MAST CELL DIFFERENTIATION IN VITRO

肥大细胞是直接免疫性疾病的主要效应细胞， 超敏反应 了解肥大细胞是如何从原始细胞 血细胞可能对某些过敏性疾病的治疗有意义 疾病 因为肥大细胞可能是唯一与造血相关的细胞， 干细胞，肥大细胞分化的早期事件的研究可能有 更广泛的意义。 研究提出 在该授权申请中，扩展了开发的肥大细胞模型系统， 在上一个补助期。 这个系统利用了 已经定型的祖细胞，而不是未定型的祖细胞，可以对干细胞产生反应， 细胞因子单独通过在甲基纤维素中产生肥大细胞集落。 人们一直关注c-kit/stem的不同作用， 细胞因子受体-配体复合物可能在不同的阶段发挥作用， 分化可能对造血有更广泛的影响， 将军 在这项拨款申请中提出的研究扩展了 肥大细胞模型系统在上一个资助期开发。 这 系统利用了这样一个事实，即提交的祖先，但不是 未定型的，可以通过产生 甲基纤维素中的肥大细胞集落。 持续关注 c-kit/干细胞因子受体-配体 复合体可能在分化的不同阶段发挥作用;然而， 该拨款申请的主要重点是解决肥大细胞上的Fc受体 细胞及其祖细胞，由于最近的挑衅性发现， 在肥大细胞中，FcRI和FcRIII都与γ链二聚体相关， 激活和细胞因子生物合成的信号。 我们 特别感兴趣的是诱导自分泌IL-3的可能性 循环可能是这些祖先的提交状态中的关键元素。 第一个具体目标是确定骨髓祖细胞， 特别是那些可能是早期肥大细胞谱系的一部分的细胞， FcRI和FcRIII，如果这些受体发出信号， 自分泌IL-3环，这是必要的承诺。 在第二 特异性靶向、肥大细胞定向祖细胞或颗粒状肥大细胞 将对MLN或腹膜冲洗液进行测试， FcRI/FcRIII介导的信号传导影响自分泌细胞的表达 细胞因子、加塔转录因子或蛋白酶。 我们还将 确定肥大细胞上FcRI的持续占用是否是必要的， 用于子细胞连续几代的持续分裂。 的 第三个具体目标是利用一个令人兴奋的新模型系统， 造血的研究;胚胎干细胞培养。 一旦 允许这些非常原始的细胞在培养物中分化， 将监测FcRI/FcRIII的信使和蛋白质的表达， 与肥大细胞的出现和自分泌IL-3相关 感应 这些实验可能会揭示相似或不同之处 在这项赠款申请中提出的建议不仅应有助于 我们对肥大细胞分化的理解， 个体发育和干细胞发育。

Mast cells are the major effector cells in diseases of immediate hypersensitivity. Understanding how mast cells develop from primitive blood cells may have implication for treatment of certain allergic diseases. Because mast cells may be uniquely related to hematopoietic stem cells, studies of early events in mast cell differentiation may have broader implications for hematopoiesis in general. The research proposed in this grant application extends the mast cell model system developed in the previous grant period. This system takes advantage of the fact that committed progenitors, but not uncommitted ones, can respond to stem cell factor alone by production of mast cell colonies in methylcellulose. There is continuing attention to the different roles that the c-kit/stem cell factor receptor-ligand complex may play in different stages of differentiation may have broader implications for hematopoiesis in general. The research proposed in this grant application extends the mast cell model system developed in the previous grant period. This system takes advantage of the fact that committed progenitors, but not uncommitted ones, can respond to stem cell factor alone by production of mast cell colonies in methylcellulose. There is continuing attention to the different roles that the c-kit/stem cell factor receptor-ligand complex may play in different stages of differentiation; however, the major focus in this grant application addresses Fc receptors on mast cells and their progenitors, because of recent provocative findings that in mast cells, both FcRI and FcRIII associated gamma chain dimers to transduce signals for activation and cytokine biosynthesis. We are particularly interested in the possibility that an induced autocrine IL-3 loop may be critical element in the committed state of these progenitors. The first specific aim is to determine whether bone marrow progenitors, particularly those which may be part of the early mast cell lineage, bear FcRI and FcRIII and if these receptors transduce a signal to induce an autocrine IL-3 loop which is necessary for commitment. In the second specific aim, mast cell-committed progenitors or granulated mast cells from MLN or peritoneal washouts will be tested to determine if FcRI/FcRIII-mediated signalling affects expression of autocrine cytokines, GATA transcription factors, or proteases. We will also determine if the continued occupancy of FcRI on mast cells in necessary for continued division of successive generations of daughter cells. The third specific aims takes advantage of an exciting new models system for the study of hematopoiesis; embryonic stem (ES) cell cultures. Once these very primitive cells are allowed to differentiate in culture, the expression of message and protein for FcRI/FcRIII will be monitored to correlate with the appearance of mast cells and autocrine IL-3 inducibility. These experiments may reveal similarities or differences between proposed in this grant application should contribute not only to our understanding of mast cell differentiation but also to Fc receptor ontogeny and stem cell development.