Gene expression profiling of human unstimulated regulatory T cells (Tregs) and naïve CD4+ T cells
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ABSTRACT: Human regulatory T cells (TR) cells have potential for the treatment of immune mediated diseases, such as graft versus host disease, but the anergic phenotype of these cells makes them difficult to expand in vitro. We have examined the requirements for growth and cytokine expression from highly purified human TR cells, and correlated these findings with the signal transduction events of these cells. We demonstrate that these cells do not proliferate or secrete IL-10 even in the presence of high doses of IL-2. Stimulation with a superagonistic anti-CD28 antibody (clone 9D4) and IL-2 partially reversed the proliferative defect, and this correlated with reversal of the defective calcium mobilization in these cells. Dendritic cells were effective at promoting TR cell proliferation, and under these conditions the proliferative capacity of TR cells was comparable to conventional CD4 lymphocytes. Blocking TGF-beta activity abrogated IL-10 expression from these cells, while addition of TGF-beta resulted in IL-10 production. These data demonstrate the ability of dendritic cells to provide proper costimulation to overcome the anergic phenotype of TR cells. In addition, these data demonstrate for the first time that TGF-beta is critical to enable TR cells to express IL-10. In order to confirm that our isolation strategy resulted in cells with characteristics of TR cells, we performed gene expression profiling of highly purified TR cells from two different individuals, which were compared to the gene expression profile of naïve CD4+CD45RA+ cells. We first performed hierarchical clustering of the gene expression profiles of unactivated naïve and TR cells from the two individuals. We show that the gene expression patterns of TR cells were highly similar between the two samples (correlation coefficient of 0.82), as were the gene expression profiles of naïve CD4 cells between the two samples (correlation coefficient of 0.91). After averaging the gene expression signal from these two individuals, we compared the gene expression profile of unactivated TR cells with naïve CD4 cells and show that TR cells over-express a variety of genes known to be associated with a TR phenotype (e.g. CTLA-4, IKZF2, IL-2RA). In addition, we also detected very high levels of expression of genes not typically associated with a TR phenotype, with the highest level of expression of IL-1 receptors in resting TR cells (Figure 2). These data confirm that the sorting strategy was effective at isolating T cells expressing a TR phenotype.
ORGANISM(S): Homo sapiens
SUBMITTER: Parthav Jailwala
PROVIDER: E-GEOD-22045 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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