Process Biochemistry, Vol.50, No.8, 1194-1201, 2015
Paving the way to construct a new vaccine against Escherichia coli from its recombinant outer membrane protein C via a murine model
Pathogenic Escherichia coli (E. coli) is one of the primary pathogens in humans and domestic animals. Outer membrane protein C (OmpC) has previously been demonstrated to be a protective antigen. In this study, the immunogenicity and protection efficacy of the recombinant OmpC (rOmpC) protein was investigated in a mouse model. OmpC from E. coli CVCC 1515 shares a high homology (93-100%) with other Escherichia and Shigella strains. OmpC was expressed in E. coli BL21 (DE3) system, with the average molecular weight of 40 kDa and with the purity of 96%. Immunization of mice with rOmpC triggered an immune response. The titers of anti-rOmpC sera against rOmpC and whole cells were 1:240,000 and 1:27,000, respectively. rOmpC provided a high level of immunogenicity to protect mice against E. coli infection and cross-protection against Shigella strains. The anti-rOmpC sera induced the phagocytic activity of neutrophils against E. coli. The survival ratios of mice immunized with rOmpC and PBS were 50% and 20%, respectively, 72 h post challenge with E. colt CVCC 1515. rOmpC also supplied partial protection against the oral infection of E. coli CICC 21530. Based on these findings, rOmpC is a potential candidate to be a vaccine against E. coil infections. (C) 2015 Elsevier Ltd. All rights reserved.