TY - JOUR
T1 - Application of a Novel Epitope- and Structure-Based Vaccinology-Assisted Fimbria-Toxin Multiepitope Fusion Antigen of Enterotoxigenic Escherichia coli for Development of Multivalent Vaccines against Porcine Postweaning Diarrhea
AU - Lu, Ti
AU - Moxley, Rodney A.
AU - Zhang, Weiping
N1 - Funding Information:
This study was supported by USDA-NIFA Agriculture and Food Research Initiative Competitive Grant no. 2017-67015-26632 and no. 2017-67015-31471 and by the University of Illinois at Urbana-Champaign. IPEC-J2 cells were kindly provided by Bruce Schultz at Kansas State University.
Publisher Copyright:
© 2020. All Rights Reserved.
PY - 2020/12
Y1 - 2020/12
N2 - Enterotoxigenic Escherichia coli (ETEC) strains producing K88 (F4) or F18 fimbriae and enterotoxins are the predominant cause of pig postweaning diarrhea (PWD). We recently identified neutralizing epitopes of fimbriae K88 and F18, heatlabile toxin (LT), heat-stable toxins type I (STa) and type II (STb), and Shiga toxin 2e (Stx2e). In this study, we explored a novel epitope- and structure-based vaccinology platform, multiepitope fusion antigen (MEFA), for PWD vaccine development. By using an epitope substitution LT toxoid, which lacks enterotoxicity but retains immunogenicity, as the backbone to present neutralizing epitopes of two ETEC fimbriae and four toxins, we generated PWD fimbria-toxin MEFA to mimic epitope native antigenicity. We then examined MEFA protein immunogenicity and evaluated MEFA application in PWD vaccine development. Mice subcutaneously immunized with PWD MEFA protein developed strong IgG responses to K88, F18, LT, and STb and moderate responses to the toxins Stx2e and STa. Importantly, MEFA-induced antibodies inhibited adherence of K88 or F18 fimbrial bacteria to pig intestinal cells and also neutralized LT, STa, STb, and Stx2e toxicity. These results indicated that PWD fimbria-toxin MEFA induced neutralizing antibodies against an unprecedent two fimbriae and four toxins and strongly suggested a potential application of this MEFA protein in developing a broadly protective PWD vaccine.
AB - Enterotoxigenic Escherichia coli (ETEC) strains producing K88 (F4) or F18 fimbriae and enterotoxins are the predominant cause of pig postweaning diarrhea (PWD). We recently identified neutralizing epitopes of fimbriae K88 and F18, heatlabile toxin (LT), heat-stable toxins type I (STa) and type II (STb), and Shiga toxin 2e (Stx2e). In this study, we explored a novel epitope- and structure-based vaccinology platform, multiepitope fusion antigen (MEFA), for PWD vaccine development. By using an epitope substitution LT toxoid, which lacks enterotoxicity but retains immunogenicity, as the backbone to present neutralizing epitopes of two ETEC fimbriae and four toxins, we generated PWD fimbria-toxin MEFA to mimic epitope native antigenicity. We then examined MEFA protein immunogenicity and evaluated MEFA application in PWD vaccine development. Mice subcutaneously immunized with PWD MEFA protein developed strong IgG responses to K88, F18, LT, and STb and moderate responses to the toxins Stx2e and STa. Importantly, MEFA-induced antibodies inhibited adherence of K88 or F18 fimbrial bacteria to pig intestinal cells and also neutralized LT, STa, STb, and Stx2e toxicity. These results indicated that PWD fimbria-toxin MEFA induced neutralizing antibodies against an unprecedent two fimbriae and four toxins and strongly suggested a potential application of this MEFA protein in developing a broadly protective PWD vaccine.
KW - ETEC, enterotoxigenic E. coli
KW - MEFA
KW - PWD
KW - fimbria
KW - multiepitope fusion antigen
KW - novel vaccinology
KW - postweaning diarrhea
KW - toxin
KW - vaccine
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U2 - 10.1128/AEM.0274-20
DO - 10.1128/AEM.0274-20
M3 - Article
C2 - 32144103
AN - SCOPUS:85096884335
SN - 0099-2240
VL - 86
SP - 1
EP - 11
JO - Applied and environmental microbiology
JF - Applied and environmental microbiology
IS - 24
ER -