Roussev R G, Coulam C B, Kaider B D, Yarkoni M, Leavis P C, Barnea E R
Center for Human Reproduction, Chicago, IL, USA.
Mol Hum Reprod. 1996 Nov;2(11):883-7. doi: 10.1093/molehr/2.11.883.
Preimplantation factor (PIF) is detected in the serum of women shortly after fertilization; its origin, however, has not been established. In this study, the embryonal origin of PIF was investigated and partial characterization of the factor was carried out. Culture media from viable human 2-8-cell stage embryos and mouse 2-cell-blastocyst stage embryos were analysed using the lymphocyte/platelet binding assay (LPBA). The assay was performed by combining culture media with donor O+ type blood-derived lymphocytes/platelets, complement and an antibody against CD2. Increased autorosette formation between lymphocytes and platelets (> 9%) was an indication for the presence of PIF. In addition, the effect of platelet-activating factor (PAF) and chaperonin 10 on PIF activity was determined. Partial purification of PIF was carried out using gel filtration and reverse-phase high purification liquid chromatography (HPLC), followed by mass spectrometry. Culture media of single human viable fertilized oocytes were negative for PIF; however, the 10-fold concentrated medium was positive for PIF. In medium in which five or more mouse embryos were cultured, PIF activity was observed starting at the morula stage and was higher by the blastocyst stage. Addition of PAF or chaperonin 10 to the PIF assay did not elicit a specific effect on PIF activity. Chromatographic data suggest that PIF activity is due to low molecular weight proteins. PIF appears to be a low molecular weight protein which is derived from viable preimplantation embryos. It is different from PAF or chaperonin 10. Its final characterization will be valuable for better understanding of maternal recognition of pregnancy and implantation.
着床前因子（PIF）在女性受精后不久的血清中即可检测到；然而，其来源尚未明确。在本研究中，对PIF的胚胎来源进行了调查，并对该因子进行了部分特性分析。使用淋巴细胞/血小板结合试验（LPBA）分析了来自存活的人类2-8细胞期胚胎和小鼠2细胞-囊胚期胚胎的培养基。该试验通过将培养基与供体O+型血来源的淋巴细胞/血小板、补体以及抗CD2抗体混合进行。淋巴细胞与血小板之间自凝团形成增加（>9%）表明存在PIF。此外，还测定了血小板活化因子（PAF）和伴侣蛋白10对PIF活性的影响。使用凝胶过滤和反相高效液相色谱（HPLC）对PIF进行了部分纯化，随后进行了质谱分析。单个存活的人类受精卵母细胞的培养基中PIF呈阴性；然而，浓缩10倍的培养基中PIF呈阳性。在培养了五个或更多小鼠胚胎的培养基中，从桑椹胚阶段开始观察到PIF活性，到囊胚阶段活性更高。向PIF试验中添加PAF或伴侣蛋白10对PIF活性没有产生特异性影响。色谱数据表明，PIF活性归因于低分子量蛋白质。PIF似乎是一种源自存活的着床前胚胎的低分子量蛋白质。它与PAF或伴侣蛋白10不同。其最终特性分析对于更好地理解母体对妊娠和着床的识别将具有重要价值。
