The phagocytic activity of human first trimester extravillous trophoblast

Abstract

It has been suggested previously that phagocytic activity in the human placenta is confined to cells of the macrophage lineage. However, earlier studies were hampered by the paucity and poor viability of cells inherent in primary trophoblast cell cultures, contamination by other cell types which themselves have phagocytic activity, lack of reliable markers of trophoblasts, and by limitations of methods available to demonstrate unequivocally the internalization of particulate material. We have overcome these limitations by using: (i) DNA transfection to provide unlimited supplies of pure trophoblast cell lines; (ii) human placental lactogen as a marker unique to trophoblast; and (iii) confocal microscopy to demonstrate unequivocally the intracellular locality of phagocytosed material. We found that both untransfected primary culture extravillous trophoblast cells, as well as the cell lines, had the capacity to phagocytose sheep red blood cells, Staphylococcus aureus and baker's yeast cells, and that this activity was inhibited by cytochalasin B and by culture at 4 degrees C. Phagocytic activity in trophoblast cells was less avid than that seen in a professional phagocyte. In physiological and pathological situations where tissue remodelling occurs, such as the rapid turnover in the periodontal ligament or during inflammation, epithelial cells and other cells that are not considered professional phagocytes actively phagocytose components of the extracellular matrix. We postulate that phagocytosis by human trophoblasts may play an important role in the extensive tissue remodelling that occurs during trophoblastic invasion of the decidua.

Examination of the Cellular Mechanisms by Which Marinobufagenin Inhibits Cytotrophoblast Function

“…2, A and B). Both 10 and 100 nM MBG and ouabain significantly increased the ratio of phosphorylated Src to total Src in CTB cells compared with controls (43,42, and 45% increase at 10, 30, and 60 min, respectively, after MBG treatment and 50, 48, and 52% increase at 10, 30, and 60 min, respectively, after ouabain treatment; p Ͻ 0.001 for each) (Fig. 3, A and B).…”

“…Guy Whitley (St. George's Hospital Medical School, London, UK). These cells are well characterized and share many characteristics with isolated primary cells, including the expression of cytokeratin-7, HLA class I antigen, HLA-G, BC-1, CD9, human chorionic gonadotropin, and human placental lactogen (42)(43)(44)(45).…”

Trophoblast phagocytic program: roles in different placental systems

“…Human trophoblast cells are able to interiorize and digest erythrocytes, releasing to the culture medium products yielded from this degradation (Contractor and Krakauer, 1976). Choy and Manyonda (1998) showed the capability of the extravillous trophoblast to ingest blood cells, bacteria and fungi particles, but not with the same avidity as seen in professional phagocytes. Mice cultured trophoblast cells also showed lower rates of erythroph- (Albieri and Bevilacqua, 1996;Albieri et al, 1999Albieri et al, , 2005.…”

Complex Expression Pattern of Wnt Ligands and Frizzled Receptors in Human Placenta and its Trophoblast Subtypes

“…JEG-3 choriocarcinoma cells were cultivated in DMEM + 10% FCS. SGHPL-5 cells, exhibiting properties of extravillous cytotrophoblasts, were cultivated in a 1:1 mixture of DMEM/Ham's F-12 supplemented with 10% FCS (GibcoBRL Life Technologies, Paisley, UK) as described [18]. Trophoblastic HTR-8/SVneo cells were cultivated in RPMI 1640 (GibcoBRL) plus 5% FCS as mentioned [19].…”