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Morimura A, Hamaguchi S, Akeda Y, Tomono K. Mechanisms Underlying Pneumococcal Transmission and Factors Influencing Host-Pneumococcus Interaction: A Review. Front Cell Infect Microbiol 2021; 11:639450. [PMID: 33996623 PMCID: PMC8113816 DOI: 10.3389/fcimb.2021.639450] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/06/2021] [Indexed: 01/21/2023] Open
Abstract
Streptococcus pneumoniae (also called pneumococcus) is not only a commensal that frequently colonizes the human upper respiratory tract but also a pathogen that causes pneumonia, sepsis, and meningitis. The mechanism of pneumococcal infection has been extensively studied, but the process of transmission has not been fully elucidated because of the lack of tractable animal models. Novel animal models of transmission have enabled further progress in investigating pneumococcal transmission mechanisms including the processes such as pneumococcal shedding, survival in the external environment, and adherence to the nasopharynx of a new host. Herein, we present a review on these animal models, recent research findings about pneumococcal transmission, and factors influencing the host-pneumococcus interaction.
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Affiliation(s)
- Ayumi Morimura
- Department of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Shigeto Hamaguchi
- Department of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan.,Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
| | - Yukihiro Akeda
- Department of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan.,Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan.,Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Kazunori Tomono
- Department of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan.,Division of Infection Control and Prevention, Osaka University Hospital, Osaka, Japan
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Wagner-Muñiz DA, Haughney SL, Kelly SM, Wannemuehler MJ, Narasimhan B. Room Temperature Stable PspA-Based Nanovaccine Induces Protective Immunity. Front Immunol 2018; 9:325. [PMID: 29599766 PMCID: PMC5863507 DOI: 10.3389/fimmu.2018.00325] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 02/06/2018] [Indexed: 01/05/2023] Open
Abstract
Streptococcus pneumoniae is a major causative agent of pneumonia, a debilitating disease particularly in young and elderly populations, and is the leading worldwide cause of death in children under the age of five. While there are existing vaccines against S. pneumoniae, none are protective across all serotypes. Pneumococcal surface protein A (PspA), a key virulence factor of S. pneumoniae, is an antigen that may be incorporated into future vaccines to address the immunological challenges presented by the diversity of capsular antigens. PspA has been shown to be immunogenic and capable of initiating a humoral immune response that is reactive across approximately 94% of pneumococcal strains. Biodegradable polyanhydrides have been studied as a nanoparticle-based vaccine (i.e., nanovaccine) platform to stabilize labile proteins, to provide adjuvanticity, and enhance patient compliance by providing protective immunity in a single dose. In this study, we designed a room temperature stable PspA-based polyanhydride nanovaccine that eliminated the need for a free protein component (i.e., 100% encapsulated within the nanoparticles). Mice were immunized once with the lead nanovaccine and upon challenge, presented significantly higher survival rates than animals immunized with soluble protein alone, even with a 25-fold reduction in protein dose. This lead nanovaccine formulation performed similarly to protein adjuvanted with Alum, however, with much less tissue reactogenicity at the site of immunization. By eliminating the free PspA from the nanovaccine formulation, the lead nanovaccine was efficacious after being stored dry for 60 days at room temperature, breaking the need for maintaining the cold chain. Altogether, this study demonstrated that a single dose PspA-based nanovaccine against S. pneumoniae induced protective immunity and provided thermal stability when stored at room temperature for at least 60 days.
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Affiliation(s)
- Danielle A. Wagner-Muñiz
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States
| | - Shannon L. Haughney
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States
| | - Sean M. Kelly
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States
| | - Michael J. Wannemuehler
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States
- Nanovaccine Institute, Iowa State University, Ames, IA, United States
| | - Balaji Narasimhan
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States
- Nanovaccine Institute, Iowa State University, Ames, IA, United States
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Habets MN, van Selm S, van Opzeeland FJ, Simonetti E, Hermans PWM, de Jonge MI, Diavatopoulos DA. Role of antibodies and IL17-mediated immunity in protection against pneumococcal otitis media. Vaccine 2016; 34:5968-5974. [PMID: 27771185 DOI: 10.1016/j.vaccine.2016.09.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 09/12/2016] [Accepted: 09/29/2016] [Indexed: 11/19/2022]
Abstract
Widespread vaccination against Streptococcus pneumoniae (the pneumococcus) has significantly reduced pneumococcal disease caused by vaccine serotypes. Despite vaccination, overall pneumococcal colonization rates in children have not reduced and otitis media (OM) by non-vaccine serotypes remains one of the most common childhood infections. Pneumococcal surface protein A (PspA) has been shown to be a promising protein antigen to induce broad protection against pneumococcal colonization. However, its ability to protect against OM remains unclear. Using our previously established mouse model of influenza-virus induced pneumococcal OM, we here show that intranasal vaccination of mice with PspA together with the mucosal adjuvant CTB results in a decrease in pneumococcal load in the middle ears. This decrease correlated with the induction of PspA-specific IgA, a balanced IgG1:IgG2a antibody response and the induction of a mucosal Th17 response. Our data suggests that the IL-17 response to PspA is more important for protection against OM, whilst the presence of antibodies may be less important, as determined in mice deficient in IL-17 signaling or antibody production. Together, these results suggest that mucosal vaccination with PspA may not only protect against colonization, but also against the development of virus-induced pneumococcal OM.
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Affiliation(s)
- Marrit N Habets
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Saskia van Selm
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Fred J van Opzeeland
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Elles Simonetti
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Peter W M Hermans
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Marien I de Jonge
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Dimitri A Diavatopoulos
- Laboratory of Pediatric Infectious Diseases, Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 10 (Route 412), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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Novel Strategy To Protect against Influenza Virus-Induced Pneumococcal Disease without Interfering with Commensal Colonization. Infect Immun 2016; 84:1693-1703. [PMID: 27001538 DOI: 10.1128/iai.01478-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/13/2016] [Indexed: 12/16/2022] Open
Abstract
Streptococcus pneumoniae commonly inhabits the nasopharynx as a member of the commensal biofilm. Infection with respiratory viruses, such as influenza A virus, induces commensal S. pneumoniae to disseminate beyond the nasopharynx and to elicit severe infections of the middle ears, lungs, and blood that are associated with high rates of morbidity and mortality. Current preventive strategies, including the polysaccharide conjugate vaccines, aim to eliminate asymptomatic carriage with vaccine-type pneumococci. However, this has resulted in serotype replacement with, so far, less fit pneumococcal strains, which has changed the nasopharyngeal flora, opening the niche for entry of other virulent pathogens (e.g., Streptococcus pyogenes, Staphylococcus aureus, and potentially Haemophilus influenzae). The long-term effects of these changes are unknown. Here, we present an attractive, alternative preventive approach where we subvert virus-induced pneumococcal disease without interfering with commensal colonization, thus specifically targeting disease-causing organisms. In that regard, pneumococcal surface protein A (PspA), a major surface protein of pneumococci, is a promising vaccine target. Intradermal (i.d.) immunization of mice with recombinant PspA in combination with LT-IIb(T13I), a novel i.d. adjuvant of the type II heat-labile enterotoxin family, elicited strong systemic PspA-specific IgG responses without inducing mucosal anti-PspA IgA responses. This response protected mice from otitis media, pneumonia, and septicemia and averted the cytokine storm associated with septic infection but had no effect on asymptomatic colonization. Our results firmly demonstrated that this immunization strategy against virally induced pneumococcal disease can be conferred without disturbing the desirable preexisting commensal colonization of the nasopharynx.
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Uraki R, Piao Z, Akeda Y, Iwatsuki-Horimoto K, Kiso M, Ozawa M, Oishi K, Kawaoka Y. A Bivalent Vaccine Based on a PB2-Knockout Influenza Virus Protects Mice From Secondary Pneumococcal Pneumonia. J Infect Dis 2015; 212:1939-48. [PMID: 26123562 DOI: 10.1093/infdis/jiv341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/10/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Secondary bacterial infections after influenza can be a serious problem, especially in young children and the elderly, yet the efficacy of current vaccines is limited. Earlier work demonstrated that a replication-incompetent PB2-knockout (PB2-KO) influenza virus possessing a foreign gene in the coding region of its PB2 segment can serve as a platform for a bivalent vaccine. METHODS In the current study, we generated the PB2-KO virus expressing pneumococcal surface protein A (PspA), PB2-KO-PspA virus, the replication of which is restricted to PB2-expressing cells. We then examined the protective efficacy of intranasal immunization with this virus as a bivalent vaccine in a mouse model. RESULTS High levels of influenza virus-specific and PspA-specific antibodies were induced in the serum and airways of immunized mice. The intranasally immunized mice were protected from lethal doses of influenza virus or Streptococcus pneumoniae. These mice were also completely protected from secondary pneumococcal pneumonia after influenza virus infection. CONCLUSIONS These findings indicate that our recombinant influenza virus serves as a novel and powerful bivalent vaccine against primary and secondary pneumococcal pneumonia as well as influenza.
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Affiliation(s)
- Ryuta Uraki
- Division of Virology, Department of Microbiology and Immunology
| | - Zhenyu Piao
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University
| | - Yukihiro Akeda
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University
| | | | - Maki Kiso
- Division of Virology, Department of Microbiology and Immunology
| | - Makoto Ozawa
- Laboratory of Animal Hygiene Transboundary Animal Diseases Center, Joint Faculty of Veterinary Medicine, Kagoshima University
| | - Kazunori Oishi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University
| | - Yoshihiro Kawaoka
- Division of Virology, Department of Microbiology and Immunology Department of Special Pathogens, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo ERATO Infection-Induced Host Responses Project (JST), Saitama, Japan Department of Pathobiological Sciences, University of Wisconsin-Madison
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A bivalent vaccine based on a replication-incompetent influenza virus protects against Streptococcus pneumoniae and influenza virus infection. J Virol 2014; 88:13410-7. [PMID: 25210171 DOI: 10.1128/jvi.01205-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Streptococcus pneumoniae is a major causative pathogen in community-acquired pneumonia; together with influenza virus, it represents an important public health burden. Although vaccination is the most effective prophylaxis against these infectious agents, no single vaccine simultaneously provides protective immunity against both S. pneumoniae and influenza virus. Previously, we demonstrated that several replication-incompetent influenza viruses efficiently elicit IgG in serum and IgA in the upper and lower respiratory tracts. Here, we generated a replication-incompetent hemagglutinin knockout (HA-KO) influenza virus possessing the sequence for the antigenic region of pneumococcal surface protein A (PspA). Although this virus (HA-KO/PspA virus) could replicate only in an HA-expressing cell line, it infected wild-type cells and expressed both viral proteins and PspA. PspA- and influenza virus-specific antibodies were detected in nasal wash and bronchoalveolar lavage fluids and in sera from mice intranasally inoculated with HA-KO/PspA virus, and mice inoculated with HA-KO/PspA virus were completely protected from lethal challenge with either S. pneumoniae or influenza virus. Further, bacterial colonization of the nasopharynx was prevented in mice immunized with HA-KO/PspA virus. These results indicate that HA-KO/PspA virus is a promising bivalent vaccine candidate that simultaneously confers protective immunity against both S. pneumoniae and influenza virus. We believe that this strategy offers a platform for the development of bivalent vaccines, based on replication-incompetent influenza virus, against pathogens that cause respiratory infectious diseases. IMPORTANCE Streptococcus pneumoniae and influenza viruses cause contagious diseases, but no single vaccine can simultaneously provide protective immunity against both pathogens. Here, we used reverse genetics to generate a replication-incompetent influenza virus carrying the sequence for the antigenic region of pneumococcal surface protein A and demonstrated that mice immunized with this virus were completely protected from lethal doses of infection with either influenza virus or Streptococcus pneumoniae. We believe that this strategy, which is based on a replication-incompetent influenza virus possessing the antigenic region of other respiratory pathogens, offers a platform for the development of bivalent vaccines.
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Piao Z, Akeda Y, Takeuchi D, Ishii KJ, Ubukata K, Briles DE, Tomono K, Oishi K. Protective properties of a fusion pneumococcal surface protein A (PspA) vaccine against pneumococcal challenge by five different PspA clades in mice. Vaccine 2014; 32:5607-13. [PMID: 25132335 DOI: 10.1016/j.vaccine.2014.07.108] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/21/2014] [Accepted: 07/31/2014] [Indexed: 12/17/2022]
Abstract
An increase in the appearance of nonvaccine serotypes in both children and adults with invasive pneumococcal disease (IPD) after introduction of pneumococcal conjugate vaccine represents a limitation of this vaccine. In this study, we generated three recombinant pneumococcal surface protein A (PspA) proteins comprising PspA families 1 and 2, and we examined the reactivity of antisera raised in mice immunized with a PspA fusion protein in combination with CpG oligonucleotides plus aluminum hydroxide gel. The protective effects of immunization with PspA fusion proteins against pneumococcal challenge by strains with five different PspA clades were also examined in mice. Flow cytometry demonstrated that PspA3+2-induced antiserum showed the greatest binding of PspA-specific IgG to all five challenge strains with different clades. PspA2+4- or PspA2+5-induced antiserum showed the lowest binding of PspA-specific IgG to clade 3. Immunization with PspA3+2 afforded significant protection against pneumococcal challenge by five strains with different clades in mice, but immunization with PspA2+4 or PspA2+5 failed to protect mice from pneumococcal challenge by strains with clades 1 and 3. The binding of PspA-specific IgG in antisera raised by three PspA fusion proteins was examined in 68 clinical isolates from adult patients with IPD. Immunization of mice with PspA3+2-induced antiserum with a high binding capacity for clinical isolates expressing clades 1-4, but not clade 5. Our results suggest that the PspA3+2 vaccine has an advantage over the PspA2+4 or PspA2+5 vaccine in terms of a broad range of cross-reactivity with clinical isolates and cross-protection against pneumococcal challenge in mice.
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Affiliation(s)
- Zhenyu Piao
- Laboratory for Clinical Research on Infectious Disease, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan; Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Japan
| | - Yukihiro Akeda
- Laboratory for Clinical Research on Infectious Disease, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan
| | - Dan Takeuchi
- Laboratory for Clinical Research on Infectious Disease, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan
| | - Ken J Ishii
- National Institute of Biomedical Innovation, Japan; Laboratory of Vaccine Science, WPI Immunology Frontier Research Center, Osaka University, Japan
| | - Kimiko Ubukata
- Department of Infectious Diseases, Keio University School of Medicine, Japan
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, USA
| | - Kazunori Tomono
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Japan
| | - Kazunori Oishi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Japan.
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Cheng C, Pal S, Tifrea D, Jia Z, de la Maza LM. A vaccine formulated with a combination of TLR-2 and TLR-9 adjuvants and the recombinant major outer membrane protein elicits a robust immune response and significant protection against a Chlamydia muridarum challenge. Microbes Infect 2014; 16:244-52. [PMID: 24291713 PMCID: PMC3965591 DOI: 10.1016/j.micinf.2013.11.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 12/17/2022]
Abstract
Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen in the World and there is a need for a vaccine. To enhance the immunogenicity of a vaccine formulated with the Chlamydia muridarum (Cm) mouse pneumonitis recombinant major outer membrane protein (MOMP), we used combinations of Pam2CSK4 + CpG-1826 and Montanide ISA 720 VG + CpG-1826 as adjuvants. Neisseria gonorrhoeae recombinant porin B (Ng-PorB) was used as the antigen control with the same adjuvants. Female BALB/c mice were immunized twice in the nares (i.n.) or in the colon (cl.) and were boosted twice by the intramuscular plus subcutaneous (i.m. + s.c.) routes. Based on the IgG2a/IgG1 ratio in sera, mice immunized with MOMP + Pam2CSK4 + CpG-1826 showed a strong Th2 response while animals vaccinated with MOMP + Montanide ISA 720 VG + CpG-1826 had a Th1 response. Both groups of mice also developed robust Cm-specific T cell proliferation and high levels of IFN-γ. Four weeks after the last immunization, the mice were challenged i.n. with 10(4) inclusion-forming units (IFU) of Cm. Using changes in body weight and number of IFU recovered from the lungs at 10 days post-challenge mice immunized i.n. + i.m./s.c. with MOMP + Pam2CSK4 + CpG-1826 were better protected than other groups. In conclusion, MOMP adjuvanted with Pam2CSK4 + CpG-1826, elicits strong humoral and cellular immune responses and induces significant protection against Chlamydia.
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Affiliation(s)
- Chunmei Cheng
- Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, CA 92697-4800, USA
| | - Sukumar Pal
- Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, CA 92697-4800, USA
| | - Delia Tifrea
- Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, CA 92697-4800, USA
| | - Zhenyu Jia
- Translational Cancer Biology, Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA 92697-4800, USA
| | - Luis M de la Maza
- Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, CA 92697-4800, USA.
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Effective protection against secondary pneumococcal pneumonia by oral vaccination with attenuated Salmonella delivering PspA antigen in mice. Vaccine 2012; 30:6816-23. [DOI: 10.1016/j.vaccine.2012.09.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 07/12/2012] [Accepted: 09/07/2012] [Indexed: 11/23/2022]
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Miller MA, Stabenow JM, Parvathareddy J, Wodowski AJ, Fabrizio TP, Bina XR, Zalduondo L, Bina JE. Visualization of murine intranasal dosing efficiency using luminescent Francisella tularensis: effect of instillation volume and form of anesthesia. PLoS One 2012; 7:e31359. [PMID: 22384012 PMCID: PMC3286442 DOI: 10.1371/journal.pone.0031359] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 01/06/2012] [Indexed: 11/18/2022] Open
Abstract
Intranasal instillation is a widely used procedure for pneumonic delivery of drugs, vaccine candidates, or infectious agents into the respiratory tract of research mice. However, there is a paucity of published literature describing the efficiency of this delivery technique. In this report we have used the murine model of tularemia, with Francisella tularensis live vaccine strain (FTLVS) infection, to evaluate the efficiency of pneumonic delivery via intranasal dosing performed either with differing instillation volumes or different types of anesthesia. FTLVS was rendered luminescent via transformation with a reporter plasmid that constitutively expressed the Photorhabdus luminescens lux operon from a Francisella promoter. We then used an IVIS Spectrum whole animal imaging system to visualize FT dissemination at various time points following intranasal instillation. We found that instillation of FT in a dose volume of 10 µl routinely resulted in infection of the upper airways but failed to initiate infection of the pulmonary compartment. Efficient delivery of FT into the lungs via intranasal instillation required a dose volume of 50 µl or more. These studies also demonstrated that intranasal instillation was significantly more efficient for pneumonic delivery of FTLVS in mice that had been anesthetized with inhaled (isoflurane) vs. parenteral (ketamine/xylazine) anesthesia. The collective results underscore the need for researchers to consider both the dose volume and the anesthesia type when either performing pneumonic delivery via intranasal instillation, or when comparing studies that employed this technique.
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Affiliation(s)
- Mark A Miller
- The University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.
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A TLR2 agonist is a more effective adjuvant for a Chlamydia major outer membrane protein vaccine than ligands to other TLR and NOD receptors. Vaccine 2011; 29:6641-9. [PMID: 21742006 DOI: 10.1016/j.vaccine.2011.06.105] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 06/22/2011] [Accepted: 06/25/2011] [Indexed: 12/24/2022]
Abstract
Chlamydia trachomatis (Ct) is the most common sexually transmitted bacterial pathogen in the World and there is an urgent need for a vaccine to prevent these infections. To determine what type of adjuvant can better enhance the immunogenicity of a Chlamydia vaccine, we formulated the recombinant major outer membrane protein (Ct-rMOMP) with several ligands for Toll-like receptors (TLR) and the nucleotide-binding oligomerization domain (NOD) including Pam(2)CSK(4) (TLR2/TLR6), Poly (I:C) (TLR3), monophosphoryl lipid A (TLR4), flagellin (TLR5), imiquimod R837 (TLR7), imidazoquinoline R848 (TRL7/8), CpG-1826 (TLR9), M-Tri-(DAP) (NOD1/NOD2) and muramyldipeptide (NOD2). Groups of female BALB/c mice were immunized intramuscularly (i.m.) three times with the Ct-rMOMP and each one of those adjuvants. Four weeks after the last immunization the mice were challenged intranasally (i.n.) with 10(4)C. trachomatis mouse pneumonitis (MoPn) inclusion forming units (IFU). As negative antigen control, mice were immunized with the Neisseria gonorrhoeae recombinant porin B (Ng-rPorB) and the same adjuvants. As a positive vaccine control, mice were inoculated i.n. with 10(4)IFU of MoPn. The humoral and cell mediated immune responses were determined the day before the challenge. Following the challenge the mice were weighed daily and, at 10 days post-challenge (p.c.), they were euthanized, their lungs weighted and the number of IFU in the lungs counted. As determined by the IgG2a/IgG1 ratio in the sera, mice immunized with Ct-rMOMP+Pam(2)CSK(4) showed a strong Th2 biased humoral immune response. Furthermore, these mice developed a robust cellular immune response with high Chlamydia-specific T cell proliferation and levels of IFN-γ production. In addition, based on changes in body weight, weight of the lungs and number of IFU recovered from the lungs, the mice immunized with Ct-rMOMP+Pam(2)CSK(4), were better protected against the i.n. challenge than any group of mice immunized with Ct-rMOMP and the other adjuvants. In conclusion, Pam(2)CSK(4) should be evaluated as a candidate adjuvant for a C. trachomatis vaccine.
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