Ps-14: Treatment of Mesenchymal Stem Cells (MSCs) with Peptidoglycan-LPS As TLR2,4 Agonist and Zymozan TLR2,6 As Augments Apoptose in Activated T Cells Time Dependently

Darabi E *, Delirezh N , Mokarizadeh A , Morshedi A , Tukmechi A ,


Objective: Adult bone marrow-derived mesenchymal stem cells (MSCs) are under study as therapeutic delivery agents that assist in the repair of damaged tissues. MSCs are recruited to sites of stress or inflammation to fulfill their repair function. The differential expression of TLRs on MSCs might contribute to the discrete changes in the function of MSCs. MSCs have been shown to suppress the activity of a broad range of immune cells, including T cells. In the present study invested the coestimolatory effect of peptidoglycanlipopolysacarid as TLR2, 4 agonist and zymozan as TLR2/6 on apoptosis induction in activated T cells by mouse mesenchymal stem cells (MSCs). Materials and Methods: MSCs were isolated from bone-marrow of mice and treated with peptidoglycan- LPS (10 ng/ml) as TLR2/4-agonist and zymozan (25 μg/ ml) as TLR2/6 agonist for different times (1 hour and 12 hours). Treated cells were co-cultured with PHA-activated splenic mononuclear cells (MNCs) for 72 hours at 37°C in a humidified 5% CO2. After 72 hours, the percentage of apoptosis in activated T cells was assessed by anti-CD3PE, Acridin-Orang/PI staining in flow cytometry. Results: We found that short term exposure (1h) of MSCs to TLR2, 4 agonist (peptidoglycan-LPS) and TLR2, 6 agonist (zymozan) con significantly increase of apoptosis in activated T cells in comparison to control group. Conclusion: Our findings suggested that different exposure terms of MSCs to combination TLR2/4 agonist,and TLR2/6 agonist differently affected apoptotic activity of MSCs against activated T cells; so, the results can be applied potently for more successful MSC-based therapy programs.