
authors.lastname: Miao
authors.affiliation: Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Microbiology, Fourth Military Medical University, Xi'an, China.
authors.forename: Xingan
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Microbiology, Fourth Military Medical University, Xi'an, China.
authors.forename: Fanglin
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Zhuyi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Neurology, George Washington University, 2150 Pennsylvania Avenue NW, Suite 7-406, Washington, DC 20037, USA.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Kaminski
mesh_terms: D000818:Animals; D018958:CD55 Antigens / Q000494:pharmacology*; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D003165:Complement System Proteins / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D006801:Humans; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D011950:Receptors, Cholinergic / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D012208:Rhabdomyosarcoma / Q000473:pathology; D057127:Single-Chain Antibodies / Q000378:metabolism
chemical_list: D018958:CD55 Antigens; D011950:Receptors, Cholinergic; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D003165:Complement System Proteins