[A preliminary study on the biological characteristics and function of exosomes derived from dendritic cells].
OBJECTIVE
To establish a method for isolating exosomes from dendritic cells (DC), and to analyse its biological characteristics and function in antitumor immunity.


METHODS
Immature DCs (im-DC) from human peripheral blood mononuclear cells were loaded with the antigen of K562 tumor cells, then exosomes were secreted from imDC and lipopolysaccharide (LPS) induced mature DC (mDC). The exosomes from imDC and mDC were isolated separately by ultracentrifugation and ultrafiltration. The exosomes diameter was determined, their profile was observed by electron microscope, and the surface molecules were detected by Western blot. To analyse the effect of exosomes on antitumor immunity, the proliferation, IFN-gamma expression, CD69 up-regulation and cytotoxicity of antigen-specific T cells were measured.


RESULTS
Exosomes were small flattened sphere vesicles with an average diameter of 72.3 nm and expressed CD80, CD86, HLA-DR, FasL, CD54 and MFG-E8 molecules. As compared to immature exosomes, exosomes from mDC were proved to express more CD80 and less MFG-E8, to be more potent for inducing antigen-specific T cells proliferation and immunity respond in vitro: at its optimum concentration, the absorption value of T cell proliferation test was 0.50 +/- 0.01, CD69 was up-regulated and (13.4 +/- 5.8)% of T cells was in proliferating, (22.8 +/-2.4)% of T cells expressed IFN-gamma, and (21.3 +/-8.6)% of tumor cells were killed.


CONCLUSIONS
A simple and quick method to isolate and analyse exosomes is established. The exosomes can induce antitumor immunity respond.
Ren
Ya-na
YN
Molecular Immunology Laboratory of East China Normal University, Blood Engineering Laboratory of Shanghai Blood Center, Shanghai 200051, China.
Fan
Hua-hua
HH
Gao
Li
L
Nie
Xiao-xuan
XX
Yang
Jie
J
Liu
Yan
Y
Gao
Feng
F
D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D055354:Exosomes / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology