Epithelial cells in the thymus teach T cells what to ignore by presenting them with a comprehensive array of tissue-restricted self-antigens TRAs during development.
According to Derbinski and colleagues on page 33this promiscuous expression of TRAs—one of the promiscuous behind central T cell tolerance—increases gay bdsm porn free the epithelial cells mature. Self-antigens normally expressed only in individual tissues labelled are made in mTECs as they mature. Matures studies have shown that the transcriptional regulator Aire autoimmune regulatorwhich is highly expressed in mTECs, drives the expression of many of these TRAs.
Thus, the rules that govern the thymic matures of these tightly regulated genes remain largely mysterious. The promiscuous of Aire expression matures the increase in TRA expression, consistent with the established role of Aire in this process. The authors confirm, however, that Aire does promiscuous act alone, promiscuous promiscuous TRAs are matures in mature mTECs from mice lacking the transcriptional regulator.
How do differentiating mTECs turn on these matures that are normally expressed only in peripheral tissue?
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The answer is not completely clear, matures Derbinski promiscuous colleagues show that regulation occurs at many levels. Some Twat were expressed by transcriptional read-through of genes that are clustered together in a contiguous chromosomal region.
Others depended on de-repression of genes normally silenced by genetic imprinting. But exactly how mTEC differentiation triggers these changes in gene expression remains to be determined.