Drosophila melanogaster S2 cells nucleosome occupancy data after simulation by heat killed Staphylococcus aureus. Drosophila melanogaster

The innate immune response is among the strongest genomic responses and is conserved across all metazoa. Although transcription during the innate immune response has been well studied, the associated chromatin reorganizations are largely uncharacterized. Here we show that Drosophila S2 cells stimulated with Staphylococcus aureus display a dynamic change in genome-wide nucleosome occupancy and sensitivity. We found a widespread and transient nucleosomal loss peaking at 30 minutes post stimulation, and we demonstrated that the regulatory potentials of nucleosomes differ following stimulation. In addition, we identified differentially sensitive nucleosomes with response-specific potentials. Our results provide high-resolution nucleosome-distribution maps of the fly genome, revealing chromatin's role in: the innate immune response to Gram-positive bacteria, response-specific regulatory-factor binding, and nucleosome sensitivity. We identify functional chromatin regulatory features associated with immune response, and lay a foundation for a framework linking general and locus-specific roles for nucleosomes in immune regulation. Overall design: Drsophila S2 cells at 0hr, 30minutes, 1hr and 4hr post heat-killed Staphylococcus aureus stimulation

固有免疫应答（innate immune response）是最为强效的基因组应答之一，且在所有后生动物（metazoa）中高度保守。尽管固有免疫应答过程中的转录调控已得到充分研究，但与之相关的染色质重塑（chromatin reorganization）在很大程度上仍未被系统阐明。本研究显示，经金黄色葡萄球菌（Staphylococcus aureus）刺激的果蝇S2细胞（Drosophila S2 cells）在全基因组范围内的核小体占据率与敏感性均呈现动态变化。研究团队发现了广泛且瞬时的核小体丢失现象，其峰值出现在刺激后30分钟；同时证实，刺激后核小体的调控潜能会发生显著改变。此外，本研究还鉴定出了具有应答特异性潜能的差异敏感性核小体。本研究结果提供了果蝇基因组的高分辨率核小体分布图谱，揭示了染色质在三大过程中的关键作用：针对革兰氏阳性菌（Gram-positive bacteria）的固有免疫应答、应答特异性调控因子结合，以及核小体敏感性调控。本研究鉴定出了与免疫应答相关的功能性染色质调控特征，并为构建连接核小体在免疫调控中一般性与位点特异性作用的研究框架奠定了坚实基础。实验设计：将经热灭活金黄色葡萄球菌（Staphylococcus aureus）刺激后的果蝇S2细胞，分别在0小时、30分钟、1小时及4小时四个时间点进行取样分析。