Premium
Immunogenicity of recombinant Lactobacillus casei ‐expressing F4 (K88) fimbrial adhesin FaeG in conjunction with a heat‐labile enterotoxin A ( LTAK 63) and heat‐labile enterotoxin B ( LTB ) of enterotoxigenic Escherichia coli as an oral adjuvant in mice
Author(s) -
Yu M.,
Qi R.,
Chen C.,
Yin J.,
Ma S.,
Shi W.,
Wu Y.,
Ge J.,
Jiang Y.,
Tang L.,
Xu Y.,
Li Y.
Publication year - 2017
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.13352
Subject(s) - enterotoxigenic escherichia coli , immunogenicity , bacterial adhesin , enterotoxin , microbiology and biotechnology , heat labile enterotoxin , escherichia coli , recombinant dna , lactobacillus casei , biology , chemistry , antigen , immunology , bacteria , gene , biochemistry , genetics
Aims The aims of this study were to develop an effective oral vaccine against enterotoxigenic Escherichia coli ( ETEC ) infection and to design new and more versatile mucosal adjuvants. Methods and Results Genetically engineered Lactobacillus casei strains expressing F4 (K88) fimbrial adhesin FaeG ( rLpPG ‐2‐FaeG) and either co‐expressing heat‐labile enterotoxin A ( LTA ) subunit with an amino acid mutation associated with reduced virulence ( LTAK 63) and a heat‐labile enterotoxin B ( LTB ) subunit of E. coli ( rLpPG ‐2‐ LTAK 63‐co‐ LTB ) or fused‐expressing LTAK 63 and LTB ( rLpPG ‐2‐ LTAK 63‐fu‐ LTB ) were constructed. The immunogenicity of rLpPG ‐2‐FaeG in conjunction with rLpPG ‐2‐ LTAK 63‐co‐ LTB or rLpPG ‐2‐ LTAK 63‐fu‐ LTB as an orally administered mucosal adjuvant in mice was evaluated. Results showed that the levels of FaeG‐specific serum IgG and mucosal sIgA , as well as the proliferation of lymphocytes, were significantly higher in mice orally co‐administered rLpPG ‐2‐FaeG and rLpPG ‐2‐ LTAK 63‐fu‐ LTB compared with those administered rLpPG ‐2‐FaeG alone, and were lower than those co‐administered rLpPG ‐2‐FaeG and rLpPG ‐2‐ LTAK 63‐co‐ LTB . Moreover, effective protection was observed after challenge with F4+ ETEC strain CVCC 230 in mice co‐administered rLpPG ‐2‐FaeG and rLpPG ‐2‐ LTAK 63‐co‐ LTB or rLpPG ‐2‐FaeG and rLpPG ‐2‐ LTAK 63‐fu‐LTB group compared with those that received rLpPG ‐2‐FaeG alone. Conclusions rLpPG ‐2‐FaeG showed greater immunogenicity in combination with LTAK 63 and LTB as molecular adjuvants. Significance and Impact of the Study Recombinant Lactobacillus provides a promising platform for the development of vaccines against F4+ ETEC infection.