Expression of Factor H Binding Protein of Meningococcus Responds to Oxygen Limitation through a Dedicated FNR-Regulated Promoter

Oriente, Francesca; Scarlato, Vincenzo; Delany, Isabel

doi:10.1128/jb.01308-09

Cited by 34 publications

(71 citation statements)

References 54 publications

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“…Increasing amounts of IPTG (Sigma)-0, 0.0075, 0.03, and 0.1 mM-were added to the initial culture medium to modulate the expression of fHbp. Immunoblotting and FACS analyses were performed using anti-fHbp var1.1 polyclonal antisera, as previously described (7,33).…”

Section: Methodsmentioning

confidence: 99%

“…Upstream of the fHbp gene and similarly oriented is the cbbA gene encoding a fructose-bisphosphate aldolase. Previous studies have shown that the fHbp gene is transcribed from a FNR-regulated promoter, responsible for oxygen-dependent regulation of fHbp, within the upstream intergenic region and at least in some strains is also transcribed in a bicistronic transcript with the cbbA gene (7).…”

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confidence: 99%

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Expression of factor H binding protein in meningococcal strains can vary at least 15-fold and is genetically determined

Biagini¹,

Spinsanti²,

Angelis³

et al. 2016

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

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Factor H binding protein (fHbp) is a lipoprotein of Neisseria meningitidis important for the survival of the bacterium in human blood and a component of two recently licensed vaccines against serogroup B meningococcus (MenB). Based on 866 different amino acid sequences this protein is divided into three variants or two families. Quantification of the protein is done by immunoassays such as ELISA or FACS that are susceptible to the sequence variation and expression level of the protein. Here, selected reaction monitoring mass spectrometry was used for the absolute quantification of fHbp in a large panel of strains representative of the population diversity of MenB. The analysis revealed that the level of fHbp expression can vary at least 15-fold and that variant 1 strains express significantly more protein than variant 2 or variant 3 strains. The susceptibility to complement-mediated killing correlated with the amount of protein expressed by the different meningococcal strains and this could be predicted from the nucleotide sequence of the promoter region. Finally, the absolute quantification allowed the calculation of the number of fHbp molecules per cell and to propose a mechanistic model of the engagement of C1q, the recognition component of the complement cascade.MenB vaccine | selected reaction monitoring mass spectrometry | SRM-MS | fHbp antigen | antigen density

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Section: Methodsmentioning

confidence: 99%

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confidence: 99%

Expression of factor H binding protein in meningococcal strains can vary at least 15-fold and is genetically determined

Biagini¹,

Spinsanti²,

Angelis³

et al. 2016

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

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“…first fHbp-overexpressing strain was prepared by transforming the recombinant ⌬LpxL1 strain with the suicide plasmid pComPindFnrD148A (32), which generated the recombinant strain ⌬LpxL1-FNR c . This strain contained the mutant activator of fHbp expression, FNR-D148A, under the control of the IPTG (isopropyl-␤-D-thiogalactopyranoside)-inducible P tac promoter, which was integrated into the chromosome.…”

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confidence: 99%

A Critical Threshold of Meningococcal Factor H Binding Protein Expression Is Required for Increased Breadth of Protective Antibodies Elicited by Native Outer Membrane Vesicle Vaccines

Koeberling

Delany

Granoff³

2011

Clin. Vaccine Immunol.

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Native outer membrane vesicles (NOMV) (not detergent treated), which are prepared from recombinant strains with attenuated endotoxin activity and overexpressed factor H binding protein (fHbp), elicited broad serum bactericidal antibody responses in mice. The amount of overexpressed fHbp required for optimal immunogenicity is not known. In this study we prepared NOMV vaccines from LpxL1 knockout (⌬LpxL1) mutants with penta-acylated lipooligosaccharide and attenuated endotoxin activity. The recombinant strains had wild-type (1؋) fHbp expression or were engineered for 3-fold-or 10-fold-increased fHbp expression (3؋ or 10؋ fHbp). Control vaccines included NOMV from ⌬LpxL1/⌬fHbp mutants or recombinant fHbp. In mice, only the 10؋ fHbp NOMV vaccine elicited significantly higher serum IgG anti-fHbp antibody titers than the corresponding 1؋ fHbp NOMV or recombinant fHbp vaccine. The 10؋ fHbp NOMV vaccine also elicited higher bactericidal responses (P < 0.05) against five group B strains with heterologous PorA than the recombinant fHbp or 1؋ fHbp NOMV vaccine. The 3؋ fHbp NOMV vaccine gave higher bactericidal titers against only one strain. Serum bactericidal titers in mice immunized with the control ⌬fHbp NOMV vaccines were <1:10, and bactericidal titers in mice immunized with the 10؋ fHbp NOMV vaccine were <1:10 after adsorption of anti-fHbp antibodies. Mixing antiserum to NOMV vaccines from fHbp knockout mutants with antiserum to recombinant fHbp did not increase anti-fHbp bactericidal titers. Thus, a critical threshold of increased fHbp expression is required for NOMV vaccines to elicit broad serum bactericidal responses, and the antibodies conferring protection are directed primarily at fHbp.

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“…In addition to MnB, other serogroups (A, C, W135, X, and Y) have been shown to contain fHBP (36,38). The recent finding that fHBP gene transcription is expressed from two separate promoters, which are regulated by both oxygen and iron availability, further suggests the important role of fHBP in the virulence and pathogenesis of N. meningitidis (91). Although some sequence variation is exhibited by fHBP (32), the protein still maintains conserved regions for binding human fH and reactivity to protective immune sera.…”

Section: Resultsmentioning

confidence: 98%

“…Although free iron concentrations in the bloodstream are low, N. meningitidis has access to iron through iron binding proteins such as transferrin, lactoferrin, and hemoglobin. Oriente et al demonstrated that fHBP expression is under the control of two independent promoters: a bicistronic transcript originating from an upstream gene and a monocistronic transcript from the promoter of fHBP, P fHBP (91). P fHBP contains a putative FNR box motif such that under oxygen limitation, transcription is upregulated from P fHBP in an FNR-dependent manner.…”

Section: Regulation Of Fhbp Expressionmentioning

confidence: 99%

Role of Factor H Binding Protein in Neisseria meningitidis Virulence and Its Potential as a Vaccine Candidate To Broadly Protect against Meningococcal Disease

McNeil

Zagursky

Lin

et al. 2013

Microbiol Mol Biol Rev

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SUMMARY Neisseria meningitidis is a Gram-negative microorganism that exists exclusively in humans and can cause devastating invasive disease. Although capsular polysaccharide-based vaccines against serogroups A, C, Y, and W135 are widely available, the pathway to a broadly protective vaccine against serogroup B has been more complex. The last 11 years has seen the discovery and development of the N. meningitidis serogroup B (MnB) outer membrane protein factor H binding protein (fHBP) as a vaccine component. Since the initial discovery of fHBP, a tremendous amount of work has accumulated on the diversity, structure, and regulation of this important protein. fHBP has proved to be a virulence factor for N. meningitidis and a target for functional bactericidal antibodies. fHBP is critical for survival of meningococci in the human host, as it is responsible for the primary interaction with human factor H (fH). Binding of hfH by the meningococcus serves to downregulate the host alternative complement pathway and helps the organism evade host innate immunity. Preclinical studies have shown that an fHBP-based vaccine can elicit serum bactericidal antibodies capable of killing MnB, and the vaccine has shown very encouraging results in human clinical trials. This report reviews our current knowledge of fHBP. In particular, we discuss the recent advances in our understanding of fHBP, its importance to N. meningitidis , and its potential role as a vaccine for preventing MnB disease.

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Expression of Factor H Binding Protein of Meningococcus Responds to Oxygen Limitation through a Dedicated FNR-Regulated Promoter

Cited by 34 publications

References 54 publications

Expression of factor H binding protein in meningococcal strains can vary at least 15-fold and is genetically determined

Expression of factor H binding protein in meningococcal strains can vary at least 15-fold and is genetically determined

A Critical Threshold of Meningococcal Factor H Binding Protein Expression Is Required for Increased Breadth of Protective Antibodies Elicited by Native Outer Membrane Vesicle Vaccines

Role of Factor H Binding Protein in Neisseria meningitidis Virulence and Its Potential as a Vaccine Candidate To Broadly Protect against Meningococcal Disease

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