Related Experiment Video
Updated: Oct 9, 2026

Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells
Published on: April 14, 2010
Integration of TCR and IL-4 signals through STAT6 and the regulation of IL-4 gene expression
C B Schmidt-Weber1, A Rao, A H Lichtman
1Immunology Research Division, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. csweber@siaf.unizh.ch
Abstract:
Signals generated by both antigen and cytokines binding to CD4(+) T cells synergize to promote helper T cell subset differentiation. For Th2 cell commitment neither IL-4 nor T cell receptor (TCR) stimulation are sufficient to drive differentiation. Th2 differentiation requires IL-4-receptor mediated signal transducers and activators of transcription 6 (STAT6) activation, but the possibility that IL-4 can directly enhance IL-4 production by T cells has remained unclear. In this report, IL-4 is shown to increase anti-CD3 or ionomycin induced IL-4 mRNA in differentiated murine Th2 cells. Anti-CD3 or ionomycin also enhances IL-4 induction of STAT6 activation, assayed by gel shift analysis of nuclear lysates. Surprisingly, cyclosporin A (CsA) also enhances STAT6 induction. Both ionomycin and CsA also enhance IL-4-induced transcriptional activity of a STAT6-linked promoter-reporter construct. In vitro calcineurin activity reduces STAT6 interactions with DNA, and CsA or FK506 can block this effect of calcineurin. These results indicate that IL-4 and TCR-generated calcium signals interact to maximize IL-4 gene expression and STAT6 activity. Calcineurin-mediated serine dephosphorylation of STAT6 and STAT6 serine phosphorylation may counter-regulate transcriptional activity of STAT6.
Related Concept Videos
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
The JAK-STAT Signaling Pathway
TGF - β Signaling Pathway
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Master Transcription Regulators