title: [Selection and identification of completely humanized anti-IL-4 single-chain antibodies].
abstract: OBJECTIVE
  To express human interleukin 4 (IL-4), select completely humanized anti-IL-4 single-chain antibodies (scFvs) from the completely humanized scFv library and identify their specificity.
  
  
  METHODS
  With IPTG-induced pET102/IL-4/BL21, human IL-4 was synthesized, and then purified and identified. Completely humanized scFvs against IL-4 were expressed from the completely humanized antibody phage library, and positive clones were selected with human IL-4 as antigen. The positive clones were tested by PCR, enzyme cleavage and sequencing. The specificity of the completely humanized anti-IL-4 scFvs was determined by dot blot hybridization.
  
  
  RESULTS
  The relative molecular mass (Mr) of IL-4 fusion protein was about 27 000. With IL-4 as antigen, we obtained the positive clones expressing anti-IL-4 antibodies. PCR showed amplified target bands of about 1000 bp. Enzyme cleavage analysis revealed that fingerprint maps of the selected clones were diverse except 2 clones. Among 4 clones expressing scFvs that had different fingerprint maps and strong binding to IL-4, sequencing showed the sequence of 3 was correct. Then, dot blot hybridization demonstrated that the scFvs expressed by the 3 clones were specific.
  
  
  CONCLUSIONS
  Completely humanized scFvs against IL-4 has been obtained successfully.
authors.affiliation: Department of Immunology, Preclinic School, Sichuan Medical University, Luzhou 646000, China.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Cao
authors.affiliation: Laboratory of Pathogeny Microbiology and Immunology, Preclinic School, Sichuan Medical University, Luzhou 646000, China.
authors.forename: Siji
authors.initials: S
authors.lastname: Nian
authors.affiliation: Laboratory of Pathogeny Microbiology and Immunology, Preclinic School, Sichuan Medical University, Luzhou 646000, China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Department of Immunology, Preclinic School, Sichuan Medical University, Luzhou 646000, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Immunology, Preclinic School, Sichuan Medical University, Luzhou 646000, China. *Corresponding author, E-mail: yuanqing_ok@hotmail.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yuan
mesh_terms: D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015847:Interleukin-4 / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D057127:Single-Chain Antibodies / Q000032:analysis / Q000235:genetics / Q000276:immunology*
chemical_list: C508598:IL4 protein, human; D057127:Single-Chain Antibodies; D015847:Interleukin-4