ABSTRACT
Background: It is more than sixty years that the concept of the fetal allograft and immunological paradox of pregnancy was proposed and in this context, several regulatory networks and mechanisms have been introduced so far. It is now generally recognized that mesenchymal stem cells exert potent immunoregulatory activity. In this study, for the first time, the potential impact of Menstrual blood Stem Cells [MenSCs], as surrogate for endometrial stem cells, on proliferative capacity of CD4+ T cells was tested
Methods: MenSCs and Bone marrow Mesenchymal Stem Cells [BMSCs] were isolated and assessed for their immunophenotypic features and multi-lineage differentiation capability. BMSCs and MenSCs with or without IFNGamma pre-stimulation were co-cultured with purified anti-CD3/CD28-activated CD4+ T cells and the extent of T cell proliferation at different MenSCs: T cell ratios were investigated by CSFE flow cytometry. IDO activity of both cell types was measured after stimulation with IFNGamma by a colorimetric assay
Results: MenSCs exhibited dual mesenchymal and embryonic markers and multilineage differentiation capacity. MenSCs significantly increased proliferation of CD4+ cells at ratios 1:2, 1:4 and 1:8. IFNGamma pre-treated BMSCs but not MenSCs significantly suppressed CD4+ T cells proliferation. Such proliferation promoting capacity of MenSCs was not correlated with IDO activity as these cells showed the high IDO activity following IFNGamma treatment
Conclusion: Although augmentation of T cell proliferation by MenSCs can be a basis for maintenance of endometrial homeostasis to cope with ascending infections, this may not fulfill the requirement for immunological tolerance to a semi-allogeneic fetus. However, more investigation is needed to examine whether or not the immunomodulatory properties of these cells are affected by endometrial microenvironment during pregnancy
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
Subject(s)
Humans , Female , Epithelial Cells , Trypsin , Immunophenotyping , Placenta , Cell Proliferation , Mice, Inbred BALB C , Flow CytometryABSTRACT
A wide range of biological activities of garlic in vitro and in vivo have been verified including its antioxidant, antitumor and anti-inflammatory effects. Indoleamine 2,3-dioxygenase [IDO] is an enzyme widely distributed in mammals and is inducible preferentially by IFN-?. IDO degrades the essential amino acid tryptophan to form N-formyl kynurenine. In the present in vitro study, the modulatory effect of 14kDa molecule isolated from garlic on IDO induction was tested. Cultures of mononuclear cells were exposed to 14kDa garlic fraction. Then, their proliferation responses and IDO metabolites were measured. A significant down-regulatory effect of garlic on IDO activity was found and also the proliferation responses of mononuclear cells increased. If these results are verified in vivo, an explanation will be provided on how garlic may interfere in IDO induction, which paves the way for elucidating its specific therapeutic effect in preventing tumor progress