Investigation of nontypeable Haemophilus influenzae outer membrane protein P6 as a new carrier for lipooligosaccharide conjugate vaccines

Wu, Tinghuai; Chen, Jing; Murphy, Timothy F.; Green, Bruce A.; Gu, Xin-Xing

doi:10.1016/j.vaccine.2005.06.014

Cited by 16 publications

(23 citation statements)

References 39 publications

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“…We chose concentrations of NTHI outer membrane antigens that were clinically relevant to those of respiratory samples of COPD donors. OMP P6, a conserved lipoprotein expressed by NTHI in vivo, is a potent immunomodulator of human macrophages and a promising vaccine candidate (24,25). OMP P2 is a well characterized porin protein and is the predominant OMP of NTHI (26,27).…”

Section: Discussionmentioning

confidence: 99%

Impaired Alveolar Macrophage Response to Haemophilus Antigens in Chronic Obstructive Lung Disease

Berenson

Wrona

Grove

et al. 2006

Am J Respir Crit Care Med

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Rationale: Interactions of nontypeable Haemophilus influenzae (NTHI) with macrophages are implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the immunologic mechanisms that mediate NTHI-macrophage inflammation are poorly understood. Outer membrane protein (OMP) P6 and lipooligosaccharide (LOS) of NTHI are potent immunomodulators. We theorized that alveolar macrophages in COPD possess fundamental immune defects that permit NTHI to evade host responses. Objective: To test this hypothesis, we obtained human alveolar and blood macrophages from exsmokers with COPD, exsmokers without COPD, and nonsmokers. Methods: Alveolar and blood macrophages from each donor were incubated with purified LOS and OMP P6 and with OMP P2 and the total outer membrane preparation (0.1-1 g/ml). Measurements: Supernatants (24 h) were assayed for IL-1␤, TNF-␣, IL-10, IL-12, and IL-8 by multianalyte multiplexed flow cytometry. Results: Comparative induction of COPD and non-COPD alveolar macrophages by LOS and OMP P6 revealed diminished IL-8, TNF-␣, and IL-1␤ responses of COPD alveolar macrophages (p р 0.03 for each). COPD alveolar macrophages also had diminished responses to total outer membrane (p р 0.03 for each). In contrast, COPD blood macrophages had no significant differences among donor groups in IL-8, TNF-␣, or IL-1␤ responsiveness to NTHI antigens. Diminished IL-12 responses of COPD blood macrophages to NTHI antigens, compared with nonsmokers, could not be independently dissociated from group differences in age and pack-years. Conclusions: These findings support a paradigm of defective immune responsiveness of alveolar macrophages, but not blood macrophages, in COPD.

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Section: Discussionmentioning

confidence: 99%

Impaired Alveolar Macrophage Response to Haemophilus Antigens in Chronic Obstructive Lung Disease

Berenson

Wrona

Grove

et al. 2006

Am J Respir Crit Care Med

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“…However, the vaccine is not protective against NTHi strains, since these strains lack the capsular antigen. Efforts to identify NTHi vaccine candidates are ongoing and include strategies using immunogenic surface-exposed loops of the P2 and P4 outer membrane proteins (15,27), the C-terminal fragment of the Hap autotransporter (22), conjugate vaccines with outer membrane protein P6 as a carrier (37), and oral vaccines composed of killed bacterial extracts (2).…”

mentioning

confidence: 99%

VapC-1 of Nontypeable Haemophilus influenzae Is a Ribonuclease

Daines

Yuan

2007

J Bacteriol

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Nontypeable Haemophilus influenzae (NTHi) organisms are obligate parasites of the human upper respiratory tract that can exist as commensals or pathogens. Toxin-antitoxin (TA) loci are highly conserved gene pairs that encode both a toxin and antitoxin moiety. Seven TA gene families have been identified to date, and NTHi carries two alleles of the vapBC family. Here, we have characterized the function of one of the NTHi alleles, vapBC-1. The gene pair is transcribed as an operon in two NTHi clinical isolates, and promoter fusions display an inverse relationship to culture density. The antitoxin VapB-1 forms homomultimers both in vitro and in vivo. The expression of the toxin VapC-1 conferred growth inhibition to an Escherichia coli expression strain and was successfully purified only when cloned in tandem with its cognate antitoxin. Using total RNA isolated from both E. coli and NTHi, we show for the first time that VapC-1 is an RNase that is active on free RNA but does not degrade DNA in vitro. Preincubation of the purified toxin and antitoxin together results in the formation of a protein complex that abrogates the activity of the toxin. We conclude that the NTHi vapBC-1 gene pair functions as a classical TA locus and that the induction of VapC-1 RNase activity leads to growth inhibition via the mechanism of mRNA cleavage.

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“…Strains 5,12,15,16,17,18,26,28,30, and 31 are NTHi strains that express HMW1-and HMW2-like proteins (2,36,40,45). Each strain was isolated in pure culture from a middle ear fluid specimen from a child with acute otitis media and was identified as H. influenzae using standard methods.…”

Section: Methodsmentioning

confidence: 99%

“…Other proteins still under active investigation as possible vaccine candidates include protein D (21), protein E (22), type IV pili (23,24), and outer membrane protein (OMP) 26 (20,25). Even lipooligosaccharide, in the form of detoxified conjugate preparations, has been investigated as a potential vaccine candidate (26)(27)(28). A recent human clinical trial, in which children were immunized with a protein D-pneumococcal polysaccharide conjugate vaccine, reported protection against pneumococcal and NTHi otitis media (29,30), but protection against NTHi disease was quite modest and did not correlate with serum anti-protein D antibody levels.…”

mentioning

confidence: 99%

Naturally Acquired HMW1- and HMW2-Specific Serum Antibodies in Adults and Children Mediate Opsonophagocytic Killing of Nontypeable Haemophilus influenzae

Winter

Barenkamp

2016

Clin Vaccine Immunol

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The HMW1 and HMW2 proteins are highly immunogenic adhesins expressed by approximately 75% of nontypeable Haemophilus influenzae (NTHi) strains, and HMW1-and HMW2-specific antibodies can mediate opsonophagocytic killing of NTHi. In this study, we assessed the ability of HMW1-and HMW2-specific antibodies in sera from healthy adults and convalescent-phase sera from children with NTHi otitis media to mediate killing of homologous and heterologous NTHi. The serum samples were examined pre-and postadsorption on HMW1 and HMW2 affinity columns, and affinity-purified antibodies were assessed for ability to mediate killing of homologous and heterologous strains. Adult serum samples mediated the killing of six prototype NTHi strains at titers of <1:10 to 1:1,280. HMW1-and HMW2-adsorbed sera demonstrated unchanged to 8-fold decreased opsonophagocytic titers against the homologous strains. Each affinity-purified antibody preparation mediated the killing of the respective homologous strain at titers of <1:10 to 1:320 and of the five heterologous strains at titers of <1:10 to 1:320, with most preparations killing most heterologous strains to some degree. None of the acute-phase serum samples from children mediated killing, but each convalescent-phase serum sample mediated killing of the infecting strain at titers of 1:40 to 1:640. HMW1-and HMW2-adsorbed convalescent-phase serum samples demonstrated >4-fold decreases in titer. Three of four affinitypurified antibody preparations mediated killing of the infecting strain at titers of 1:20 to 1:320, but no killing of representative heterologous strains was observed. HMW1-and HMW2-specific antibodies capable of mediating opsonophagocytic killing are present in the serum from normal adults and develop in convalescent-phase sera of children with NTHi otitis media. Continued investigation of the HMW1 and HMW2 proteins as potential vaccine candidates for the prevention of NTHi disease is warranted. Nontypeable Haemophilus influenzae (NTHi) comprises small Gram-negative bacteria that colonize the upper respiratory tract of humans beginning at a very early age (1). Although these organisms are normally commensals, when host defenses are compromised by underlying medical conditions, such as malnutrition, immunodeficiency, chronic lung disease, or acute viral infection, disease caused by NTHi may develop (2, 3). Among children in the developed world, NTHi is currently responsible for an estimated 40 to 50% of the cases of acute otitis media and an even higher percentage of cases of chronic and recurrent disease (4, 5). Among adults, particularly among patients with chronic obstructive pulmonary disease, NTHi is a major cause of illness, particularly during the acute exacerbations that often characterize this disease (6). A vaccine capable of preventing disease caused by these organisms would offer substantial benefit to adult and pediatric populations alike.NTHi vaccine development efforts are ongoing in a number of laboratories. Published studies have suggested that NTHi outer membrane pr...

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Investigation of nontypeable Haemophilus influenzae outer membrane protein P6 as a new carrier for lipooligosaccharide conjugate vaccines

Cited by 16 publications

References 39 publications

Impaired Alveolar Macrophage Response to Haemophilus Antigens in Chronic Obstructive Lung Disease

Impaired Alveolar Macrophage Response to Haemophilus Antigens in Chronic Obstructive Lung Disease

VapC-1 of Nontypeable Haemophilus influenzae Is a Ribonuclease

Naturally Acquired HMW1- and HMW2-Specific Serum Antibodies in Adults and Children Mediate Opsonophagocytic Killing of Nontypeable Haemophilus influenzae

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