Signaling Dynamics of Leukocyte-Tumor Cell Interactions

描述（由申请人提供）：成功的癌症免疫治疗将取决于理解免疫细胞与其肿瘤靶点之间的复杂关系。中性粒细胞是抗体依赖性宿主抗肿瘤的关键参与者，而T细胞在抗体非依赖性抗肿瘤机制中至关重要。然而，对抗原反应的跨膜信号的性质以及效应物和靶标之间的化学通讯仍然知之甚少。这个NCI项目建立了高速显微镜技术，这是这个实验室所独有的；通过使用非常短的快门速度，细胞内的化学信号没有足够的时间移动，因此保留了大量的时空信息。引人注目的是，这些研究揭示了化学信号在细胞内和细胞间遵循的路线，从而提供了一种全新的研究信号转导的方法。我们现在将利用这个新工具以前所未有的细节研究免疫细胞和肿瘤细胞之间的相互作用。我们将确定化学信息，如钙和氧化波，如何在中性粒细胞和抗体调理的靶标之间传播，包括多细胞肿瘤球体。特别是，我们将利用生物物理、生化和计算工具解决信号如何在两个或多个细胞之间快速传播以及这些事件如何导致肿瘤细胞凋亡的问题。初步研究表明，至少有四种钙波与细胞毒性T淋巴细胞（CTL）介导的肿瘤细胞杀伤有关。这些信号将使用生化、生物物理和遗传工具进行系统剖析。特别是，我们将探索T细胞信号处理的动态机制。例如，我们将探索与MHC I类分子结合的不同肽抗原如何在ctl中引发不同的信号和功能。研究ctl诱导肿瘤细胞死亡的机制，包括穿孔素在肿瘤细胞异常钙信号传导中的潜在作用。通过使用新的成像，计算和免疫细胞工具的融合，我们的研究将在细胞复杂性的新水平上揭示和表征白细胞介导的肿瘤细胞破坏机制。这些新发现可能会导致癌症免疫治疗的进步。

DESCRIPTION (provided by applicant): The successful immunotherapy of cancer will depend upon understanding the complex relationships between immune cells and their tumor targets. Neutrophils are key participants in antibody-dependent host resistance to cancer whereas T cells are crucial in antibody-independent anti-tumor mechanisms. However, the nature of transmembrane signaling in response to antigens and the chemical communication between effectors and targets remain poorly understood. This NCI program has established the technique of high speed microscopy, which is unique to this laboratory; by using very brief shutter speeds, chemical signals within cells do not have enough time to move, which thereby retains a great deal of spatiotemporal information. Strikingly, these studies have revealed the routes chemical signals follow within and among cells, thus providing a completely new way of studying signal transduction. We will now exploit this new tool to study the interactions among immune and tumor cells in unprecedented detail. We will determine how chemical information, such as calcium and oxidant waves, travel among neutrophils and antibody-opsonized targets, including multi-cellular tumor spheroids. In particular, we will address how rapid signals travel among two or more cells and how these events lead to tumor cell apoptosis using biophysical, biochemical and computational tools. Preliminary studies have revealed at least four calcium waves associated with cytotoxic T lymphocyte (CTL)-mediated tumor cell killing. These signals will be systematically dissected using biochemical, biophysical, and genetic tools. In particular, we will explore the dynamic mechanism of signal processing by T cells. For example, we will explore how different peptide antigens bound to MHC class I molecules elicit different signals and functions in CTLs. The mechanism of CTL-induced tumor cell death will be studied, including the potential role of perforin in aberrant calcium signaling in tumor cells. By using a confluence of new imaging, computational, and immune cell tools, our studies will reveal and characterize mechanisms of leukocyte-mediated tumor cell destruction at a novel level of cellular complexity. These new insights are likely to lead to advances in immunotherapy of cancer.