In vitro study on human trophoblast cells infected with HCMV.
ABSTRACT Human trophoblast cells were isolated and cultured in vitro in order to investigate possible pathogenesis of intrauterine infection caused by HCMV. Trophoblast cells were obtained by compound enzymes digestion and discontinuous percoll gradient. Cells and purity were identified by using immunocytochemistry assay with anti-CK7, Vim and beta-hCG antibodies. HCMV AD169 strain replication in isolated trophoblast cells and cell apoptosis were detected at different time points post infection (p.i.). The results showed that highly purified trophoblast cells were obtained. Specific virus replication was increased dramatically at the 24th h p.i., and then increased slowly during 48 h and 72 h. Apoptosis rate of trophoblast cells infected with HCMV was (34.68+/-3.14)% at 24th h p.i., while that in control group was (15.32+/-2.34)% (P<0.05). It was suggested that highly purified trophoblast cells can be isolated by the simplified cell purification method. HCMV can infect human trophoblast cells, and be quickly replicated, resulting in the accelerated apoptosis of human trophoblast cells during early time.
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ABSTRACT: A fibroblast cell strain that expressed cytokeratins 8 and 18 was isolated from explanted first trimester placenta. Its properties were consistent with an origin in the villous fibroblast-myofibroblast lineage, including expression of vimentin, smooth muscle alpha-actin and fibroblast surface protein. The cells grew rapidly in vitro, and exhibited tightly aligned bipolar morphology at confluence, absence of multi-nucleated cells, lack of secreted chorionic gonadotrophin, and absence of HLA G, placental alkaline phosphatase and pregnancy-specific beta-1 glycoprotein (SP1). On these criteria it was concluded they were not trophoblasts. On the basis of their morphology, cytokeratin expression and absence of CD34 and endoglin it was concluded they were not endothelial cells. They lacked desmin and smooth muscle myosin and so were not vascular smooth muscle cells. Further mesenchymal cell isolates were studied to determine the generality of these findings. Phenotypic heterogeneity was a consistent characteristic, but cytokeratin-positive cells were always present both in first trimester and term strains. Desmin was absent from almost all the cells isolated using the protocols employed, despite its occurrence in a significant subpopulation of cells in the villous stroma. Cytokeratins 8 and 18 can be observed in the stromal compartment of both first trimester and term placental villi. Cytokeratin has hitherto been regarded as a highly reliable marker for cells of the trophoblast lineage in vitro. These observations suggest that care should be taken in characterization of placental cell isolates; trophoblasts should be identified by the presence of cytokeratin 7 in preference to cytokeratin 8/18. The functional significance of cytokeratin expression in placental mesenchymal cells remains to be established.Placenta 12/1999; 20(8):615-25. · 3.12 Impact Factor
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ABSTRACT: Cells were isolated from human term placentae by trypsinisation of fragments of chorionic villi and fractionation of cells on a Percoll density gradient into six layers. A panel of 10 monoclonal antibodies to antigens on or in trophoblast cells (placental alkaline phosphatase (PLAP), cytokeratin-7, beta-human chorionic gonadotrophin (beta-hCG), human leucocyte antigen-G (HLA-G)), leucocytes (CD45), monocytes, macrophages, dendritic cells, B cells (HLA class II), mesenchyme cells (vimentin), fibroblasts (fibroblast antigen) and nucleated cells excluding villous trophoblast (HLA class I, CD9) was used to characterise the cells by flow cytometry. For staining intracellular antigens (cytokeratin, vimentin, beta-hCG) the cells were first fixed and permeabilised. The upper two layers from the gradient (density 1.013-1.039 g/ml) contained predominantly PLAP-positive cells or fragments, probably derived from the syncytiotrophoblast. Cytokeratin-positive cells accumulated mainly in the layer of density 1.039-1.052 g/ml and comprised the majority of the cell types identified in this fraction. Few or no cells reactive with antibodies to beta-hCG or HLA-G were identified in any layer. Non-trophoblast cells were heavier, being present mainly at densities 1.052-1.079 g/ml (CD45, HLA class I, vimentin) and 1.066-1.092 g/ml (fibroblast). Fewer than 10% of cells in any layer were HLA class II- or CD9-positive. Further purification of trophoblast cells was by negative immunomagnetic separation with removal of CD45-positive cells and HLA class II-positive cells to less than 1%. On culture of the cells from each layer, those of density 1.039-1.066 g/ml exhibited characteristics of cytotrophoblast cells; they secreted high levels of human chorionic gonadotrophin and formed adherent multinucleate cells. This procedure enabled the selection and enrichment of cytotrophoblast cells and/or syncytiotrophoblast fragments that are suitable for cellular and molecular studies.Placenta 05/2005; 26(4):308-18. · 3.12 Impact Factor
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ABSTRACT: Placental apoptosis is increased in vivo in preeclampsia (PE) and intrauterine growth restriction (IUGR). The cause and pathological implications of this phenomenon are unknown. This study considers the apoptotic susceptibility of villous trophoblasts from normal, PE, and IUGR pregnancies. Cultured cytotrophoblasts (CTs) and an in vitro model of syncytialization were used. CTs were isolated from term placentas of 12 normal, 12 PE, and 12 IUGR pregnancies. Apoptosis was determined by terminal dUTP nick-end labeling (TUNEL), Annexin V binding, and ADP:ATP ratios. Cells were stimulated with tumor necrosis factor-alpha/interferon-gamma or reduced oxygen (<5 KPa). For CTs, ADP:ATP <1 correlates with Annexin V binding. For normal pregnancy, tumor necrosis factor-alpha and depleted oxygen significantly increased TUNEL, Annexin V binding and ADP:ATP in CTs and syncytiotrophoblasts (STs). Spontaneous apoptosis was similar between groups for both cell types. After stimulation, TUNEL and Annexin V binding of CTs were significantly raised in PE and IUGR as compared with normal pregnancy. After oxygen reduction, ADP:ATP in CTs and STs were significantly elevated in IUGR. TUNEL was also increased in STs in PE after oxygen depletion and was significantly raised in STs from IUGR pregnancies after stimulation with both agonists. This is the first description of enhanced apoptosis in isolated villous trophoblasts in PE and IUGR. These intrinsic differences may represent an important factor in the pathophysiology of these conditions.American Journal Of Pathology 02/2003; 162(2):637-43. · 4.52 Impact Factor