NATURAL AND SYNTHETIC THYMIC PEPTIDES AS THERAPEUTICS FOR IMMUNE DYSFUNCTION

Natural thymic peptides have been isolated from calf thymus by mild ac id extraction. Pharmaceutical containing natural peptides (Thymalin(R) ) was put into practice as immunocorrector. One of the immunomodulator y molecules (L-Glu-L-Trp) has been isolated from Thymalin by reversed- phase high performance liquid chromatography. Pharmaceutical containin g this agent (Thymogen(R)) was designed on the base of synthesized dip eptide. A novel immunomodulatory dipeptide was synthesized and termed Vilon(R). Both natural and synthetic pharmaceuticals activated T-cell differentiation, T-cell recognition of peptide-MHC complexes, induced the changes in intracellular composition of cyclic nucleotides and cyt okine [interleukin (IL-2), interferon (IFN)] excretion of blood lympho cytes. Synthetic dipeptides activated neutrophil chemotaxis and phagoc ytosis. They had no influence on antioxidant response in thymocytes in comparison with natural peptides. Thymalin and Thymogen were used in persons with chronic pathology and immune dysfunction. The results ind icate that thymic peptides participate in the regulating mechanisms of inflammatory processes as cytokine antagonists and show the differenc e between natural and synthetic products. It is important for the drug s designed to prevent immune dysfunction development. (C) 1998 Publish ed by Elsevier Science Ltd on behalf of the International Society for Immunopharmacology.