Mesenchymal Stem Cells Derived from Dental Pulp Inhibit T Cell Proliferation

Method: To investigate whether DP-MSCs exert an inhibitory effect on immune response during allostimulation, we stimulated peripheral blood mononuclear cells, obtained from healthy volunteers, in mixed lymphocyte culture (MLC), and evaluated cell proliferation either in the absence or in the presence of third-party allogenic DP-MSCs for 7days. The immunosuppressive function of DP-MSCs was then tested by coculturing CD3/CD28-stimulated allogenic CD8+T cells with or without DP-MSCs for 3 days. For dose-response experiments, allogenic CD8+T cells were incubated with various numbers of DP-MSCs. T-cell proliferation was analyzed on a flow cytometer.

Result: The presence of DP-MSCs led to significant suppression of T cell proliferation in response to allogeneic stimulation and CD3/CD28 Ab-coated beads, demonstrating that the DP-MSCs effect on T cells in an MLC is not mediated via its action on the APCs (Antigen Presenting Cells). DP-MSCs inhibit allogenic stimulated proliferation T cells in a dose-dependent manner.

Conclusion: The experiments confirmed the dose-dependent inhibitory effect of DP-MSCs on lymphocyte proliferation by allogenic stimulation. The mixed lymphocyte culture test offers a simple method for characterization and verification of the immunosuppressive potential of DP-MSC, being prepared for clinical use. The immunomodulatory activity makes DP-MSCs suitable for suppression of T-cell mediated reaction in the setting of allogenic pulp tissue engineering.