Recruitment of Inflammatory and Immune Cells in the Gut

The recruitment of leukocytes from peripheral blood into the intestine is required for the maintenance of intestinal health and protection from microbial insult. However, during immune-mediated gastrointestinal conditions (e.g., inflammatory bowel disease (IBD), celiac disease), the recruitment process becomes dysregulated. Several families of molecules regulate the influx of these cells into immune sites both during homeostasis and inflammation. Interference with some of these molecules has already shown efficacy in the clinics and antibodies that target the molecules involved have been approved by the FDA for use in IBD. In this chapter, we discuss basic aspects of the diverse families of relevant molecules that mediate the leukocyte adhesion cascade under physiological and inflammatory conditions to relevant immune compartments. Finally, we discuss the translational applications of targeting-specific steps of the leukocyte adhesion cascade for therapeutic purposes in human IBD.