Specific inhibition of tissue kallikrein 1 with a human monoclonal antibody reveals a potential role in airway diseases.
KLK1 (tissue kallikrein 1) is a member of the tissue kallikrein family of serine proteases and is the primary kinin-generating enzyme in human airways. DX-2300 is a fully human antibody that inhibits KLK1 via a competitive inhibition mechanism (Ki=0.13 nM). No binding of DX-2300 to KLK1 was observed in a surface-plasmon-resonance biosensor assay when KLK1 was complexed to known active-site inhibitors, suggesting that DX-2300 recognizes the KLK1 active site. DX-2300 did not inhibit any of the 21 serine proteases that were each tested at a concentration of 1 microM. We validated the use of DX-2300 for specific KLK1 inhibition by measuring the inhibition of KLK1-like activity in human urine, saliva and bronchoalveolar lavage fluid, which are known to contain active KLK1. In human tracheobronchial epithelial cells grown at the air/liquid interface, DX-2300 blocked oxidative-stress-induced epidermal-growth-factor receptor activation and downstream mucus cell proliferation and hypersecretion, which have been previously shown to be mediated by KLK1. In an allergic sheep model of asthma, DX-2300 inhibited both allergen-induced late-phase bronchoconstriction and airway hyper-responsiveness to carbachol. These studies demonstrate that DX-2300 is a potent and specific inhibitor of KLK1 that is efficacious in in vitro and in vivo models of airway disease.
Sexton
Daniel J
DJ
Discovery Research, Dyax Corp., 300 Technology Square, Cambridge, MA 02139, USA. dsexton@dyax.com
Chen
Ting
T
Martik
Diana
D
Kuzmic
Petr
P
Kuang
Guannan
G
Chen
Jie
J
Nixon
Andrew E
AE
Zuraw
Bruce L
BL
Forteza
Rosanna M
RM
Abraham
William M
WM
Wood
Clive R
CR
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism / Q000494:pharmacology*; D001249:Asthma / Q000201:enzymology* / Q000276:immunology / Q000628:therapy*; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D002478:Cells, Cultured; D006801:Humans; D051379:Mice; D029424:Pulmonary Disease, Chronic Obstructive / Q000201:enzymology* / Q000276:immunology / Q000628:therapy*; D012756:Sheep; D020840:Tissue Kallikreins / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000378:metabolism / Q000502:physiology*
D000911:Antibodies, Monoclonal; D020840:Tissue Kallikreins