title: Isolation and characterization of a human antibody fragment specific for Ts1 toxin from Tityus serrulatus scorpion.
abstract: Scorpion stings are a common event that occurs in tropical and subtropical areas of the world, being a public health problem in certain countries. In most places, medical treatment relays on antivenoms obtained from the sera of hyper-immunized horses, however some efforts are being made to prepare specific antibodies of human origin, using phage display methodology. This communication describes the strategy followed for obtaining a protective human single chain antibody (scFv) capable of partially neutralizing the effect of Ts1, the major toxin isolated from the venom of the Brazilian scorpion Tityus serrulatus. Phage display technique allowed the isolation of scFv 15e from a human library of antibodies, after four rounds of selection against Ts1. This clone codes for 124 amino acids belonging to the family VH6 and 114 amino acids of family VK4. This scFv also recognizes toxins from the scorpions Tityus packyurus and Tityus cambridgei from the Amazonian region. Mice challenged with a LD(50) of Ts1 in the presence of this scFv were substantially resistant to intoxication. ScFv 15e is a leading compound for the development of better anti-scorpion antidotes.
authors.affiliation: Department of Molecular Medicine and Bioprocesses, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Col. Chamilpa 510-3, Cuernavaca 62210, Mexico.
authors.forename: Itzel
authors.initials: I
authors.lastname: Amaro
authors.forename: Lidia
authors.initials: L
authors.lastname: Riaño-Umbarila
authors.forename: Baltazar
authors.initials: B
authors.lastname: Becerril
authors.forename: Lourival D
authors.initials: LD
authors.lastname: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003429:Cross Reactions / Q000276:immunology; D000939:Epitopes / Q000276:immunology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006801:Humans; D019476:Insect Proteins / Q000276:immunology*; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D019151:Peptide Library; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D012604:Scorpion Venoms / Q000276:immunology*; D012605:Scorpions / Q000276:immunology; D016415:Sequence Alignment; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000939:Epitopes; D019476:Insect Proteins; D019151:Peptide Library; D011994:Recombinant Proteins; D012604:Scorpion Venoms; D057127:Single-Chain Antibodies; C120263:scorpion toxin Ts1, Tityus