A mouse monoclonal, anti-idiotypic, anti-opioid receptor antibody (Ab2-AOR) has been generated from monoclonal anti-morphine antibodies (Ab1). Hybridoma culture supernatants were screened by a solid phase radioimmunoassay (RIA), based on their competition with radiolabelled morphine for Ab1. One of the Ab2s that gave a positive RIA also competed at rat brain opioid receptors with tritiated opioid ligands dihydromorphine (DHM), naloxone, etorphine, Tyr-d-Ala-Gly-Phe-d-Leu (DADLE), Tyr-d-Ala-Gly-NMe-Phe-Gly-ol (DAMGE) and Tyr-d-Pen-Gly-Phe-d-Pen (DPDPE). SDS-PAGE revealed Ab2-AOR to be highly purified after successive affinity and protein A-Sepharose chromatography. Ab2-AOR at concentrations of 10-100 nM competed with both μ- and δ-selective specific ligands for brain opioid receptors. Less than 13 μg/ml Ab2-AOR completely inhibited specific opioid radioligand binding to both soluble and membrane-bound opioid receptors. To demonstrate its anti-δ receptor activity further, a double-antibody ELISA procedure was developed that is based on the binding of Ab2-AOR to immobilized NG 108-15 cells (which contain only δ opioid receptors). Dose-dependent, opioid peptide- and opiate alkaloid-competitive binding of Ab2-AOR-containing ascites fluid to NG 108-15 cells was observed. A μ opioid agonist effect was demonstrated for Ab2-AOR, in that it decreased by 70% [3H]thymidine incorporation into DNA of fetal brain cell aggregates. This agonist-like action of Ab2-AOR was blocked by naltrexone. The antibody bound specifically to brain tissue sections and the presence of diprenorphine blocked this interaction. Hence, an Ab2 with μ and δ specificity has been characterized.
- Monoclonal anti-idiotypic antibody
- Opioid peptide
- Opioid receptor
- Tissue print
ASJC Scopus subject areas
- Molecular Biology
- Cellular and Molecular Neuroscience