Transcriptome analysis of thymic APC subsets, mTECs and thymic DCs in comparison to splenic DCs

Thymic antigen-presenting cells (APCs), including thymic dendritic cells (t-DCs) and medullary thymic epithelial cells (mTECs) have been described to play a critical role in thymic Treg generation. Our findings could show that both these thymic APCs can induce a more pronounced demethylation of Foxp3 and other Treg-specific epigenetic signature genes in developing Tregs when compared to splenic DCs. In order to elucidate the unique properties of thymic APCs, gene expression profiling was performed in comparison to splenic DCs. Transcriptome analysis of thymic APCs revealed differential expression of costimulatory molecules that could be involved in stable Treg generation. Importantly, both mTEC- and t-DC- induced alloantigen-specific Tregs displayed significantly higher efficacy in prolonging skin allograft acceptance when compared to alloantigen-specific Tregs generated by splenic DCs. Overall design: Thymic APCs, including mTECs and t-DCs and splenic DCs were isolated ex vivo from thymus as CD45-EpCAM+Ly51- (mTECs) and CD45+EpCAM-CD11chiLin- (t-DCs) and from spleen as CD11chiLin- (splenic DCs) (Lin is defined as CD90, CD49b, F4/80 and CD19), respectively.

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Garg G, Nikolouli E, Hardtke-Wolenski M, Toker A, Ohkura N, Beckstette M, Miyao T, Geffers R, Floess S, Gerdes N, Lutgens E, Osterloh A, Hori S, Sakaguchi S, Jaeckel E, Huehn J