Differential effect of the activation of protein kinase A on the protein synthesis and secretion in the T-helper 2 cell line D10.G4.1.
The authors analysed the effect of protein kinase A (PKA) activation on the protein synthesis and secretion in the T-helper 2 cell line D10.G4.1 (D10) using an assay that allows the detection of almost all secreted proteins of a cell. IL-4 and IL-10 were quantified. Three groups of secretory products could be defined. The T-cell receptor (TCR)-induced production of the first group (A) of proteins including IL-4 was enhanced by low concentrations of PKA activators. At higher concentrations the enhancement was less marked. The synthesis and secretion of a second group (B) of proteins including IL-10 remained unaffected. The production of a third group (C) of proteins was inhibited in a concentration-dependent manner. Biochemical analysis revealed a block of phospholipase C gamma (PLC gamma) activity by PKA activators. When D10 cells were stimulated by a phorbol ester plus calcium ionophore the production of group A proteins was enhanced almost fourfold, whereas production of group B proteins was unaffected by PKA activation. This effect was observed at all concentrations of various PKA activators tested. The secretion of group C proteins was no longer inhibited. The same results were obtained when analysing IL-4 and IL-10 m-RNA by Northern blotting. The data demonstrate a lymphokine specific mode of action on a single cell basis. Furthermore, it suggests that the inhibitory action of PKA in D10 cells is due partly to blocking of PLC gamma activity.
Teschendorf
C
C
Department of Internal Medicine, University of Essen, Germany.
Trenn
G
G
Höffkes
H G
HG
Brittinger
G
G
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D004789:Enzyme Activation; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D051381:Rats; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018418:Th2 Cells / Q000378:metabolism; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D016753:Interleukin-10; D015847:Interleukin-4; D017868:Cyclic AMP-Dependent Protein Kinases; D010738:Type C Phospholipases; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine