Comparison of stable human Treg and Th clones by transcriptional profiling
(2009) 2nd European Congress of Immunology — Location: Berlin, Germany (13.September.2009)
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- et. al.
- Abstract
- Objectives: Our long-term objective is to assess the contribution of regulatory T cells (Treg) in the immune suppressive environment that seems to prevail in human tumors, and notably in melanoma metastases. Because FOXP3 mRNA and protein are not specific markers of human Tregs, this question has remained difficult to address rigorously. We attempted to derive stable human Treg clones, and used them as a model to gain insight into human Treg biology. Methods : From cancerous and non-cancerous patients, we derived stable clones of CD4+ Treg, defined as clones that expressed high CD25 at rest, were anergic in vitro, and suppressed the proliferation of co-cultured CD4+ cells. We analyzed the methylation status of a conserved regulatory region in FOXP3 intron 1 by methyl specific qPCR on bisulfite-treated gDNA in a panel of Treg and T helper (Th) clones. We also compared Treg and Th clones by expression microarrays. Results : A conserved region of FOXP3 intron 1 was demethylated in all Treg clones, whereas it was methylated in non-regulatory Th and cytotoxic T cell (CTL) clones. In our panel of human clones, this stable epigenetic mark correlated better with suppressive activity than did FOXP3 mRNA or protein expression. We used expression microarrays to compare Treg and Th clones after activation, which is required for suppressive function. The transcriptional profile that is specific of activated Treg clones includes a TGF-b signature. Both activated Treg and Th clones produced the latent form of TGF-b. However, SMAD2 phosphorylation was observed after activation in the Treg but not in the Th clones, indicating that only activated Treg clones produced the bioactive form of TGF-b. A TGF-b signature was also displayed by a Th clone ''suppressed'' by a Treg clone. Conclusion : The hallmark of our panel of activated human Treg clones is to produce bioactive TGF-b which has autocrine actions on Tregs and can have paracrine actions on other T cells.
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Stockis, J., & et al. (2009). Comparison of stable human Treg and Th clones by transcriptional profiling. European Journal of Immunology, 39(Issue S1), S418 (Poster PB06/38). https://hdl.handle.net/2078.5/216724 (Original work published 2009)