Human Amniotic Epithelial Cells Affect the Functions of Neutrophils

Background and Objectives@#As a stem cell group, Human amniotic epithelial cells (HAECs) have numerous advantages over their embryonic and adult counterparts for therapeutic utility. They are closer to clinical applications compared to other stem cell types. Additionally, the anti-inflammatory and immunoregulatory properties of HAECs toward several immune cells have been shown previously. Nevertheless, despite the ever-increasing importance of neutrophils in the immune and non-immune processes, a few studies investigated the interaction of neutrophils and HAECs. To increase the current knowledge of HAECs immunology which is necessary for optimizing their future clinical applications, here we explored the effect of HAECs on two chief neutrophil functions; respiratory burst and phagocytosis. @*Methods@#and Results: Freshly isolated human blood neutrophils were co-cultured with different number of HAECs for about 24 or 48 hours, then the oxidative burst and phagocytosis of stimulated neutrophils were assessed and compared. The results demonstrated a substantial elevation in the phagocytosis percentage, conversely a significant reduction in the oxidative burst of HAECs-cocultured neutrophils. These effects were dose-dependent, but did not show similar patterns. Likewise, the elongation of coculture period inversely influenced the HAECs-induced effects on the two neutrophil functions. @*Conclusions@#The present study, for the first time, investigated the HAECs-mediated effects on the two main neutrophil functions. The findings suggest that HAECs by enhancement of phagocytic ability and simultaneously, attenuation of oxidative burst capacity of neutrophils protect the fetus from both microbial treats and oxidative stress and their consequent inflammation; thus corroborate the current anti-inflammatory vision of HAECs.

Indoleamine 2,3-dioxygenase is dispensable for the immunomodulatory function of stem cells from human exfoliated deciduous teeth

Objective: In this study, we sought to better understand the immunoregulatory function of stem cells derived from human exfoliated deciduous teeth [SHED]. We studied the role of the interferon gamma [IFN-gamma]-indoleamine 2,3-dioxygenase [IDO]-axis in immunoregulation of SHED compared to bone marrow derived mesenchymal stem cells [BMMSCs] under the same conditions

Materials and Methods: In this cross-sectional study, recently isolated human T cells were stimulated either by mitogen or inactivated allogeneic peripheral blood mononuclear cells [PBMCs]. These T cells were subsequently co-cultured with, either SHED or BMMSCs in the presence or absence of 1-methyl-tryptophan [1-MT] or neutralizing anti-human-IFN-gamma antibodies. In all co-cultures we evaluated lymphocyte activation as well as IDO activity

Results: SHED, similar to conventional BMMSCs, had anti-proliferative effects on stimulated T cells and reduced their cytokine production. This property of SHED and BMMSCs was changed by IFN-gamma neutralization. We detected IDO in the immunosuppressive supernatant of all co-cultures. Removal of IDO decreased the immunosuppression of BMMSCs

Conclusion: SHED, like BMMSCs, produced the IDO enzyme. Although IFN-gamma is one of inducer of IDO production in SHED, these cells were not affected by IFN-gamma in the same manner as BMMSCs. Unlike BMMSCs, the IDO enzyme did not contribute to their immunosuppression and might have other cell-type specific roles

Variations in T-helper 17 and regulatory T cells during the menstrual cycle in peripheral blood of women with recurrent spontaneous abortion

Disorders in immune system regulation may result in pregnancy abnormalities such as recurrent spontaneous abortion [RSA]. This study aims to determine the ratio of regulatory T [Treg] and T helper [Th] 17 cells in unexplained RSA [URSA] women during proliferative and secretory phases of their menstrual cycles compared to healthy non-pregnant women. In this case control study, 25 women with URSA and 35 healthy, non-pregnant women were enrolled. The percentage of Th17 and Treg cells in participants peripheral blood were determined by flow cytometry. The percentage of Th17 cells and their related cytokines in serum [IL-17A] were higher in the proliferative and secretory phases of the menstrual cycles of URSA women compared to the control women. However, a lower percentage of Treg cells and their related cytokines in serum, transforming growth factor [TGF] beta1 and interleukin [IL]-10 were detected in the proliferative but not the secretory phase of the URSA group. The ratio of Th17/CD4+ Treg was higher in the URSA group than the control group. We observed an increased ratio of Th17/CD4+ Treg during the proliferative and secretory phases in URSA women. The imbalance between Th17 and Treg cells during the proliferative phase of menstrual cycles in the URSA group may be considered a cause for spontaneous abortion