title: Cellular and nerve fibre catecholaminergic thymic network: steroid hormone dependent activity.
abstract: The thymus plays a critical role in establishing and maintaining the peripheral T-cell pool. It does so by providing a microenvironment within which T-cell precursors differentiate and undergo selection processes to create a functional population of major histocompatibility complex-restricted, self-tolerant T cells. These cells are central to adaptive immunity. Thymic T-cell development is influenced by locally produced soluble factors and cell-to-cell interactions, as well as by sympathetic noradrenergic and endocrine system signalling. Thymic lymphoid and non-lymphoid cells have been shown not only to express beta- and alpha(1)- adrenoceptors (ARs), but also to synthesize catecholamines (CAs). Thus, it is suggested that CAs influence T-cell development via both neurocrine/endocrine and autocrine/paracrine action, and that they serve as immunotransmitters between thymocytes and nerves. CAs acting at multiple sites along the thymocyte developmental route affect T-cell generation not only numerically, but also qualitatively. Thymic CA level and synthesis, as well as AR expression exhibit sex steroid-mediated sexual dimorphism. Moreover, the influence of CAs on T-cell development exhibits glucocorticoid-dependent plasticity. This review summarizes recent findings in this field and our current understanding of complex and multifaceted neuroendocrine-immune communications at thymic level.
authors.affiliation: Immunology Research Centre Branislav Janković, Institute of Virology, Vaccines and Sera Torlak, Belgrade, Serbia. Gordana.Leposavic@pharmacy.bg.ac.rs
authors.forename: G
authors.initials: G
authors.lastname: Leposavić
authors.forename: I
authors.initials: I
authors.lastname: Pilipović
authors.forename: M
authors.initials: M
authors.lastname: Perišić
mesh_terms: D000320:Adrenergic Fibers / Q000378:metabolism*; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D002450:Cell Communication; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006801:Humans; D008297:Male; D011941:Receptors, Adrenergic / Q000378:metabolism*; D012727:Sex Characteristics; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000276:immunology / Q000294:innervation* / Q000378:metabolism*
chemical_list: D002395:Catecholamines; D012739:Gonadal Steroid Hormones; D011941:Receptors, Adrenergic