Pharmacological characterization of type B cholecystokinin binding sites on the human JURKAT T lymphocyte cell line.
Recent studies have demonstrated the presence and the regulatory function of some neuropeptides in the immune system. In the present study, we have used labeled cholecystokinin (26-33) amide to characterize high affinity cholecystokinin (CCK) binding sites on a human JURKAT lymphoma cell line. Binding was temperature dependent, saturable, and specific. Analysis of the data demonstrated a single class of binding sites with high affinity for the ligand (Kd approximately 3.2 +/- 0.5 x 10(-11) M) and a binding capacity of 0.42 fmol/10(6) cells (approximately 300 sites/cell). These CCK binding sites displayed a typical CCK-B pharmacological profile, established by use of several agonists and antagonists selective for the CCK receptor types, namely compound L-364,718, the Merck CCK antagonist selective for the peripheral CCK receptor (CCK-A), and compound L-365,260, the Merck CCK antagonist selective for the central CCK receptor (CCK-B). The CCK cyclic analogue recently developed in our laboratory that is highly selective for the CCK-B receptor (i.e., JMV320) also showed high affinity for the CCK receptor on the JURKAT cell line. The presence of CCK-B-like binding sites on a lymphoid cell line could provide a useful model for pharmacological characterization of CCK-B binding sites and could contribute to a better understanding of their regulation.
Lignon
M F
MF
Centre CNRS-INSERM de Pharmacologie-Endocrinologie, Faculté de Pharmacie, Montpellier, France.
Bernad
N
N
Martinez
J
J
D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D006801:Humans; D015458:Leukemia, T-Cell / Q000378:metabolism / Q000473:pathology; D051379:Mice; D011949:Receptors, Cholecystokinin / Q000145:classification / Q000187:drug effects*; D012844:Sincalide / Q000031:analogs & derivatives* / Q000494:pharmacology; D013388:Succinimides / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000378:metabolism*; D013945:Thymoma / Q000378:metabolism / Q000473:pathology
C044758:Bolton Hunter-cholecystokinin octapeptide; D011949:Receptors, Cholecystokinin; D013388:Succinimides; D012844:Sincalide