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Naturally Acquired HMW1- and HMW2-Specific Serum Antibodies in Adults and Children Mediate Opsonophagocytic Killing of Nontypeable Haemophilus influenzae. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 23:37-46. [PMID: 26512048 DOI: 10.1128/cvi.00502-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/23/2015] [Indexed: 12/11/2022]
Abstract
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 affinity-purified 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.
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Davis GS, Marino S, Marrs CF, Gilsdorf JR, Dawid S, Kirschner DE. Phase variation and host immunity against high molecular weight (HMW) adhesins shape population dynamics of nontypeable Haemophilus influenzae within human hosts. J Theor Biol 2014; 355:208-18. [PMID: 24747580 DOI: 10.1016/j.jtbi.2014.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 03/21/2014] [Accepted: 04/04/2014] [Indexed: 12/16/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a bacterium that resides within the human pharynx. Because NTHi is human-restricted, its long-term survival is dependent upon its ability to successfully colonize new hosts. Adherence to host epithelium, mediated by bacterial adhesins, is one of the first steps in NTHi colonization. NTHi express several adhesins, including the high molecular weight (HMW) adhesins that mediate attachment to the respiratory epithelium where they interact with the host immune system to elicit a strong humoral response. hmwA, which encodes the HMW adhesin, undergoes phase variation mediated by 7-base pair tandem repeats located within its promoter region. Repeat number affects both hmwA transcription and HMW-adhesin production such that as the number of repeats increases, adhesin production decreases. Cells expressing large amounts of HMW adhesins may be critical for the establishment and maintenance of NTHi colonization, but they might also incur greater fitness costs when faced with an adhesin-specific antibody-mediated immune response. We hypothesized that the occurrence of large deletion events within the hmwA repeat region allows NTHi cells to maintain adherence in the presence of antibody-mediated immunity. To study this, we developed a mathematical model, incorporating hmwA phase variation and antibody-mediated immunity, to explore the trade-off between bacterial adherence and immune evasion. The model predicts that antibody levels and avidity, catastrophic loss rates, and population carrying capacity all significantly affected numbers of adherent NTHi cells within a host. These results suggest that the occurrence of large, yet rare, deletion events allows for stable maintenance of a small population of adherent cells in spite of HMW adhesin specific antibody-mediated immunity. These adherent subpopulations may be important for sustaining colonization and/or maintaining transmission.
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Affiliation(s)
- Gregg S Davis
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - Simeone Marino
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Med Sci II SPC 5620, Ann Arbor, MI 48109, USA.
| | - Carl F Marrs
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA.
| | - Janet R Gilsdorf
- Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109, USA; Department of Pediatrics, University of Michigan Medical School, L2225 Women׳s Hospital, Ann Arbor, MI 48109, USA.
| | - Suzanne Dawid
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Med Sci II SPC 5620, Ann Arbor, MI 48109, USA; UMHS Pediatric Infectious Diseases, University of Michigan Health System, D5101 MPB, Ann Arbor, MI 48109, USA.
| | - Denise E Kirschner
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Med Sci II SPC 5620, Ann Arbor, MI 48109, USA.
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Antibodies to the HMW1/HMW2 and Hia adhesins of nontypeable haemophilus influenzae mediate broad-based opsonophagocytic killing of homologous and heterologous strains. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:613-21. [PMID: 24574538 DOI: 10.1128/cvi.00772-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The HMW1/HMW2 and Hia proteins are highly immunogenic surface adhesins of nontypeable Haemophilus influenzae (NTHi). Approximately 75% of NTHi strains express HMW1/HMW2 adhesins, and most of the remaining 25% express an Hia adhesin. Our objective in this study was to assess the ability of antisera raised against purified HMW1/HMW2 proteins or recombinant Hia proteins to mediate opsonophagocytic killing of a large panel of unrelated NTHi strains. Native HMW1/HMW2 proteins were purified from three HMW1/HMW2-expressing NTHi strains. Recombinant fusion proteins expressing surface-exposed segments of either of two prototype Hia proteins were purified from Escherichia coli transformants. Immune sera raised in guinea pigs were assessed for their ability to mediate killing of NTHi in an opsonophagocytic assay with the HL-60 phagocytic cell line. The three HMW1/HMW2 antisera mediated killing of 22 of 65, 43 of 65, and 28 of 65 unrelated HMW1/HMW2-expressing NTHi strains, respectively. As a group, the three sera mediated killing of 48 of 65 HMW1/HMW2-expressing strains. The two Hia immune sera mediated killing of 12 of 24 and 13 of 24 unrelated Hia-expressing NTHi strains, respectively. Together, they mediated killing of 15 of 24 Hia-expressing strains. Neither the HMW1/HMW2 nor the Hia antisera mediated killing of NTHi expressing the alternative adhesin type. Antibodies directed against native HMW1/HMW2 proteins and recombinant Hia proteins are capable of mediating broad-based opsonophagocytic killing of homologous and heterologous NTHi strains. A vaccine formulated with a limited number of HMW1/HMW2 and Hia proteins might provide protection against disease caused by most NTHi strains.
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Hong W, Peng D, Rivera M, Gu XX. Protection against nontypeable Haemophilus influenzae challenges by mucosal vaccination with a detoxified lipooligosaccharide conjugate in two chinchilla models. Microbes Infect 2009; 12:11-8. [PMID: 19782149 DOI: 10.1016/j.micinf.2009.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 09/09/2009] [Accepted: 09/11/2009] [Indexed: 11/17/2022]
Abstract
Otitis media (OM) can occur following outset of upper respiratory tract infections. Inhibition of bacterial colonization in nasopharynx (NP) by mucosal vaccination may prevent OM by reducing bacterial invasion of the middle ears (MEs). In this study, 80 chinchillas were intranasally (i.n.) immunized with a detoxified lipooligosaccharide (dLOS)-tetanus toxoid conjugate vaccine of nontypeable Haemophilus influenzae (NTHi) mixed with cholera toxin (CT) or CT alone. All vaccinated animals responded with elevated levels of mucosal and serum anti-LOS antibodies. Two weeks after the last immunization, 40 chinchillas were challenged i.n. with NTHi to evaluate NP colonization and ME infection while the rest of the animals were challenged transbullarly (T.B.) to examine the development of OM. Compared to the control group, the vaccination inhibited not only bacterial colonization in NP and transmission to MEs in the i.n. challenge group but also bacterial colonization in NP and transmission to unchallenged ears in the T.B. challenge group. Though no difference was found in the challenged ears of either group right after the T.B. challenge, an early clearance of NTHi from NP and unchallenged ears as well as less severity of OM in the unchallenged ears were observed in vaccinated animals. Current results along with our previous data indicate that mucosal vaccination is capable of inhibiting NTHi NP colonization and preventing OM occurrence in chinchillas; the i.n. challenge model is preferable for testing the mucosal vaccines while the T.B. challenge model is superior for testing the systemic vaccines.
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Affiliation(s)
- Wenzhou Hong
- Vaccine Research Section, National Institute on Deafness and Other Communication Disorders, Rockville, Maryland 20850, USA
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5
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Mucosal immunization of mice with recombinant OMP P2 induces antibodies that bind to surface epitopes of multiple strains of nontypeable Haemophilus influenzae. Mucosal Immunol 2009; 2:63-73. [PMID: 19079335 PMCID: PMC4497548 DOI: 10.1038/mi.2008.70] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nontypeable Haemophilus influenzae (NTHI) is a significant cause of otitis media in children and exacerbations in patients with chronic obstructive pulmonary disease. Vaccine research for NTHI has focused on the outer membrane proteins (OMPs) of NTHI. The goal of this study was to evaluate mucosal and systemic immune responses to recombinant OMP P2 (rP2) of NTHI. Enzyme-linked immunosorbent assay (ELISA) demonstrated that both mucosal and systemic routes of immunization resulted in antibodies to rP2. Whole-cell ELISA and flow cytometry indicated that mucosal immunization induced antibodies to epitopes that are on the bacterial surface of the homologous strain as well as several heterologous strains. In contrast, systemic immunization induced antibodies to non-surface exposed epitopes. These data show for the first time that mucosal immunization of mice with rP2 induces antibodies that recognize surface exposed epitopes on multiple strains, indicating that P2 is a candidate for development of a mucosal vaccine for NTHI.
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Winter LE, Barenkamp SJ. Antibodies specific for the high-molecular-weight adhesion proteins of nontypeable Haemophilus influenzae are opsonophagocytic for both homologous and heterologous strains. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 13:1333-42. [PMID: 17021246 PMCID: PMC1694446 DOI: 10.1128/cvi.00221-06] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The HMW1/HMW2-like adhesion proteins of nontypeable Haemophilus influenzae (NTHI) are expressed by 75% of NTHI strains. Antibodies directed against these proteins are opsonophagocytic in vitro and are protective in an animal model of infection. The objective of the present study was to determine the opsonophagocytic activity of high-titer anti-HMW1/HMW2 immune sera against both homologous and heterologous NTHI strains. Chinchillas were immunized with purified HMW1/HMW2-like proteins from five prototype NTHI strains. Serum opsonophagocytic activity was monitored in an assay that uses a human promyelocytic cell line, HL-60, as the source of phagocytic cells. Preimmune sera did not demonstrate opsonophagocytic killing of any strains. In contrast, the immune sera demonstrated killing of the five homologous NTHI strains at titers ranging from 1:320 to 1:640. The immune sera also demonstrated killing of eight heterologous NTHI strains that express HMW1/HMW2-like proteins at titers ranging from 0 to 1:640. Killing of heterologous strains sometimes demonstrated a prozone phenomenon. None of the immune sera killed NTHI strains that did not express HMW1/HMW2-like proteins. Adsorption of immune sera with HMW1/HMW2-like proteins purified from either homologous or heterologous NTHI strains eliminated opsonophagocytic killing of homologous strains in most cases. These data demonstrate that antibodies produced following immunization with the HMW1/HMW2-like proteins are opsonophagocytic for both homologous and heterologous NTHI and strongly suggest that common epitopes recognized by functionally active antibodies exist on the HMW1/HMW2-like proteins of unrelated NTHI strains. The results argue for the continued investigation of the HMW1/HMW2-like proteins as potential vaccine candidates for the prevention of NTHI disease.
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Affiliation(s)
- Linda E Winter
- Department of Pediatrics, St. Louis University School of Medicine, Saint Louis, MO 63104-1095, USA
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Neary JM, Murphy TF. Antibodies directed at a conserved motif in loop 6 of outer membrane protein P2 of nontypeable Haemophilus influenzae recognize multiple strains in immunoassays. ACTA ACUST UNITED AC 2006; 46:251-61. [PMID: 16487307 DOI: 10.1111/j.1574-695x.2005.00033.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The P2 porin is the most abundant protein in the outer membrane of nontypeable Haemophilus influenzae. Analysis of P2 sequences from a limited number of strains reveals the presence of both heterogeneous and conserved surface-exposed loops of the P2 molecule among strains. We have previously shown that antibodies raised against the loop 6 sequence of P2 from strain 5657 are bactericidal against multiple isolates. In this study, we determined the nucleotide sequence of the loop 6 region of the P2 molecule from 108 strains of nontypeable H. influenzae in order to assess more rigorously the degree of conservation of loop 6. Based on this analysis, we identified a conserved sequence, different from that of strain 5657, that occurs in approximately one-third of the strains sequenced. To assess the potential of this peptide as a vaccine antigen, antibodies raised to a multiple antigenic peptide corresponding to this sequence were characterized with respect to specificity for the P2 molecule and reactivity with heterologous strains in immunoblot assay, flow cytometry and bactericidal assays. Antibodies were reactive to the P2 molecule of 16 of 20 strains tested by immunoblot assay. Antibodies recognized nine of the 20 strains in a flow cytometry assay, and 13 of 20 demonstrated complement-mediated killing in bactericidal assays. These results support the concept of using conserved regions of the P2 protein as a vaccine antigen.
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Affiliation(s)
- John M Neary
- Department of Microbiology, University of Buffalo, State University of New York, Buffalo, NY, USA
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Daines DA, Bothwell M, Furrer J, Unrath W, Nelson K, Jarisch J, Melrose N, Greiner L, Apicella M, Smith AL. Haemophilus influenzae luxS mutants form a biofilm and have increased virulence. Microb Pathog 2005; 39:87-96. [PMID: 16099134 DOI: 10.1016/j.micpath.2005.06.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 05/23/2005] [Accepted: 06/20/2005] [Indexed: 01/22/2023]
Abstract
To gain insight into the role of luxSHi in disease pathogenesis, we inactivated that gene in several non-typeable Haemophilus influenzae isolates with an antibiotic resistance cassette. Gene inactivation was confirmed by PCR and by Southern blot analysis in each strain. Culture filtrates from luxSHi mutants contained a decreased amount of autoinducer-2 (AI-2) activity in comparison to the wild-type isolates using the Vibrio harveyi BB170 bioassay. Culture filtrates from Escherichia coli strain DH5alpha expressing a cloned luxSHi contained 350-fold more AI-2 activity per cell than E. coli DH5alpha containing the vector alone. The growth rate in several liquid media, and the cell density after overnight growth were not significantly different between the parents and the luxSHi mutants. Two clinical H. influenzae and their luxSHi mutants produced an identical biofilm in a flow system. Invasion of human cells by the luxSHi mutants, in comparison to the wild-type parents was strain-dependent, and cell type-dependent, but the luxSHi mutants tended to be more invasive. The luxSHi mutant of an otitis media isolate, strain R3157 appeared more virulent in the chinchilla model of otitis media: there were more bacteria in the middle ear, a greater inflammatory response and more goblet cell hyperplasia 10 days after the inoculation. We conclude that the H. influenzae homologue of luxS modulates certain virulence traits.
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Affiliation(s)
- Dayle A Daines
- Section on Microbial Pathogens, Seattle Biomedical Research Institute, 307 Westlake Ave North, Suite 500, Seattle, WA 98109-5219, USA
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9
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Winter LE, Barenkamp SJ. Human antibodies specific for the high-molecular-weight adhesion proteins of nontypeable Haemophilus influenzae mediate opsonophagocytic activity. Infect Immun 2004; 71:6884-91. [PMID: 14638776 PMCID: PMC308909 DOI: 10.1128/iai.71.12.6884-6891.2003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The HMW1- and HMW2-like adhesion proteins of nontypeable Haemophilus influenzae are expressed by 75% of these strains, and antibodies directed against these proteins are protective in animal models of infection. The purpose of the present study was to define the functional activity of human antibodies specific for these proteins in an in vitro complement-dependent opsonophagocytic assay. Human promyelocytic cell line HL-60 served as the source of phagocytic cells, and a commercial preparation of intravenous immunoglobulin (IVIG) served as the source of human antibodies. High-molecular-weight (HMW) proteins were purified from four prototype nontypeable H. influenzae strains and used to prepare solid-phase affinity columns. IVIG was adsorbed on each column to remove strain-specific anti-HMW antibodies and to allow recovery of affinity-purified anti-HMW antibody fractions. Unadsorbed IVIG killed each of the prototype strains at titers of 1:80 to 1:320. HMW-adsorbed sera demonstrated fourfold decreases in opsonophagocytic titer against the homologous strains compared to unadsorbed IVIG. Affinity-purified anti-HMW antibody preparations demonstrated opsonophagocytic titers of 1:20 to 1:80 against the respective homologous strains and opsonophagocytic titers as high as 1:80 against heterologous strains. None of the affinity-purified anti-HMW antibody preparations was opsonophagocytic for a representative nontypeable H. influenzae strain that did not express HMW1- or HMW2-like proteins. These data demonstrate that human antibodies specific for the HMW1/HMW2-like adhesion proteins of nontypeable H. influenzae are opsonophagocytic and that such antibodies recognize epitopes shared by the HMW proteins of unrelated nontypeable H. influenzae strains. These results argue for continued investigation of the HMW1/HMW2-like proteins as potential vaccine candidates for prevention of disease due to nontypeable H. influenzae.
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Affiliation(s)
- Linda E Winter
- Department of Pediatrics, St. Louis University School of Medicine, and the Pediatric Research Institute, Cardinal Glennon Children's Hospital, St. Louis, Missouri 63104-1095, USA
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10
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Coleman HN, Daines DA, Jarisch J, Smith AL. Chemically defined media for growth of Haemophilus influenzae strains. J Clin Microbiol 2003; 41:4408-10. [PMID: 12958278 PMCID: PMC193788 DOI: 10.1128/jcm.41.9.4408-4410.2003] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A chemically defined medium that supports the growth of both encapsulated and nontypeable Haemophilus influenzae strains in broth to densities that are >/= 10(9) CFU/ml or on agar plates is described. The mean generation time of a panel of clinical isolates was comparable to that in rich, chemically undefined media (brain-heart infusion broth supplemented with heme and beta-NAD).
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Affiliation(s)
- Hannah N Coleman
- Seattle Biomedical Research Institute, Seattle, Washington 98109, USA
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11
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Kyd JM, Cripps AW, Novotny LA, Bakaletz LO. Efficacy of the 26-kilodalton outer membrane protein and two P5 fimbrin-derived immunogens to induce clearance of nontypeable Haemophilus influenzae from the rat middle ear and lungs as well as from the chinchilla middle ear and nasopharynx. Infect Immun 2003; 71:4691-9. [PMID: 12874350 PMCID: PMC165997 DOI: 10.1128/iai.71.8.4691-4699.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rat middle ear and lung clearance model has been used to show that the nontypeable Haemophilus influenzae 26-kDa outer membrane protein OMP26 is highly efficacious as a mucosal immunogen, inducing significantly enhanced clearance in immunized rats upon direct challenge of these two anatomic sites. Similarly, the chinchilla model of middle ear and nasopharyngeal clearance has been used to show that two P5 fimbrin adhesin-derived immunogens, LB1 and lipoprotein D (LPD)-LB1(f)(2,1,3), are highly efficacious as parenteral immunogens. Both induced significantly augmented clearance of nontypeable H. influenzae upon challenge of these sites. Here, these three nontypeable H. influenzae immunogens in addition to six bovine serum albumin and keyhole limpet hemocyanin conjugates of the synthetic peptide LB1(f) were assayed for relative efficacy in the reciprocal rodent model system. OMP26 was assayed in the chinchilla host by a parenteral immunization route, with clearance of the middle ear and nasopharynx used as outcome measures. Both LB1 and LPD-LB1(f)(2,1,3) were assayed in the rat host with a mucosal immunization route and clearance of nontypeable H. influenzae from the lungs and middle ears as outcome measures. Both of the immunogens were found to induce a high-titered and specific immune responses in the heterologous host system. Moreover, each was found to be highly efficacious in the reciprocal host system, providing strong support for the continued development and inclusion of both OMP26 and P5 fimbrin-derived peptides as candidate vaccine antigens directed at otitis media caused by nontypeable H. influenzae.
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Affiliation(s)
- Jennelle M Kyd
- Division of Science and Design, Gadi Research Centre, University of Canberra, Canberra, Australia.
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Affiliation(s)
- Stephen Ira Pelton
- Maxwell Finland Laboratory for Infectious Diseases, Boston Medical Center, Boston, Mass., USA
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13
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Abstract
Passive immunization of chinchillas with serum specific for either LB1 or for LPD-LB1 (f)(2,1,3) prior to challenge with heterologous NTHI isolates (relative to diversity in region three of P5-fimbrin), significantly inhibited the signs and incidence of otitis media (P < or = 0.01) induced by any of the challenge isolates. The ability of these antisera to induce total eradication of NTHI from the nasopharynx was not however equivalent among challenged cohorts. The data thus suggested that while early, complete eradication of NTHI from the nasopharynx was highly protective, reduction of the bacterial load to below a critical threshold level appeared to be similarly effective. Both immunogens thus remain strong vaccine candidates.
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Affiliation(s)
- L O Bakaletz
- The Ohio State University College of Medicine and Public Health, Department of Pediatrics, Division of Molecular Medicine, Children's Research Institute, Columbus, OH 43205-2696, USA.
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Rynnel-Dagöö B, Agren K. The nasopharynx and the middle ear. Inflammatory reactions in middle ear disease. Vaccine 2000; 19 Suppl 1:S26-31. [PMID: 11163459 DOI: 10.1016/s0264-410x(00)00274-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The host-parasite interactions in the nasopharynx with bacterial colonization and antigen uptake in the lymphoid tissue, the adenoid, has an impact on the maturation of local and systemic immunity. The adenoid is a part of mucosa associated lymphoid tissue and is responsible for both effector and inductor functions in the nasopharynx. Increasing evidence supports the role of serum antibody in protecting the middle ear cavity from disease. There is evidence for a minor immunologic defect in a number of children with recurrent episodes of AOM.
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Affiliation(s)
- B Rynnel-Dagöö
- Department of Clinical Sciences, Division of Oto-Rhino-Laryngology, Karolinska Institutet, Huddinge University Hospital, 17177, Stockholm, Sweden.
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Bolduc GR, Bouchet V, Jiang RZ, Geisselsoder J, Truong-Bolduc QC, Rice PA, Pelton SI, Goldstein R. Variability of outer membrane protein P1 and its evaluation as a vaccine candidate against experimental otitis media due to nontypeable Haemophilus influenzae: an unambiguous, multifaceted approach. Infect Immun 2000; 68:4505-17. [PMID: 10899849 PMCID: PMC98360 DOI: 10.1128/iai.68.8.4505-4517.2000] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candidate vaccine antigens for preventing otitis media caused by nontypeable Haemophilus influenzae (NTHI) should possess one or more conserved epitopes. We sought to evaluate the candidacy of P1, a surface-expressed outer membrane protein knowing that this antigen is subject to diversifying selection. Therefore, we selected NTHI strains from among >500 phylogenically variant isolates representative of the diversity found in natural populations of H. influenzae. Twenty-three variants of P1 (</=95% similarity) were identified among 42 strains. When chinchillas were immunized with recombinant P1 (rP1) obtained from one of these isolates (BCH-3), all animals developed antibodies specific for rP1. Immunized animals were protected against disease when challenged with BCH-3, but not with an ompP1 mutant of BCH-3 or a strain (BCH-2) possessing a heterologous P1 (91% identity). We conclude that (i) while P1 induces protection against NTHI-mediated otitis media, development of a polyvalent vaccine reflecting the variability of P1 would be necessary to construct an efficacious vaccine and (ii) use of a phylogenically characterized collection of representative isolates in concert with gene sequencing, cloning, gene inactivation, and animal testing offers an efficient, rational, and rigorous strategy for evaluating the potential problems associated with variability of vaccine targets and specificity of related immune responses.
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Affiliation(s)
- G R Bolduc
- The Maxwell Finland Laboratory for Infectious Diseases, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Kennedy BJ, Novotny LA, Jurcisek JA, Lobet Y, Bakaletz LO. Passive transfer of antiserum specific for immunogens derived from a nontypeable Haemophilus influenzae adhesin and lipoprotein D prevents otitis media after heterologous challenge. Infect Immun 2000; 68:2756-65. [PMID: 10768970 PMCID: PMC97485 DOI: 10.1128/iai.68.5.2756-2765.2000] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We recently determined that passive transfer of serum directed against a synthetic peptide called LB1 or a recombinant fusion protein immunogen [LPD-LB1(f)(2,1,3)] could prevent otitis media after challenge with a homologous nontypeable Haemophilus influenzae (NTHI) isolate. NTHI residing in the nasopharynx was rapidly cleared from this site, thus preventing it from ascending the eustachian tube and inducing otitis media in chinchillas compromised by an ongoing viral upper respiratory tract infection. While LB1 is based solely on one NTHI adhesin, the latter immunogen, LPD-LB1(f)(2,1,3), was designed to incorporate two NTHI antigens shown to play a role in the pathogenesis of otitis media; lipoprotein D (LPD) and the P5-homologous fimbrin adhesin. The design of LPD-LB1(f)(2,1,3) also accommodated for the recently demonstrated existence of three major groupings, based on amino acid sequence diversity, in the third surface-exposed region of P5-fimbrin. LPD-LB1(f)(2,1,3) was thus designed to potentially confer broader protection against challenge by diverse strains of NTHI. Chinchillas were passively immunized here with serum specific for either LB1 or for LPD-LB1(f)(2,1,3) prior to challenge with a member of all three groups of NTHI relative to diversity in region 3. The transferred serum pools were also analyzed for titer, specificity, and several functional activities. We found that both serum pools had equivalent ability to mediate C'-dependent killing and to inhibit adherence of NTHI strains to human oropharyngeal cells. When passively transferred, both serum pools significantly inhibited the signs and incidence of otitis media (P </= 0.01) induced by any of the three challenge isolates. Despite providing protection against disease, the ability of these antisera to induce total eradication of NTHI from the nasopharynx was not equivalent among NTHI groups. These data thus suggested that while early, complete eradication of NTHI from the nasopharynx was highly protective, reduction of the bacterial load to below a critical threshold level appeared to be similarly effective.
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Affiliation(s)
- B J Kennedy
- The Ohio State University College of Medicine and Public Health, Department of Pediatrics, Division of Molecular Medicine, Columbus, Ohio 43205-2696, USA
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17
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Abstract
Moraxella catarrhalis has again been recognized as a significant pathogen. The past decade has witnessed an increased amount of research and understanding of the pathogenesis of the organism. This review will summarize the research pertaining to the epidemiology and components of pathogenesis in M. catarrhalis.
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Affiliation(s)
- R Karalus
- Department of Microbiology, State University of New York at Buffalo, Buffalo, NY 14214, USA
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18
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Abstract
Streptococcus pneumoniae infection and disease have been modeled in several animal species including infant and adult mice, infant and adult rats, infant Rhesus monkeys, and adolescent and adult chinchillas. Most are models of sepsis arising from intravenous or intraperitoneal inoculation of bacteria, and a few were designed to study disease arising from intranasal infection. Chinchillas provide the only animal model of middle ear pneumococcal infection in which the disease can be produced by very small inocula injected into the middle ear (ME) or intranasally, and in which the disease remains localized to the ME in most cases. This model, developed at the University of Minnesota in 1975, has been used to study pneumococcal pathogenesis at a mucosal site, immunogenicity and efficacy of pneumococcal capsular polysaccharide (PS) vaccine antigens, and the kinetics and efficacy of antimicrobial drugs. Pathogenesis experiments in the chinchilla model have revealed variation in ME virulence among different pneumococcal serotypes, enhancement of ME infection during concurrent intranasal influenza A virus infections, and natural resolution of pneumococcal otitis media (OM) without intervention. Research has explored the relative contribution of pneumococcal and host products to ME inflammation. Pneumococcal cell wall components and pneumolysin have been studied in the model. Host inflammatory responses studied in the chinchilla ME include polymorphonuclear leukocyte oxidative products, hydrolytic enzymes, cytokine and eicosanoid metabolites, and ME epithelial cell adhesion and mucous glycoprotein production. Both clinical (tympanic membrane appearance) and histopathology (ME, Eustachian tube, inner ear) endpoints can be quantified. Immunologic and inflammatory studies have been facilitated by the production of affinity-purified antichinchilla immunoglobulin G (IgG), IgM, and secretory IgA polyclonal antibody reagents, and the identification of cross-reactivity between human and chinchilla cytokines, and between guinea pig and chinchilla C3. Alteration of ME mucosa by pneumococcal neuraminidase and alteration of ME epithelial cell (MEEC) surface carbohydrates during intranasal pneumococcal infection have been demonstrated. Pathogenesis studies have been aided by cultured chinchilla MEEC systems, in which the ability of platelet activating factor and interleukin (IL)-1 beta to stimulate epithelial mucous glycoprotein synthesis has recently been demonstrated. Because chronic OM with effusion is characterized by presence of large amounts of mucous glycoprotein in the ME, pneumococcus may have an important role in both acute and chronic ME disease. Both unconjugated PS and PS-protein-conjugated vaccines are immunogenic after intramuscular administration without adjuvant in chinchillas. Passive protection studies with human hyperimmune immunoglobulin demonstrated that anti-PS IgG alone is capable of protecting the chinchilla ME from direct ME challenge with pneumococci. Active PS immunization studies demonstrated protection following direct ME and intranasal pneumococcal challenge with and without concurrent influenza A virus infection. An attenuated influenza A virus vaccine also showed protection for pneumococcal OM. Antimicrobial treatment of acute OM has been based almost exclusively on empirical drug use and clinical trials without a foundation of ME pharmacokinetics. Studies in the chinchilla model have started to bring a rational basis to drug selection and dosing. Microassays have been developed using high-pressure liquid chromatography for many relevant drugs. Studies have explored the in vivo ME response in pneumococcal OM to antimicrobial drugs at supra- and sub-minimum inhibitory concentration (MIC), the effect of concurrent influenza A virus infection on ME drug penetration, and the effect of treatment on sensorineural hearing loss produced by pneumococcal OM.
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Affiliation(s)
- G S Giebink
- Otitis Media Research Center, University of Minnesota School of Medicine, Minneapolis 55455, USA
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19
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Bakaletz LO, Kennedy BJ, Novotny LA, Duquesne G, Cohen J, Lobet Y. Protection against development of otitis media induced by nontypeable Haemophilus influenzae by both active and passive immunization in a chinchilla model of virus-bacterium superinfection. Infect Immun 1999; 67:2746-62. [PMID: 10338477 PMCID: PMC96578 DOI: 10.1128/iai.67.6.2746-2762.1999] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three separate studies, two involving active-immunization regimens and one involving a passive-transfer protocol, were conducted to initially screen and ultimately more fully assess several nontypeable Haemophilus influenzae outer membrane proteins or their derivatives for their relative protective efficacy in chinchilla models of otitis media. Initial screening of these antigens (P5-fimbrin, lipoprotein D, and P6), delivered singly or in combination with either Freund's adjuvant or alum, indicated that augmented bacterial clearance from the nasopharynx, the middle ears, or both anatomical sites could be induced by parenteral immunization with P5-fimbrin combined with lipoprotein D, lipoprotein D alone, or the synthetic chimeric peptide LB1 (derived from P5-fimbrin), respectively. Data from a second study, wherein chinchillas were immunized with LB1 or lipoprotein D, each delivered with alum, again indicated that clearance of nontypeable H. influenzae could be augmented by immunization with either of these immunogens; however, when this adjuvant was used, both antibody titers in serum and efficacy were reduced. A third study was performed to investigate passive delivery of antisera directed against either LB1, lipoprotein D, nonacylated lipoprotein D, or a unique recombinant peptide designated LPD-LB1(f)2,1,3. The last three antiserum pools were generated by using the combined adjuvant of alum plus monophosphoryl lipid A. Passive transfer of sera specific for LB1 or LPD-LB1(f)2,1,3 to adenovirus-compromised chinchillas, prior to intranasal challenge with nontypeable H. influenzae, significantly reduced the severity of signs and incidence of otitis media which developed (P </= 0.001). Collectively, these data indicate the continued merit of further developing LB1 and LPD-LB1(f)2,1,3 as components of vaccines for otitis media.
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Affiliation(s)
- L O Bakaletz
- Division of Otologic Research, Department of Otolaryngology, College of Medicine, The Ohio State University, Columbus, Ohio, USA.
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20
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Hotomi M, Saito T, Yamanaka N. Specific mucosal immunity and enhanced nasopharyngeal clearance of nontypeable Haemophilus influenzae after intranasal immunization with outer membrane protein P6 and cholera toxin. Vaccine 1998; 16:1950-6. [PMID: 9796049 DOI: 10.1016/s0264-410x(98)00122-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is one of the leading pathogens in otitis media. Studies of vaccines against NTHi have focused on outer membrane proteins (OMPs). One outer membrane protein P6 is highly conserved among strains and is an attractive candidate for a subunit bacterial vaccine. In this study, mucosal immunity induced by intranasal immunization with P6 and cholera toxin (CT) was investigated in a mouse model. Intranasal immunization with P6 and CT evoked a good mucosal IgA as well as a systemic IgG response against P6. On the other hand, intranasal immunization with P6 alone induced a weak mucosal IgA response. Enzyme linked immunospot assay detected anti-P6 specific antibody producing cells in the nasopharyngeal mucosa of immunized mice. The protective response of intranasal immunization was demonstrated by enhancement of nasopharyngeal clearance of NTHi and inhibition of adherence of NTHi to cultured human epithelial cells. Based on these results, intranasal immunization with P6 and CT may be an effective approach to protect human from H. influenzae infections in the upper respiratory tract.
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Affiliation(s)
- M Hotomi
- Department of Otorhinolaryngology, Wakayama Medical College, Japan
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21
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Yang YP, Loosmore SM, Underdown BJ, Klein MH. Nasopharyngeal colonization with nontypeable Haemophilus influenzae in chinchillas. Infect Immun 1998; 66:1973-80. [PMID: 9573078 PMCID: PMC108152 DOI: 10.1128/iai.66.5.1973-1980.1998] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Colonization of the nasopharynx by a middle ear pathogen is the first step in the development of otitis media in humans. The establishment of an animal model of nasopharyngeal colonization would therefore be of great utility in assessing the potential protective ability of candidate vaccine antigens (especially adhesins) against otitis media. A chinchilla nasopharyngeal colonization model for nontypeable Haemophilus influenzae (NTHI) was developed with antibiotic-resistant strains. This model does not require coinfection with a virus. There was no significant difference in the efficiency of NTHI colonization between adult (1- to 2-year-old) and young (2- to 3-month-old) animals. However, the incidence of middle ear infection following nasopharyngeal colonization was significantly higher in young animals (83 to 89%) than in adult chinchillas (10 to 30%). Chinchillas that had recovered either from a previous middle ear infection caused by NTHI or from an infection by intranasal inoculation with NTHI were completely protected against nasopharyngeal colonization with a homologous strain and were found to be the best positive controls in protection studies. Systemic immunization of chinchillas with inactivated whole-cell preparations significantly protected animals not only against homologous NTHI colonization but also partially against heterologous NTHI infection. In all protected animals, significant serum anti-P6 and anti-HMW antibody responses were observed. The outer membrane P6 and high-molecular-weight (HMW) proteins appear to be promising candidate vaccine antigens to prevent nasopharyngeal colonization and middle ear infection caused by NTHI.
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Affiliation(s)
- Y P Yang
- Research Center, Pasteur Merieux Connaught Canada, North York, Ontario.
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22
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Loosmore SM, Yang YP, Oomen R, Shortreed JM, Coleman DC, Klein MH. The Haemophilus influenzae HtrA protein is a protective antigen. Infect Immun 1998; 66:899-906. [PMID: 9488373 PMCID: PMC107993 DOI: 10.1128/iai.66.3.899-906.1998] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/1997] [Accepted: 12/30/1997] [Indexed: 02/06/2023] Open
Abstract
The htrA gene from two strains of nontypeable Haemophilus influenzae has been cloned and sequenced, and the encoded approximately 46-kDa HtrA proteins were found to be highly conserved. H. influenzae HtrA has approximately 55% identity with the Escherichia coli and Salmonella typhimurium HtrA stress response proteins, and expression of the H. influenzae htrA gene was inducible by high temperature. Recombinant HtrA (rHtrA) was expressed from E. coli, and the purified protein was found to have serine protease activity. rHtrA was found to be very immunogenic and partially protective in both the passive infant rat model of bacteremia and the active chinchilla model of otitis media. Immunoblot analysis indicated that HtrA is antigenically conserved in encapsulated and nontypeable H. influenzae species. Site-directed mutagenesis was performed on the htrA gene to ablate the endogenous serine protease activity of wild-type HtrA, and it was found that eight of nine recombinant mutant proteins had no measurable residual proteolytic activity. Two mutant proteins were tested in the animal protection models, and one, H91A, was found to be partially protective in both models. H91A HtrA may be a good candidate antigen for a vaccine against invasive H. influenzae type b disease and otitis media and is currently in phase I clinical trials.
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Affiliation(s)
- S M Loosmore
- Pasteur Merieux Connaught Canada Research, North York, Ontario.
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23
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Faden HS. Immunology of the middle ear: role of local and systemic antibodies in clearance of viruses and bacteria. Ann N Y Acad Sci 1997; 830:49-60. [PMID: 9616666 DOI: 10.1111/j.1749-6632.1997.tb51878.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- H S Faden
- State University of New York at Buffalo, School of Medicine and Biomedical Sciences 14222, USA.
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24
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Abstract
Considerable evidence suggests that otitis media (OM) can be prevented by systemic immunization. Building on the highly effective H. influenzae type b (Hib) conjugate vaccine technology, pneumococcal conjugate vaccines are being developed to circumvent T-independence of these antigens and provide durable immunity at a very young age. Several pneumococcal conjugate vaccines are currently in clinical testing. Potential vaccine antigens of nontypable H. influenzae (NTHi) include OMP, HMW, pili, and fimbriae. Several OMPs show extensive homology among strains, but surface, determinants of others are highly variable so that antibodies to surface epitopes of one strain will not bind to surface epitopes of another. Several M. catarrhalis OMP and HMW antigens have vaccine potential, but no functional correlates of protection have been identified, and there is no clear evidence that antibody to M. catarrhalis is associated with OM protection. Attenuated viral vaccines also hold promise of preventing childhood OM. Two clinical trials with killed influenza vaccines have shown a significant reduction in OM among vaccine recipients compared to control children during periods of high influenza disease activity in the community. Passive immunoprophylaxis also has potential for preventing OM. Human bacterial polysaccharide immune globulin was protective for pneumococcal OM in children and in the chinchilla OM model. High-dose respiratory syncytial virus-enriched immunoglobulin reduced the incidence and severity of RSV lower respiratory tract infection in high-risk children. Passive immunoprophylaxis may also be effective in children with specific immune deficiencies, such as IgG2 deficiency, and patients who fail to respond to vaccines.
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Affiliation(s)
- G S Giebink
- Department of Pediatrics and Otolaryngology, University of Minnesota School of Medicine, Minneapolis 55455, USA.
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25
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Akkoyunlu M, Melhus A, Capiau C, van Opstal O, Forsgren A. The acylated form of protein D of Haemophilus influenzae is more immunogenic than the nonacylated form and elicits an adjuvant effect when it is used as a carrier conjugated to polyribosyl ribitol phosphate. Infect Immun 1997; 65:5010-6. [PMID: 9393790 PMCID: PMC175723 DOI: 10.1128/iai.65.12.5010-5016.1997] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The nonacylated form of protein D (PDm) of Haemophilus influenzae has been shown to induce the production of antibodies that are bactericidal to homologous and heterologous nontypeable H. influenzae (NTHi) strains. In this study, immunization of rats with lipoprotein D (LPD) induced higher levels of anti-protein D immunoglobulin G and A serum antibodies than immunization with PDm, and the bactericidal activities of sera from LPD-immunized rats were greater than those of sera from PDm-immunized rats. Immunization with LPD or PDm did not prevent the development of acute otitis media (AOM) when rats were challenged with 10(4) CFU of an NTHi strain. However, on the eighth day of bacterial challenge, 50% (5 of 10) of LPD-immunized rats had recovered from otitis media and 30% (3 of 10) had negative middle ear cultures, whereas only 30% (3 of 10) of PDm-immunized rats had recovered, though none was culture positive. Immunization with an inactivated homologous bacterial strain elicited 70% protection (i.e., 7 of 10 rats) in the rat otitis media model. LPD and PDm were also conjugated to the H. influenzae type b (Hib) capsular polysaccharide, polyribosyl ribitol phosphate (PRP), to test protein D-conjugated PRP vaccine's potential for protection against Hib infection. When two LPD-conjugated and two PDm-conjugated PRP vaccines, each containing a different protein concentration, and a tetanus toxoid-conjugated vaccine (ACT-HIB) were tested in the experimental model of rat otitis induced with a Hib strain (Minn A), both of the LPD-conjugated and one of the PDm-conjugated vaccines induced significant protection from AOM, the level of protection being highest in animals given the vaccine with the highest LPD content. Sera from these rats also manifested the highest anti-PRP and anti-LPD antibody levels and the highest bactericidal activities against a Hib strain and an NTHi strain.
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Affiliation(s)
- M Akkoyunlu
- Department of Medical Microbiology, University of Lund, Malmö University Hospital, Sweden.
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26
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Gu XX, Sun J, Jin S, Barenkamp SJ, Lim DJ, Robbins JB, Battey J. Detoxified lipooligosaccharide from nontypeable Haemophilus influenzae conjugated to proteins confers protection against otitis media in chinchillas. Infect Immun 1997; 65:4488-93. [PMID: 9353024 PMCID: PMC175645 DOI: 10.1128/iai.65.11.4488-4493.1997] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Detoxified-lipooligosaccharide (dLOS)-protein conjugates from nontypeable Haemophilus influenzae (NTHi) elicited a significant rise of anti-LOS antibodies with bactericidal activity in rabbits (X.-X. Gu, C.-M. Tsai, T. Ueyama, S. J. Barenkamp, J. B. Robbins, and D. J. Lim, Infect. Immun. 64:4047-4053, 1996). In this study, we evaluated whether vaccination with the conjugates would protect against NTHi otitis media in chinchillas. Fifty-eight chinchillas received three subcutaneous or intramuscular injections of dLOS-conjugated tetanus toxoid, dLOS-conjugated high-molecular-weight proteins from NTHi, or saline (control) in Freund's adjuvant and then were challenged by intrabullar inoculation with 140 CFU of NTHi. All vaccinated animals responded with elevated serum titers of anti-LOS antibody, and 49% (19 of 39) demonstrated bactericidal activity against the homologous strain. Otitis media with culture-positive NTHi effusions developed in all 19 controls and 56% (22 of 39) of the vaccinated animals during a period of 21 days (P < 0.001). Bacterial counts of the middle ear effusions were lower in the vaccine groups than in the controls (P < 0.01). The incidences of infection in the unchallenged ear or inner ear were 26 or 28% in the vaccine groups and 53 or 58% in the controls (P < 0.05). The signs of infection observed by otoscopy were less severe in the vaccine groups than in the controls. There was no significant difference between the two vaccine groups. These data indicate that active immunization with LOS-based conjugates reduces the incidence of NTHi-induced otitis media.
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Affiliation(s)
- X X Gu
- Laboratory of Immunology, National Institute on Deafness and Other Communication Disorders, Rockville, Maryland 20850, USA.
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27
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Bakaletz LO, Leake ER, Billy JM, Kaumaya PT. Relative immunogenicity and efficacy of two synthetic chimeric peptides of fimbrin as vaccinogens against nasopharyngeal colonization by nontypeable Haemophilus influenzae in the chinchilla. Vaccine 1997; 15:955-61. [PMID: 9261941 DOI: 10.1016/s0264-410x(96)00298-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The OMP P5-homologous fimbriae of nontypeable Haemophilus influenzae (NTHi) are an adhesin and a virulence factor for otitis media in chinchilla models. We synthesized two peptides (LB1 and LB2) which incorporate determinants of the fimbrial subunit co-linearly synthesized with a "promiscuous" T-cell epitope from the fusion protein of measles virus. Sera obtained from immunized rabbits and chinchillas demonstrated significant reciprocal titers against both the homologous peptide and isolated fimbrial protein. Antisera also immunolabeled native fimbriae of whole unfixed NTHi. Immunization with LB1 or fimbrin resulted in elimination of NTHi from the chinchilla nasopharynx 2-3 weeks earlier than controls, respectively.
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Affiliation(s)
- L O Bakaletz
- Department of Otolaryngology, Ohio State University, Columbus 43210-1282, USA
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28
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Bernstein JM, Bronson PM, Wilson ME. Immunoglobulin G Subclass Response to Major outer Membrane Proteins of Nontypable Haemophilus Influenzae in Children with Acute Otitis Media. Otolaryngol Head Neck Surg 1997; 116:363-71. [PMID: 9121792 DOI: 10.1016/s0194-59989770275-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Children with acute otitis media as the result of nontypable Haemophilus influenzae often develop serum bactericidal and/or opsonic IgG antibodies to this organism during convalescence. Outer membrane proteins appear to be the principal targets for such antibodies. In this study we characterized the IgG subclass responses to major outer membrane proteins of nontypable H. influenzae in otitis-prone children in whom this organism had colonized. Three of the major outer membrane proteins (P2, P5, and P6) were isolated from the homologous nontypable H. influenzae strain recovered from the middle ear at the time of acute infection. Sera were obtained during the acute phase and at 1 and 6 months thereafter. The outer membrane proteins, which were isolated by preparative sodium dodecylsulfate-polyacrylamide gel electrophoresis, were used as test antigens in a quantitative IgG subclass enzyme immunoassay. The results of this analysis indicate that the temporal characteristics and distribution of IgG subclass antibodies were found to differ for each of the outer membrane proteins. Moreover, substantial variation between patients was observed with respect to both temporal characteristics and subclass distribution of the IgG response to the three outer membrane proteins. Significantly, sera from two of three otitis-prone subjects contained detectable levels of IgG antibody to the conserved P6 outer membrane protein at the time of acute infection, with serum from one subject also containing detectable levels of lgG3 antibody to this same protein. Nevertheless, the organism persisted in the middle ears of these patients. The results of this study indicate that otitis-prone children manifest a highly variable IgG subclass response to both conserved (P6) and variable (P2) outer membrane proteins of nontypable H. influenzae. Further study is required to ascertain whether these IgG subclass antibodies are biologically efficacious and whether otitis-prone children possess the immunologic maturity to respond to nontypable H. influenzae outer membrane protein-based vaccines in a predictable manner.
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Affiliation(s)
- J M Bernstein
- Department of Otolaryngology, State University of New York at Buffalo, USA
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29
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DeMaria TF, Murwin DM, Leake ER. Immunization with outer membrane protein P6 from nontypeable Haemophilus influenzae induces bactericidal antibody and affords protection in the chinchilla model of otitis media. Infect Immun 1996; 64:5187-92. [PMID: 8945564 PMCID: PMC174506 DOI: 10.1128/iai.64.12.5187-5192.1996] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The role of nontypeable Haemophilus influenzae (NTHi) outer membrane protein (OMP) P6 in the pathogenesis of otitis media (OM) has not been defined. OMPs, fimbriae, pili, and lipooligosaccharide are several types of surface antigens of NTHi that are currently being evaluated as potential vaccine candidates. P6 is antigenically conserved among both nontypeable and type b H. influenzae strains and elicits bactericidal as well as protective antibodies; however, initial evaluation of a vaccine mixture of P6 combined with other NTHi OMPs failed to induce bactericidal antibody or protection in the chinchilla model of OM. We undertook an assessment of the ability of immunization with isolated P6 lipoprotein alone to confer protection. Chinchillas were immunized with P6 and challenged 10 days after the final immunization with either 3 x 10(3) CFU of NTHi delivered directly into the middle ear to induce OM or 5 x 10(8) CFU of NTHi delivered intranasally to establish nasopharyngeal colonization. All immunized animals responded with elevated serum titers of anti-P6 antibody, which also demonstrated bactericidal activity against homologous as well as a heterologous NTHi isolate. By 14 days post-transbullar challenge, the number of chinchillas with middle ear fluid and the incidence of NTHi culture-positive middle ear fluids were reduced 48 and 51%, respectively, in the P6-immunized chinchillas relative to the sham-immunized cohort. Nasopharyngeal colonization levels were comparable in the two cohorts. These data demonstrate that active immunization with P6 results in the production of NTHi-specific bactericidal antibody in the chinchilla and also affords a reduction in the incidence of NTHi-induced OM; however, parenteral immunization does not appear to affect the extent or duration of nasopharyngeal colonization by NTHi.
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Affiliation(s)
- T F DeMaria
- Otologic Research Laboratories, The Ohio State University College of Medicine, Columbus 43210, USA.
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30
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Harrison CJ. The other effect of intravenously administered respiratory syncytial virus-enriched immune globulin for prophylaxis: less acute otitis media. J Pediatr 1996; 129:193-6. [PMID: 8765615 DOI: 10.1016/s0022-3476(96)70241-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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31
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Barenkam SJ, St Geme JW. Identification of surface-exposed B-cell epitopes on high molecular-weight adhesion proteins of nontypeable Haemophilus influenzae. Infect Immun 1996; 64:3032-7. [PMID: 8757830 PMCID: PMC174184 DOI: 10.1128/iai.64.8.3032-3037.1996] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We previously reported that two surface-exposed high-molecular-weight proteins, HMW1 and HMW2, expressed by a prototypic strain of nontypeable Haemophilus influenzae (NTHI) mediate attachment to human epithelial cells. These proteins are members of a family of highly immunogenic proteins common to most nontypeable Haemophilus strains. We also reported that immunization with an HMW1-HMW2 mixture modified the course of disease in an animal model of otitis media, suggesting the potential usefulness of these proteins as NTHI vaccine components. Identification of surface-accessible B-cell epitopes could be important to efforts to develop recombinant or synthetic peptide vaccines based upon these high-molecular-weight proteins. Thus, the purpose of the present study was to identify surface-accessible epitopes on the HMW1 and HMW2 proteins by using monoclonal antibodies (MAbs) and to determine the prevalence of these epitopes among the high-molecular-weight proteins expressed by heterologous nontypeable Haemophilus strains. MAbs were generated by immunizing mice with high-molecular-weight proteins purified from prototype strains and were screened by immunoelectron microscopy (IEM) for the ability to recognize surface epitopes. Two MAbs, designated AD6 and 10C5, that recognized surface epitopes by IEM were recovered. In order to map the epitopes recognized by these two MAbs, we constructed a set of HMW1 and HMW2 recombinant fusion proteins using the pGEMEX vectors and examined the reactivity of the MAbs with these fusion proteins. MAb AD6 recognized an epitope in both HMW1 and HMW2 which mapped to the last 75 amino acids at the carboxy termini of the two proteins. When examined for reactivity with heterologous strains, MAb AD6 recognized high-molecular-weight proteins in 75% of 125 unrelated nontypeable Haemophilus strains and, in addition, reacted with three of three such strains when examined by IEM. MAb 10C5 recognized an epitope that mapped to a 155-amino-acid segment near the carboxy terminus of HMW1. This epitope was adjacent to but distinct from the AD6 epitope and was absent from HMW2. The 10C5 epitope was expressed by 40% of the AD6 reactive strains. Identification of shared surface-exposed epitopes on the high-molecular-weight adhesion proteins suggests the possibility of developing recombinant or synthetic peptide-based vaccines protective against disease caused by the majority of NTHI strains.
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Affiliation(s)
- S J Barenkam
- Department of Pediatrics, St. Louis University School of Medicine, Missouri, USA
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Akkoyunlu M, Forsgren A. Local and systemic antibody levels against protein D ofHaemophilus influenzaefollowing immunization and infection in rats. APMIS 1996. [DOI: 10.1111/j.1699-0463.1996.tb04933.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Over the past decade, Branhamella catarrhalis has emerged as an important human pathogen. The bacterium is a common cause of otitis media in children and of lower respiratory tract infections in adults with chronic obstructive pulmonary disease. B. catarrhalis is exclusively a human pathogen. It colonizes the respiratory tract of a small proportion of adults and a larger proportion of children. Studies involving restriction enzyme analysis of genomic DNA show that colonization is a dynamic process, with the human host eliminating and acquiring new strains frequently. The surface of B. catarrhalis contains outer membrane proteins, lipooligosaccharide, and pili. The genes which encode several outer membrane proteins have been cloned, and some of these proteins are being studied as potential vaccine antigens. Analysis of the immune response has been limited by the lack of an adequate animal model of B. catarrhalis infection. New information regarding outer membrane structure should guide studies of the human immune response to B. catarrhalis. Immunoassays which specifically detect antibodies to determinants exposed on the bacterial surface will elucidate the most relevant immune response. The recognition of B. catarrhalis as an important human pathogen has stimulated research on the epidemiology and surface structures of the bacterium. Future studies to understand the mechanisms of infection and to elucidate the human immune response to infection hold promise of developing new methods to treat and prevent infections caused by B. catarrhalis.
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Affiliation(s)
- T F Murphy
- Department of Medicine, State University of New York at Buffalo, USA.
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Melhus A, Hermansson A, Forsgren A, Prellner K. Effect of Haemophilus influenzae type b conjugate vaccine in combination with peroral immunization with Escherichia coli on experimental otitis media. Int J Pediatr Otorhinolaryngol 1996; 36:1-12. [PMID: 8803686 DOI: 10.1016/0165-5876(95)01319-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The protective ability of a conjugated Haemophilus influenzae type b vaccine, ACT-HIB, used singly or in combination with orally administered Escherichia coli, was investigated in a rat model for acute otitis media. The humoral response to ACT-HIB was also analyzed. The study demonstrated that ACT-HIB vaccination resulted in a prompt antibody response, and that ACT-HIB was efficient in preventing middle ear infections caused by Haemophilus influenzae type b. The efficiency increased if the vaccine was combined with Escherichia coli. The results suggest that Escherichia coli could possibly be useful in the future as a vaccine vehicle, and since Haemophilus influenzae acute mastoiditis seems to be almost exclusively due to serotype b, the incidence of this infection may be reduced with the conjugated Haemophilus influenzae type b vaccines.
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Affiliation(s)
- A Melhus
- Department of Medical Microbiology, Lund University, Malmö General Hospital, Sweden
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Barenkamp SJ. Immunization with high-molecular-weight adhesion proteins of nontypeable Haemophilus influenzae modifies experimental otitis media in chinchillas. Infect Immun 1996; 64:1246-51. [PMID: 8606086 PMCID: PMC173911 DOI: 10.1128/iai.64.4.1246-1251.1996] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Prevention of nontypeable Haemophilus influenzae otitis media by vaccination is an important health care goal. Proteins important in bacterial adherence deserve consideration as potential vaccine candidates. Two colleagues and I previously identified a family of immunogenic high-molecular-weight proteins important in adherence of nontypeable H. influenzae to human epithelial cells (J.W. St. Geme III, S. Falkow, and S.J. Barenkamp, Proc. Natl. Acad. Sci. USA, 90:2875-2879, 1993). In the work described here, I determined whether immunization with two such adherence proteins, HMW1 and HMW2, purified from prototype nontypeable Haemophilus strain 12, would modify the course of experimental otitis media caused by the homologous strain. Chinchillas received three monthly subcutaneous injections with 40 microgram of an HMW1/HMW2 protein mixture in Freud's adjuvant. One month after the last injection, animals were challenged by intrabullar inoculation with 300 CFU of nontypeable H. influenzae 12. Infection developed in five of five control animals versus 5 of 10 immunized animals (P = 0.08, Fisher exact, one-tailed). Among infected animals, bacterial counts in middle ear fluid specimens 7 days postchallenge were significantly greater in control animals than in immunized animals (P = 0.014, Mann-Whitney U test). Serum antibody titers following immunization were comparable in uninfected and infected animals. However, infection in immunized animals was uniformly associated with the appearance of bacteria downregulated in expression of the high-molecular-weight proteins, suggesting bacterial selection in response to immunologic pressure. Although protection following immunization was incomplete, these data suggest that the high-molecular-weight adhesion proteins are potentially important protective antigens which might represent one component of a multicomponent nontypeable Haemophilus vaccine.
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Affiliation(s)
- S J Barenkamp
- Department of Pediatrics, St. Louis University School of Medicine, Missouri, USA
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36
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Abstract
Nontypable Haemophilus influenzae is a common cause of human disease and is associated with significant morbidity and considerable societal cost. At present, measures to prevent nontypable H. influenzae disease are limited to prophylactic antibiotics and, on occasion, exogenous antibody preparations. However, because these interventions are often inadequate, there is interest in developing an effective vaccine. Given the marked diversity among epidemiologically unrelated strains and the frequent strain specificity of the immune response to infection, efforts have focused on identifying bacterial antigens that are highly conserved and capable of stimulating protective antibody. With the recent identification of several such antigens, attention must now turn toward selecting the appropriate combination of these molecules and determining the optimal strategy for their presentation to the immune system. The ultimate goal is to induce broad-based and long-lasting protection.
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Affiliation(s)
- J W St Geme
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
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37
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Melhus A, Hermansson A, Akkoyunlu M, Forsgren A, Prellner K. Experimental recurrent otitis media induced by Haemophilus influenzae: protection and serum antibodies. Am J Otolaryngol 1995; 16:383-90. [PMID: 8572254 DOI: 10.1016/0196-0709(95)90075-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To study whether acute otitis media caused by encapsulated or nontypeable Haemophilus influenzae confers cross-reactive protective immunity in an animal model system and to explore the possible involvement of various humoral specific antibodies in protection. MATERIALS AND METHODS Rats were intrabullarly challenged with H influenzae type b and two different nontypeable H influenzae strains. One month after the initial infection, the animals were rechallenged ipsilaterally or contralaterally with either a homologous or heterologous strain, and the susceptibility to reinfection was investigated by otomicroscopy. RESULTS The animals challenged and rechallenged with the type b strain were well-protected ipsilaterally and contralaterally, while the protection after homologous rechallenge with a nontypeable strain was partial in the ipsilateral ear and very poor in the contralateral ear. Middle ears previously infected with a nontypeable strain remained fully susceptible to infections with heterologous strains, but there was an indication of cross-protection in the animal groups where the first episode of acute otitis media was caused by type b and the second by a nontypeable strain. Using the Western blot technique and an enzyme linked immunosorbant assay, the serological response to different outer membrane proteins, especially protein D, of H influenzae during and after middle ear infection were investigated. The serological response from the type b infected animals were generally more distinct, while the antibody levels against protein D were lower in these groups compared with the groups infected with nontypeable strains. CONCLUSIONS These data indicate that H influenzae type-b-induced experimental otitis media results in a better protection than a nontypeable-induced, and H influenzae b confers a cross protection.
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Affiliation(s)
- A Melhus
- Department of Medical Microbiology, Lund University, Malmö General Hospital, Sweden
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Karma PH, Bakaletz LO, Giebink GS, Mogi G, Rynnel-Dagöö B. Immunological aspects of otitis media: present views on possibilities of immunoprophylaxis of acute otitis media in infants and children. Int J Pediatr Otorhinolaryngol 1995; 32 Suppl:S127-34. [PMID: 7665281 DOI: 10.1016/0165-5876(94)01150-v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The article reviews, based on current knowledge of immunological events affecting the middle ear, the possibilities and prospects for the prevention of otitis media (OM) by immunologic measures. While pneumococcal capsular polysaccharide vaccines proved not to be effective against infant acute otitis media (AOM), pneumococcal conjugate vaccines provide good immunogenicity even in infants, and call for trials with better prospects of clinical efficacy. The other future approaches currently under development are vaccines against nontypable Haemophilus influenzae and Branhamella catarrhalis, anti-viral immunoprophylaxis, combinations of the above alternatives, or passive immunization. Also, the use of new routes or ways of immunization are under study. Furthermore, the ways to modify the present treatment practices of AOM to favour good immunologic responses in infants and children must be studied.
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Affiliation(s)
- P H Karma
- Department of Otorhinolaryngology, Helsinki University Central Hospital, Finland
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Rahman M, Holme T, Jönsson I, Krook A. Lack of serotype-specific antibody response to lipopolysaccharide antigens of Moraxella catarrhalis during lower respiratory tract infection. Eur J Clin Microbiol Infect Dis 1995; 14:297-304. [PMID: 7649192 DOI: 10.1007/bf02116522] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An enzyme immunoassay (EIA) was used to determine the antibody response to different serotypes of lipopolysaccharide (LPS) antigens of Moraxella catarrhalis in adult patients with lower respiratory tract infections (LRTI). Moraxella catarrhalis was isolated from sputum or nasopharyngeal samples from 20 patients with LRTI. Sixteen of the isolates were serotype A, four were type B and none were type C. The antibody response to the different LPS serotypes was determined in paired sera from patients suffering from LRTI. In addition to the 20 patients with Moraxella catarrhalis isolated (Group 1), a group of seven patients with LRTI of unknown etiology (Group 2) and a group of ten patients with LRTI of known other bacterial etiology (Group 3) were selected for this study. An increase in antibody levels of > 1.5-fold (convalescent-/acute-phase serum) was recorded in approximately half of the patients, not only in the first group (Moraxella catarrhalis isolated) but also in the other two groups. However, in the first and second groups there was a correlation between an increase in antibody levels in the LPS EIA and in an EIA using whole bacterial cells as antigen. In the group of patients in whom Moraxella catarrhalis was isolated, the antibody response to LPS antigens was not serotype specific. The antibody response to type-A and type-B LPS was more predominant than the response to type-C LPS in most patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Rahman
- Microbiology and Tumorbiology Centre, Karolinska Institute, Stockholm, Sweden
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40
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Haase EM, Yi K, Morse GD, Murphy TF. Mapping of bactericidal epitopes on the P2 porin protein of nontypeable Haemophilus influenzae. Infect Immun 1994; 62:3712-22. [PMID: 7520420 PMCID: PMC303022 DOI: 10.1128/iai.62.9.3712-3722.1994] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The P2 porin protein is the major outer membrane protein of nontypeable Haemophilus influenzae and is a potential target of a protective immune response. Nine monoclonal antibodies (MAbs) to P2 were developed by immunizing mice with nontypeable H. influenzae whole organisms. Each MAb reacted exclusively with the homologous strain in a whole-cell immunodot assay demonstrating exquisite strain specificity. All nine MAbs recognized abundantly expressed surface-exposed epitopes on the intact bacterium by immunofluorescence and immunoelectron microscopy. Each MAb was bactericidal to the homologous strain in an in vitro complement-mediated killing assay. Immunoblot assay of cyanogen bromide cleavage products of purified P2 indicated that MAb 5F2 recognized the 10-kDa fragment, and the other eight MAbs recognized the 32-kDa fragment. Competitive ELISAs confirmed that 5F2 recognized an epitope that is different from the other eight MAbs. To further localize epitopes, MAbs 5F2 and 6G3 were studied in protein footprinting by using reversed-phase high-performance liquid chromatography. Three potential epitope-containing peptides which were reactive in an enzyme-linked immunosorbent assay with both 5F2 and 6G3 were isolated. These peptides were identified by N-terminal amino acid sequence and localized to loops 5 and 8 of the proposed model for P2. Fusion proteins consisting of glutathione S-transferase fused with variable-length peptides from loops 5 and 8 were expressed in the pGEX-2T vector. Immunoblot assay of fusion peptides of loops 5 and 8 confirmed that 5F2 recognized an epitope within residues 338 to 354 of loop 8; 6G3 and the remaining MAbs recognized an epitope within residues 213 to 229 of loop 5. These studies indicate that nontypeable H. influenzae contains bactericidal epitopes which have been mapped to two different surface-exposed loops of the P2 molecule. These potentially protective epitopes are strain specific and abundantly expressed on the surface of the intact bacterium.
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Affiliation(s)
- E M Haase
- Department of Veterans Affairs Medical Center, Buffalo, New York
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41
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Sirakova T, Kolattukudy PE, Murwin D, Billy J, Leake E, Lim D, DeMaria T, Bakaletz L. Role of fimbriae expressed by nontypeable Haemophilus influenzae in pathogenesis of and protection against otitis media and relatedness of the fimbrin subunit to outer membrane protein A. Infect Immun 1994; 62:2002-20. [PMID: 7909539 PMCID: PMC186460 DOI: 10.1128/iai.62.5.2002-2020.1994] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Nontypeable Haemophilus influenzae is a primary pathogen in both acute otitis media (OM) and chronic OM, yet the pathogenesis of this disease is not fully understood. Although fimbriae have been observed on all clinical OM isolates examined to date, their role in pathogenesis remains unclear. Therefore, the gene which codes for the fimbrial subunit protein (fimbrin) in nontypeable H. influenzae 1128 was isolated, cloned, and sequenced. The nucleotide sequence of the fimbrin gene was found to contain an open reading frame of 1,077 bp which would encode a mature fimbrin protein consisting of 338 amino acid with a calculated molecular mass of 36.4 kDa. The translated amino acid sequence was found to be homologous with various OmpA proteins of other gram-negative bacteria, and algorithmic analysis predicted that this protein is organized as a coiled coil. To directly test whether fimbriae are involved in pathogenesis, the fimbrin gene was disrupted, and the biological consequences of disruption were absence of both expression of the fimbrial appendage and the specific immunogold labeling thereof with antisera directed against isolated fimbrial protein, reduced adherence to human oropharyngeal cells in vitro, augmented clearance from the tympanum post-transbullar inoculation, and significantly reduced induction of OM post-intranasal inoculation in a chinchilla model compared with the fimbriated parent strain. We additionally find that either passive immunization or active immunization against isolated fimbrial protein confers partial protection against transbullar challenge. A Western blot (immunoblot) indicated a degree of serological relatedness among fimbrin proteins of 15 nontypeable and type b isolates. These data suggest that fimbrin could be useful as a component of a vaccine to protect against OM.
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Affiliation(s)
- T Sirakova
- Department of Otolaryngology, College of Medicine, Ohio State University, Columbus
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42
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Green BA, Doyle WJ, Cowell JL. Chinchilla model of experimental otitis media for study of nontypable Haemophilus influenzae vaccine efficacy. Methods Enzymol 1994; 235:59-68. [PMID: 8057928 DOI: 10.1016/0076-6879(94)35131-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- B A Green
- Department of Bacteriology Research, Lederle-Praxis Biologicals, Inc., West Henrietta, New York 14586
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43
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Shurin PA, Rehmus JM, Johnson CE, Marchant CD, Carlin SA, Super DM, Van Hare GF, Jones PK, Ambrosino DM, Siber GR. Bacterial polysaccharide immune globulin for prophylaxis of acute otitis media in high-risk children. J Pediatr 1993; 123:801-10. [PMID: 8229496 DOI: 10.1016/s0022-3476(05)80865-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We evaluated the prevention of recurrences of acute otitis media (AOM) by bacterial polysaccharide immune globulin (BPIG), a hyperimmune human immune globulin prepared by immunizing donors with bacterial polysaccharide vaccines. We used a randomized, stratified, double-blind, placebo-controlled design. Children < or = 24 months of age with 1 to 3 prior episodes of AOM received BPIG, 0.5 ml/kg, or saline placebo intramuscularly at entry and 30 days later. During the 120-day follow-up period, AOM was diagnosed by using clinical criteria and was confirmed with tympanocentesis and culture of the middle ear exudates. Eighty-eight episodes of AOM were observed in 76 patients who completed the study. The incidence of AOM during the entire 120-day study period was similar in BPIG and placebo recipients. Pneumococcal AOM was significantly less frequent in BPIG recipients (0.21 episode per patient) than in placebo recipients (0.45 episode per patient; p = 0.05). Time spent free of AOM was significantly prolonged in recipients of BPIG, in comparison with placebo recipients (51 vs 35 days; p = 0.034). This study demonstrated that circulating antibody, even without stimulation of specific local immunity, may prevent infection of the middle ear. The use of immune globulin preparations for longer periods or at a higher dosage might decrease the incidence of recurrent AOM in otitis-prone children, and deserves further evaluation.
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Affiliation(s)
- P A Shurin
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York
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44
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Green BA, Vazquez ME, Zlotnick GW, Quigley-Reape G, Swarts JD, Green I, Cowell JL, Bluestone CD, Doyle WJ. Evaluation of mixtures of purified Haemophilus influenzae outer membrane proteins in protection against challenge with nontypeable H. influenzae in the chinchilla otitis media model. Infect Immun 1993; 61:1950-7. [PMID: 8478084 PMCID: PMC280788 DOI: 10.1128/iai.61.5.1950-1957.1993] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) is one of the leading causative agents of bacterial otitis media, and no vaccine has been shown to be effective against it. Three outer membrane lipoproteins of NTHi have been investigated extensively and are leading candidates for inclusion in a vaccine against this organism. Hi-PAL (P6), recombinant PCP (rPCP), and e (P4) proteins are antigenically conserved among NTHi strains and elicit bactericidal and protective antibodies. A genetic fusion of the rPCP and Hi-PAL proteins has also been reported. Mixtures of these proteins were used for active immunization experiments in the chinchilla model of otitis media. Chinchillas were immunized either with a mixture of all three lipoproteins or with the mixture of rPCP-PAL hybrid plus e protein. When these animals were challenged with a NTHi strain injected directly into the middle ears, no protection from infection or disease, as measured by otoscopy, was observed in either group. However, effusion and inflammation measured by tympanometry were significantly reduced in animals immunized with the three lipoproteins. Animals that had been immunized with either whole NTHi cells or total outer membranes and then challenged with the homologous strain were significantly protected from both infection and disease, as determined by tympanometry and otoscopy. Unlike other animals antisera, chinchilla antisera against the purified proteins had no bactericidal activity against NTHi but did fix complement on the cell surface. Thus, the chinchilla immune responses to mixtures of these lipoproteins differ from the immune responses observed in other animal species. Further evaluation of these proteins for their vaccine potential remains to be done.
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Affiliation(s)
- B A Green
- Lederle-Praxis Biologicals, Inc., West Henrietta, New York 14586-9728
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45
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Faden H, Hong J, Murphy T. Immune response to outer membrane antigens of Moraxella catarrhalis in children with otitis media. Infect Immun 1992; 60:3824-9. [PMID: 1500191 PMCID: PMC257395 DOI: 10.1128/iai.60.9.3824-3829.1992] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The systemic and local antibody responses to homologous strains of Moraxella catarrhalis were investigated in 14 children with otitis media. A total of 8 children (57%) demonstrated a rise in serum antibody of the immunoglobulin G (IgG) (5 of 14), IgM (5 of 14), or IgA (6 of 14) classes of immunoglobulin to outer membrane antigens. Local antibody consisted of IgG (100%), IgM (29%), and IgA (71%). The IgG and IgA specific antibody present in middle-ear effusions appeared to represent local production rather than passive diffusion from the systemic circulation. These data suggest that young children develop an antibody response to M. catarrhalis in the middle ear during otitis media but fail to develop systemic antibody in a uniform manner.
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Affiliation(s)
- H Faden
- Department of Pediatrics, State University of New York School of Medicine, Buffalo 14126
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46
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Bernstein JM, Faden HS, Loos BG, Murphy TF, Ogra PL. Recurrent otitis media with non-typable Haemophilus influenzae: the role of serum bactericidal antibody. Int J Pediatr Otorhinolaryngol 1992; 23:1-13. [PMID: 1592547 DOI: 10.1016/0165-5876(92)90074-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of serum bactericidal antibody on colonization with non-typable Haemophilus influenzae (NTHI) was studied in 26 children. Serum bactericidal antibody did not prevent colonization with NTHI in the nasopharynx. Antibody was present in 53% before, 91% during and 100% after documented colonization of the nasopharynx with NTHI. In addition, 5 children with recurrent otitis media with effusion (OME) due to NTHI were observed for bactericidal serum antibody during a 4-year period. Bactericidal antibody against the causative NTHI strain was not detected in the acute sera of any patient during each episode, but was observed in the convalescent sera of all of the patients. The bactericidal antibody in the convalescent serum did not appear to be protective against colonization and recurrence of disease by a different heterologous strain of NTHI. However, bactericidal antibody was augmented in some cases by a heterologous infection with NTHI. We confirmed the emergence of new strains of NTHI with DNA fingerprinting and outer membrane protein (OMP) analysis. The data suggest that the immune response to NTHI in OME is usually strain-specific, and furthermore, the results demonstrate that strain-specific bactericidal antibody does not prevent colonization in the nasopharynx with the homologous or heterologous bacterial strains. In general, bactericidal antibody is not cross-protective against heterologous strains of NTHI causing a second or third episode of otitis media with NTHI.
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Affiliation(s)
- J M Bernstein
- Department of Otolaryngology, State University of New York, Buffalo
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47
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Wallace FJ, Cripps AW, Clancy RL, Husband AJ, Witt CS. A role for intestinal T lymphocytes in bronchus mucosal immunity. Immunology 1991; 74:68-73. [PMID: 1937575 PMCID: PMC1384673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rats immunized by intra-Peyer's patch (IPP) injection with non-typable Haemophilus influenzae (NTHI) have been shown to clear this organism from the respiratory tract faster than non-immunized rats. We therefore performed a series of experiments in order to determine the mechanism of action of the enhanced pulmonary clearance. The experiments show that homing of intestinal T cells to the respiratory tract is an important component in the observed immunity, while specific antibody adsorbed to bacteria does not influence pulmonary bacterial clearance rate. Mucosally derived lymphocytes were collected from the thoracic duct of rats primed by IPP inoculation with NTHI, and intravenously transfused to recipient rats. These rats were shown to clear bacteria from bronchial spaces faster than non-transfused rats, or rats transfused with non-immune lymphocytes. Lymphocytes collected from the spleens of immunized rats were also capable of conferring the ability to accelerate pulmonary clearance. When thoracic duct lymphocytes (TDL) purified for T lymphocytes were transferred to recipients, the NTHI clearance rate was accelerated. In experiments to evaluate the activity of specific antibody, it was demonstrated that NTHI opsonized with antibody from bronchial washings of immunized rats was not cleared from the respiratory tract of naive rats faster than non-opsonized controls. These data indicate that immune clearance of NTHI from the respiratory tract following gut immunization is dependent upon antigen-primed lymphocytes, that primed T cells are capable of conferring this protection, and that a primary role for specific antibody in the process cannot be established.
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Affiliation(s)
- F J Wallace
- Auspharm Institute of Mucosal Immunology, Jesmond, Australia
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Green BA, Farley JE, Quinn-Dey T, Deich RA, Zlotnick GW. The e (P4) outer membrane protein of Haemophilus influenzae: biologic activity of anti-e serum and cloning and sequencing of the structural gene. Infect Immun 1991; 59:3191-8. [PMID: 1715322 PMCID: PMC258152 DOI: 10.1128/iai.59.9.3191-3198.1991] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Outer membrane proteins of nontypeable (NT) Haemophilus influenzae are among the major candidates for inclusion in vaccines against these organisms. This article reports the purification of the e (P4) lipoprotein of H. influenzae and the subsequent production of antiserum directed against this protein. The anti-e polyclonal serum cross-reacted with e protein in multiple clinical NT H. influenzae isolates. Monoclonal antibody analysis of e protein showed at least one surface-exposed epitope to be conserved among NT H. influenzae strains. Anti-e serum also had bactericidal activity against multiple clinical isolates of NT H. influenzae. These results are in contrast to previous reports in the literature that purified P4 protein did not elicit biologically active antibodies. Anti-e antibodies exhibited synergistic bactericidal activity directed against NT H. influenzae when mixed with antibodies directed against another Haemophilus lipoprotein, PCP. This bactericidal synergy was observed against a variety of NT clinical isolates. We also report the cloning of the Haemophilus e lipoprotein, or hel, gene encoding the e protein and its expression and processing in Escherichia coli. The nucleotide sequence of the gene and deduced amino acid sequence of the protein are given. These results demonstrate that e protein is a viable candidate to be a component of a vaccine against NT H. influenzae.
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Affiliation(s)
- B A Green
- Praxis Biologics, Inc., Rochester, New York 14623
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Svinhufvud M, Prellner K, Hermansson A, Schalén C. Experimental recurrent pneumococcal otitis media. Protection and serum antibodies. Acta Otolaryngol 1991; 111:1083-9. [PMID: 1763630 DOI: 10.3109/00016489109100760] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To elucidate immune mechanisms in otitis media, middle ear infection was induced in 12 rats by intratympanic inoculation of Streptococcus pneumoniae type 3, either the ipsilateral or the contralateral middle ear being re-challenged 4 weeks later. Otomicroscopy inspection confirmed the presence of acute otitis media (AOM) in all rats after the first challenge. After re-challenge, protection against AOM was noted both in the ipsilateral and contralateral ears. Serum antibody concentrations increased after the initial challenge, reaching a maximum at 4-7 days, but had decreased to pre-immune levels at re-challenge, after which no new increase was noted. Serum IgG-antibodies to pneumococcal type 3-polysaccharide were triggered following the initial induction of unilateral pneumococcal AOM, but mucosal immune mechanisms are argued to be a more probable explanation of the ipsilateral protection seen after re-challenge.
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Affiliation(s)
- M Svinhufvud
- Department of Oto-Rhino-Laryngology University Hospital, Lund, Sweden
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