Role of Vitamin A in T Cell Homing to the Gut
Vitamin A supplementation significantly reduces infant mortality in developing countries, largely by reducing persistent diarrhea that is often aggravated by malnutrition. Vitamin A contributes to maintaining the integrity of mucosal epithelia and enhancing IgA responses in the gut. Recently, we found that vitamin A is essential for the homing of T cells to gut tissues. Retinoic acid (RA), an oxidative metabolite of retinol, even at 0.1 to 1 nM, enhances the expression of the gut-homing receptors, the integrin α4β7 and the chemokine receptor CCR9, on T cells upon activation in vitro, and grants them the capacity of migrating to the small intestine. The RA receptors RARα and/or β are involved in this effect. Dendritic cells of the gut-associated lymphoid organs, Peyer's patches and mesenteric lymph nodes, express the RAproducing enzymes, and can produce RA from retinol (vitamin A). Antigenic stimulation of T cells with these dendritic cells enhances α4β7 expression on T cells, depending on the production of RA by dendritic cells and its binding to RAR in T cells. Therefore, vitamin A-derived RA imprints T cells with the gut-homing specificity. Possible roles of this effect in the development of diseases and possible future treatments for them are discussed.
No Supplementary Data
No Article Media
Document Type: Research Article
Publication date: November 1, 2006
More about this publication?
- Current Immunology Reviews publishes frontier reviews on all the latest advances in clinical immunology. The journal's aim is to publish the highest quality review articles dedicated to clinical research in the field. The journal is essential reading for all researchers and clinicians in clinical immunology.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Ingenta Connect is not responsible for the content or availability of external websites