Cutting edge: protein kinase C beta expression is critical for export of Il-2 from T cells.
Protein kinase C (PKC) plays an integral part in T cell activation and IL-2 secretion. We investigated the role of a particular PKC isoform, PKCbeta, in IL-2 production and secretion. The T cell lymphoma line HuT 78 secretes IL-2 in response to the phorbol ester PMA. A PKCbeta-deficient clone of HuT 78, K-4, did not secrete IL-2 in response to PMA stimulation. As assessed by RT-PCR, K-4 expressed mRNA for IL-2 following PMA activation, and intracellular IL-2 protein was detected by immunofluorescence. An enhanced green fluorescent protein-linked PKCbeta construct was microinjected into K-4 cells, which were then stimulated with PMA; those cells that expressed PKCbeta could secrete IL-2, as determined by an in situ immunofluorescent assay. This study demonstrates that PKCbeta is not necessary for transcription of the IL-2 gene or translation of mRNA to protein, but that expression of this PKC isoform is critical to the export of IL-2 molecules from T cells.
Long
A
A
Departments of. Biochemistry and Pharmacology, Royal College of Surgeons in Ireland, St. Stephen's Green, Dublin 2, Ireland. aclong@rcsi.ie
Kelleher
D
D
Lynch
S
S
Volkov
Y
Y
D002478:Cells, Cultured; D002999:Clone Cells; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis / Q000378:metabolism*; D007527:Isoenzymes / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D008213:Lymphocyte Activation / Q000235:genetics; D008845:Microinjections; D011493:Protein Kinase C / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D064546:Protein Kinase C beta; D021381:Protein Transport / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000201:enzymology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D007376:Interleukin-2; D007527:Isoenzymes; D012333:RNA, Messenger; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D013755:Tetradecanoylphorbol Acetate