CHEMICAL MEDIATORS OF ACUTE PULMONARY DISORDERS

这项合作和协同努力的主要目标仍然是在生理、细胞和分子方面描述肥大细胞多样性和功能的调节。有令人信服的证据表明，肥大细胞起源于骨髓，作为具有最小肉芽的固定祖细胞循环，并在炎症组织事件中经历组织依赖性的成熟和分化，并进一步调节。随着分泌颗粒肥大细胞胰蛋白酶、LTC4合成酶和gp49B1的cDNA和基因的分离和鉴定，以及对它们功能的认识，现在可以解决肥大细胞祖细胞中基因调控、调节细胞生物学、类二十烷生成的分离途径和细胞因子对效应途径的调控。胰蛋白酶的选择性功能和胞吐后的可用性已经建立，其调控将从染色体结构、转录调控和转录稳定性方面来定义。同样，LTC4合成酶（致力于半胱氨酸白三烯生物合成的终端途径蛋白）的表达将在转录和转录后水平上被表征。通过选择性分子和免疫化学探针，我们将评估富含半胱氨酸的低分子量磷脂酶A2超家族的复杂性，以及各种磷脂酶A2在为半胱氨酸白三烯提供花生四烯酸和分离的、依赖于前列腺素内过氧化物合酶-1和-2的PGD2合成中所起的作用。肥大细胞似乎富含对肥大细胞相关成员和成员之间生化差异的反调控，包括gp49Bl和PIR-B （p91）。具有干细胞因子、白细胞介素-6 （IL-6）和IL-10的小鼠骨髓源性肥大细胞祖细胞的发育提供了分泌颗粒蛋白酶缺乏的祖肥大细胞（PrMC），并且在缺乏持续的sem细胞因子刺激的情况下无法增殖到IL-3，从而进一步表征细胞因子的作用。与自然发生的气道反应性相关的基因位点在肥大细胞缺陷小鼠中降低，将通过重复回交和一种新的功能分析来更狭窄地定位，以方便地识别高应答者。综上所述，这些研究将提供关于决定关键效应功能的关键肥大细胞基因的调控表达的具体信息，旨在进一步了解在生理和病理刺激下肥大细胞表型/功能的组织调控决定。

The major objective of this collaborative and synergistic effort continues to be to characterize in physiologic, cellular, and molecular terms the regulation of mast cell diversity and function. There is compelling evidence that mast cells, arising from bone marrow, circulate as committed progenitors with minimal granulation and undergo tissue-dependent maturation and differentiation with further modulation during an inflammatory tissue event. With the cDNA and genes have been isolated and characterized for secretory granule mast cell tryptases, LTC4 synthase, and gp49B1 and with recognition of their functions, gene regulation, regulatory cell biology, segregated pathways of eicosanoid generation and cytokine regulation of effector pathways in committed mast cell progenitors can now be addressed. The regulation of tryptases for which selective functions and availability after exocytosis have been established will be defined in terms of chromosome structure, transcriptional regulation, and transcript stability. Similarly, the expression of LTC4 synthase, the terminal pathway protein committed to biosynthesis of the cysteinyl leukotrienes, will be characterized at transcriptional and post-transcriptional levels. The complexity of the cystein-enriched low molecular weight phospholipase A2 superfamily and the role of the various phospholipase A2 enzymes in supplying arachidonic acid for cysteinyl leukotrienes and segregated, prostaglandin endoperoxide synthase-1 and -2 dependent, PGD2 synthesis will be assessed with selective molecular and immunochemical probes. The mast cell appears enriched with counter-regulatory for mast cell-associated members and for biochemical differences between members, including gp49Bl and PIR-B (p91). The development of mouse bone marrow-derived mast cell progenitors with stem cell factors, interleukin-6 (IL-6), and IL-10 has provided progenitor mast cells (PrMC) deficient in secretory granule proteases and unable to proliferate to IL-3 in the absence of continued sem cell factor stimulation for further characterization of cytokine effects. The genetic loci associated with naturally occurring airway reactivity, which is decreased in mast cell-deficient mice, will be more narrowly localized by repetitive back crosses with a newly available functional assay to conveniently recognize high responders. Taken together, these studies will provide specific information on the regulated expression of key mast cell genes defining critical effector functions with the intent of providing further insights into the tissue-regulated determination of mast cell phenotype/function under physiologic and pathobiologic stimuli.