Background & Aims : Mesenchymal stem cells (MSCs) are adult cells which are identified as non-hematopoietic and pluripotent stem cells. Specific stimulation of toll like receptors on the surface of mesenchymal stem cells could change immune responses of these cells into the pre or anti-inflammation phenotype. The aim of this study was to evaluate the effect of peptidoglycan-lipopolysaccharide on the polarization of stem cells into the anti inflammation phenotype and apoptosis induction in T cells.

  Materials & Methods : MSCs were isolated from the femoral and tibial bone marrow and re-suspended in DMEM media, and kept in 5% CO₂ incubator at 37 ° C for 24 hours. After that the cell concentration reached to 70 % treated with toll like receptor’s agonist with high (10 ng/ml) and low (5 ng/ml) doses for 1 and 12 hours. Then supernatant of cell culture flask were collected for nitric oxide measurement. Apoptosis percentage in T cells was assayed by flowcytometry in the presence of Acridine orange/ propidium iodide (AO/PI).

  Result : The percentage of apoptosis in activated T cells significantly (P<0.05) was higher in long term (12 h) and low dose (5 ngr/ml) treatment with TLR4 agonist than the control. Also, the finding indicated that the nitric oxide production significantly (P<0.05) was higher at short term (1 h) and high dose (10 ngr/ml) of TLR agonist in comparison to the control.

  Conclusion : It should be concluded that the amount of agonist and duration of treatment in stem cells can affect the apoptosis activity and nitric oxide production in MSCs.

  SOURCE: URMIA MED J 2014: 24(12): 1004 ISSN: 1027-3727