Interleukin-23: Linking Mesenteric Lymph Node Dendritic Cells With Th1 Immunity in Crohn's Disease  Maria Rescigno, Iliyan D. Iliev  Gastroenterology  Volume 137, Issue 5, Pages 1566-1570 (November 2009) DOI: 10.1053/j.gastro.2009.09.029 Copyright © 2009 AGA Institute Terms and Conditions

Figure 1 Human MLN are populated by conventional (cDC) and pDC. In healthy individuals, CD103+ cDC express CCR7, migrate from the LP to the MLN, where they release RA and TGF-β, and are able to prime tolerogenic T-cell responses. In contrast, CD103− DC produce IL-12 upon stimulation and are responsible for Th1 cell induction. cDC from MLN of UC patients, which produce IL-12 and IL-10 but not IL-23, are also able to induce Th1 responses, but at a lesser extent. UC has been further characterized with prevalent Th17 and Th2 infiltration in the LP. In MLN of CD patients, cDC outnumber pDC. In addition, activated cDC release IL-12 and IL-23 and are highly prone to prime inflammatory Th1 responses, with presumably concomitant reduction of Treg cell development. This correlates with significant Th1 and Th17 infiltration in the LP of CD patients. What drives the development of Th17 cells remains to be understood. Red bar, Th1/Th17 prevalence in the LP; NC, normal controls; UC, ulcerative colitis; CD, Crohn's disease. Gastroenterology 2009 137, 1566-1570DOI: (10.1053/j.gastro.2009.09.029) Copyright © 2009 AGA Institute Terms and Conditions