Site-directed polyclonal Abs specific for a synthetic peptide with sequence homology to the predicted N-terminal sequence of the human κ opioid receptor [anti-κR-(33-52)] are capable of binding to normal human cells and cell lines expressing mRNA specific for the human κ receptor. Flow cytometric analysis of 1) a neuronal cell line (NT2), 2) blood-denved CD14+ monocytes, 3) monocyte-like cell lines (U937 and THP 1), 4) blood-derived CD3+ T cells and a T cell line, and 5) human B cell lines bound anti-κR-(33-52) in a specific manner. Anti-κR-(33-52) was also found to specifically neutralize the immunosuppressive activities associated with the κR-selective agonist U50,488H. This antiserum was found to block U50,488H-mediated inhibition of 1) Staphylococcus aureus Cowen strain I-induced B and T lymphocyte proliferation, 2) PHA-induced T lymphocyte proliferation, and 3) S. aureus Cowen strain I-induced IgG production. However, this antiserum failed to neutralize μR-selective agonist (Tyr-D-Ala-Gly-NMe-Phe-Gly-ol)-mediated suppression of IgG synthesis. Finally, the κR-selective antagonist nor-binaltorphimine hydrochloride inhibits the binding of anti-κR-(33-52) to the U937 cell line. These results suggest that anti-κR-(33-52) specifically interacts with the human κR molecule. Studies conducted with anti-κR-(33-52) indicated that this antiserum effectively blocked U50,488H-mediated immunosuppression, but by itself did not enhance or suppress lymphocyte activation. These data suggest that anti-κR-(33-52) 1) does not interact with the effector binding site of the receptor, but sterically interferes with U50,488H binding to the receptor; and/or 2) the antiserum interacts with a secondary binding site that is important for ligand binding, but may not be involved in signal transduction.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of Immunology|
|State||Published - Feb 15 1997|
ASJC Scopus subject areas
- Immunology and Allergy