Immunosuppressive effects of rat mesenchymal stem cells: involvement of CD4+CD25+ regulatory T cells.
BACKGROUND
Recent studies show that mesenchymal stem cells (MSCs) have immunomodulatory properties. They suppress the immune response to alloantigen and modify the proliferation of T cells. CD4+CD25+ regulatory T cells have strong immunomodulatory potential. However, little is known about the effects of rat MSCs (rMSCs) on the development of regulatory T cells.


METHODS
MSCs were obtained from bone marrow of male Sprague-Dawley rats, and co-cultured with CD3+ T cells from allogeneic spleen cells. The proportion of CD4+CD25+ regulatory T cells was analyzed by flow cytometry. To further confirm the immunosuppressive activity of rMSCs, we used MTT assay and flow cytometry of CD3+ T cells to investigate the proliferative responses of CD3+ T cells to mitogenic stimuli. Enzyme-linked immunosorbent assay was performed to detect alterations of the cytokines TNF-alpha, TGF-beta and IL-10.


RESULTS
The proliferation of CD3+ T cells decreased when co-cultured with rMSCs, and the degree of inhibition was concentration-dependent. The percentage of CD4+CD25+ regulatory T cells increased when CD3+ T cells were co-cultured with different concentrations of rMSCs. The levels of pro-inflammatory cytokine (TNF-alpha) decreased while anti-inflammatory (TGF-beta, IL-10) cytokines increased in mixed lymphocyte reaction.


CONCLUSIONS
rMSCs inhibit allogeneic T cell proliferation in mixed cell cultures. This immunosuppressive effect seems to be mediated by inducing the generation of CD4+CD25+ regulatory T cells and soluble factors.
Ye
Zhou
Z
Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
Wang
Yan
Y
Xie
Hai-Yang
HY
Zheng
Shu-Sen
SS
D000818:Animals; D017252:CD3 Complex / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D007108:Immune Tolerance / Q000276:immunology*; D016753:Interleukin-10 / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000166:cytology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D017252:CD3 Complex; D015704:CD4 Antigens; D053645:Interleukin-2 Receptor alpha Subunit; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10