Abstract:

A multi-epitope vaccine against porcine Escherichia coli infection was designed by means of immunoinformatics to block the adhesion and colonization of enterotoxigenic Escherichia coli(ETEC)strain to intestinal epithelial cells of piglets to prevent piglet diarrhea.The B cell epitopes,Th cell epitopes,and CTL cell epitopes of adhesin 987P and F18 of ETEC were predicted by immunoinformatics tools,and the dominant epitopes were screened.The dominant epitopes were linked to the multi-epitope vaccine by Linker according to three different epitopes,and their antigenicity,allergenicity,and tertiary structure were predicted.The results showed that seven dominant epitopes were selected.The antigenicity test showed that the antigenicity of fusion peptide Ⅰ,fusion peptide Ⅱ,and fusion peptide Ⅲ were 1.069 2,1.089 2,and 1.050 7,respectively.The results of the allergy test showed that the fusion peptides Ⅰ,Ⅱ,and Ⅲ had no allergen.Based on the three-dimensional modeling of the fusion peptides,the results showed that the structural epitopes were well exposed,easy to bind to antibodies,and met the requirements of epitope design in protein molecular conformation.In addition,according to different rules,we arranged three kinds of amino acid sequences,which were inversely translated into nucleotide sequences according to the codon preference of lactic acid bacteria and inserted into pET28a plasmids to obtain pET28a-9F1,pET28a-9F2,and pET28a-9F3 plasmids respectively.

Key words: Escherichia coli, Multi-epitope vaccine, Immunoinformatics, 987P, F18

CLC Number: 

• S852.6