Development and evolutionary aspects of thymic T cell education to neuroendocrine self.
Thymic epithelial cells, including nurse cells (TECs/TNCs), from various species synthesize neuroendocrine-related precursors belonging to neurohypophysial, tachykinin and insulin hormone families. The thymic repertoire of neuroendocrine-related polypeptides illustrates at the molecular level the paradoxical role of the thymus in both T cell positive and negative selection. On the one hand, these precursors are a source of signals which interact with neuroendocrine-type receptors expressed by target pre-T cells according to the cryptocrine type of cell-to-cell signaling. On the other hand, the same precursors constitute a source of self-antigens which are presented to pre-T cells by the thymic major histocompatibility complex system. Basically, the model of thymic T cell education to neuroendocrine self was established by the identification in TECs/TNCs of immunoreactive (ir) oxytocin as the self-antigen of the neurohypophysial family. Nevertheless, through the expression in TECs/TNCs of ir-neurokinin A and ir-insulin-like growth factor-II, the model also applies to the tachykinin and insulin hormone families.
Geenen
V
V
Department of Endocrinology and Molecular Medicine, Liège University Medical School, Tilman, Belgium.
Benhida
A
A
Kecha
O
O
Achour
I
I
Vandermissen
E
E
Vanneste
Y
Y
Goxe
B
B
Martens
H
H
D000818:Animals; D000941:Antigens / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D019143:Evolution, Molecular; D006801:Humans; D008285:Major Histocompatibility Complex / Q000235:genetics / Q000276:immunology; D009481:Neurophysins / Q000502:physiology*; D009490:Neurosecretory Systems / Q000276:immunology* / Q000378:metabolism; D010121:Oxytocin / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism; D017634:Self Tolerance; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology*
D000941:Antigens; D001324:Autoantigens; D009481:Neurophysins; D011498:Protein Precursors; D010121:Oxytocin