Interleukin-4 mRNA and protein in activated human T cells are enhanced by interleukin-7.
We studied the effect of the stroma-derived cytokine interleukin-7 (IL-7) on the expression of IL-4 in human T cells at mRNA and protein level. The results demonstrate that IL-7 did not induce IL-4 mRNA in resting T cells. However, concanavalin A (con A)-induced IL-4 mRNA expression was enhanced by costimulation with con A plus IL-7. Nuclear run-on analysis revealed that IL-7 did not affect the transcription rate of the IL-4 gene. The half-life of con A-induced IL-4 transcripts, however, was increased upon con A plus IL-7 treatment, indicating that the effect of IL-7 is mediated at posttranscriptional level. In accordance with the mRNA results, IL-4 protein was not detected in supernatants of unstimulated T cells or T cells exposed to IL-7. In contrast, IL-7 augmented the con A-induced secretion of IL-4 protein significantly. In addition, it was noticed that anti-IL-1 beta and anti-tumor necrosis factor-alpha (anti-TNF-alpha) did not abolish the effect of IL-7 on the con A-induced IL-4 secretion, indicating that the IL-7 effect is not mediated by the release of these cytokines. These results indicate that a stroma-derived factor can affect IL-4 expression in activated human T cells.
Dokter
W H
WH
Department of Medicine, University of Groningen, The Netherlands.
Sierdsema
S J
SJ
Esselink
M T
MT
Halie
M R
MR
Vellenga
E
E
D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D015847:Interleukin-4 / Q000032:analysis* / Q000235:genetics* / Q000378:metabolism; D015851:Interleukin-7 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics
D015851:Interleukin-7; D012333:RNA, Messenger; D003208:Concanavalin A; D015847:Interleukin-4