Dalmasso G, Nguyen HT, Charrier-Hisamuddin L et al. Am J Physiol Gastrointest Liver Physiol 2010;299:G687–96.
In this study, Dalmasso and colleagues showed that the PepT1 (SLC15A1) di- and tri-peptide transporter can transport an immune-active bacterial component, l-Ala-γ-d-Glu-meso-diaminopimelic acid (Tri-DAP), into intestinal epithelial cells, with subsequent activation of nuclear factor-κB and interleukin-8 production.
The PepT1 peptide transporter is highly expressed in the small bowel and is induced in chronic inflammation in the colon. PepT1 is of relevance to IBD, with recent work demonstrating upregulation of PepT1 in IBD and association with a genetic polymorphism in IBD [1,2]. Dalmasso and colleagues investigated the role of PepT1 in the transport of l-Ala-γ-d-Glu-meso-diaminopimelic acid (Tri-DAP), a peptide released during bacterial peptidoglycan degradation. Tri-DAP is recognized by NOD1, an intracellular innate immune receptor.