Measuring Phagosomal Temperatures

描述（由申请人提供）：细胞内温度梯度是否调节细胞功能？酶促反应依赖于温度，这是我们对生物化学的理解的基础，然而我们倾向于假设细胞内温度梯度，如果它们真的发生了，一定会很快消散，以至于无关紧要。我们假设细胞内温度梯度可能与离子梯度（如Ca++或pH）在调节细胞功能方面一样重要。解决这个问题的挑战是建立一种方法来测量亚细胞水平上有意义的温度变化，并确定一个生物过程，在这个过程中，这种假设的温度调节的作用可以很容易地被评估。我们正在开发测量巨噬细胞亚细胞温度变化的方法，并将这些测量应用于吞噬过程，这是一个强烈激活细胞的过程，在这个过程中，降解酶被用来杀死潜在的威胁微生物。提出的初步数据表明，显著的“吞噬体加热”发生。该项目的创新之处在于，细胞内温度变化尚未被认为是调节细胞功能的重要因素。通过这个项目，我们打算为我们对分子和细胞生物学调控机制的理解增加一种新的信号传导方法。所开发的方法将适用于分子和细胞生物学的所有领域。

DESCRIPTION (provided by applicant): Do intracellular temperature gradients regulate cellular functions? It is fundamental to our understanding of biochemistry that enzymatic reactions are temperature-dependent, yet we tend to presume that intracellular temperature gradients, if they occur at all, must be dissipated so quickly as to be inconsequential. We hypothesize that intracellular temperature gradients may be as significant as ion gradients (e.g. Ca++ or pH) in regulating cellular functions. The challenge in addressing this question is to establish methodology for measuring meaningful changes in temperature at the subcellular level and to identify a biological process in which the role of this hypothesized temperature regulation can readily be assessed. We are developing methodology for measuring subcellular temperature changes in macrophages and applying these measurements to the process of phagocytosis, a process that strongly activates the cells and one in which degradative enzymes are enlisted to kill potentially threatening microbes. Preliminary data presented demonstrate that significant "Phagosomal Heating" occurs. The project is innovative in that intracellular temperature variations have not yet been implicated as important for regulating cellular functions. With this project, we intend to add a novel method of signaling to our understanding of molecular and cellular biology regulatory mechanisms. The approaches developed will be applicable to all areas molecular and cellular biology.