Interferon-gamma-enhanced Of Immunosuppression Mediated By Adipose Stem Cells With Interferon-gamma

Objective:Adipose stem cells (Adipose -derived stem cells, ADSCs) can differentiate into bone cells, cartilage cells, smooth muscle cells, myocardial cells and nerve cells. Adipose. derived stem cells have more broad application prospects than bone marrow mesenchymal stem cells in tissue engineering because of the charactedstics such as easy to obtain, and thus become one of the research hotspots today. Adipose-derived stem cells and mesenchymal stem cells have very similar biological properties, and they are also very close in terms of cell surface marker expression profile.To observe the growth characteristics of human adipose derived stem cells and to test their stem cell features and immunology characters. To investigate the expression of human leukocyte antigen Ⅱ in adipose-derived stem cells and its immunogenicity and immunomodulatory effect, and to explore the specific mechanism. Methods:After isolation and culture, the adipose-derived stem cells were stimulated with interferon-γ, and the expression of human leukocyte antigen Ⅱ was detected by flow cytometry, the expression of indoleamine 2, 3-dioxygenase (IDO) was determined by real-time PCR and western blot. Adipose-derived stem cells were used to stimulate lymphocytes, and the cell proliferation was observed. The lymphocytes were stimulated with phytohemagglutinin (PHA), and then 1×102-1×105 adipose-derived stemcells were added to inhibit the proliferation; meanwhile, adipose-derived stem cells, a third party, at dose of 1×102-1×105 were added to the ongoing two-way mixed lymphocyte reaction, and the cell number was calculated as count perminute. Result:The harvested adipose-derived stem cells had a strong expansion in vitro with "S"shape growth curve. The third generation cells were positive for CD29, CD44, CD90 and human leukocyte antigen Ⅰ, and negative for CD34, CD45, CD31 and human leukocyte antigen Ⅱ. Besides, the lymphocytes had no response induced by allogeneic adipose-derived stem cells. The expression of human leukocyte antigen Ⅱ and indoleamine 2,3-dioxygenase was low in adipose-derived stem cells, but up-regulated with stimulation of interferon-y. Adipose-derived stem cells could not stimulate lymphocyte proliferation, but could inhibit lymphocyte proliferation induced by phytohemagglutinin or allogeneic lymphocytes, and interferon-y was highly expressed in the supernatant of co-culture of adipose-derived stem cells and mixed lymphocytes.Conclusion:The differentiation potential of adipose-derived stem cells used in experiments was confirmed, and they had a weak rejection to the host, which indicates that the adipose-derived stem cells may be a candidate for call treatment and tissue engineering. These results indicate that the adipose-derived stem cells have low immunogenicity and can inhibit cell proliferation of lymphocytes in vitro, and the addition of exogenous interferon-y can enhance the immunosuppressive effects of adipose-derived stem cells.