Discovery of an Anti-TNF- 9-mer Peptide from a T7 Phage Display Library for the Treatment of Inflammatory Bowel Disease

Inhibiting TNF-& alpha;-mediated acute inflammation isan effectivetreatment against inflammatory bowel disease. In this study, TNF-& alpha;-basedT7 phage display library screening combined with in vitro and in vivoassays was applied. A lead peptide, pep2 (ACHAWAPTR, K (D) = 5.14 & mu;M), could directly bind to TNF-& alpha;and block TNF-& alpha;-triggered signaling activation. Peptide pep2inhibits TNF-& alpha;-induced cytotoxicity and attenuates the inflammationby decreasing NF-& kappa;B and MAPK signaling activities in a varietyof cells. Furthermore, pep2 attenuated colitis induced by dextransodium sulfate in mice in both prophylactic and therapeutic settings.Moreover, pep2 reduced the phosphorylation of p38, ERK1/2, JNK1/2,p65, and I & kappa;B & alpha; in colonic tissues as well as downregulatedinflammatory genes. And HIS3, TRP5, and ARG9 may be the key aminoacids in pep2 to bind TNF-& alpha; by molecular docking. Collectively,targeting TNF-& alpha; with pep2 can attenuate the inflammation invivo and vitro by inhibiting NF-& kappa;B and MAPK signaling pathways.