dr n. biol. Jolanta Artym, prof. dr hab. n. biol. Michał Zimecki
Key words: thymus, thymic hormons, thymosin, immunotherapy
Abstract
The thymus, by virtue of hormonal secretion, fulfils a role of central organ in the immune system, steering processes of T-cell maturation. Thymic hormones are peptides or proteins of a multidirectional (pleiotropic) immunoregulatory action. They regulate activity of not only T cells but also natural killer (NK) cells, dendritic cells (DC) and macrophages. The hormones bind to TLR-9 membrane receptors and activate intracellular signaling pathways leading to release of numerous cytokines of pro- and anti-inflammatory properties. Thanks to such regulatory actions they adjust the immune response to ongoing requirements of organisms by intensifying it during defense against pathogens or tumors, but weakening the response in a sustained inflammation, e.g. of autoaggressive basis. Active hormones were isolated for the first time 40 years ago from calf thymuses. Until now their corrective, immune properties have been confirmed in many laboratory, preclinical and clinical studies. At present, in the clinical practice, both purified thymus extracts (mainly of calf’s origin), containing several active peptides, as well as single synthetic peptides, identical with native ones, are applied. The preparations are administered enterally or parenterally and possess a status of diet supplements or registered therapeutics. They are safe for patients and do not create any serious adverse effects. One of the synthetic thymus peptides – thymosin alpha 1 (Ta1) has a status of a prescriptive drug and is commercially available in more than 30 countries with a particular indication for use in chronic viral liver inflammation, solid and blood tumors.
In the article various clinical application of thymus hormones was reviewed, with a particular case of Ta. The presently known mechanism of action of these hormones was also described.
