Novel Optical Technique for Recovery of Fetal Cells in Maternal Blood

描述（由申请人提供）：目前基于细胞的产前诊断技术，如羊膜穿刺术、绒毛膜绒毛取样（CVS）和经皮脐血取样（PUBS）是侵入性的，存在严重的胎儿丢失风险。利用孕妇外周血中循环的胎儿细胞进行无创产前诊断，因其对胎儿无风险而受到广泛关注。虽然几种胎儿细胞类型已经成为研究的目标，但研究主要集中在胎儿有核红细胞（fNRBC）上。然而，由于母体血液中fNRBC的浓度非常低，受到母源有核红细胞（mNRBC）的干扰，以及无法找到广泛适用的识别物来区分fNRBC和mNRBC，可靠地检测和分离足够数量的活细胞用于临床仍然是一个巨大的挑战。胎儿NRBC在核形态和血红蛋白分子结构上与母体NRBC不同。最近，麻省理工学院的首席研究员和他的同事们开发了生物医学光散射光谱（LSS），并展示了其独特的能力，可以在不损伤细胞的情况下光学探测核形态。本课课组进一步发展了LSS，并开发了能够在小共聚焦体积内监测亚细胞细胞器的共聚焦吸收散射光谱技术（CLASS）。这个研究项目的目的是双重的。(1)我们将使用实验室开发的现有CLASS设备来鉴定fNRBC原生光学生物标志物。(2)基于这些生物标记物，我们将开发一种快速，简单和强大的光学技术，将CLASS显微镜和光学镊子结合在同一仪器中，可以从母体外周血样本中富集和恢复完整的fNRBC。这将导致一种临床上有用的产前基因检测方法。

DESCRIPTION (provided by applicant): Present cell-based techniques of prenatal diagnosis such as amniocentesis, chorionic villus sampling (CVS) and percutaneous umbilical blood sampling (PUBS) are invasive and present significant risks of fetal loss. Non-invasive prenatal diagnosis utilizing fetal cells circulating in maternal peripheral blood during pregnancy has received much attention since it poses no risk to the fetus. Although several fetal cell types have been targeted, the search has focused on fetal nucleated red blood cells (fNRBC). However, because of very low concentration of fNRBC in the maternal blood, interference by nucleated red blood cells of maternal origin (mNRBC) and the failure to find broadly applicable identifiers that can differentiate fNRBC from mNRBC reliable detection and isolation of viable cells in amounts sufficient for clinical use remains a monumental challenge. Fetal NRBC differ from maternal NRBC in both nuclear morphology and hemoglobin molecular structure. Recently the principal investigator and his colleagues at MIT have developed biomedical light scattering spectroscopy (LSS) and showed its unique ability to optically probe nuclear morphology without damaging cells. Our group has further advanced LSS and developed the confocal absorption and scattering spectroscopic technique (CLASS) capable of monitoring subcellular organelles in small confocal volumes. The objective of this research program is twofold. (1) We will use the existing CLASS equipment developed in our laboratory to identify fNRBC native optical biomarkers. (2) Based on these biomarkers, we will develop a fast, simple and robust optical technique which combines CLASS microscopy and optical tweezers in the same instrument and which will enable enrichment and recovery of intact fNRBC from a sample of maternal peripheral blood. This will lead to a clinically useful method for prenatal genetic testing. PUBLIC HEALTH RELEVANCE: Amniocentesis is performed on approximately one-half million pregnant women in the United States each year, and is known to have an approximately 0.5% miscarriage rate. In addition it is estimated that 7 out of 8 women to whom amniocentesis is offered by their physician refuse the procedure because of the risk. This application offers a safe, noninvasive solution to the dangers associated with amniocentesis.