Molecular Analysis Of Human Naive And Memory T Cells

人类初始 T 细胞和记忆 T 细胞的分子分析

• 批准号: 6668156
• 负责人: Nan-ping Peter Weng
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6668156
• 关键词: CD antigens; T lymphocyte; actins; anergy; complementary DNA; cytokine; gene expression; human tissue; immunogenetics; immunologic memory; leukocyte activation /transformation; microarray technology; nucleic acid sequence

Role of IL-15 as a growth factor and activator for memory CD8 T cells: Memory T lymphocytes, arising from naive T lymphocytes after antigenic stimulation and being long-lived, are the cellular basis for immunological memory. Recent studies of CD8 T cells suggest that generation of CD8 memory T cells requires the engagement of TCR with antigen yet the maintenance of CD8 memory T cells appears to be dependent on cytokines, such as IL-15, independent of TCR. Although considerable progresses have been made in understanding the molecular and cellular events of TCR induced differentiation and proliferation in the past decade, less is known about the mechanisms of IL-15 action. In an effort to analyze the molecular and cellular changes induced by IL-15, and to compare IL-15- and TCR-mediated stimulation, we recently conducted a parallel comparitive analysis of genome-scale gene expression, proliferation, effector molecule production, and cytotoxicity in memory phenotype CD8 T cells stimulated in vitro with IL-15 or anti-CD3 mAb. Our study reveals several interesting and unexpected findings. We have identified 207 cDNA clones whose expression levels were significantly changed (at least 2-fold) in memory phenotype CD8 T cells after IL-15 and/or anti-CD3 stimulation. Approximately, 76% of those cDNA clones exhibited a similar pattern of changes with either IL-15 or anti-CD3 treatment. Furthermore, memory phenotype CD8+ T cells exhibited similar degree of cellular proliferation; production of effector molecules (IFNg, TNFb, granzyme B and perforin), and cytotoxicity in response to TCR or IL-15 mediated stimulations. These findings provide molecular evidence of IL-15 mediated events in memory phenotype CD8 T cells, and suggest IL-15 mimics TCR crosslinking induced gene expression, proliferation, and cytotoxic effector functions. Despite a remarkable resemblance of the action of IL-15 and TCR crosslinking, we have identified differences between these two stimulations in gene expression: 32 cDNA clones are uniquely regulated in response to IL-15, and 17 clones are unique to anti-CD3 treatment. Furthermore, analysis of protein levels of the differentially expressed surface activation markers confirmed differential increase in CD53 expression by IL-15 and differential increase of CD2 expression by anti-CD3 treated in memory CD8+ T cells. Taken together, these results indicate that IL-15 not only promotes survival but also activates the effector function of memory phenotype CD8+ T cells.

IL-15作为记忆性CD 8 T细胞的生长因子和激活剂的作用：记忆性T淋巴细胞，在抗原刺激后由幼稚T淋巴细胞产生并且是长寿的，是免疫记忆的细胞基础。最近对CD 8 T细胞的研究表明，CD 8记忆T细胞的产生需要TCR与抗原的接合，而CD 8记忆T细胞的维持似乎依赖于细胞因子，如IL-15，而不依赖于TCR。尽管在过去的十年中，在理解TCR诱导的分化和增殖的分子和细胞事件方面取得了相当大的进展，但对IL-15作用的机制知之甚少。为了分析IL-15诱导的分子和细胞变化，并比较IL-15和TCR介导的刺激，我们最近对IL-15或抗CD 3 mAb体外刺激的记忆表型CD 8 T细胞的基因组规模的基因表达、增殖、效应分子产生和细胞毒性进行了平行比较分析。我们的研究揭示了几个有趣和意想不到的发现。我们已经鉴定了207个cDNA克隆，其表达水平在IL-15和/或抗CD 3刺激后在记忆表型CD 8 T细胞中显著改变（至少2倍）。大约76%的这些cDNA克隆在IL-15或抗CD 3处理下表现出类似的变化模式。此外，记忆表型CD 8 + T细胞表现出相似程度的细胞增殖;效应分子（IFNg、TNF B、颗粒酶B和穿孔素）的产生，以及响应于TCR或IL-15介导的刺激的细胞毒性。这些发现提供了IL-15介导的记忆表型CD 8 T细胞事件的分子证据，并表明IL-15模拟TCR交联诱导的基因表达、增殖和细胞毒性效应子功能。尽管IL-15和TCR交联的作用非常相似，但我们已经确定了这两种刺激在基因表达中的差异：32个cDNA克隆响应于IL-15而被独特地调节，17个克隆是抗CD 3治疗所特有的。此外，差异表达的表面活化标志物的蛋白质水平的分析证实了在记忆性CD 8 + T细胞中通过IL-15处理的CD 53表达的差异增加和通过抗CD 3处理的CD 2表达的差异增加。总之，这些结果表明IL-15不仅促进存活，而且激活记忆表型CD 8 + T细胞的效应子功能。