Coelomocyte Activation and the Sea Urchin Immune System

这项调查的目的是探索免疫系统 紫海胆，Strongylocentrotus purpuratus， 体腔细胞激活的分子机制。 profilin基因 从体腔细胞克隆的SpCoel 1在细胞中上调 对损伤或外来体腔液的注入作出反应。 该分子参数表示在 体腔细胞的激活，并将用于评估 海胆免疫系统对实验性的 挑战. 我们将确定最有效的刺激， 使SpCoel 1的转录速率最大化， 体腔细胞 这一分析表明， 能力的体腔细胞，并建议的配体范围 这些细胞可以检测到。 为了进一步分析对 外部刺激，体腔细胞增殖，包括时间 体腔液中新细胞出现的过程，以及 动物中增殖中心的位置将是 表征了 体腔细胞活化最可能涉及 出现了一些新的转录物物种， 防御功能。 转录本群体的差异， 与静息细胞相比，活化的细胞将用于克隆， 表征活化相关基因。 提供一种分子 理解，SpCoel 1的调控区将通过以下方式分析： 比较调节表达的蛋白质-DNA结合模式， 激活和静息体腔细胞，并在早期发育 当这个基因也在细胞中表达时， 体腔细胞前体 %%% 棘皮动物的免疫系统反应迅速， 保护海胆免受感染和修复损伤。 它 是一种非特异性系统，其效应细胞是 体腔内的体腔细胞。 尽管该系统 与哺乳动物的免疫系统相比， 在功能上与高等植物的重要成分同源， 脊椎动物的免疫系统 主要细胞反应 脊椎动物的适应性免疫是由细胞介导的， 类型也以非特定方式运行，因此 棘皮动物的防御系统可能没有太大变化， 祖先的形态 基因表达与基因调控 在无脊椎动物免疫系统中的表达是一个几乎未探索的 生物学领域。 对海胆的初步研究结果 发现了一个关键基因，它在癌症的早期阶段被激活， 防御反应。 进一步研究这个基因是如何调控的 以及基因产物如何在免疫细胞激活中发挥作用， 揭示了非特异性免疫的细胞机制 以及这些重要的生态生物如何保护 自己受伤或感染。

The purpose of this investigation is to explore the immune system of the purple sea urchin, Strongylocentrotus purpuratus, and the molecular mechanisms of coelomocyte activation. The profilin gene (SpCoel1), cloned from coelomocytes, is upregulated in cells responding to injury or to injections of foreign coelomic fluid. This molecular parameter denotes changes that occur during activation of coelomocytes and will be used to assess the magnitude of responses shown by the sea urchin immune system to experimental challenge. We will identify stimuli that are most effective in maximizing the transcription rate of SpCoel1 and in activating coelomocytes. This analysis will indicate the recognition capabilities of the coelomocytes, and suggest the range of ligands these cells can detect. To further analyze the response to external stimuli, coelomocyte proliferation, including the time course of the appearance of new cells in the coelomic fluid, and the location of the proliferative centers in the animal will be characterized. Coelomocyte activation most likely involves the appearance of a number of new transcript species that are required for defense functions. Differences in the transcript population in activated cells compared to resting cells will be used to clone and characterize activation related genes. To provide a molecular understanding, the regulatory region of SpCoel1 will be analyzed by comparing protein-DNA binding patterns that regulate expression in activated and resting coelomocytes, and in early developmental stages when this gene is also expressed in cells that may be coelomocyte precursors. %%% The echinoderm immune system responds quickly and efficiently in protecting sea urchins from infection and repairing injuries. It is a non-specific system, the effector cells of which are the coelomocytes found within the body cavities. Although this system appears primitive compared to the mammalian immune system, it may be functionally homologous to important elements of higher vertebrate immune systems. Primary cellular responses in vertebrates that underlie adaptive immunity are mediated by cell types that also function in a non-specific manner, so the echinoderm defense system may not have changed much from the basic, ancestral form. Gene expression and the regulation of gene expression in invertebrate immune systems is an almost unexplored area of biology. Initial results of research on sea urchins have identified a critical gene that is activated in early stages of a defense response. Further studies of how this gene is regulated and how the gene-product functions in immune-cell activation will shed new light on the cellular mechanisms of non-specific immune function and how these ecologically important organisms defend themselves from injury or infection.