GDNF fusion protein for targeted-drug delivery across the human blood–brain barrier
Article first published online: 13 DEC 2007
Copyright © 2007 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 100, Issue 2, pages 387–396, 1 June 2008
How to Cite
Boado, R. J., Zhang, Y., Zhang, Y., Wang, Y. and Pardridge, W. M. (2008), GDNF fusion protein for targeted-drug delivery across the human blood–brain barrier. Biotechnol. Bioeng., 100: 387–396. doi: 10.1002/bit.21764
- Issue published online: 22 APR 2008
- Article first published online: 13 DEC 2007
- Manuscript Accepted: 26 NOV 2007
- Manuscript Revised: 7 NOV 2007
- Manuscript Received: 4 OCT 2007
- blood–brain barrier;
- drug targeting;
- Parkinson's disease;
Glial-derived neurotrophic factor (GDNF) is a neurotrophin that could be developed as a neurotherapeutic for Parkinson's disease, stroke, and motor neuron disease. However, GDNF does not cross the blood–brain barrier (BBB). Human GDNF was re-engineered by fusion of the mature GDNF protein to the carboxyl terminus of the chimeric monoclonal antibody (MAb) to the human insulin receptor (HIR). The HIRMAb-GDNF fusion protein is bi-functional, and both binds the HIR, to trigger receptor-mediated transport across the BBB, and binds the GDNF receptor (GFR)-α1, to activate GDNF neuroprotection pathways behind the BBB. COS cells were dual transfected with the heavy chain (HC) and light chain fusion protein expression plasmids, and the HC of the fusion protein was immunoreactive with antibodies to both human IgG and GDNF. The HIRMAb-GDNF fusion protein bound with high affinity to the extracellular domain of both the HIR, ED50 = 0.87 ± 0.13 nM, and the GFRα1, ED50 = 1.68 ± 0.17 nM. The HIRMAb-GDNF fusion protein activated luciferase gene expression in human neural SK-N-MC cells dual transfected with the c-ret kinase and a luciferase reporter gene under the influence of the rat tyrosine hydroxylase promoter, and the ED50, 1.68 ± 0.45 nM, was identical to the ED50 in the GFRα1 binding assay. The fusion protein was active in vivo in a rat middle cerebral artery occlusion model, where the stroke volume was reduced 77% (P < 0.001). In conclusion, these studies describe the re-engineering of GDNF, to make this neurotrophin transportable across the human BBB. Biotechnol. Bioeng. 2008;100: 387–396. © 2007 Wiley Periodicals, Inc.