title: Properties and pharmacokinetics of two humanized antibodies specific for L-selectin.
abstract: BACKGROUND
  The participation of L-selectin in leukocyte recruitment during inflammation has suggested the use of L-selectin inhibitors as potential anti-inflammatory therapeutics. Blocking monoclonal antibodies could serve as such therapeutic agents, particularly if humanized to reduce their immunogenicity and improve their serum half-life.
  
  
  OBJECTIVE
  For this purpose, two mouse monoclonal antibodies, DREG-55 and DREG-200, that block human L-selectin were humanized and characterized.
  
  
  METHODS
  The resulting humanized antibodies, HuDREG-55 and HuDREG-200, constructed with human IgG4 constant regions, were evaluated for their specificity, affinity and ability to block L-selectin-dependent adhesion in in vitro assays. Their pharmacokinetic behavior in rhesus monkeys was also studied.
  
  
  RESULTS
  HuDREG-55 and HuDREG-200 were found to retain the specificity and affinity, within 2-fold, of the parent murine antibodies. HuDREG-55 and HuDREG-200 block L-selectin-dependent adhesion of human lymphocytes to high endothelial venules in frozen sections of lymph nodes. In addition, HuDREG-55 and HuDREG-200 are inhibitory in a novel L-selectin-dependent adhesion assay. This assay utilizes flow cytometry to measure binding of polymerized liposomes containing an analog of sialyl Lewis X, sialyl Lewis X glycoliposomes, to peripheral blood neutrophils and lymphocytes. Studying the pharmacokinetics of HuDREG-55 and HuDREG-200 in rhesus monkeys showed terminal elimination half-lives at 12.0 and 20.3 days, respectively.
  
  
  CONCLUSIONS
  The shorter terminal elimination half-life of HuDREG-55 in rhesus monkeys may be due to the ability of HuDREG-55 but not HuDREG-200 to bind rhesus monkey L-selectin.
authors.affiliation: Protein Design Labs, Inc., Fremont, CA 94555, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Co
authors.forename: N F
authors.initials: NF
authors.lastname: Landolfi
authors.forename: J O
authors.initials: JO
authors.lastname: Nagy
authors.forename: J H
authors.initials: JH
authors.lastname: Tan
authors.forename: V
authors.initials: V
authors.lastname: Vexler
authors.forename: M
authors.initials: M
authors.lastname: Vasquez
authors.forename: L
authors.initials: L
authors.lastname: Roark
authors.forename: S
authors.initials: S
authors.lastname: Yuan
authors.forename: P R
authors.initials: PR
authors.lastname: Hinton
authors.forename: J
authors.initials: J
authors.lastname: Melrose
authors.forename: C
authors.initials: C
authors.lastname: Klingbeil
authors.forename: C
authors.initials: C
authors.lastname: Queen
authors.forename: E L
authors.initials: EL
authors.lastname: Berg
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology* / Q000493:pharmacokinetics*; D000915:Antibody Affinity; D000918:Antibody Specificity; D002448:Cell Adhesion; D003001:Cloning, Molecular; D003429:Cross Reactions; D004729:Endothelium, Lymphatic / Q000378:metabolism; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D007147:Immunoglobulin Light Chains / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D019041:L-Selectin / Q000276:immunology*; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008253:Macaca mulatta; D051379:Mice; D008969:Molecular Sequence Data; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology; D013045:Species Specificity; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D008081:Liposomes; D011994:Recombinant Proteins; D019041:L-Selectin