title: Design and construction of immune phage antibody library against Tetanus neurotoxin: Production of single chain antibody fragments.
abstract: BACKGROUND
  Tetanus neurotoxin (TeNT) is composed of a light (LC) and heavy chain (HC) polypeptides, released by anaerobic bacterium Clostridium tetani and can cause fatal life-threatening infectious disease. Toxin HC and LC modules represents receptor binding and zinc metalloprotease activity, respectively. The passive administration of animal-derived antibodies against tetanus toxin has been considered as the mainstay therapy for years. However, this treatment is associated with several adverse effects due to the presence of anti-isotype antibodies.
  
  
  OBJECTIVE
  In the present study, we have produced the fully human single chain antibody fragments (HuScFv) from two human antibody phage display libraries.
  
  
  METHODS
  Twenty-four different HuscFvs were isolated from two anti TeNT immune libraries. Our produced human ScFv (HuScFv) were converted to IgG platform and analyzed regarding their specific reactivity to TeNT.
  
  
  RESULTS
  All of the selected scFvs have the same VL but different VH. Three HuscFvs from the first library (TTX15, 51, 75) and two HuscFvs from the second library (TTX16, 20) were chosen to convert to IgG1 using pOptiVEC and pcDNA3.3 systems. Production of IgG1 from transfected DG44 and binding capacity of them to tetanus toxin and toxoid were measured by ELISA. ELISA results showed no detectable production of TTX16 and TTX20 IgG1. Although, TTX51 and TTX75 were converted and produced as IgG1, no reactivity to tetanus toxin and toxoid was observed. However, TTX15 was successfully produced as whole IgG1 platform with reactivity to both tetanus toxin and toxoid. The latter would be an appropriate replacement for conventional polyclonal antibodies if would meet the further characterization including specificity determination, affinity measurement and toxin neutralizing assays.
  
  
  CONCLUSIONS
  Our results demonstrated production of functional IgG1 derived from TTX15 scFv and might be an appropriate replacement for polyclonal Tetabulin but it needs further characterization.
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Sanam
authors.initials: S
authors.lastname: Sadreddini
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mehrnosh
authors.initials: M
authors.lastname: Seifi-Najmi
authors.affiliation: Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Babollah
authors.initials: B
authors.lastname: Ghasemi
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hossein Samadi
authors.initials: HS
authors.lastname: Kafil
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Vahideh
authors.initials: V
authors.lastname: Alinejad
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Sevil
authors.initials: S
authors.lastname: Sadreddini
authors.affiliation: Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Younesi
authors.affiliation: Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Jadidi-Niaragh
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.|Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Yousefi
mesh_terms: D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology / Q000382:microbiology; D003017:Clostridium tetani / Q000276:immunology / Q000472:pathogenicity; D015195:Drug Design; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000276:immunology; D019151:Peptide Library; D011485:Protein Binding; D015202:Protein Engineering; D057127:Single-Chain Antibodies / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D013742:Tetanus / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D013744:Tetanus Toxin / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000276:immunology; D013745:Tetanus Toxoid / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D019151:Peptide Library; D057127:Single-Chain Antibodies; D013744:Tetanus Toxin; D013745:Tetanus Toxoid; C035979:tetanospasmin; D008666:Metalloendopeptidases
keywords: ScFv; Tetanus neurotoxin; neutralizing antibodies