School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom; Department of Pathology, College of Medicine, Qassim University, Buraidah, Saudi Arabia.
Department of Medical Biochemistry, College of Medicine, Qassim University, Buraidah, Saudi Arabia.
J Reprod Immunol. 2020 Sep;141:103152. doi: 10.1016/j.jri.2020.103152. Epub 2020 May 28.
During first trimester of human pregnancy, the maternal system develops immunity against infection and to provide protection of allogeneic foetus from abortion. This study was undertaken to determine the role of trophoblast specific CD74 isoforms in first trimester trophoblast derived cells under normal and lipopolysaccharide (LPS) stimulated conditions.
Gene and protein of CD74 were determined in first trimester trophoblast derived cells, JEG-3 and ACH-3 P and also in human placenta by PCR, western blotting and immunoprecipitation. Effect of LPS mediated infection on the regulation of CD74 isoforms was studied intracellularly and also on the cells surface by flow cytometry.
Data demonstrated that JEG-3 and ACH-3 P cells under normal conditions have not expressed CD74 isoforms neither intracellularly or nor on the surface. These results were further validated directly in human placenta. However, treatment of these trophoblast cells with a bacterial LPS, significantly upregulated CD74 mRNA expression (p < 0.05). Furthermore, expression of CD74 on the surface was not detected even after stimulation with LPS. Interestingly, CD74 isoform at 35 kDa was significantly detected intracellularly upon stimulation with LPS (p < 0.05). These results were further confirmed by western blotting followed by immunoprecipitation.
To the best of our knowledge, this is the first study concluded that the bacterial LPS induce infection in the first trimester trophoblasts via intracellular upregulation of CD74. Data indicated that the lack of cell surface expression of trophoblastic specific isoforms of CD74 may provide protection for human pregnancy in the first trimester.
在人类妊娠的早期，母体系统会发展出针对感染的免疫能力，并保护异体胎儿免受流产。本研究旨在确定在正常和脂多糖（LPS）刺激条件下，滋养层特异性 CD74 异构体在早孕滋养层衍生细胞中的作用。
通过 PCR、western blot 和免疫沉淀法在早孕滋养层衍生细胞 JEG-3 和 ACH-3 P 以及人胎盘内检测 CD74 的基因和蛋白。通过流式细胞术研究 LPS 介导的感染对内源性和细胞表面 CD74 异构体调节的影响。
数据表明，JEG-3 和 ACH-3 P 细胞在正常条件下既不表达细胞内也不表达细胞表面的 CD74 异构体。这些结果在人胎盘内得到了进一步验证。然而，用细菌 LPS 处理这些滋养层细胞，显著上调了 CD74 mRNA 的表达（p<0.05）。此外，即使在 LPS 刺激后，也未检测到 CD74 在细胞表面的表达。有趣的是，在 LPS 刺激后，细胞内的 CD74 异构体在 35kDa 处明显被检测到（p<0.05）。这一结果通过 western blot 结合免疫沉淀得到了进一步的证实。
据我们所知，这是首次研究表明，细菌 LPS 通过细胞内 CD74 的上调诱导早孕滋养层感染。数据表明，滋养层特异性 CD74 异构体缺乏细胞表面表达可能为人类妊娠的早期提供保护。
