Natural Killer Dendritic Cells in Listeria Infection

李斯特菌感染中的自然杀伤树突状细胞

• 批准号: 7131216
• 负责人: Ronald P Dematteo
• 金额: $ 27.6万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2008-05-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7131216
• 关键词: Listeria; Listeria infections; dendritic cells; immune response

DESCRIPTION (provided by applicant): While there is general consensus that interferon-gamma (IFN-gamma) is vital to the clearance of Listeria monocytogenes, the cellular source of IFN-gamma has been controversial. Some investigators have concluded that NK cells are responsible, while others have implicated T cells. Recently, we have identified a novel cell type that secretes large amounts of IFN-gamma and exists in the spleen and other organs of normal mice. Because these unique cells lyse targets directly, activate naive T cells in vitro and in vivo, and express both the natural killer cell marker NK1.1 and the dendritic cell marker CD11c, we have labeled them as natural killer dendritic cells (NKDC). A few other investigators have recognized NKDC-like cells in rodents and humans. We have preliminary data that splenic NKDC produce IFN-gamma during Listeria infection in mice. Therefore, we hypothesize that NKDC are critical to the immune response against Listeria. While the lytic and antigen-presenting abilities of NKDC may be important, we have chosen to focus exclusively on their IFN-gamma production for this 2-year application. We propose to assess the biologic significance of IFN-gamma production by NKDC during Listeria infection in mice and dissect the mechanisms by which it is regulated. In Aim 1, we will determine the extent of NKDC involvement in IFN-gamma production during Listeria infection. To exclude the possibility that other cells make IFN-gamma in vivo, but are unable to do so once they are removed from their local environment in the spleen, we will make use of a recently described technique of in vivo intracellular cytokine analysis of splenocytes. In Aim 2, we will establish the mechanism of IFN-gamma production by NKDC during Listeria infection. Specifically, we will test IL-12, IL-18, and Toll-like receptor 9 as we have found these to regulate NKDC IFN-gamma production in response to bacterial CpG. In Aim 3, we will determine whether NKDC production of IFN-gamma is sufficient to induce an immune response against Listeria. We will adoptively transfer NKDC from wild-type mice into IFN-gamma deficient mice and then assess their response to Listeria infection. NKDC will be compared to NK cells and other splenic cell subsets that make IFN-gamma as identified in Aim 1. Our proposed experiments will begin to define the role of NKDC in the immune response to Listeria, a pathogen that is a cause of human mortality and a potential agent for bioterrorism, and provide a greater understanding of how this novel cell type may participate in other types of immunity.

描述（由申请人提供）：虽然人们普遍认为干扰素-γ (IFN-γ) 对于单核细胞增生李斯特氏菌的清除至关重要，但 IFN-γ 的细胞来源一直存在争议。一些研究人员得出结论，NK 细胞是罪魁祸首，而另一些研究人员则认为 T 细胞与此有关。最近，我们发现了一种新的细胞类型，它能分泌大量的 IFN-γ，存在于正常小鼠的脾脏和其他器官中。由于这些独特的细胞直接裂解靶标，在体外和体内激活幼稚 T 细胞，并表达自然杀伤细胞标记 NK1.1 和树突状细胞标记 CD11c，因此我们将它们标记为自然杀伤树突状细胞 (NKDC)。其他一些研究人员已经在啮齿类动物和人类中发现了类似 NKDC 的细胞。我们有初步数据表明，小鼠李斯特菌感染期间，脾脏 NKDC 会产生 IFN-γ。因此，我们假设 NKDC 对于针对李斯特菌的免疫反应至关重要。虽然 NKDC 的裂解和抗原呈递能力可能很重要，但我们选择在这个为期 2 年的应用中专门关注其 IFN-γ 的产生。我们建议评估小鼠李斯特菌感染期间 NKDC 产生 IFN-γ 的生物学意义，并剖析其调节机制。在目标 1 中，我们将确定 NKDC 在李斯特菌感染期间参与 IFN-γ 产生的程度。为了排除其他细胞在体内产生 IFN-γ，但一旦将其从脾脏的局部环境中移出后就无法这样做的可能性，我们将利用最近描述的脾细胞体内细胞内细胞因子分析技术。在目标 2 中，我们将建立李斯特菌感染期间 NKDC 产生 IFN-γ 的机制。具体来说，我们将测试 IL-12、IL-18 和 Toll 样受体 9，因为我们发现它们可以响应细菌 CpG 调节 NKDC IFN-γ 的产生。在目标 3 中，我们将确定 NKDC 产生的 IFN-γ 是否足以诱导针对李斯特菌的免疫反应。我们将把野生型小鼠的 NKDC 过继转移到 IFN-γ 缺陷小鼠中，然后评估它们对李斯特菌感染的反应。 NKDC 将与目标 1 中确定的产生 IFN-γ 的 NK 细胞和其他脾细胞亚群进行比较。我们提出的实验将开始定义 NKDC 在对李斯特菌（一种导致人类死亡的病原体和生物恐怖主义的潜在媒介）的免疫反应中的作用，并更好地了解这种新型细胞类型如何参与其他类型的免疫。