Targeted delivery of a SNARE protease to sensory neurons using a single chain antibody (scFv) against the extracellular domain of P2X(3) inhibits the release of a pain mediator.
P2X3 (P2X purinoceptor 3) is predominantly expressed on nociceptive sensory neurons and plays a crucial role in signalling leading to chronic inflammatory pain and some features of neuropathic pain. Thus it represents a potential target for pain therapeutics. BoNT/A (botulinum neurooxin type A) effectively relieves certain types of pain through inhibiting the neuronal release of pain peptides. A recombinant single-chain variable fragment (scFv) antibody designated MH7C was generated against the extracellular domain of P2X3 using phage display. The genes encoding the scFv and activated di-chain form of BoNT/A without the C-terminal-binding subdomain (LC-HN-HCN/A) were ligated and expressed in Escherichia coli cells as a composite fusion protein. The purified protein bound and entered P2X3-containing sensory neurons, cleaved synaptosomal-associated protein of 25 kDa and inhibited the release of a pain peptide. This novel fusion protein designated 'LC-HN-HCN/A-MH7C' has potential clinical applications in the treatment of chronic inflammatory and sympathetically maintained neuropathic pain.
Hui
H
Ma
§International Centre for Neurotherapeutics, Dublin City University, Dublin 9, Ireland.
Jianghui
J
Meng
§International Centre for Neurotherapeutics, Dublin City University, Dublin 9, Ireland.
Jiafu
J
Wang
*School of Biotechnology, Dublin City University, Dublin 9, Ireland.
Stephen
S
Hearty
J Oliver
JO
Dolly
Richard
R
O'Kennedy
D000818:Animals; D019274:Botulinum Toxins, Type A / Q000737:chemistry* / Q000235:genetics; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology; D006801:Humans; D051379:Mice; D010146:Pain / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D058477:Receptors, Purinergic P2X3 / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D011984:Sensory Receptor Cells / Q000187:drug effects* / Q000378:metabolism; D057127:Single-Chain Antibodies / Q000737:chemistry* / Q000235:genetics; D050825:Synaptosomal-Associated Protein 25 / Q000378:metabolism*
D058477:Receptors, Purinergic P2X3; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D050825:Synaptosomal-Associated Protein 25; D019274:Botulinum Toxins, Type A; C545476:incobotulinumtoxinA; D015740:Calcitonin Gene-Related Peptide