Transgenerational Microchimerism in Pregnancy Loss

妊娠失败中的跨代微嵌合现象

• 批准号: 7306029
• 负责人: J. Lee Nelson
• 金额: $ 23.17万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7306029
• 关键词: Abbreviations; Adult; Alleles; Biological Assay; Blood Circulation; Blood specimen; Cell Count; Cells; Conceptus; Conflict (Psychology); DNA; Family; Family Study; Family member; Fetus; Future; Generations; Genes; Genetic Polymorphism; Genetic Variation; Genotype; HLA Antigens; HLA-DRB1; Immune; Immune response; Individual; Knowledge; Life; Live Birth; Long-Term Effects; Methods; Microchimerism; Mothers; Other Genetics; Peripheral Blood Mononuclear Cell; Polymerase Chain Reaction; Population; Pregnancy; Pregnancy Outcome; Pregnancy loss; Purpose; Recording of previous events; Recurrence; Resources; Serum; Source; Spontaneous abortion; Terminology; Testing; Thinking; Time; Woman; human leukocyte antigen gene; interest; peripheral blood; proband; success; trafficking

DESCRIPTION (provided by applicant): Microchimerism (Mc) refers to harboring a small number of cells or DNA from a genetically distinct individual. During pregnancy Mc is naturally acquired in the exchange of cells between a mother and conceptus. In prior studies we found that a mother's cells persist in her progeny into adult life. During pregnancy a woman who is already host to Mc from her mother acquires an additional source of Mc as cells and cell-free DNA from the conceptus enter her circulation. These observations raise the question of whether HLA-relationships across generations influence the outcome of pregnancy in women and, as genetic diversity is generally thought to be good, whether excessive HLA-sharing across generations contributes to recurrent idiopathic pregnancy loss (RPL). HLA molecules are central to immune responses, to distinguishing self from "other" and extensive polymorphism is the hallmark feature of HLA genes. Due to the polymorphism in HLA genes most of the time there are numerous differences in HLA alleles among family members. However, occasionally an increase of HLA-sharing is observed in families, either due to HLA-homozygosity or heterozygous HLA-identity. Previous studies have suggested that excessive HLA-sharing of a woman and her partner is associated with idiopathic RPL, although studies have been conflicting. The first Specific Aim of this R21 proposal will test the hypothesis that HLA-relationships over three generations have less HLA-disparity (increased sharing) when women probands have primary idiopathic RPL compared to probands with a live birth and no history of miscarriage. HLA-genotyping will be conducted for DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, A, B and C for women with primary idiopathic RPL, their mothers, conceptus, and partners. Specific Aim 2 will identify and quantify Mc from the proband's mother (MP-Mc) in consecutive blood samples from before, during and after pregnancy for probands with primary idiopathic RPL with a subsequent miscarriage or with a live birth and healthy women with no history of miscarriage. For this purpose a panel of HLA-specific and other genetic polymorphism specific quantitative PCR assays has been developed and will be employed to tested peripheral blood mononuclear cells. Specific Aim 3 will quantify Mc from the conceptus of the proband (CP-Mc) in the same peripheral blood samples using the same methods as in Aim 2 to test peripheral blood mononuclear cells as well as serum. In addition to the hypothesis of Aim 1, a second hypothesis will be tested in Aims 2 and 3, that dynamic changes in Mc, either MP-Mc or CP-Mc or both, is associated with idiopathic RPL. The consequences and long-term effects of harboring Mc from multiple sources are largely unknown as naturally acquired Mc from pregnancy has only recently been recognized. To our knowledge there are no prior studies investigating HLA-sharing or Mc across generations in idiopathic RPL. Harboring a small number of cells (or DNA) that originated from a genetically distinct individual is referred to as microchimerism (Mc). The finding that women harbor Mc from their own mothers and later acquire Mc from their own pregnancy(ies) raises questions about whether interactions between cell populations across generations sometimes influences pregnancy success. Because they help distinguish one cell from another particular genes, called HLA genes, are of special interest to investigate.

描述（由申请人提供）：微嵌合（Mc）是指含有来自遗传上不同的个体的少量细胞或DNA。在怀孕期间，Mc 是在母亲和胎儿之间的细胞交换中自然获得的。在之前的研究中，我们发现母亲的细胞在其后代中持续存在直至成年。在怀孕期间，当来自母亲的细胞和游离 DNA 进入她的循环时，已经从母亲那里获得 Mc 的女性会获得额外的 Mc 来源。这些观察结果提出了这样的问题：不同代际的 HLA 关系是否会影响女性的妊娠结局，而且由于遗传多样性通常被认为是有益的，因此不同代际之间过多的 HLA 共享是否会导致复发性特发性妊娠丢失 (RPL)。 HLA 分子对于免疫反应、区分自身与“他人”至关重要，而广泛的多态性是 HLA 基因的标志性特征。由于 HLA 基因的多态性，大多数时候家庭成员之间的 HLA 等位基因存在许多差异。然而，偶尔会在家庭中观察到 HLA 共享的增加，这可能是由于 HLA 纯合性或杂合性 HLA 同一性所致。先前的研究表明，女性及其伴侣过度共享 HLA 与特发性 RPL 相关，但研究结果相互矛盾。该 R21 提案的第一个具体目标将检验以下假设：与活产且无流产史的先证者相比，当女性先证者患有原发性特发性 RPL 时，三代人之间的 HLA 关系具有较小的 HLA 差异（增加共享）。将对患有原发性特发性 RPL 的女性及其母亲、胎儿和伴侣进行 DRB1、DRB3、DRB4、DRB5、DQA1、DQB1、A、B 和 C 的 HLA 基因分型。具体目标 2 将在怀孕前、怀孕期间和怀孕后的连续血液样本中识别和量化先证者母亲 (MP-Mc) 的 Mc，这些先证者患有原发性特发性 RPL，随后流产或活产，以及没有流产史的健康女性。为此目的，开发了一组 HLA 特异性和其他遗传多态性特异性定量 PCR 检测方法，并将用于测试外周血单核细胞。具体目标 3 将使用与目标 2 中相同的方法来量化相同外周血样本中先证者概念 (CP-Mc) 的 Mc，以测试外周血单核细胞以及血清。除了目标 1 的假设外，目标 2 和 3 中还将检验第二个假设，即 Mc 的动态变化（MP-Mc 或 CP-Mc 或两者）与特发性 RPL 相关。携带多种来源的 Mc 的后果和长期影响在很大程度上尚不清楚，因为怀孕期间自然获得的 Mc 直到最近才被认识到。据我们所知，之前没有研究调查特发性 RPL 中跨代 HLA 共享或 Mc 的情况。含有少量源自遗传上不同的个体的细胞（或 DNA）被称为微嵌合（Mc）。女性从自己的母亲那里携带 Mc，后来又从自己的怀孕中获得 Mc，这一发现提出了一个问题：代际细胞群之间的相互作用有时是否会影响怀孕的成功。因为它们有助于区分一个细胞与另一种特定的基因（称为 HLA 基因），因此值得研究。