Gastrin-CCK-B type receptors on human T lymphoblastoid Jurkat cells.
The presence of specific receptors for gastrointestinal hormones on T cells and their involvement in the immune response are still matters of debate. We reported the effects of gastrin-cholecystokinin (CCK)-related peptides on J.RT3-T3.5 Jurkat cells. A single class of high-affinity binding sites (dissociation constant approximately 0.1 nM) for gastrin and CCK-8 was evident on these cells. These peptides dose-dependently induced a transient increase in intracellular Ca2+ concentration ([Ca2+]i), which was independent of extracellular Ca2-. L-365,260 was 150- to 300-fold more potent than L-364,718 to inhibit radiolabeled ligand binding or peptide-stimulated [Ca2+]i increase, confirming the gastrin-CCK-B nature of the receptor. Gastrin caused a rise in inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] level within 5 s of stimulation. Finally, gastrin increased interleukin (IL)-2 secretion in J.RT3-T3.5 cells. We conclude that 1) J.RT3-T3.5 cells possess "gastrin-CCK-B type" receptors coupled to phospholipase C activation, Ins(1,4,5)P3 formation, and Ca2+ release from intracellular Ca2+ pools, and 2) these receptors could be involved in the regulation of IL-2 production.
Dornand
J
J
Laboratoire de Biochimie des Membranes, Institut National de la Santé et de la Recherche Médicale CJF 92-07, Faculté de Pharmacie, Montpellier, France.
Roche
S
S
Michel
F
F
Bali
J P
JP
Cabane
S
S
Favero
J
J
Magous
R
R
D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D005755:Gastrins / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007376:Interleukin-2 / Q000096:biosynthesis; D007457:Iodine Radioisotopes; D010418:Pentagastrin / Q000378:metabolism / Q000494:pharmacology; D011949:Receptors, Cholecystokinin / Q000032:analysis* / Q000378:metabolism; D012844:Sincalide / Q000378:metabolism / Q000494:pharmacology; D013601:T-Lymphocytes / Q000737:chemistry*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism
D005755:Gastrins; D007376:Interleukin-2; D007457:Iodine Radioisotopes; D011949:Receptors, Cholecystokinin; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases; D010418:Pentagastrin; D012844:Sincalide; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium