Protective immune response of bacterially-derived recombinant FaeG in piglets.
FaeG is the key factor in the infection process of K88ad enterotoxigenic Escherichia coli(ETEC) fimbrial adhesin. In an attempt to determine the possibility of expressing recombinant FaeG with immunogenicity for a new safe and high-production vaccine in E. coli, we constructed the recombinant strain, BL21 (DE3+K88), which harbors an expression vector with a DNA fragment of faeG, without a signal peptide. Results of 15% SDS-polyacrylamide slab gel analysis showed that FaeG can be stably over-expressed in BL21 (DE3+K88) as inclusion bodies without FaeE. Immunoglobulin G (IgG) and M (IgM) responses in pregnant pigs, with boost injections of the purified recombinant FaeG, were detected 4 weeks later in the sera and colostrum. An in vitro villius-adhesion assay verified that the elicited antibodies in the sera of vaccinated pigs were capable of preventing the adhesion of K88ad ETEC to porcine intestinal receptors. The protective effect on the mortality rates of suckling piglets born to vaccinated mothers was also observed one week after oral challenge with the virulent ETEC strain, C83907 (K88ad, CT+, ST+). The results of this study proved that the adhesin of proteinaceous bacterial fimbriae or pili could be overexpressed in engineered E. coli strains, with protective immune responses to the pathogen.
Yahong
Huang
H
Department of Biological Science and Technology, School of Life Sciences of Nanjing University, Nanjing 210093, China.
Liang
Wanqi
W
Pan
Aihu
A
Zhou
Zhiai
Z
Wang
Qiang
Q
Huang
Cheng
C
Chen
Jianxiu
J
Zhang
Dabing
D
D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000833:Animals, Suckling; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D022361:Escherichia coli Vaccines / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D005260:Female; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D007114:Immunization / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood*; D008858:Microscopy, Phase-Contrast; D011247:Pregnancy; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D013552:Swine
D018830:Adhesins, Escherichia coli; D022361:Escherichia coli Vaccines; C494388:FaeG protein, E coli; D007074:Immunoglobulin G; D011994:Recombinant Proteins