Placenta Lab, Department of Obstetrics, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany.
Placenta Lab, Department of Obstetrics, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany.
Placenta. 2024 Feb;146:42-49. doi: 10.1016/j.placenta.2023.12.005. Epub 2023 Dec 20.
The transplacental passage of cells between a mother and her fetus, known as microchimerism, is a less studied process during pregnancy. The frequency of maternal microchimeric cells in fetal tissues in physiological pregnancies and mechanisms responsible for transplacental cell trafficking are poorly understood. This study aimed to evaluate the placental trafficking of maternal peripheral blood mononuclear cells (PBMC) using human ex vivo placenta perfusion.
Ten placentas and maternal PBMC were obtained after healthy pregnancies. Flow cytometry was used to characterize PBMC subtypes. They showed a higher percentage of CD3 T cells compared to CD56 NK cells. The isolated PBMC were stained with a fluorescent dye and perfused through the maternal circuit of the placenta in an ex vivo perfusion system. Subsequent immunofluorescence staining for CD3 T cells and CD56 NK cells was performed on placental tissue sections, and the number of detectable PBMC in different tissue areas was counted using fluorescence microscopy.
The applied method allowed discrimination of perfused autologous maternal cells from cells resident in the placenta before perfusion. Further, it allows additional immunohistochemical labelling and distinction of immune cell subsets. Perfused PBMC were detected in all analyzed placentas, mostly in contact to the syncytiotrophoblast. CD3 T cells were identified more frequently than CD56 NK cells and some CD3 T cells were found inside fetoplacental tissues and vasculature. The results indicate that also other PBMCs than T or NK cells adhere to or enter villous tissue, but they have not been specified in this analysis.
Previous studies have detected maternal cells in the fetal circulation which we could mimick in our ex vivo placenta perfusion experiments with fluorescence labelled autologous maternal PBMC. The applied experimental settings did not allow comparison of transmigration abilities of PBMC subsets, but slight modifications of the model will permit further studies of cell transfer processes and microchimerism in pregnancy.
细胞在母体和胎儿之间的胎盘转移,即微嵌合体现象,是妊娠过程中研究较少的一个过程。生理妊娠中胎儿组织中母源微嵌合细胞的频率及其介导的细胞转移机制尚不清楚。本研究旨在使用人离体胎盘灌注评估母体外周血单个核细胞(PBMC)向胎盘的转移。
从健康妊娠的 10 例胎盘和母体外周血 PBMC 中获取标本。采用流式细胞术对 PBMC 亚型进行鉴定,结果显示其 CD3 T 细胞的比例高于 CD56 NK 细胞。分离的 PBMC 用荧光染料染色,通过离体胎盘灌注系统在母体循环中灌注。随后对胎盘组织切片进行 CD3 T 细胞和 CD56 NK 细胞免疫荧光染色,并使用荧光显微镜计数不同组织区域可检测到的 PBMC 数量。
所应用的方法能够区分灌注的自体母源细胞和灌注前胎盘内的细胞。此外,它还允许进行额外的免疫组织化学标记和免疫细胞亚群的区分。在所有分析的胎盘均检测到灌注的 PBMC,主要位于合体滋养层表面。鉴定到的 CD3 T 细胞多于 CD56 NK 细胞,一些 CD3 T 细胞存在于胎-胎盘组织和脉管中。结果表明,除 T 细胞或 NK 细胞外,其他 PBMC 也可黏附或进入绒毛组织,但在本分析中尚未确定。
之前的研究已经在胎儿循环中检测到母源细胞,我们可以在离体胎盘灌注实验中用荧光标记的自体母源 PBMC 来模拟。所应用的实验设置不允许比较 PBMC 亚群的迁移能力,但对模型的稍加修改将允许进一步研究妊娠中的细胞转移过程和微嵌合体现象。