ABSTRACT
Toll-like receptor [TLR]-mediated inflammatory processes are supposed to be involved in pathophysiology of spontaneous abortion and preterm labor. Here, we investigated functional responses of human endometrial stromal cells [ESCs] and whole endometrial cells [WECs] to lipopolysaccharide [LPS] and lipoteichoic acid [LTA] Endometrial tissues were obtained from 15 cycling women who underwent laparoscopic tubal ligation. Modulation of TLR2, TLR4 and MyD88 expression and production of pro-inflammatory cytokines by WECs and ESCs in response to LPS and LTA were assessed. WECs and ESCs expressed significant levels of TLR4 and MyD88 transcripts but, unlike WECs, ESCs failed to express TLR2 gene. Regardless of positive results of Western blotting, ESCs did not express TLR4 at their surface as judged by flow cytometry. Immunofluorescent staining revealed intracellular localization of TLR4 with predominant perinuclear pattern. LPS stimulation marginally increased TLR4 gene expression in both cell types, whereas such treatment significantly upregulated MyD88 gene expression after 8 hr [p<0.05]. At the protein level, however, LPS activation significantly increased TLR4 expression by ESCs [p<0.05]. LTA stimulation of WECs was accompanied with non-significant increase of TLR2 and MyD88 transcripts. LPS and LTA stimulation of WECs caused significant production of IL-6 and IL-8 in a dose-dependent manner [p<0.05]. Similarly, ESCs produced significant amounts of IL-6, IL-8 and also TNF-alpha in response to LPS activation [p<0.05]. Our results provided further evidence of initiation of inflammatory processes following endometrial TLR activation by bacterial components which could potentially be harmful to developing fetus
ABSTRACT
Despite the extensive information available in the literature, cell surface marker signature of human Amniotic Epithelial Cells [hAECs] remains controversial. The aim of the present study was to characterize immunophenotypic features, proliferative capacity and immunogenicity of hAECs. We also tested whether expression of some cell surface markers is influenced by the type of trypsin used for tissue digestion. Single cell suspensions of amniotic membranes from four human placentas were isolated by enzymatic digestion and expression of CD9, CD10, CD29, CD34, CD38, CD44, CD45, CD73, CD105, CD133, HLA-I, HLA-DR, HLA-G, SSEA-4, STRO-1 and OCT-4 was then evaluated by flow cytometry. The differential impact of four trypsin types on the yield and expression of CD105 and HLA-I was also determined. The proliferative capacity of cultured hAECs was assessed and compared in the presence and absence of Epidermal Growth Factor [EGF]. To test their immunogenicity, hAECs were injected into Balb/c mice and the reactivity of hyperimmunized sera was examined by immunofluorescence staining. Nearly all purified cells expressed mesenchymal markers, CD9, CD10, CD29, and CD73 and the embryonic marker, SSEA-4. A large proportion of the cells also expressed STRO-1 and OCT-4. The purified cells also expressed HLA-G and HLA-I. A very small proportion of hAECs expressed CD34, CD38, CD44, CD133 and HLA-DR. The type of trypsin used for enzymatic digestion affected both the percentage and expression of HLA-I and CD105. hAECs revealed substantial proliferative capacity only when cultured in the medium supplemented with EGF. These cells were shown to be capable of inducing high amounts of anti-donor antibodies. Here we provided evidence that hAECs are immunogenic cells with high level of HLA-I expression. Furthermore, this work highlighted the impact of isolation procedure on the immunophenotype of hAEC