REVERSE GENETIC ANALYSIS IN TISSUE INJURY

组织对损伤的反应是多形核细胞的早期回流 随后单核细胞/巨噬细胞流入伤口区域。 来自巨噬细胞的促有丝分裂因子不仅被认为是 对于正常的伤口愈合是必不可少的，但也涉及到 慢性炎症可能发生的纤维化。转化生长 因子-β（TGF β），一种促有丝分裂因子，在细胞增殖中起重要作用。 组织调节，已被证明是由血小板分泌和激活 巨噬细胞 虽然TGF β被认为主要在细胞内发挥其强大的调节作用， 通过影响其他生长因子和细胞外基质 由于TGF-β在体内的作用（导致其整体增加）， 明白该项目的目标是研究TGF β在 通过制备突变TGF β，其不仅无活性，而且 当其与突变体形成异源二聚体时，其与野生型TGF β结合。 这利用了这样一个事实，即TGF β被翻译为一种 预前体并加工成活性蛋白。 显性TGF β突变基因将与一个启动子连接，该启动子仅 在活化的巨噬细胞中有活性（visna病毒长末端重复序列），和 该构建体将用于开发转基因模型。是 主要研究者的最终目标是研究 巨噬细胞来源的TGF β在慢性炎症中的作用，主要是在肺部。 有了这个转基因模型，各种实验方法可以用来 产生肺损伤，提供的信息不仅对作用 巨噬细胞源性TGF β在慢性炎症中的作用， 正常的伤口愈合

Tissue responds to damage with an early reflux of polymorphonuclear cells and subsequent influx of monocytes/macrophages into the wound area. Mitogenic factors derived from macrophages have not only been recognized as essential to normal wound-healing, but have also been implicated in the fibrosis that can occur with chronic inflammation. Transforming growth factor-beta (TGFbeta), a mitogenic factor that plays a strong role in tissue regulation, has been shown to be secreted by platelets and activated macrophages. Although TGFbeta is thought to play its strong regulatory role primarily through effects on other growth factors and the extracellular matrix (resulting in its overall increase), the in vivo role of TGFbeta is poorly understood. The goal of this project is to study the effects of TGFbeta in vivo by preparing a mutant TGFbeta that is not only inactive, but also will inactivate wild-type TGFbeta when it forms a heterodimer with the mutant. This takes advantage of the fact that TGFbeta is translated as a prepro-form and is processed to an active protein. The dominant TGFbeta mutant gene will be linked to a promoter that is only active in activated macrophages (visna virus long terminal repeat), and this construct will be used to develop a transgenic model. It is the eventual goal of the principal investigator to examine the role of macrophage-derived TGFbeta in chronic inflammation, primarily in the lung. With this transgenic model, various experimental methods could be used to produce lung damage, providing information not only on the role of macrophage-derived TGFbeta in chronic inflammation but also on its role in normal wound-healing.