Mesenchymal Stem Cell-Secreted TGF-β1 Restores Treg/Th17 Skewing Induced by Lipopolysaccharide and Hypoxia Challenge via miR-155 Suppression

Abstract

Background. Regulatory T cell (Treg)/T helper (Th) 17 skewing is important in the development of acute respiratory distress syndrome (ARDS). Immunomodulatory effects of mesenchymal stem cell- (MSC-) secreted transforming growth factor- (TGF-) β1 on CD4+ T cells are environment-sensitive and lack discussion in hypoxic and inflammatory conditions. Methods. Mouse splenic CD4+ T cells were precoated with anti-CD3 (5 μg/ml) and anti-CD28 (2 μg/ml) overnight. RAW264.7 cells were added as antigen-presenting cells (APCs). T cells with and without RAW264.7 cells were treated with various LPS concentrations of 0, 10, 100, and 1000 ng/ml or/and at hypoxia condition of 5% O2. Based on LPS (100 ng/ml) and hypoxia conditions (5% O2) as stimuli, MSCs were set as direct coculture or indirect coculture by transwell system. Anti-TGF-β1 neutralization antibody was added to explore the role of TGF-β1 among the soluble factors secreted by MSCs; miR-155 overexpression of CD4+ T cells was performed by transfection, and then, cells were added to the MSC-CD4+ T cell coculture system in hypoxic- and LPS-stimulated condition. After 48 hours, cells or supernatants were collected for detection of frequency of Treg and Th17 subsets, CD4+ T cell apoptosis and proliferation capacity assay by flow cytometry, secretion of INF-γ, IL-17A, IL-21, TGF-β1, and IL-10 by ELISA, and levels of miR-155, Rorc, Foxp3, and Ptpn2 mRNA expression of CD4+ T cells by RT-PCR. Results. MSCs could restore skewed Treg/Th17 induced by LPS and hypoxia compared to groups without MSCs with increased secretion of TGF-β1, IL-10, and IL-17A ( P < 0.05 ) and attenuate the increased expression of miR-155 in CD4+ T cells via cell-to-cell contact mechanism while TGF-β1 neutralization significantly inhibited the effects of MSCs restoring skewed Treg/Th17 and abolished its effect on miR-155 expression in CD4+ T cells. Conclusions. These findings suggested miR-155 suppression of CD4+ T cells mediated MSC-secreted TGF-β1 modulating skewed Treg/Th17 induced by LPS-hypoxia challenge, providing evidence when proposing future T lymphocyte-targeted cell therapy in a specific condition.

Elk1 enhances inflammatory cell infiltration and exacerbates acute lung injury/acute respiratory distress syndrome by suppressing Fcgr2b transcription

“…The pathophysiological mechanisms underlying ALI/ARDS involve the hyperaggregation and activation of platelets and leukocytes, enhanced permeability of the alveolar-capillary endothelial and epithelial barriers, infiltration by inflammatory cells, and the accumulation of protein-rich edematous fluid in the extravascular space (Liu et al 2022a , b ; He et al 2021 ). Th17 cells, a subset of CD4 + T cells, secrete IL-17 and play a pivotal role in mediating lung inflammation, contributing to the development of ARDS (Cheng et al 2022 ; Xue et al 2022 ). In this study, lung specimens from ARDS models underwent comprehensive pathomorphological analysis, focusing on edema, glycogen deposition, fibrosis, and inflammatory cell infiltration.…”

Interleukin-18-primed human umbilical cord-mesenchymal stem cells achieve superior therapeutic efficacy for severe viral pneumonia via enhancing T-cell immunosuppression

“…As reported, TGF-β1 is an essential regulator of cell proliferation, survival, and apoptosis; and TGF-β1 has anti-apoptotic effects in myelo-monocytic leukaemic cells co-cultured with stromal cells [ 52 ]. In addition, in an LPS-induced ARDS mouse model, MSCs overexpressing TGF-β1 could regulate lung inflammation and attenuate lung injuries by modulating the imbalance of Th17/Treg in the lungs [ 53 ]. We also found TGF-β1 participate the immunosuppression and anti-apoptosis pathways of IL18-hUCMSC in vitro and in vivo, by using the Fresolimumab (GC1008) and TGF beta-1,2,3 monoclonal antibody to block the activity of TGF-β1 (Fig.…”

Human umbilical cord mesenchymal stem cell-derived TGFBI attenuates streptozotocin-induced type 1 diabetes mellitus by inhibiting T-cell proliferation

“…However, several studies have demonstrated that mesenchymal stem/stromal cell-secreted TGFB could regulate Treg production to relieve inflammation. Interestingly, TGFBI also belongs to the TGFB family, which may affect T-cell function through another pathway [ 46 , 47 ]. The complete mechanism by which TGFBI regulates the immunosuppressive capacity of hUC-MSCs still needs further investigation.…”