Characterization of the enterobactin-specific antibodies induced by a novel enterobactin conjugate vaccine.

In this study, we aimed to develop an innovative Ent conjugate vaccine that can induce high level of antibodies directed against Ent, and to provide solid evidence demonstrating siderophore-binding capacity of Ent-specific antibodies. Using a simple method, we successfully conjugated purified Ent to different carriers including keyhole limpet hemocyanin (KLH), bovine serum albumin, and CmeC, a vaccine candidate for Campylobacter control. Subcutaneous immunization of rabbits with the KLH-Ent conjugate triggered strong systemic IgG immune response with up to 16,384 fold increase in IgG titer directed against whole conjugate and up to 4,096 fold increase in the level of specific anti-Ent IgG. To evaluate the binding ability of Ent-specific IgG to the Ent derivatives present in vivo, various Ent derivatives were chemically synthesized and a unique ELISA method was developed. The Ent-specific IgG also displayed exceptional reactivity to ferric Ent, linear trimer of Ent, and different salmochelins. Growth assays further demonstrated the Ent-specific antibodies significantly inhibited Ent-dependent growth of Campylobacter spp. and E. coli Collectively, this study reports an efficient method to prepare new type of Ent conjugate vaccines for inducing high level of Ent-specific antibodies, which can bind to various Ent derivatives and display lipocalin-like bacteriostatic feature.Importance Ent-mediated high affinity iron acquisition is a universal and critical contributor for Gram-neg...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research