{alpha}4{beta}7 integrin: beyond T cell trafficking

Integrins and chemokines are critical for immune cell recruitment to tissue under homeostatic and pathological conditions.1 The heterodimeric integrin α4β7, expressed on T cells, specifies the recruitment of T cells to the intestinal mucosa upon its interaction with its ligand MAdCAM-1.1 Intestinal specificity is imprinted in T cells via upregulation of α4β7 integrin upon their interaction with CD103 dendritic cells (DCs) in the mesenteric lymph node when their cognate antigen is being presented by the major histocompatibility complex.2 The vitamin A metabolite retinoic acid (RA), produced by CD103 DCs via the enzyme retinaldehyde dehydrogenase 2 (encoded by Aldh1a2 gene), acting on T cells plays a critical role in this intestinal imprinting,3 and DCs with this capacity can be identified by an assay that detects this enzymatic activity (ALDE+).4 Pharmacological intervention in tissue-specific recruitment of T cells has the...
Source: Gut - Category: Gastroenterology Authors: Tags: Commentary Source Type: research