A proliminary study on the regulatory function of human plasma exosomes-like vesicles.
- Author:
Yue-E MA
1
;
Ya-Na REN
;
Jie YANG
;
Dan LI
;
Chen-Zhi GUO
;
Juan GUO
;
Bing NI
;
Hua-Hua FAN
Author Information
- Publication Type:Journal Article
- MeSH: CD4-Positive T-Lymphocytes; immunology; Cells, Cultured; Exosomes; Flow Cytometry; Humans; Immunologic Factors; Interleukin-2 Receptor alpha Subunit; Leukocytes, Mononuclear; immunology; T-Lymphocytes, Regulatory; immunology
- From: Chinese Journal of Hematology 2010;31(6):376-380
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo identify the exosomes-like vesicles from the plasma and study their biologic characteristics and regulatory effect.
METHODSThe exosomes-like vesicles were purified from healthy donors plasma with a series of high-speed centrifugations and ultrafiltration. Morphology was identified by transmission electron microscopy and biologic characteristics by Western blot and flow cytometry. CD4(+)T cells and CD4(+)CD25(+)CD127low Treg cells were purified from peripheral blood mononuclear cells (PBMCs) by Magnetic cell sorting. After exosomes-like vesicles cultured with CD4(+)T cells or CD4(+)CD25(+)CD127low Treg cells, cell proliferation and apoptosis were assayed. Phosphorylated β-catenin level in Wnt signaling by phosflow.
RESULTSExosomes-like vesicles from plasma were similar to previously described exosomes in shapes and size and expressed exosome marker proteins CD63 and CD81 as well as the MHC-II molecule, costimulatory molecules CD86 etc. After co-cultured with CD4(+) T cells, exosomes-like vesicles inhibited the proliferation of the T cells in a dose-dependent manner. After Treg cells cultured with exosomes-like vesicles for 14 days, the survival rate of the Treg cells was 57.07%, while that of the control Treg was 30.91%. Frizzled receptors 2, 3, 4and LRP6 gene mRNA expressed (the relative gray value was 48.50, 34.84, 23.85, 49.73) in the Treg cells by RT-PCR, and Wnt molecular expressed in exosomes-like vesicles. After Treg cells co-cultured with exosomes-like vesicles, the MFI of phosphorylated β-catenin decreased (from 20.06 ± 2.99 to 12.41 ± 2.08), and the expression of Bcl-2 mRNA was upregulated significantly (the relative gray value from 0.45 to 84.97).
CONCLUSIONSExosomes-like vesicles existed in human plasma and express immune regulatory molecules. They can suppress the proliferation of activated CD4(+) T cells induce their apoptosis and pro-long the survival of natural Treg cells via Wnt signaling pathway.