The Discovery of the Brain Immunomodulators

Abstract

The term “thymosin” was introduced by Goldstein et al. (48,49) and Hooper et al. (50) and was used for a biologically active fraction isolated from bovine thymus tissue (51). Among the members of Tβ-thymosin (Tβ) family, Tβ₄ is the major peptide in different cells of human, calf, rat, or mouse. Thymosin β₄ (Tβ₄) has been reported to induce terminal deoxynucleotidyl transferase activity in vivo and in vitro, inhibit the migration of guinea pig peritoneal macrophages, stimulate the hypothalamic secretion of luteinizing hormone-releasing hormone (51), or induce phenotypic changes in the Molt-4 leukemic cell line (52). Although several biological activities of Tβ₄ have been reported in the literature, its physiological role and biochemical mechanisms of action on the brain and immune cells still remain unknown.