[Age-dependent sensitivity of human lymphocytes to the immunomodulating effect of bovine and human diacetyl splenopentin].

Both newborns and elderly adults suffer from physiological immunodeficiency. The molecular mechanisms responsible for this immunodeficiency are currently investigated by many laboratories. The aim of our investigations was to answer the question wether these immunodeficiencies could be influenced by bovine and/or human diacetyl-splenopentin, two newly developed immunostimulatory peptides. The in vitro effects of these peptides were studied using the lymphocyte transformation test and the detection of the immunoglobulin production (IgG, IgM) by lymphocytes. Thymopentin was used as standard for these investigations. The age dependence of lymphocyte sensitivity was estimated using cells of the following groups of blood donors: newborns (cord blood); young donors (20-30 yr); old donors (over 70 yr). All peptides were shown to have the same effects. The stimulated lymphocyte proliferation (PHA, anti-CD3) was inhibited in young donors and further increased in old donors. There was no influence in the case of newborns. The biological activity of human diacetyl-splenopentin was shown to be higher in comparison with bovine diacetyl-splenopentin.