Characterization of novel neutralizing monoclonal antibodies specific to human neurturin

Neurturin (NTN) a structural and functional relative of glial cell line-der ived neurotrophic factor, was originally identified based on its ability to support the survival of sympathetic neurons in culture. Similar to glial c ell line-derived neurotrophic factor (GDNF), Neurturin has been shown to bi nd to a high affinity glycosylphosphatidylinositol (GPI)-linked receptor (G FR alpha 2) and induce phosphorylation of the tyrosine kinase receptor Ret, resulting in the activation of the mitogen activated protein kinase (MAPK) signalling pathway. A panel of six novel murine monoclonal antibodies (MAb s) specific to human Neurturin has been developed and characterized. Four o f the MAbs tested inhibit, to varying degrees, binding of NTN to the GPI-li nked GFR alpha 2 receptor, Three MAbs cross-react with the murine homolog, These antibodies have been shown to be useful reagents for Western blotting , immunohistochemistry, and also for the development of a sensitive, quanti tative enzyme-linked immunosorbent assay (ELISA) for human NTN. Novel, spec ific MAbs,vith varying epitope specificities and blocking activity will be valuable tools for both the in vitro and in vivo characterization of NTN an d its relationship to the GFR alpha 2 and Ret receptors.