Le rôle central du thymus dans l'éducation des cellules T aux principes neuroendocrines

The thymus is the site of expression of peptides belonging to the neurohypophysial peptide family. The classical model of neurosecretion established by the Scharrers for the hypothalamo-neurohypophysial axis howver cannot be applied to characterize the secretory pathways of neurohypophysial-related peptides in the thymic epithelium. The novel model of cryptocrine signaling has been proposed by John W. Funder to describe the molecular relationships between fixed epithelial cells and migratory differentiating cells. In the thymus, cryptocrine signaling is further closely associated to the presentation of the 'self' molecular structure by major histocompatibility complex-derived proteins to developing T cells. Altogether, the model of the thymic repertoire of neuroendocrine self-antigens transposes to the molecular level the dual physiological role of the thymus in T cell negative and positive selection. Moreover, this model should also contribute to a better understanding of the molecular mechanisms underlying the establishment of central T-cell self-tolerance to neurodocrine functions.