Gene Regulation by HDAC7 in Thymic Selection

Histone deacetylase 7 (HDAC7) is highly expressed in CD4+/CD8+ thymocytes and functions as a signal-dependent repressor of gene transcription during T cell development. In this study, we express HDAC7 mutant proteins in a T cell line and use DNA microarrays to identify transcriptional targets of HDAC7 in T cells. Gene expression changes are compared to differential gene expression profiles associated with positive and negative thymic selection. This analysis reveals that HDAC7 regulates an extensive set of genes that are differentially expressed during both positive and negative thymic selection. Many of these genes play important functional roles in positive and negative selection, primarily via coupling between antigen receptor and downstream signaling events. Keywords: microarray gene expression profiling, comparison of perturbation of HDAC7 gene function with differential expression during thymic selection DO11.10 cells were transduced with different viruses encoding mutants of HDAC7, MEF2D, or Nur77. All microarrays were hybridized with untreated DO11.10 cells in one channel and transdced/treated cells in the other. Hybridizations are done with 4-12 replicates. DO11.10 TCR-transgenic thymocytes were also compared to MHC-deficient thymocytes and DO11.10 TCR-transgenic thymocytes from animals that had been injected with antigenic peptide at different timepoints prior to harvest of thymocytes.组蛋白去乙酰化酶7（Histone deacetylase 7, HDAC7）在CD4+/CD8+双阳性胸腺细胞中高表达，在T细胞发育过程中作为信号依赖性基因转录抑制因子发挥功能。本研究在T细胞系中表达HDAC7突变体蛋白，并通过DNA微阵列（DNA microarrays）技术鉴定T细胞中HDAC7的转录靶基因。将基因表达变化与胸腺阳性选择、阴性选择相关的差异基因表达谱进行对比分析，结果显示HDAC7调控了一系列在胸腺阳性选择与阴性选择过程中均存在差异表达的广泛基因集；其中多数基因主要通过偶联抗原受体与下游信号事件，在胸腺阳性、阴性选择过程中发挥重要功能。 关键词：微阵列基因表达谱分析，HDAC7基因功能扰动与胸腺选择过程中差异表达的对比分析 本研究使用编码HDAC7、MEF2D或Nur77突变体的不同病毒转导DO11.10细胞。所有微阵列实验均采用双通道杂交：一个通道使用未处理的DO11.10细胞作为对照，另一个通道使用转导/处理后的DO11.10细胞，每组杂交设置4~12次生物学重复。此外，本研究还将DO11.10 TCR转基因胸腺细胞分别与MHC缺陷型胸腺细胞，以及提前不同时间注射抗原肽后收获的DO11.10 TCR转基因胸腺细胞进行对比分析。