The role of Ca2+ in mediating the inhibition by glucocorticoids of human natural killer (NK) activity was investigated using Ca2+ entry blockers (verapamil and its desmethoxy-derivatives LU46973 and LU47093) and calmodulin antagonists (pimozide and two naphthalenesulfopamide derivatives, W-7 and W-13). Peripheral blood mononuclear (PBM) cell preparations were incubated for 20 h with 1 x 10(-6) M cortisol and these agents in various combinations (concentration range: 1 x 10(-7) - 1 x 10(-5) M) and then assayed in a direct 4-h cytolytic assay using 51Cr-labeled K 562 target cells. Exposure to cortisol led to a significant reduction of NK cell activity (about 50% with respect to the spontaneous activity). Ca2+ entry blockers displayed per se a dose-dependent depressive effect on cytotoxicity and gave significant enhancement of cortisol-dependent inhibition. Calmodulin antagonists were per se minimally effective but clearly amplified the cortisol-mediated inhibition. Raising extracellular Ca2+ by CaCl2 or intracellular Ca2+ by the ionophore A23187 yelded an appreciable reduction of these effects. Our data are compatible with the view that extracellular and intracellular Ca2+ play a role in the control of human NK cell activity. Moreover, it is conceivable that the mechanisms involved in glucocorticoid inhibition of NK cell activity involve Ca2+-dependent pathways.

Studies on the mechanism of cortisol inhibition of human natural killer cell activity: effects of calcium entry blockers and calmodulin antagonists.

CAVALLO, Rossana;ANGELI, Alberto
1987

Abstract

The role of Ca2+ in mediating the inhibition by glucocorticoids of human natural killer (NK) activity was investigated using Ca2+ entry blockers (verapamil and its desmethoxy-derivatives LU46973 and LU47093) and calmodulin antagonists (pimozide and two naphthalenesulfopamide derivatives, W-7 and W-13). Peripheral blood mononuclear (PBM) cell preparations were incubated for 20 h with 1 x 10(-6) M cortisol and these agents in various combinations (concentration range: 1 x 10(-7) - 1 x 10(-5) M) and then assayed in a direct 4-h cytolytic assay using 51Cr-labeled K 562 target cells. Exposure to cortisol led to a significant reduction of NK cell activity (about 50% with respect to the spontaneous activity). Ca2+ entry blockers displayed per se a dose-dependent depressive effect on cytotoxicity and gave significant enhancement of cortisol-dependent inhibition. Calmodulin antagonists were per se minimally effective but clearly amplified the cortisol-mediated inhibition. Raising extracellular Ca2+ by CaCl2 or intracellular Ca2+ by the ionophore A23187 yelded an appreciable reduction of these effects. Our data are compatible with the view that extracellular and intracellular Ca2+ play a role in the control of human NK cell activity. Moreover, it is conceivable that the mechanisms involved in glucocorticoid inhibition of NK cell activity involve Ca2+-dependent pathways.
49
601
616
GATTI G ;MASERA R ;CAVALLO R ;SARTORI ML ;DELPONTE D ;CARIGNOLA R ;SALVADORI A ;ANGELI A
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/31040
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 9
  • ???jsp.display-item.citation.isi??? ND
social impact