Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies.
The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. Here, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Using this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS-specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens.
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853;
Linxiao
0000-0002-8063-9001
L
Chen
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853;
Jenny L
JL
Valentine
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853;
Chung-Jr
CJ
Huang
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853;
Christine E
CE
Endicott
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853;
Tyler D
TD
Moeller
Department of Microbiology, University of Iowa, Iowa City, IA 52242;
Jed A
JA
Rasmussen
Genetics Program, University of Iowa, Iowa City, IA 52242;
Joshua R
JR
Fletcher
Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712; Department of Infectious Diseases, The University of Georgia College of Veterinary Medicine, Athens, GA 30602;
Joseph M
JM
Boll
Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853;
Joseph A
JA
Rosenthal
Complex Carbohydrate Research Center, The University of Georgia, Athens, GA 30602.
Justyna
J
Dobruchowska
Complex Carbohydrate Research Center, The University of Georgia, Athens, GA 30602.
Zhirui
Z
Wang
Complex Carbohydrate Research Center, The University of Georgia, Athens, GA 30602.
Christian
C
Heiss
Complex Carbohydrate Research Center, The University of Georgia, Athens, GA 30602.
Parastoo
P
Azadi
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853; Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853;
David
D
Putnam
Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712; Department of Infectious Diseases, The University of Georgia College of Veterinary Medicine, Athens, GA 30602;
M Stephen
MS
Trent
Department of Microbiology, University of Iowa, Iowa City, IA 52242; Genetics Program, University of Iowa, Iowa City, IA 52242;
Bradley D
BD
Jones
Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853; Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853; md255@cornell.edu.
Matthew P
MP
DeLisa
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D005604:Francisella tularensis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D019081:O Antigens / Q000276:immunology; D022161:Transport Vesicles / Q000235:genetics / Q000378:metabolism*; D014406:Tularemia / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D014611:Vaccination
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D019081:O Antigens
O-antigen polysaccharide; anti-glycan antibodies; glycan; glycoconjugate vaccine; humoral immune response