title: [Study of immunomodulatory function of exosomes derived from human umbilical cord mesenchymal stem cells].
abstract: OBJECTIVE
  To investigate the immumodulation ability of exosomes secreted from human umbilical cord-derived mesenchymal stem cells (hUC-MSCs).
  
  
  METHODS
  hUC-MSCs were isolated and cultured.Exosomes were isolated from the culture media of the third-generation hUC-MSCs. The expression of specific surface marker CD9 and CD81 were detected by Western blot, and the concentration of hUC-MSCs exosomes(hUC-MSCs-ex) was evaluated by BCA assay. CD3/CD28-stimulated peripheral blood mononuclear cells(PBMCs) from healthy donor were co-cultured with different concentration of hUC-MSCs-ex for 72 h. The percentage of Th17 and Treg cells and the proliferation of CD4⁺ and CD8⁺ T cells were detected by flow cytometry. ELISA was used to test the level of IFN-γ, IL-6, TNF-α and TGF-β1.
  
  
  RESULTS
  hUC-MSCs-ex inhibited the proliferation of CD4⁺ and CD8⁺ cells obviously,and increased the proportion of CD4⁺ CD25⁺ FoxP3⁺ Treg cells, with high expression of CD81 and CD9. After CD3/CD28 monoclonal antibody stimulated, the percentage of CD45⁺ CD4⁺ Ki67⁺ and CD45⁺ CD8⁺ Ki67⁺ cells were 85.3% ± 5.6% and 72.6% ± 6.3%, respectively. Meanwhile, the level of TGF-β1 were elevated and the level of IFN-γ, IL-6 and TNF-α were decreased (P<0.05).
  
  
  CONCLUSIONS
  hUC-MSCs-ex has the immunomodulatory functionin vitro, which could be a new therapeutic agent for the treatment of immune disorders.
authors.affiliation: State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Jinsong
authors.initials: J
authors.lastname: Wang
authors.forename: Muyun
authors.initials: M
authors.lastname: Liu
authors.affiliation: Shenzhen Beike Cell Engineering Research Institute, Shenzhen 518057, China, Email: huxiang@beike.cc.
authors.forename: Xiang
authors.initials: X
authors.lastname: Hu
authors.affiliation: Email: xufeili@vip.163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
mesh_terms: D018414:CD8-Positive T-Lymphocytes; D018920:Coculture Techniques; D055354:Exosomes; D005434:Flow Cytometry; D006801:Humans; D007165:Immunosuppression Therapy; D015850:Interleukin-6; D007963:Leukocytes, Mononuclear; D059630:Mesenchymal Stem Cells; D050378:T-Lymphocytes, Regulatory; D058504:Th17 Cells; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; D014470:Umbilical Cord
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; C439524:TNF protein, human; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha