Evasin-displaying lactic acid bacteria bind different chemokines and neutralize CXCL8 production in Caco-2 cells

Chemokines are key signals in the immune system and play an important role as proinflammatory mediators in the pathology of inflammatory bowel disease and colorectal cancer, making them an important target for therapy. Recombinant lactic acid bacteria (LAB) were engineered to bind CC and CXC chemokines by displaying chemokine-binding proteins evasin-1, evasin-3 and evasin-4 on their surface. Evasin genes were cloned into lactococcal surface display vector and overexpressed in L. lactis NZ9000 and NZ9000ΔhtrA in fusion with secretion signal and surface anchor. Evasin-displaying bacteria removed from 15% to 90% of 11 different chemokines from the solution as determined with ELISA and Luminex multiplexing assays, whereby L. lactis NZ9000ΔhtrA proved more efficient. Lactobacillus salivarius ATCC 11741 was coated with L. . lactis-expressed evasin fusion protein, and its ability to bind chemokines was also confirmed. Evasin-3-displaying L. lactis removed 76.0% of IL-1β-induced CXCL8 from the supernatant of Caco-2 epithelial cells. It also prevented secretion of CXCL8 from Caco-2 cells in a time-dependent manner when added before induction with IL-1β. Evasin-displaying LAB have the ability to bind multiple chemokines simultaneously and exert synergistic activity. This innovative treatment approach therefore has the potential for mucosal therapy of inflammatory bowel disease or colorectal cancer.