title: Humanized-monoclonal antibody against heterologous Leptospira infection.
abstract: Patients with leptospirosis are commonly treated with antibiotics. Jarisch-Herxheimer reaction caused by toxic bacterial substances massively released as a result of the antibiotic mediated-bacterial lysis occurs in some patients which may aggravate the existing severe clinical manifestations. In this study, a humanized-murine single-chain monoclonal antibody (HuScFv) was produced and tested as an alternative of antibiotics for treatment of leptospirosis. Complementary DNA was prepared from total RNA of a murine hybridoma clone secreting monoclonal antibody (MAb) specific to LipL32 of pathogenic Leptospira spp. The MAb had therapeutic efficacy in Leptospira challenged hamsters. The VH and VL coding sequences were amplified using the cDNA as a template. The sequences were linked to form a single-chain variable murine DNA fragment (muscFv). CDR sequences of the muscFv were grafted onto the best matching human VH and VL immunoglobulin frameworks. After cloning of the humanized murine DNA sequences (huscFv) into a phagemid vector and the vector was introduced into competent Escherichia coli, the HuScFv was produced. On the same weight basis, the HuScFv possessed equal neutralizing activities to the murine ScFv counterpart against heterologous Leptospira-mediated hemolysis in vitro and rescued hamsters from a heterologous Leptospira lethal challenge. The HuScFv antibody has high therapeutic potential as an alternative to antibiotics for human leptospirosis, especially for drug hypersensitive patients.
authors.affiliation: Graduate Program, Faculty of Allied Health Sciences, Thammasat University, Rangsit Center, Pathum-thani 12120, Thailand.
authors.forename: Santi
authors.initials: S
authors.lastname: Maneewatch
authors.forename: Yuwaporn
authors.initials: Y
authors.lastname: Sakolvaree
authors.forename: Pramuan
authors.initials: P
authors.lastname: Tapchaisri
authors.forename: Patcharin
authors.initials: P
authors.lastname: Saengjaruk
authors.forename: Thaweesak
authors.initials: T
authors.lastname: Songserm
authors.forename: Surasakdi
authors.initials: S
authors.lastname: Wongratanachewin
authors.forename: Pongsri
authors.initials: P
authors.lastname: Tongtawe
authors.forename: Potjanee
authors.initials: P
authors.lastname: Srimanote
authors.forename: Urai
authors.initials: U
authors.lastname: Chaisri
authors.forename: Wanpen
authors.initials: W
authors.lastname: Chaicumpa
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D015153:Blotting, Western; D003001:Cloning, Molecular; D019295:Computational Biology; D006224:Cricetinae; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007919:Leptospira / Q000276:immunology*; D007922:Leptospirosis / Q000276:immunology / Q000628:therapy*; D008074:Lipoproteins / Q000276:immunology; D051379:Mice; D009500:Neutralization Tests
chemical_list: D000911:Antibodies, Monoclonal; D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D018076:DNA, Complementary; C406589:LipL32 protein, Leptospira; D008074:Lipoproteins