The Role of Fetal Cell Microchimerism in Maternal Repair

描述（由申请人提供）：我们正在请求支持来测试一个假设，即胎儿细胞，通过怀孕生理获得，并在流产、流产或分娩后保留在成年女性体内，包含一种新的细胞群，我们称之为“妊娠相关祖细胞（妊娠相关祖细胞，PAPC）”。迄今为止，围绕成体干细胞可塑性的争论几乎忽略了怀孕在女性中的作用。PAPCs，如果被证明是真正的干细胞，将具有胚胎起源的发育优势，并且可以在没有伦理争议的情况下从以前怀孕过的成年女性中提取。我们在未输血的成年女性中有广泛的初步数据表明，通过妊娠获得的胎儿细胞（根据Y染色体以及胎儿特异性DNA多态性进行鉴定）在外周血和临床病变器官中可检测到，并且具有多谱系能力。由于需要从活检和/或尸检标本中获得临床材料，这些研究都是描述性的，而不是机械性的。我们的假设将在动物模型中得到验证，一只表达绿色荧光蛋白（GFP）或荧光素酶的转基因雄性小鼠与野生型雌性小鼠杂交。这将使我们能够控制生殖史，并测试关于母体中胎儿细胞的可塑性和活性的多种假设。GFP和荧光素酶序列是显性转基因。一半的幼崽将携带转基因，并在部分或全部细胞中表达绿色荧光标记，这取决于它们的结构。胎儿细胞呈绿色荧光，可以使用多种技术在母体组织中识别和跟踪，包括体内全动物成像，荧光显微镜和实时PCR扩增。在具体目的1中，我们将检验特定因素影响母体胎儿细胞微嵌合（FCMC）发育的假设。在具体目标2中，我们将使用化学、手术、遗传和缺血模型来确定胎儿细胞是否在特定的组织损伤情况下被招募，并通过分析整体健康和寿命、靶器官功能、伤口愈合差异和差异基因表达来促进母体损伤的修复。在具体目标3中，我们将检查小鼠嵌合胎儿细胞的细胞表面特征，并进行微阵列分析，以确定FCMC是由一种还是多种细胞类型引起的。在具体目标4中，我们将验证胎儿干细胞比成体干细胞具有优势的假设，并有助于延长存活时间或改善器官功能。长期目标是确定怀孕是否通过获得具有治疗潜力的独特细胞而给女性带来长期优势。

DESCRIPTION (provided by applicant): We are requesting support to test the hypothesis that fetal cells, acquired physiologically through pregnancy, and retained in the adult human female following abortion, miscarriage, or delivery, encompass a novel population of cells that we have termed the "Pregnancy-Associated Progenitor Cell (PAPC)." To date, the controversy surrounding the plasticity of adult stem cells has virtually ignored the role of pregnancy in females. PAPCs, if shown to be true stem cells, would have the developmental advantages of being fetal in origin yet could be retrieved without ethical controversy from an adult female who has previously been pregnant. We have extensive preliminary data in the human adult, non-transfused female that fetal cells (identified on the basis of the Y chromosome as well as fetal-specific DNA polymorphisms), acquired through pregnancy, are detectable in peripheral blood and clinically diseased organs, and have multi-lineage capacity. Due to the necessity of obtaining clinical material from biopsy and/or autopsy specimens, these studies have been descriptive and not mechanistic. Our hypothesis will be tested in an animal model, a transgenic male mouse expressing either green fluorescent protein (GFP) or luciferase bred to wild-type female mice. This will allow us to control reproductive histories, and test multiple hypotheses regarding the plasticity and activity of fetal cells in the maternal body. The GFP and luciferase sequences are dominant transgenes. Half of the fetal pups will carry the transgene, and express the green fluorescent marker in some or all of their cells, depending on the construct. Fetal cells fluoresce green and can be identified and tracked in maternal tissues using a variety of techniques, including in vivo whole animal imaging, fluorescence microscopy, and real-time PCR amplification. In specific aim 1 we will test the hypothesis that specific factors affect the development of fetal cell microchimerism (FCMC) in the mother. In specific aim 2 we will use chemical, surgical, genetic, and ischemic models to determine if fetal cells are recruited in specific tissue injury scenarios and contribute to the repair of maternal injury by analyzing overall well being and longevity, target organ function, differences in wound healing, and differential gene expression. In specific aim 3 we will examine the cell surface characteristics of the murine microchimeric fetal cells and perform microarray analysis to determine whether FCMC is due to 1 or multiple cell types. In specific aim 4 we will test the hypothesis that fetal stem cells have an advantage over adult stem cells and contribute to prolonged survival or improved organ function. The long-term objective is to determine if pregnancy confers a long-term advantage to a female by resulting in the acquisition of unique cells that have therapeutic potential.