Low stimulation of peripheral lymphocytes, following in vitro application of Emdogain

Fast tissue regeneration after therapeutic manipulations is a central problem of periodontology, oral surgery and trauma of the periodontal tissues, including bone. Several products, which augment tissue regeneration, have been manufactured and assayed in clinical practice with positive results. Emdogain is a recent addition in this field, as a tissue-regenerating product. The substance is a derivative of amelogenin, obtained from porcine embryonic tissues. At the present time, it is not known whether the substance can induce a local (due to the uptake of the substance) or systemic immune response. The aim of the present study was to evaluate, in vitro, the ability of Emdogain to influence, in vitro, the immune system. Peripheral blood lymphocytes, isolated for 10 healthy donors, were cultured in the presence of various concentrations of the substance, in order to determine the rate of cell proliferation, the expression of surface antigens and the production of cytokines and immunoglobulins. Under our experimental conditions, Emdogain produced a slight increase of the proliferation of lymphocytes, restricted to the CD25 (IL-2 receptor) fraction of the CD4 positive T-lymphocytes, and a concomitant decrease of CD19 positive B-lymphocytes. Other cell fractions (CD8 positive T-cells, B-cells and NK-cells) were not affected. Under our conditions too, immunoglobulin and cytokin (IL-2 and IL-6) production was not modified, even after a 3-day application of concentrations much higher than those used in clinical practice. Our data suggest that Emdogain slightly induce an immune response, restricted to the activated fraction of CD4 T-lymphocytes in vitro.