Identification of an autoimmune serum containing antibodies against the Barr body.
Identification of an autoimmune serum containing antibodies against the Barr body.
复制标题
含有抗巴尔体抗体的自身免疫血清的鉴定。
DOI：
10.1073/pnas.151259598
复制
发表时间：
2001
影响因子：
11.1
通讯作者：
Yang,TP
中科院分区：
文献类型：
--
作者：
Hong,B;Reeves,P;Panning,B;Swanson,MS;Yang,TP
哺乳动物雌性体细胞中一条X染色体的转录失活导致失活的X染色体浓缩成异染色质或巴尔体。关于巴尔体的分子组成和结构或导致其在雌性细胞核中形成的机制知之甚少。由于自身免疫性疾病患者的血清通常含有针对多种细胞成分的抗体，因此我们推断某些自身免疫性血清可能含有针对与巴尔体相关的蛋白质的抗体。因此，我们通过人成纤维细胞的免疫荧光筛选自身免疫血清，并鉴定出一种免疫染色独特的核结构的血清，其大小和核定位与巴尔体一致。这些结构的数量与含有2至5条X染色体的二倍体雌性成纤维细胞中预期的巴尔体数量一致。用血清免疫染色，然后用抗XISTRNA的探针进行荧光原位杂交，证明来自自身抗体的主要荧光信号与XISTRNA共定位。对血清的进一步分析表明，它染色人类中期染色体和与雌性小鼠成纤维细胞中的非活性X一致的核结构。然而，在雌性小鼠胚胎干细胞或来自雌性小鼠E7.5胚胎的细胞中，它没有表现出定位于巴尔小体样结构。在来自雌性E7.5胚胎的细胞中缺乏失活X的染色表明抗原可能在X失活开始后的阶段参与X失活。这种识别与巴尔体相关的抗原的自身抗体的证明为鉴定巴尔体的分子组分和检查X灭活的分子基础提供了策略。
Transcriptional inactivation of one X chromosome in mammalian female somatic cells leads to condensation of the inactive X chromosome into the heterochromatic sex chromatin, or Barr body. Little is known about the molecular composition and structure of the Barr body or the mechanisms leading to its formation in female nuclei. Because human sera from patients with autoimmune diseases often contain antibodies against a variety of cellular components, we reasoned that some autoimmune sera may contain antibodies against proteins associated with the Barr body. Therefore, we screened autoimmune sera by immunofluorescence of human fibroblasts and identified one serum that immunostained a distinct nuclear structure with a size and nuclear localization consistent with the Barr body. The number of these structures was consistent with the number of Barr bodies expected in diploid female fibroblasts containing two to five X chromosomes. Immunostaining with the serum followed by fluorescencein situhybridization with a probe againstXISTRNA demonstrated that the major fluorescent signal from the autoantibody colocalized withXISTRNA. Further analysis of the serum showed that it stains human metaphase chromosomes and a nuclear structure consistent with the inactive X in female mouse fibroblasts. However, it does not exhibit localization to a Barr body-like structure in female mouse embryonic stem cells or in cells from female mouse E7.5 embryos. The lack of staining of the inactive X in cells from female E7.5 embryos suggests the antigen(s) may be involved in X inactivation at a stage subsequent to initiation of X inactivation. This demonstration of an autoantibody recognizing an antigen(s) associated with the Barr body presents a strategy for identifying molecular components of the Barr body and examining the molecular basis of X inactivation.