title: Exosomes derived from atorvastatin-modified bone marrow dendritic cells ameliorate experimental autoimmune myasthenia gravis by up-regulated levels of IDO/Treg and partly dependent on FasL/Fas pathway.
abstract: BACKGROUND
  Previously, we have demonstrated that spleen-derived dendritic cells (DCs) modified with atorvastatin suppressed immune responses of experimental autoimmune myasthenia gravis (EAMG). However, the effects of exosomes derived from atorvastatin-modified bone marrow DCs (BMDCs) (statin-Dex) on EAMG are still unknown.
  
  
  METHODS
  Immunophenotypical characterization of exosomes from atorvastatin- and dimethylsulfoxide (DMSO)-modified BMDCs was performed by electron microscopy, flow cytometry, and western blotting. In order to investigate whether statin-DCs-derived exosomes (Dex) could induce immune tolerance in EAMG, we administrated statin-Dex, control-Dex, or phosphate-buffered saline (PBS) into EAMG rats via tail vein injection. The tracking of injected Dex and the effect of statin-Dex injection on endogenous DCs were performed by immunofluorescence and flow cytometry, respectively. The number of Foxp3(+) cells in thymuses was examined using immunocytochemistry. Treg cells, cytokine secretion, lymphocyte proliferation, cell viability and apoptosis, and the levels of autoantibody were also carried out to evaluate the effect of statin-Dex on EAMG rats. To further investigate the involvement of FasL/Fas in statin-Dex-induced apoptosis, the underlying mechanisms were studied by FasL neutralization assays.
  
  
  RESULTS
  Our data showed that the systemic injection of statin-Dex suppressed the clinical symptoms of EAMG rats. These statin-Dex had immune regulation functions in immune organs, such as the spleen, thymus, and popliteal and inguinal lymph nodes. Furthermore, statin-Dex exerted their immunomodulatory effects in vivo by decreasing the expression of CD80, CD86, and MHC class II on endogenous DCs. Importantly, the therapeutic effects of statin-Dex on EAMG rats were associated with up-regulated levels of indoleamine 2,3-dioxygenase (IDO)/Treg and partly dependent on FasL/Fas pathway, which finally resulted in decreased synthesis of anti-R97-116 IgG, IgG2a, and IgG2b antibodies.
  
  
  CONCLUSIONS
  Our data suggest that atorvastatin-induced immature BMDCs are able to secrete tolerogenic Dex, which are involved in the suppression of immune responses in EAMG rats. Importantly, our study provides a novel cell-free approach for the treatment of autoimmune diseases.
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Li
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.|Department of Neurology, The Central Hospital of Taian, Taian, 271000, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xu
authors.affiliation: Central Laboratory, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Long-Tao
authors.initials: LT
authors.lastname: Yue
authors.affiliation: School of Basic Medical Sciences, Jining Health School, Jining, 272000, People's Republic of China.
authors.forename: Xin-Xin
authors.initials: XX
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Cong-Cong
authors.initials: CC
authors.lastname: Wang
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China.
authors.forename: Yan-Bin
authors.initials: YB
authors.lastname: Li
authors.affiliation: College of Basic Medical Sciences, Shandong University of Traditional Chinese Medicine, Jinan, 250355, People's Republic of China.
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Dou
authors.affiliation: Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, People's Republic of China. ruisheng_duan@yahoo.com.
authors.forename: Rui-Sheng
authors.initials: RS
authors.lastname: Duan
mesh_terms: D000818:Animals; D001853:Bone Marrow; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects / Q000648:ultrastructure; D004195:Disease Models, Animal; D055354:Exosomes / Q000502:physiology*; D053222:Fas Ligand Protein / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000378:metabolism*; D008854:Microscopy, Electron; D020720:Myasthenia Gravis, Autoimmune, Experimental / Q000188:drug therapy*; D051381:Rats; D011917:Rats, Inbred Lew; D015398:Signal Transduction / Q000187:drug effects; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects*; D019014:fas Receptor / Q000378:metabolism*
chemical_list: D016207:Cytokines; D053222:Fas Ligand Protein; C491899:Fas protein, mouse; D051858:Forkhead Transcription Factors; C500522:Foxp3 protein, rat; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D019014:fas Receptor