Inhibitory effect of human syncytiotrophoblast plasma membrane vesicles on Jurkat cells activated by phorbol ester and calcium ionophore.
The effects of syncytiotrophoblast plasma membrane vesicles (STPM) on stimulated Jurkat leukemic T cells have been investigated. STPM inhibited IL-2 production and the expression of protein P55 of the IL-2 receptor (IL-2R P55), when Jurkat cells were stimulated by a combination of calcium ionophore A23187 (CaI) + phorbol 12-myristate 13-acetate (PMA). STPM also inhibited IL-2R P55 when cells were stimulated by PMA alone, a situation in which IL-2 production is negligible. On the other hand, STPM had no effect on the sustained mobilization of intracellular Ca2+ induced by CaI nor on the PKC-dependent CD3 down regulation induced by PMA. Finally STPM had no effect on intracellular cAMP levels. These results show that (i) the inhibitory effect of STPM on IL-2R P55 expression is independent of the inhibition of IL-2 production, and (ii) the inhibitory effects of STPM are at least partially independent of phosphatidylinositol 4,5-bisphosphate hydrolysis. They suggest that STPM affect a signaling pathway activated by PMA but possibly PKC independent.
Thibault
G
G
Laboratoire d'Immunologie, Faculté de Médecine, Tours, France.
Degenne
D
D
Lacord
M
M
Guillaumin
J M
JM
Girard
A C
AC
Bardos
P
P
D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D017252:CD3 Complex; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002462:Cell Membrane / Q000276:immunology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D011247:Pregnancy / Q000276:immunology*; D011493:Protein Kinase C / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014327:Trophoblasts / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D005576:Colforsin; D000001:Calcimycin; D000242:Cyclic AMP; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium