Overexpression of TGF?1 in murine mesenchymal stem cells improves lung inflammation by impacting the Th17/Treg balance in LPS-induced ARDS mice.
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ABSTRACT: BACKGROUND:T helper 17 cells (Th17)/regulatory T cells (Treg), as subtypes of CD4+ T cells, play an important role in the inflammatory response of acute respiratory distress syndrome (ARDS). However, there is still a lack of effective methods to regulate the differentiation balance of Th17/Treg. It was proven that mesenchymal stem cells (MSCs) could regulate the differentiation of CD4+ T cells, but the mechanism is still unclear. TGF?1, a paracrine cytokine of MSCs, could also regulate the differentiation of Th17/Treg but is lowly expressed in MSCs. Therefore, mouse MSCs (mMSCs) overexpressing TGF?1 were constructed by lentivirus transduction and intratracheally transplanted into LPS-induced ARDS mice in our study. The aim of this study was to evaluate the therapeutic effects of mMSCs overexpressing TGF?1 on inflammation and immunoregulation by impacting the Th17/Treg balance in LPS-induced ARDS mice. METHODS:mMSCs overexpressing TGF?1 were constructed using lentiviral vectors. Then, mouse bone-marrow-derived MSCs (mBM-MSC) and mBM-MSC-TGF?1 (mBM-MSC overexpressing TGF?1) were transplanted intratracheally into ARDS mice induced by lipopolysaccharide. At 3 and 7 days after transplantation, the mice were sacrificed, and the homing of the mMSCs was assayed by ex vivo optical imaging. The relative numbers of Th17 and Treg in the lungs and spleens of mice were detected by FCM. IL-17A and IL-10 levels in the lungs of mice were analysed by western blot. Permeability and inflammatory cytokines were evaluated by analysing the protein concentration of BALF using ELISA. Histopathology of the lungs was assessed by haematoxylin and eosin staining and lung injury scoring. Alveolar lung fibrosis was assessed by Masson's trichrome staining and Ashcroft scoring. The mortality of ARDS mice was followed until 7?days after transplantation. RESULTS:The transduction efficiencies mediated by the lentiviral vectors ranged from 82.3 to 88.6%. Overexpressing TGF?1 inhibited the proliferation of mMSCs during days 5-7 (p??0.05). Compared to that in the LPS?+?mBM-MSC-NC group mice, engraftment of mMSCs overexpressing TGF?1 led to much more differentiation of T cells into Th17 or Treg (p??0.05). CONCLUSION:MSCs overexpressing TGF?1 could regulate lung inflammation and attenuate lung injuries by modulating the imbalance of Th17/Treg in the lungs of ARDS mice.
SUBMITTER: Chen J
PROVIDER: S-EPMC7374869 | biostudies-literature | 2020 Jul
REPOSITORIES: biostudies-literature
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