The inhibitory effect of PGE2 on T cell activation is not associated with inhibition of PKC translocation.
We have recently reported on the effect of PGE2 on T cell activation and suggested that their immunosuppressive effect may involve the PKC activation pathway. In the present study, we further investigated the potential interference of PGE2 with PHA induced signaling in T lymphocytes. We demonstrate that the PHA mediated increase in IP3, the putative mobilizer of intracellular Ca2+, is slightly affected following cell incubation with PGE2. Treatment of cell culture with the tumor promoter TPA abrogates the suppressive activity of PGE2 whereas exogenous diacylglycerol (1,2-diolein) has only a marginal effect. This suggests that PGE2 affect PKC activity at sites distal to IP3 and DG generation. We also demonstrate that the PGE2 suppressive effect on T lymphocyte activation is not related to an inhibition of PKC translocation.
Piau
J P
JP
Institut de pathologie moleculaire, U15 INSERM, CHU Cochin-Port Royal, Paris, France.
Gacon
G
G
Chouaib
S
S
D002478:Cells, Cultured; D015232:Dinoprostone / Q000494:pharmacology*; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects*; D010835:Phytohemagglutinins; D011493:Protein Kinase C / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology / Q000276:immunology*
D007295:Inositol Phosphates; D010835:Phytohemagglutinins; D011493:Protein Kinase C; D015232:Dinoprostone