T Cell-specific Expression of the MurineCD3δ Promoter

Abstract

T cell-specific expression of human and mouse CD3␦ is known to be governed by an enhancer element immediately downstream from the gene. Here we demonstrate by transgenic and in vitro studies that the murine CD3␦ (mCD3␦) promoter prefers to be expressed in cells of the T lineage. Deletion analyses of a promoter segment (؊401/؉48 bp) followed by transient transfections indicate that upstream elements between ؊149 and ؊112 bp contribute to full expression of the gene. Furthermore, a core promoter region ؊37/؉29 appears to contribute to a T cell specificity. Using substitution mutant scanning, four positive and one negative regulatory elements were found within the mCD3␦ core promoter. The first two positive elements comprise two classical initiator-like sites, which recruit TFII-I, whereas a third contains a functional Ets binding site. Immediately adjacent to the observed transcription start site is a negative element that utilizes the transcription regulator YY1. The last positive regulatory element contains a potentially functional CREB binding site and the minor transcriptional start site. Because NERF-2, Elf-1, and Ets-1 are expressed preferentially in lymphocytes and because, in addition, YY1 represses the promoter activity strongly in non-T cells, we conclude that the combination of these transcription factors contributes to the T cell-specific expression pattern of mouse CD3␦.Recent studies have shown that B and T lymphocytes and natural killer cells originate from a common stem progenitor (1, 2). One of the earliest events in commitment to development of the T cell lineage is expression of the CD3 genes, which even precedes TCR 1 -␤ rearrangement (3). Functionally the CD3␥, ␦, and ⑀ proteins form the scaffold upon which the TCR⅐CD3 complex or the pre-TCR⅐CD3 complex is assembled. The genes encoding the CD3␥, ␦, and ⑀ membrane proteins are tightly linked on chromosome 9 in the mouse and on chromosome 11 in human (4). The CD3␥ and ␦ promoters are oriented head to head as a divergently transcribed gene pair, their transcription start sites being around 1.5 kb apart (4). Remarkably, no regulatory principles that govern all three CD3 genes have been recognized so far. This is particularly striking because CD3␥ and CD3␦ appear to have evolved from one common ancestor gene relatively recently (5).Both the mouse and human CD3␦ gene comprise five exons that are organized in a similar fashion. A T cell-specific enhancer element ␦A is found immediately downstream from the 3Ј-untranslated region of mouse and human CD3␦ and is thought to govern the T cell-specific expression of the gene (3). A second element ␦B, which is found in the mouse only, increases the activity of the ␦A enhancer but has no activity by itself (3).Different lines of evidence indicate that expression of most T cell-specific genes is regulated by assembly of promoter and enhancer elements resulting in large complexes that comprise multiple transcription factors (6). Little is known about the CD3␦ promoter and its importance for continued expression...

DNA motifs in human and mouse proximal promoters predict tissue-specific expression

“…After correction, predictors for bone marrow, uterus, trachea, adipose tissue, and hypothalamus fail to predict significantly (P Ͼ 0.01). contexts (27)(28)(29), and it has been observed to repress transcription of genes outside of T cells and enhance their transcription in T cells (30).…”

Gene expression profiling of isolated tumour cells from anaplastic large cell lymphomas: insights into its cellular origin, pathogenesis and relation to Hodgkin lymphoma

“…For example, we validated the absence of ETS1, a transcription factor controlling the expression of several T-cell-specific genes in ALCL. [32][33][34][35] GATA3, EOMES and members of the NFAT family are also downregulated at varying levels (data not shown).…”

Mechanisms controlling titer and expression of bidirectional lentiviral and gammaretroviral vectors

“…We, therefore, focused on strategies preventing either the expression of antisense message or the protection of dsRNA in packaging cells. Importantly, incorporating a T-cell-specific murine CD3d promoter 34 into a bidirectional GV vector did not prevent expression of the antisense message and thus did not overcome titer restrictions possibly due to interaction of the internal promoter with enhancer sequences of the 5 0 promoter as described before (Supplementary Figure S2). 35 Consequently, we focused on the screening of RNAi suppressor proteins by cotransfecting either empty vector (ctrl), HIV Tat, 36 human foamy virus Tas, 37 tomato bushy stunt virus p19, 38 betanodamuravirus B2 39 or NovB2 21,40 expression plasmid to a normal transfection mixture for the production of GV bidirectional vectors.…”