Neuropeptides as therapeutic approach to autoimmune diseases.

ABSTRACT

Because there are no particular molecular signatures of self, autoimmunity is the inevitable evolutionary price of being able to make effective responses against a wide variety of pathogens by the immune system. Without the various phenomena referred to as immune tolerance, the organism would surely self-destruct. Considerable evidence suggests that various endogenous neuropeptides play a major role in the education of our immune system to be self-tolerant. The fact that neuropeptides regulate various layers involved in maintenance of tolerance, including regulation of the balance between pro-inflammatory and anti-inflammatory responses and between self-reactive Th1/Th17 cells and regulatory T cells, makes them attractive candidates for the development of new therapies for the treatment of autoimmune disorders. Here we use the vasoactive intestinal peptide of a prototype of immunomodulatory neuropeptide to review the most relevant data found for other neuropeptides with similar characteristics, including melanocyte-stimulating hormone, urocortin, adrenomedullin, neuropeptide Y, cortistatin and ghrelin. We also evaluate the challenges that must be overcome before achieving their clinical application and offer our opinion on how a physiologically functional neuropeptide system contributes to general health.