Alkaline Phosphatase: Keeping the Peace at the Gut Epithelial Surface Shipra Vaishnava, Lora V. Hooper  Cell Host & Microbe  Volume 2, Issue 6, Pages 365-367 (December 2007) DOI: 10.1016/j.chom.2007.11.004 Copyright © 2007 Elsevier Inc. Terms and Conditions

Figure 1 IAP Is Part of a Negative Feedback Loop that Senses LPS and Activates a Detoxification Mechanism that Maintains Homeostasis at the Gut Epithelial Surface Intestinal alkaline phosphatase (IAP) is expressed under the control of LPS from the normal microbiota. The enzyme localizes to the apical brush border of intestinal epithelial cells and removes phosphates from glutamines in the LPS lipid A moiety. Unlike intact LPS, dephosphorylated LPS fails to activate MyD88-dependent TLR signaling that promotes proinflammatory responses including neutrophil recruitment. Although TLRs are depicted as having an epithelial localization, the cellular origin of the TLR signaling in this model has not yet been established. (Illustration courtesy of Chris Etheredge.) Cell Host & Microbe 2007 2, 365-367DOI: (10.1016/j.chom.2007.11.004) Copyright © 2007 Elsevier Inc. Terms and Conditions