Dataset Information

MiR-155 inhibition sensitizes CD4+ Th cells for TREG mediated suppression.

ABSTRACT:

Background

In humans and mice naturally occurring CD4(+)CD25(+) regulatory T cells (nTregs) are a thymus-derived subset of T cells, crucial for the maintenance of peripheral tolerance by controlling not only potentially autoreactive T cells but virtually all cells of the adaptive and innate immune system. Recent work using Dicer-deficient mice irrevocably demonstrated the importance of miRNAs for nTreg cell-mediated tolerance.

Principal findings

DNA-Microarray analyses of human as well as murine conventional CD4(+) Th cells and nTregs revealed a strong up-regulation of mature miR-155 (microRNA-155) upon activation in both populations. Studying miR-155 expression in FoxP3-deficient scurfy mice and performing FoxP3 ChIP-Seq experiments using activated human T lymphocytes, we show that the expression and maturation of miR-155 seem to be not necessarily regulated by FoxP3. In order to address the functional relevance of elevated miR-155 levels, we transfected miR-155 inhibitors or mature miR-155 RNAs into freshly-isolated human and mouse primary CD4(+) Th cells and nTregs and investigated the resulting phenotype in nTreg suppression assays. Whereas miR-155 inhibition in conventional CD4(+) Th cells strengthened nTreg cell-mediated suppression, overexpression of mature miR-155 rendered these cells unresponsive to nTreg cell-mediated suppression.

Conclusion

Investigation of FoxP3 downstream targets, certainly of bound and regulated miRNAs revealed the associated function between the master regulator FoxP3 and miRNAs as regulators itself. miR-155 is shown to be crucially involved in nTreg cell mediated tolerance by regulating the susceptibility of conventional human as well as murine CD4(+) Th cells to nTreg cell-mediated suppression.

SUBMITTER: Stahl HF

PROVIDER: S-EPMC2743997 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature

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Publications

miR-155 inhibition sensitizes CD4+ Th cells for TREG mediated suppression.

Stahl Heiko F HF Fauti Tanja T Ullrich Nina N Bopp Tobias T Kubach Jan J Rust Werner W Labhart Paul P Alexiadis Vassili V Becker Christian C Hafner Mathias M Weith Andreas A Lenter Martin C MC Jonuleit Helmut H Schmitt Edgar E Mennerich Detlev D

PloS one 20090924 9

<h4>Background</h4>In humans and mice naturally occurring CD4(+)CD25(+) regulatory T cells (nTregs) are a thymus-derived subset of T cells, crucial for the maintenance of peripheral tolerance by controlling not only potentially autoreactive T cells but virtually all cells of the adaptive and innate immune system. Recent work using Dicer-deficient mice irrevocably demonstrated the importance of miRNAs for nTreg cell-mediated tolerance.<h4>Principal findings</h4>DNA-Microarray analyses of human as ...[more]

PMID: 19777054

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