title: Suppressor effect of prostaglandins on T colony formation.
abstract: This study evaluated the action of prostaglandins on T colony formation. A single step culture process was used which involved direct seeding of freshly isolated peripheral blood mononuclear cells (MC) in semi-solid agar culture medium containing phytohaemagglutinin (PHA). Suppression of endogenous production of prostaglandins with 10(-6) M indomethacin increased T colony formation by up to 100%. Similarly, addition of synthetic prostaglandin E (PGE) to the culture system demonstrated a dose-dependent reduction of T colony formation by PHA-stimulated non-adherent cells. The 50% inhibitory dose (ID 50) was 10(-7) M for PGE2 and 1.3 x 10(-7) M for PGE1. Prostaglandin F had no effect on T colony formation. The synthesis of PGE by adherent cells can be increased two- to three-fold in the presence of T colony promoting activity released by PHA-stimulated lymphocytes. We conclude that monocyte produced PGE is responsible for the suppressor effect exerted by these cells on T colony formation. The PGE inhibitory role is interpreted as a feedback mechanism, modulated by lymphokines released by PHA-activated lymphocytes.
mesh_terms: D002999:Clone Cells / Q000187:drug effects / Q000502:physiology*; D015232:Dinoprostone; D006801:Humans; D009000:Monocytes / Q000378:metabolism; D010835:Phytohemagglutinins / Q000494:pharmacology; D011453:Prostaglandins / Q000096:biosynthesis / Q000502:physiology*; D011458:Prostaglandins E / Q000096:biosynthesis; D011465:Prostaglandins, Synthetic / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*
chemical_list: D010835:Phytohemagglutinins; D011453:Prostaglandins; D011458:Prostaglandins E; D011465:Prostaglandins, Synthetic; D015232:Dinoprostone