DIFFERENTIATION OF GRANULOCYTES AND MACROPHAGES

该项目的长期目标是了解介导细胞增殖和分化的细胞因子信号通路的生理控制。这些途径被细胞因子不恰当地激活，或者在包括癌症、自身免疫、炎症和传染病在内的广泛疾病中被破坏。先前在该基金资助下的工作使用功能性遗传筛选确定了细胞因子信号的关键负调控因子家族，称为细胞因子信号抑制因子（SOCS）。基因缺失实验表明，SOCS-1是抑制内源性干扰素- γ潜在致死效应所必需的分子，生化实验表明，SOCS-1与活化的JAK激酶相互作用并抑制其活性。本项目的目的是：(1)分析三种不同的SOCS蛋白（SOCS-1至- 3）在基因缺失小鼠中的独特和冗余生理作用。在致死性表型（如SOCS-1 -/-和SOCS-3-/-小鼠）的情况下，将进行组织特异性的条件基因缺失或与细胞因子缺失小鼠的杂交，以确定缺陷的作用部位。(2)通过对不同SOCS或细胞因子缺失的小鼠进行遗传杂交，确定不同SOCS蛋白抑制不同细胞因子作用的特异性；(3)确定与SOCS蛋白相互作用的生理分子靶点，介导其抑制作用，并确定每种相互作用的生化和生物学后果。相互作用蛋白将通过共关联、直接结合和定义肽特异性识别来鉴定，并定量确定每个相互作用的结合亲和力。所有基于体外生物效应或生化相互作用的分析将在整个动物中通过产生适当的基因缺失或修饰的小鼠（例如产生仅删除一个相互作用结构域的SOCS蛋白）和通过适当的遗传杂交（例如与已删除拟议相互作用伴侣的小鼠）进行验证。这些研究有望确定经生理验证的治疗靶点，用于设计具有治疗价值的分子，以治疗与外源性或内源性细胞因子信号通路激活相关的疾病，特别是炎症、白血病和其他癌症。

The long term aim of this project is to understand the physiological control of cytokine signaling pathways that mediate cellular proliferation and differentiation. These pathways are activated inappropriately by cytokines or are otherwise subverted in a wide range of diseases including cancer, autoimmunity and inflammatory and infectious diseases. Previous work funded under this grant using functional genetic screens identified a family of critical negative regulators of cytokine signaling called the supressors of cytokine signaling (SOCS). Gene deletion experiments revealed that SOCS-1 is an essential molecule required to keep in check the potentially lethal effects of endogenous interferon-gamma and biochemical experiments revealed that SOCS-1 interacts with activated JAK kinases and inhibits their activity. The aims of the present project are: (1) to analyse in gene-deleted mice the unique and redundant physiological roles of three different SOCS proteins (SOCS-1 to - 3). In the case of a lethal phenotype (as for SOCS-1 -/- and SOCS-3-/- mice) tissue-specific, conditional gene deletions or crosses to cytokine-deleted mice will be performed to identify the site of action of the defect. (2) to determine the specificity of different SOCS proteins in inhibiting the actions of different cytokines by performing genetic crosses of mice with different SOCS or cytokine deletions; and (3) to identify the physiological molecular targets that interact with SOCS proteins to mediate their inhibitory effects and determine the biochemical and biological consequences of each interaction. Interacting proteins will be identified by co-association, direct binding and definition of peptide specificity recognition and the quantitative binding affinity of each interaction determined. All analyses based on in vitro biological effects or biochemical interactions will be verified in the whole animal by generating appropriate gene-deleted or -modified mice (e.g. producing a SOCS protein with only one interaction domain deleted) and by appropriate genetic crosses (e.g with mice in which the proposed interaction partner has been deleted). These studies are expected to define physiologically-validated therapeutic targets for the design of molecules that should have therapeutic value in treating diseases associated with the exogenous or endogenous activation of cytokine signaling pathways, especially inflammation, leukemias and other cancers.