Design and evaluation of a multi-epitope assembly peptide vaccine against Acinetobacter baumannii infection in mice

Abstract

Aim: To design a multi-epitope assembly peptide (MEP) of Acinetobacter baumannii and evaluate its immunogenicity and protective immunity in Balb/c mice. Methods: The T- and B-cell epitopes of outer membrane proteins FilF and NucAb from A. baumannii were predicted and identified by using bioinformatics software and immunological tests. Peptides with predicted high adhesin probability from A. baumannii Ata protein was used as the backbone, two B-cell epitopes and one CD4+ T-cell epitope from FilF were linked to the N-terminal of the backbone, and two B-cell epitopes and one CD4+ T-cell epitope from NucAb were linked to the C-terminal of the backbone to construct the MEP. The gene of the MEP was expressed in E. coli BL21, and its immunogenicity and protective efficacy were evaluated in Balb/c mice. Results: A recombinant protein with a molecular weight of about 37 kDa was successfully purified, and was identified as the recombinant multi-epitope assembly peptide (rMEP) by Western blot analysis. The animal tests showed that the rMEP was highly immunogenic and could induce high levels of IgG antibody and provide potent protection (88.9%) against lethal doses of A. baumannii. Conclusions: This is the first report of the design and study of a rMEP vaccine against A. baumannii. The results indicate that the rMEP is a promising vaccine candidate for the control of infections caused by A. baumannii.