Structural modifications of outer membrane vesicles to refine them as vaccine delivery vehicles

Kim, Sang-Hyun; Kh, Kim; Lee, Sang-Rae; Kim, Ekyune; Kim, Myeong-Su; Lee, Eun-Young; Gho, Yong Song; Kim, Jung-Woo; Bishop, Russell E.; Chang, Kyu‐Tae

doi:10.1016/j.bbamem.2009.08.001

Cited by 95 publications

(84 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on these results, we analyzed OMVs derived from an msbB deletion mutant as a detoxified vaccine candidate. OMVs derived from a ⌬msbB strain demonstrated a significantly lower induction of inflammatory markers compared to WT (O1) OMVs in macrophages, which is consistent with the published literature on underacylated LPS (72,82,83). The beneficial effects of mutations resulting in OMV donor strains with underacylated LPS are under investigation for a second generation of OMV-based N. meningitidis vaccines (54,84,85).…”

Section: Discussionsupporting

confidence: 77%

Lipopolysaccharide Modifications of a Cholera Vaccine Candidate Based on Outer Membrane Vesicles Reduce Endotoxicity and Reveal the Major Protective Antigen

et al. 2013

View full text Add to dashboard Cite

The causative agent of the life-threatening gastrointestinal infectious disease cholera is the Gram-negative, facultative human pathogen Vibrio cholerae. We recently started to investigate the potential of outer membrane vesicles (OMVs) derived from V. cholerae as an alternative approach for a vaccine candidate against cholera and successfully demonstrated the induction of a long-lasting, high-titer, protective immune response upon immunization with OMVs using the mouse model. In this study, we present immunization data using lipopolysaccharide (LPS)-modified OMVs derived from V. cholerae, which allowed us to improve and identify the major protective antigen of the vaccine candidate. Our results indicate that reduction of endotoxicity can be achieved without diminishing the immunogenic potential of the vaccine candidate by genetic modification of lipid A. Although the protective potential of anti-LPS antibodies has been suggested many times, this is the first comprehensive study that uses defined LPS mutants to characterize the LPS-directed immune response of a cholera vaccine candidate in more detail. Our results pinpoint the O antigen to be the essential immunogenic structure and provide a protective mechanism based on inhibition of motility, which prevents a successful colonization. In a detailed analysis using defined antisera, we can demonstrate that only anti-O antigen antibodies, but not antibodies directed against the major flagellar subunit FlaA or the most abundant outer membrane protein, OmpU, are capable of effectively blocking the motility by binding to the sheathed flagellum and provide protection in a passive immunization assay.

show abstract

Section: Discussionsupporting

confidence: 77%

Lipopolysaccharide Modifications of a Cholera Vaccine Candidate Based on Outer Membrane Vesicles Reduce Endotoxicity and Reveal the Major Protective Antigen

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Reactogenicity may be related to an inflammatory response induced by the vaccine strains, perhaps induced in part by stimulation of Toll-like receptors by components of the vaccine strain, such as flagellins (18,47). Given our data showing that the msbB mutant V. cholerae strains described here were not completely deficient for colonization and also failed to stimulate TLR4 to any significant extent, we suggest that it is worth considering inclusion of msbB mutations in future V. cholerae vaccine strains, as has been done for vaccine formulations against other Gram-negative pathogens (8,22,23,30,44). Obviously, in order to try such an approach, it will be necessary to determine whether the nonstimulatory LPS produced by msbB mutant strains retains sufficient antigenicity to serve as a protective target of vaccination.…”

Section: Discussionmentioning

confidence: 96%

Polymyxin B Resistance in El Tor Vibrio cholerae Requires Lipid Acylation Catalyzed by MsbB

Matson

Yoo²,

Håkansson³

et al. 2010

J Bacteriol

View full text Add to dashboard Cite

Antimicrobial peptides are critical for innate antibacterial defense. Both Gram-negative and Gram-positive microbes have mechanisms to alter their surfaces and resist killing by antimicrobial peptides. In Vibrio cholerae, two natural epidemic biotypes, classical and El Tor, exhibit distinct phenotypes with respect to sensitivity to the peptide antibiotic polymyxin B: classical strains are sensitive and El Tor strains are relatively resistant. We carried out mutant screens of both biotypes, aiming to identify classical V. cholerae mutants resistant to polymyxin B and El Tor V. cholerae mutants sensitive to polymyxin B. Insertions in a gene annotated msbB (encoding a predicted lipid A secondary acyltransferase) answered both screens, implicating its activity in antimicrobial peptide resistance of V. cholerae. Analysis of a defined mutation in the El Tor biotype demonstrated that msbB is required for resistance to all antimicrobial peptides tested. Mutation of msbB in a classical strain resulted in reduced resistance to several antimicrobial peptides but in no significant change in resistance to polymyxin B. msbB mutants of both biotypes showed decreased colonization of infant mice, with a more pronounced defect observed for the El Tor mutant. Mass spectrometry analysis showed that lipid A of the msbB mutant for both biotypes was underacylated compared to lipid A of the wild-type isolates, confirming that MsbB is a functional acyltransferase in V. cholerae.Pathogenic bacteria that colonize the digestive tract must overcome a variety of stresses imposed upon them by the host. Epithelial cells in the crypts of the intestinal lumen (Paneth cells and enterocytes) produce large amounts of antimicrobial peptides called defensins (16). Defensins, like most antimicrobial peptides, are thought to act by associating with the lipopolysaccharide (LPS) on the bacterial surface (through electrostatic interactions) and then permeabilizing the membranes, leading to cell death (37, 48). Gram-negative bacteria have developed a wide range of strategies to overcome the antimicrobial activity of these peptides, including production of proteases that degrade the peptides (41

show abstract

“…More recently, the release of membrane-derived vesicles by Grampositive Staphylococcus aureus, Mycobacterium ulcerans, and Bacillus spp. was reported (18)(19)(20)(21), suggesting that vesicle production is a widespread phenomenon among microbial species.…”

mentioning

confidence: 99%

Bacillus anthracis produces membrane-derived vesicles containing biologically active toxins

Rivera¹,

Cordero²,

Nakouzi³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

339

345

View full text Add to dashboard Cite

Extracellular vesicle production is a ubiquitous process in Gram-negative bacteria, but little is known about such process in Gram-positive bacteria. We report the isolation of extracellular vesicles from the supernatants of Bacillus anthracis, a Gram-positive bacillus that is a powerful agent for biological warfare. B. anthracis vesicles formed at the outer layer of the bacterial cell had double-membrane spheres and ranged from 50 to 150 nm in diameter. Immunoelectron microscopy with mAbs to protective antigen, lethal factor, edema toxin, and anthrolysin revealed toxin components and anthrolysin in vesicles, with some vesicles containing more than one toxin component. Toxin-containing vesicles were also visualized inside B. anthracis -infected macrophages. ELISA and immunoblot analysis of vesicle preparations confirmed the presence of B. anthracis toxin components. A mAb to protective antigen protected macrophages against vesicles from an anthrolysin-deficient strain, but not against vesicles from Sterne 34F2 and Sterne δT strains, consistent with the notion that vesicles delivered both toxin and anthrolysin to host cells. Vesicles were immunogenic in BALB/c mice, which produced a robust IgM response to toxin components. Furthermore, vesicle-immunized mice lived significantly longer than controls after B. anthracis challenge. Our results indicate that toxin secretion in B. anthracis is, at least, partially vesicle-associated, thus allowing concentrated delivery of toxin components to target host cells, a mechanism that may increase toxin potency. Our observations may have important implications for the design of vaccines, for passive antibody strategies, and provide a previously unexplored system for studying secretory pathways in Gram-positive bacteria.

show abstract

Structural modifications of outer membrane vesicles to refine them as vaccine delivery vehicles

Cited by 95 publications

References 39 publications

Lipopolysaccharide Modifications of a Cholera Vaccine Candidate Based on Outer Membrane Vesicles Reduce Endotoxicity and Reveal the Major Protective Antigen

Lipopolysaccharide Modifications of a Cholera Vaccine Candidate Based on Outer Membrane Vesicles Reduce Endotoxicity and Reveal the Major Protective Antigen

Polymyxin B Resistance in El Tor Vibrio cholerae Requires Lipid Acylation Catalyzed by MsbB

Bacillus anthracis produces membrane-derived vesicles containing biologically active toxins

Contact Info

Product

Resources

About