Department of Oral Microbiology and Immunology, Dental Research Institute, and BK21 Program, School of Dentistry, Seoul National University, Seoul 110-749, Republic of Korea.
Int Immunopharmacol. 2012 Aug;13(4):454-60. doi: 10.1016/j.intimp.2012.05.010. Epub 2012 May 29.
Lipoteichoic acid (LTA) is a major virulence factor of Gram-positive bacteria including Staphylococcus aureus. Despite its pivotal role in causing sepsis, the systemic immune responses to LTA in human cells are poorly understood. Here, we produced highly-pure and structurally-intact LTA from S. aureus and examined the gene expression profile of LTA-stimulated human peripheral blood mononuclear cells (PBMCs). The LTA preparation did not contain any detectable biologically-active impurities and stimulated Toll-like receptor 2. Protein expression profiling using a cytokine array kit and ELISA revealed expression of MCP-1/CCL2, IL-6, and IL-1β. We performed transcriptional profiling of PBMCs in response to S. aureus LTA using an Affymetrix genechip microarray. A total of 208 genes were significantly (fold change>1.5 and P<0.05) altered, with 157 up-regulated and 51 down-regulated genes in response to S. aureus LTA treatment. The up-regulated genes were involved in recognition (30 genes), cellular adhesion (6 genes), signal transduction (42 genes), co-stimulation (4 genes), chemokines, cytokines and their receptors (51 genes), apoptosis (9 genes), and negative regulation (15 genes). The down-regulated genes were involved in recognition (12 genes), antigen processing and presentation (9 genes), signal transduction (27 genes), and chemotaxis (3 genes). The microarray results were validated using real-time RT-PCR with 21 up-regulated genes and 9 down-regulated genes. Our results provide a more comprehensive overview of the transcriptional changes in PBMCs in response to S. aureus LTA, and contribute to the understanding of the pathophysiological role of S. aureus LTA during the systemic inflammatory response.
脂磷壁酸（LTA）是包括金黄色葡萄球菌在内的革兰氏阳性菌的主要毒力因子。尽管其在引起败血症方面起着关键作用，但人类细胞中对 LTA 的全身免疫反应仍知之甚少。在这里，我们从金黄色葡萄球菌中制备了高度纯净且结构完整的 LTA，并研究了 LTA 刺激人外周血单核细胞（PBMC）的基因表达谱。LTA 制剂不含任何可检测到的具有生物活性的杂质，并刺激 Toll 样受体 2。使用细胞因子阵列试剂盒和 ELISA 进行蛋白质表达谱分析显示，MCP-1/CCL2、IL-6 和 IL-1β的表达。我们使用 Affymetrix 基因芯片微阵列对金黄色葡萄球菌 LTA 刺激 PBMC 进行了转录谱分析。共有 208 个基因（fold change>1.5 and P<0.05）显著改变，金黄色葡萄球菌 LTA 处理后 157 个基因上调，51 个基因下调。上调的基因参与识别（30 个基因）、细胞黏附（6 个基因）、信号转导（42 个基因）、共刺激（4 个基因）、趋化因子、细胞因子及其受体（51 个基因）、细胞凋亡（9 个基因）和负调控（15 个基因）。下调的基因参与识别（12 个基因）、抗原加工和呈递（9 个基因）、信号转导（27 个基因）和趋化作用（3 个基因）。使用实时 RT-PCR 验证了微阵列结果，验证了 21 个上调基因和 9 个下调基因。我们的结果提供了对金黄色葡萄球菌 LTA 刺激 PBMC 转录变化的更全面概述，并有助于理解金黄色葡萄球菌 LTA 在全身炎症反应期间的病理生理作用。
