1
|
Gil E, Noursadeghi M, Brown JS. Streptococcus pneumoniae interactions with the complement system. Front Cell Infect Microbiol 2022; 12:929483. [PMID: 35967850 PMCID: PMC9366601 DOI: 10.3389/fcimb.2022.929483] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/08/2022] [Indexed: 11/21/2022] Open
Abstract
Host innate and adaptive immunity to infection with Streptococcus pneumoniae is critically dependent on the complement system, demonstrated by the high incidence of invasive S. pneumoniae infection in people with inherited deficiency of complement components. The complement system is activated by S. pneumoniae through multiple mechanisms. The classical complement pathway is activated by recognition of S. pneumoniae by C-reactive protein, serum amyloid P, C1q, SIGN-R1, or natural or acquired antibody. Some S. pneumoniae strains are also recognised by ficolins to activate the mannose binding lectin (MBL) activation pathway. Complement activation is then amplified by the alternative complement pathway, which can also be activated by S. pneumoniae directly. Complement activation results in covalent linkage of the opsonic complement factors C3b and iC3b to the S. pneumoniae surface which promote phagocytic clearance, along with complement-mediated immune adherence to erythrocytes, thereby protecting against septicaemia. The role of complement for mucosal immunity to S. pneumoniae is less clear. Given the major role of complement in controlling infection with S. pneumoniae, it is perhaps unsurprising that S. pneumoniae has evolved multiple mechanisms of complement evasion, including the capsule, multiple surface proteins, and the toxin pneumolysin. There is considerable variation between S. pneumoniae capsular serotypes and genotypes with regards to sensitivity to complement which correlates with ability to cause invasive infections. However, at present we only have a limited understanding of the main mechanisms causing variations in complement sensitivity between S. pneumoniae strains and to non-pathogenic streptococci.
Collapse
Affiliation(s)
- Eliza Gil
- Division of Infection and Immunity, University College London, London, United Kingdom
- *Correspondence: Eliza Gil,
| | - Mahdad Noursadeghi
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Jeremy S. Brown
- Division of Medicine, University College London, London, United Kingdom
| |
Collapse
|
2
|
Nakahashi-Ouchida R, Uchida Y, Yuki Y, Katakai Y, Yamanoue T, Ogawa H, Munesue Y, Nakano N, Hanari K, Miyazaki T, Saito Y, Umemoto S, Sawada SI, Mukerji R, Briles DE, Yasutomi Y, Akiyoshi K, Kiyono H. A nanogel-based trivalent PspA nasal vaccine protects macaques from intratracheal challenge with pneumococci. Vaccine 2021; 39:3353-3364. [PMID: 34016473 DOI: 10.1016/j.vaccine.2021.04.069] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/20/2021] [Accepted: 04/30/2021] [Indexed: 12/17/2022]
Abstract
Current polysaccharide-based pneumococcal vaccines are effective but not compatible with all serotypes of Streptococcus pneumoniae. We previously developed an adjuvant-free cationic nanogel nasal vaccine containing pneumococcal surface protein A (PspA), which is expressed on the surfaces of all pneumococcal serotypes. Here, to address the sequence diversity of PspA proteins, we formulated a cationic nanogel-based trivalent pneumococcal nasal vaccine and demonstrated the vaccine's immunogenicity and protective efficacy in macaques by using a newly developed nasal spray device applicable to humans. Nasal vaccination of macaques with cationic cholesteryl pullulan nanogel (cCHP)-trivalent PspA vaccine effectively induced PspA-specific IgGs that bound to pneumococcal surfaces and triggered complement C3 deposition. The immunized macaques were protected from pneumococcal intratracheal challenge through both inhibition of lung inflammation and a dramatic reduction in the numbers of bacteria in the lungs. These results demonstrated that the cCHP-trivalent PspA vaccine is an effective candidate vaccine against pneumococcal infections.
Collapse
Affiliation(s)
- Rika Nakahashi-Ouchida
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Department of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yohei Uchida
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yoshikazu Yuki
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; HanaVax Inc., Tokyo 103-0012, Japan
| | - Yuko Katakai
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Tomoyuki Yamanoue
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Hiromi Ogawa
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Yoshiko Munesue
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Nozomi Nakano
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Kouji Hanari
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | | | - Yuki Saito
- Toko Yakuhin Kogyo Co., Ltd., 930-0211, Japan
| | - Shingo Umemoto
- Department of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Faculty of Medicine, Department of Otorhinolaryngology and Head and Neck Surgery, Oita University, Oita 879-5593, Japan
| | - Shin-Ichi Sawada
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Reshmi Mukerji
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-2170, United States
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-2170, United States
| | - Yasuhiro Yasutomi
- Laboratory of Immunoregulation and Vaccine Research, Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, 305-0843, Japan
| | - Kazunari Akiyoshi
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Hiroshi Kiyono
- Department of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; HanaVax Inc., Tokyo 103-0012, Japan; Mucosal Immunology and Allergy Therapeutics, Institute for Global Prominent Research, Chiba University, Chiba 263-8522, Japan; CU-UCSD Center for Mucosal Immunology, Allergy and Vaccine (cMAV), Division of Gastroenterology, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0063, United States.
| |
Collapse
|
3
|
Pinto TCA, Costa NS, Pina SECM, Souza ARV, Oliveira LMA, Moura CAB, Kegele FCO, Merquior VLC, Botelho ACN, Peralta JM, Teixeira LM. Virulence-Associated Characteristics of Serotype 14 and Serogroup 9 Streptococcus pneumoniae Clones Circulating in Brazil: Association of Penicillin Non-susceptibility With Transparent Colony Phenotype Variants. Front Microbiol 2020; 11:2009. [PMID: 32983022 PMCID: PMC7479199 DOI: 10.3389/fmicb.2020.02009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/29/2020] [Indexed: 12/05/2022] Open
Abstract
Streptococcus pneumoniae remains a major agent of invasive diseases, especially in children and the elderly. The presence of pneumococcal capsule, pneumococcal surface protein A (PspA), and pilus type 1 (PI-1) and the ability of colony phase variation are assumed to play important roles in the virulence potential of this microorganism. Differences in the capsular polysaccharide allow the characterization of more than 90 pneumococcal serotypes; among them, serotype 14 and serogroup 9 stand out due to their prevalence in the pre- pneumococcal conjugate vaccine era and frequent association with penicillin non-susceptibility. Here we investigated the distribution of PI-1 and pspA genes and colony phase variants among 315 S. pneumoniae isolates belonging to serotype 14 and serogroup 9, recovered over 20 years in Brazil, and correlated these characteristics with penicillin susceptibility and genotype as determined by multilocus sequence typing. All strains were shown to carry pspA genes, with those of family 2 (pspA2) being the most common, and nearly half of the strains harbored P1-1 genes. The pspA gene family and the presence of PI-1 genes were conserved features among strains belonging to a given clone. A trend for increasing the occurrence of pspA2 and PI-1 genes over the period of investigation was observed, and it coincided with the dissemination of CC156 (Spain9V-3) clone in Brazil, suggesting a role for these virulence attributes in the establishment and the persistence of this successful clone. Opaque variant was the colony phenotype most frequently observed, regardless of clonal type. On the other hand, the transparent variant was more commonly associated with penicillin-non-susceptible pneumococci and with strains presenting evidence of recombination events involving the genes coding for polysaccharide capsule and PspA, suggesting that pneumococcal transparent variants may present a higher ability to acquire exogenous DNA. The results bring to light new information about the virulence potentials of serotype 14 and serogroup 9 S. pneumoniae isolates representing the major clones that have been associated with the emergence and the dissemination of antimicrobial resistance in our setting since the late 1980s.
Collapse
Affiliation(s)
- Tatiana C. A. Pinto
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Natália S. Costa
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sandrine E. C. M. Pina
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Aline R. V. Souza
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Laura M. A. Oliveira
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Camille A. B. Moura
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabíola C. O. Kegele
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Fernandes Figueira, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Vânia L. C. Merquior
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ana Caroline N. Botelho
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - José M. Peralta
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lúcia M. Teixeira
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- *Correspondence: Lúcia M. Teixeira,
| |
Collapse
|
4
|
The Modified Surface Killing Assay Distinguishes between Protective and Nonprotective Antibodies to PspA. mSphere 2019; 4:4/6/e00589-19. [PMID: 31826968 PMCID: PMC6908419 DOI: 10.1128/msphere.00589-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The most important finding of this study is that the MSKA can be used as an in vitro functional assay. Such an assay will be critical for the development of PspA-containing vaccines. The other important findings relate to the locations and nature of the protection-eliciting epitopes of PspA. There are limited prior data on the locations of protection-eliciting PspA epitopes, but those data along with the data presented here make it clear that there is not a single epitope or domain of PspA that can elicit protective antibody and there exists at least one region of the αHD which seldom elicits protective antibody. Moreover, these data, in concert with prior data, strongly make the case that protective epitopes in the αHD are highly conformational (≥100-amino-acid fragments of the αHD are required), whereas at least some protection-eliciting epitopes in the proline-rich domain are encoded by ≤15-amino-acid sequences. Pneumococcal surface protein A (PspA) elicits antibody protective against lethal challenge by Streptococcus pneumoniae and is a candidate noncapsular antigen for inclusion in vaccines. Evaluation of immunity to PspA in human trials would be greatly facilitated by an in vitro functional assay able to distinguish protective from nonprotective antibodies to PspA. Mouse monoclonal antibodies (MAbs) to PspA can mediate killing by human granulocytes in the modified surface killing assay (MSKA). To determine if the MSKA can distinguish between protective and nonprotective MAbs, we examined seven MAbs to PspA. All bound recombinant PspA, as detected by enzyme-linked immunosorbent assay and Western blotting; four gave strong passive protection against fatal challenge, two were nonprotective, and the seventh one only delayed death. The four that were able to provide strong passive protection were also most able to enhance killing in the MSKA, the two that were not protective in mice were not effective in the MSKA, and the MAb that was only weakly protective in mice was weakly effective in the MSKA (P < 0.001). One of the four most protective MAbs tested reacted to the proline-rich domain of PspA. Two of the other most protective MAbs and the weakly protective MAb reacted with a fragment from PspA’s α-helical domain (αHD), containing amino acids (aa) 148 to 247 from the N terminus of PspA. The fourth highly protective MAb recognized none of the overlapping 81- or 100-aa fragments of PspA. The two nonprotective MAbs recognized a more N-terminal αHD fragment (aa 48 to 147). IMPORTANCE The most important finding of this study is that the MSKA can be used as an in vitro functional assay. Such an assay will be critical for the development of PspA-containing vaccines. The other important findings relate to the locations and nature of the protection-eliciting epitopes of PspA. There are limited prior data on the locations of protection-eliciting PspA epitopes, but those data along with the data presented here make it clear that there is not a single epitope or domain of PspA that can elicit protective antibody and there exists at least one region of the αHD which seldom elicits protective antibody. Moreover, these data, in concert with prior data, strongly make the case that protective epitopes in the αHD are highly conformational (≥100-amino-acid fragments of the αHD are required), whereas at least some protection-eliciting epitopes in the proline-rich domain are encoded by ≤15-amino-acid sequences.
Collapse
|
5
|
PspA facilitates evasion of pneumococci from bactericidal activity of neutrophil extracellular traps (NETs). Microb Pathog 2019; 136:103653. [PMID: 31398527 DOI: 10.1016/j.micpath.2019.103653] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/09/2019] [Accepted: 08/05/2019] [Indexed: 02/02/2023]
Abstract
Pneumococcal strains are variably resistant to killing by neutrophil extracellular traps (NETs). We hypothesize that this variability in resistance is due to heterogeneity in pneumococcal surface protein A (PspA), a structurally diverse virulence factor of Streptococcus pneumoniae. Pneumococcal strains showed variability in induction of NETs and in susceptibility to killing by NETs. The variability in susceptibility to NETs-mediated killing of pneumococcal strains is attributed to PspA, as strains lacking the surface expression of PspA were significantly more sensitive to NETs-mediated killing compared to the wild-type strains. Using pspA switch mutants we were further able to demonstrate that NETs induction and killing by NETs is a function of PspA as mutants with switch PspA demonstrated donor phenotype. Antibody to PspA alone showed an increase in induction of NETs, and NETs thus generated were able to trap and kill pneumococci. Pneumococci opsonized with antibody to PspA showed increase adherence to NETs but a decrease susceptibility to killing by NETs. In conclusion we demonstrate a novel role for pneumococcal PspA in resisting NETs mediated killing and allowing the bacteria to escape containment by blocking binding of pneumococci to NETs.
Collapse
|
6
|
Miao X, He J, Zhang L, Zhao X, Ge R, He QY, Sun X. A Novel Iron Transporter SPD_1590 in Streptococcus pneumoniae Contributing to Bacterial Virulence Properties. Front Microbiol 2018; 9:1624. [PMID: 30079056 PMCID: PMC6062600 DOI: 10.3389/fmicb.2018.01624] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/28/2018] [Indexed: 12/27/2022] Open
Abstract
Streptococcus pneumoniae, a Gram-positive human pathogen, has evolved three main transporters for iron acquisition from the host: PiaABC, PiuABC, and PitABC. Our previous study had shown that the mRNA and protein levels of SPD_1590 are significantly upregulated in the ΔpiuA/ΔpiaA/ΔpitA triple mutant, suggesting that SPD_1590 might be a novel iron transporter in S. pneumoniae. In the present study, using spd1590-knockout, -complemented, and -overexpressing strains and the purified SPD_1590 protein, we show that SPD_1590 can bind hemin, probably supplementing the function of PiuABC, to provide the iron necessary for the bacterium. Furthermore, the results of iTRAQ quantitative proteomics and cell-infection studies demonstrate that, similarly to other metal-ion uptake proteins, SPD_1590 is important for bacterial virulence properties. Overall, these results provide a better understanding of the biology of this clinically important bacterium.
Collapse
Affiliation(s)
- Xinyu Miao
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Jiaojiao He
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Liang Zhang
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Xinlu Zhao
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Ruiguang Ge
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qing-Yu He
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Xuesong Sun
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| |
Collapse
|
7
|
Visan L, Rouleau N, Proust E, Peyrot L, Donadieu A, Ochs M. Antibodies to PcpA and PhtD protect mice against Streptococcus pneumoniae by a macrophage- and complement-dependent mechanism. Hum Vaccin Immunother 2017; 14:489-494. [PMID: 29135332 PMCID: PMC5806646 DOI: 10.1080/21645515.2017.1403698] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Currently marketed Streptococcus pneumoniae (Spn) vaccines, which contain polysaccharide capsular antigens from the most common Spn serotypes, have substantially reduced pneumococcal disease rates but have limited coverage. A trivalent pneumococcal protein vaccine containing pneumococcal choline-binding protein A (PcpA), pneumococcal histidine triad protein D (PhtD), and detoxified pneumolysin is being developed to provide broader, cross-serotype protection. Antibodies against detoxified pneumolysin protect against bacterial pneumonia by neutralizing Spn-produced pneumolysin, but how anti-PhtD and anti-PcpA antibodies protect against Spn has not been established. Here, we used a murine passive protection sepsis model to investigate the mechanism of protection by anti-PhtD and anti-PcpA antibodies. Depleting complement using cobra venom factor eliminated protection by anti-PhtD and anti-PcpA monoclonal antibodies (mAbs). Consistent with a requirement for complement, complement C3 deposition on Spn in vitro was enhanced by anti-PhtD and anti-PcpA mAbs and by sera from PhtD- and PcpA-immunized rabbits and humans. Moreover, in the presence of complement, anti-PhtD and anti-PcpA mAbs increased uptake of Spn by human granulocytes. Depleting neutrophils using anti-Ly6G mAbs, splenectomy, or a combination of both did not affect passive protection against Spn, whereas depleting macrophages using clodronate liposomes eliminated protection. These results suggest anti-PhtD and anti-PcpA antibodies induced by pneumococcal protein vaccines protect against Spn by a complement- and macrophage-dependent opsonophagocytosis.
Collapse
Affiliation(s)
- Lucian Visan
- a Sanofi Pasteur , Research & Non Clinical Safety Department , Marcy l'Etoile , France
| | - Nicolas Rouleau
- a Sanofi Pasteur , Research & Non Clinical Safety Department , Marcy l'Etoile , France
| | - Emilie Proust
- a Sanofi Pasteur , Research & Non Clinical Safety Department , Marcy l'Etoile , France
| | - Loïc Peyrot
- a Sanofi Pasteur , Research & Non Clinical Safety Department , Marcy l'Etoile , France
| | - Arnaud Donadieu
- a Sanofi Pasteur , Research & Non Clinical Safety Department , Marcy l'Etoile , France
| | - Martina Ochs
- a Sanofi Pasteur , Research & Non Clinical Safety Department , Marcy l'Etoile , France
| |
Collapse
|
8
|
Andre GO, Converso TR, Politano WR, Ferraz LFC, Ribeiro ML, Leite LCC, Darrieux M. Role of Streptococcus pneumoniae Proteins in Evasion of Complement-Mediated Immunity. Front Microbiol 2017; 8:224. [PMID: 28265264 PMCID: PMC5316553 DOI: 10.3389/fmicb.2017.00224] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/31/2017] [Indexed: 12/14/2022] Open
Abstract
The complement system plays a central role in immune defense against Streptococcus pneumoniae. In order to evade complement attack, pneumococci have evolved a number of mechanisms that limit complement mediated opsonization and subsequent phagocytosis. This review focuses on the strategies employed by pneumococci to circumvent complement mediated immunity, both in vitro and in vivo. At last, since many of the proteins involved in interactions with complement components are vaccine candidates in different stages of validation, we explore the use of these antigens alone or in combination, as potential vaccine approaches that aim at elimination or drastic reduction in the ability of this bacterium to evade complement.
Collapse
Affiliation(s)
- Greiciely O Andre
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| | - Thiago R Converso
- Centro de Biotecnologia, Instituto ButantanSão Paulo, Brazil; Programa de Pós-graduação Interunidades em Biotecnologia, Universidade de São PauloSão Paulo, Brazil
| | - Walter R Politano
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| | - Lucio F C Ferraz
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| | - Marcelo L Ribeiro
- Laboratório de Farmacologia, Universidade São Francisco Bragança Paulista, Brazil
| | | | - Michelle Darrieux
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| |
Collapse
|
9
|
Wiedinger K, Pinho D, Bitsaktsis C. Utilization of cholera toxin B as a mucosal adjuvant elicits antibody-mediated protection against S. pneumoniae infection in mice. THERAPEUTIC ADVANCES IN VACCINES 2017; 5:15-24. [PMID: 28344805 DOI: 10.1177/2051013617691041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/07/2016] [Indexed: 11/16/2022]
Abstract
BACKGOUND The introduction of the pneumococcal conjugate and polysaccharide vaccines have been valuable tools for combating invasive pneumococcal infection in children and healthy adults. Despite the available vaccination strategies, pneumococcal pneumonia and associated diseases continue to cause substantial morbidity and mortality, particularly in individuals with chronic disease and ageing populations. Next-generation pneumococcal vaccines will need to be highly immunogenic across patient populations providing both mucosal and systemic protective immunity. Mucosal immunization is an effective strategy for stimulating the immune response at the site of pathogen entry while increasing systemic immunity. In this study we utilized intranasal immunization with pneumococcal surface protein A (PspA), in combination with the mucosal adjuvant cholera toxin B (CTB), to characterize the immune components providing protection against S. pneumoniae challenge. METHODS Mice were immunized intranasally with CTB and PspA individually, and in combination, followed by lethal bacterial challenge with S. pneumoniae, strain A66.1. Animals were monitored for survival and tested for lung bacterial burden, cytokine production as well as S. pneumoniae-specific antibody titer in mouse sera. The primary immunological contributor to the observed protection was confirmed by cytokine neutralization and serum passive transfer. RESULTS The combination of CTB and PspA provided complete protection against bacterial challenge, which coincided with a significant decrease in lung bacterial burden. Increases in the T-helper (Th) 1 cytokines, interferon (IFN)-γ and interleukin (IL)-2 were observed in the lung 24 h post-challenge while decreases in proinflammatory mediators IL-6 and tumor necrosis factor (TNF)-α were also recorded at the same time point. The adjuvanted PspA immunization induced significant titers of S. pneumoniae-specific antibody in the serum of mice prior to infection. Serum adoptive transfer passively protected animals against subsequent challenge while IFN-γ neutralization had no impact on the outcome of immunization, suggesting a primary role for antibody-mediated protection in the context of this immunization strategy. CONCLUSION Mucosal immunization with CTB and PspA induced a local cellular immune response and systemic humoral immunity which resulted in effective reduction of pulmonary bacterial burden and complete protection against S. pneumoniae challenge. While induction of the pleiotropic cytokine IFN-γ likely contributes to control of infection through activation of effector pathways, it was not required for protection. Instead, immunization with PspA and CTB-induced S. pneumoniae-specific antibodies in the serum prior to infection that were sufficient to protect against mucosal challenge.
Collapse
|
10
|
Francis JP, Richmond PC, Strickland D, Prescott SL, Pomat WS, Michael A, Nadal-Sims MA, Edwards-Devitt CJ, Holt PG, Lehmann D, van den Biggelaar AHJ. Cord blood Streptococcus pneumoniae-specific cellular immune responses predict early pneumococcal carriage in high-risk infants in Papua New Guinea. Clin Exp Immunol 2016; 187:408-417. [PMID: 27859014 PMCID: PMC5290304 DOI: 10.1111/cei.12902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 10/03/2016] [Accepted: 10/27/2016] [Indexed: 12/01/2022] Open
Abstract
In areas where Streptococcus pneumoniae is highly endemic, infants experience very early pneumococcal colonization of the upper respiratory tract, with carriage often persisting into adulthood. We aimed to explore whether newborns in high‐risk areas have pre‐existing pneumococcal‐specific cellular immune responses that may affect early pneumococcal acquisition. Cord blood mononuclear cells (CBMC) of 84 Papua New Guinean (PNG; high endemic) and 33 Australian (AUS; low endemic) newborns were stimulated in vitro with detoxified pneumolysin (dPly) or pneumococcal surface protein A (PspA; families 1 and 2) and compared for cytokine responses. Within the PNG cohort, associations between CBMC dPly and PspA‐induced responses and pneumococcal colonization within the first month of life were studied. Significantly higher PspA‐specific interferon (IFN)‐γ, tumour necrosis factor (TNF)‐α, interleukin (IL)‐5, IL‐6, IL‐10 and IL‐13 responses, and lower dPly‐IL‐6 responses were produced in CBMC cultures of PNG compared to AUS newborns. Higher CBMC PspA‐IL‐5 and PspA‐IL‐13 responses correlated with a higher proportion of cord CD4 T cells, and higher dPly‐IL‐6 responses with a higher frequency of cord antigen‐presenting cells. In the PNG cohort, higher PspA‐specific IL‐5 and IL‐6 CBMC responses were associated independently and significantly with increased risk of earlier pneumococcal colonization, while a significant protective effect was found for higher PspA‐IL‐10 CBMC responses. Pneumococcus‐specific cellular immune responses differ between children born in pneumococcal high versus low endemic settings, which may contribute to the higher risk of infants in high endemic settings for early pneumococcal colonization, and hence disease.
Collapse
Affiliation(s)
- J P Francis
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - P C Richmond
- School of Paediatrics and Child Health, University of Western Australia, Perth, Australia
| | - D Strickland
- Telethon Kids Institute, University of Western Australia, Perth, Australia
| | - S L Prescott
- School of Paediatrics and Child Health, University of Western Australia, Perth, Australia
| | - W S Pomat
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - A Michael
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - M A Nadal-Sims
- Telethon Kids Institute, University of Western Australia, Perth, Australia
| | - C J Edwards-Devitt
- Telethon Kids Institute, University of Western Australia, Perth, Australia
| | - P G Holt
- Telethon Kids Institute, University of Western Australia, Perth, Australia
| | - D Lehmann
- Telethon Kids Institute, University of Western Australia, Perth, Australia
| | | |
Collapse
|
11
|
Choline Binding Proteins from Streptococcus pneumoniae: A Dual Role as Enzybiotics and Targets for the Design of New Antimicrobials. Antibiotics (Basel) 2016; 5:antibiotics5020021. [PMID: 27314398 PMCID: PMC4929436 DOI: 10.3390/antibiotics5020021] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 05/04/2016] [Accepted: 05/16/2016] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is an important pathogen responsible for acute invasive and non-invasive infections such as meningitis, sepsis and otitis media, being the major cause of community-acquired pneumonia. The fight against pneumococcus is currently hampered both by insufficient vaccine coverage and by rising antimicrobial resistances to traditional antibiotics, making necessary the research on novel targets. Choline binding proteins (CBPs) are a family of polypeptides found in pneumococcus and related species, as well as in some of their associated bacteriophages. They are characterized by a structural organization in two modules: a functional module (FM), and a choline-binding module (CBM) that anchors the protein to the choline residues present in the cell wall through non-covalent interactions. Pneumococcal CBPs include cell wall hydrolases, adhesins and other virulence factors, all playing relevant physiological roles for bacterial viability and virulence. Moreover, many pneumococcal phages also make use of hydrolytic CBPs to fulfill their infectivity cycle. Consequently, CBPs may play a dual role for the development of novel antipneumococcal drugs, both as targets for inhibitors of their binding to the cell wall and as active cell lytic agents (enzybiotics). In this article, we review the current state of knowledge about host- and phage-encoded pneumococcal CBPs, with a special focus on structural issues, together with their perspectives for effective anti-infectious treatments.
Collapse
|
12
|
Abstract
Streptococcus pneumoniae is an opportunistic pathogen globally associated with significant morbidity and mortality. It is capable of causing a wide range of diseases including sinusitis, conjunctivitis, otitis media, pneumonia, bacteraemia, sepsis, and meningitis. While its capsular polysaccharide is indispensible for invasive disease, and opsonising antibodies against the capsule are the basis for the current vaccines, a long history of biomedical research indicates that other components of this Gram-positive bacterium are also critical for virulence. Herein we review the contribution of pneumococcal virulence determinants to survival and persistence in the context of distinct anatomical sites. We discuss how these determinants allow the pneumococcus to evade mucociliary clearance during colonisation, establish lower respiratory tract infection, resist complement deposition and opsonophagocytosis in the bloodstream, and invade secondary tissues such as the central nervous system leading to meningitis. We do so in a manner that highlights both the critical role of the capsular polysaccharide and the accompanying and necessary protein determinants. Understanding the complex interplay between host and pathogen is necessary to find new ways to prevent pneumococcal infection. This review is an attempt to do so with consideration for the latest research findings.
Collapse
|
13
|
Kristian SA, Ota T, Bubeck SS, Cho R, Groff BC, Kubota T, Destito G, Laudenslager J, Koriazova L, Tahara T, Kanda Y. Generation and Improvement of Effector Function of a Novel Broadly Reactive and Protective Monoclonal Antibody against Pneumococcal Surface Protein A of Streptococcus pneumoniae. PLoS One 2016; 11:e0154616. [PMID: 27171010 PMCID: PMC4865217 DOI: 10.1371/journal.pone.0154616] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/17/2016] [Indexed: 01/21/2023] Open
Abstract
A proof-of-concept study evaluating the potential of Streptococcus pneumoniae Pneumococcal Surface Protein A (PspA) as a passive immunization target was conducted. We describe the generation and isolation of several broadly reactive mouse anti-PspA monoclonal antibodies (mAbs). MAb 140H1 displayed (i) 98% strain coverage, (ii) activity in complement deposition and opsonophagocytic killing (OPK) assays, which are thought to predict the in vivo efficacy of anti-pneumococcal mAbs, (iii) efficacy in mouse sepsis models both alone and in combination with standard-of-care antibiotics, and (iv) therapeutic activity in a mouse pneumonia model. Moreover, we demonstrate that antibody engineering can significantly enhance anti-PspA mAb effector function. We believe that PspA has promising potential as a target for the therapy of invasive pneumococcal disease by mAbs, which could be used alone or in conjunction with standard-of-care antibiotics.
Collapse
Affiliation(s)
- Sascha A. Kristian
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Takayuki Ota
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| | - Sarah S. Bubeck
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
- * E-mail:
| | - Rebecca Cho
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Brian C. Groff
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Tsuguo Kubota
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| | - Giuseppe Destito
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - John Laudenslager
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Lilia Koriazova
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Tomoyuki Tahara
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| | - Yutaka Kanda
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Correlation between in vitro complement deposition and passive mouse protection of anti-pneumococcal surface protein A monoclonal antibodies. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 22:99-107. [PMID: 25410204 DOI: 10.1128/cvi.00001-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The shortcomings of the licensed polysaccharide-based pneumococcal vaccine are driving efforts toward development of a protein-based vaccine that is serotype independent and effective in all age groups. An opsonophagocytic killing assay (OPKA) is used to evaluate the antibody response against polysaccharide-based pneumococcal vaccines. However, the OPKA is not reliable for noncapsular antigens. Thus, there is a need to develop an in vitro surrogate for protection for protein vaccine candidates like pneumococcal surface antigen A (PspA). PspA is a serologically variable cell surface virulence factor. Based on its sequence, PspA has been classified into families 1 (clade 1 and 2), 2 (clades 3, 4 and 5), and 3 (clade 6). Here, we report the characterization of 18 IgG anti-PspA monoclonal antibodies (anti-PspA(hkR36A) MAbs) generated from mice immunized with heat-killed strain R36A (clade 2). An enzyme-linked immunosorbent assay (ELISA)-based analysis of the reactivity of the MAbs with recombinant PspAs from the 6 clades indicated that they were family 1 specific. This was confirmed by flow cytometry using a hyperimmune serum generated against PspA from R36A. Eight MAbs that bind at least one clade 1- and clade 2-expressing strain were evaluated for complement deposition, bactericidal activity, and passive protection. The anti-PspA(hkR36A) MAb-dependent deposition of complement on pneumococci showed a positive correlation with passive protection against strain WU2 (r = 0.8783, P = 0.0041). All of our protective MAbs showed bactericidal activity; however, not all MAbs that exhibited bactericidal activity conferred protection in vivo. The protective MAbs described here can be used to identify conserved protection eliciting B cell epitopes for engineering a superior PspA-based vaccine.
Collapse
|
16
|
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: 1.0] [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.
Collapse
|
17
|
Bischof A, Brumshagen C, Ding N, Kirchhof G, Briles DE, Gessner JE, Welte T, Mack M, Maus UA. Basophil Expansion Protects Against Invasive Pneumococcal Disease in Mice. J Infect Dis 2014; 210:14-24. [DOI: 10.1093/infdis/jiu056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
18
|
A modified surface killing assay (MSKA) as a functional in vitro assay for identifying protective antibodies against pneumococcal surface protein A (PspA). Vaccine 2013; 32:39-47. [PMID: 24211169 DOI: 10.1016/j.vaccine.2013.10.080] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/08/2013] [Accepted: 10/24/2013] [Indexed: 11/20/2022]
Abstract
Streptococcus pneumoniae causes otitis media, meningitis and pneumonia in patients worldwide; predominantly affecting young children, the elderly, and the immune compromised. Current vaccines against invasive pneumococcal disease are based on the polysaccharide capsules of the most clinically relevant serotypes. Due to serotype replacement, non-vaccine serotypes of S. pneumoniae have become more clinically relevant and as a result pneumococcal vaccines are becoming increasingly complex. These events emphasize the need to evaluate the potential for pneumococcal cross-reactive proteins to contribute to future vaccines. Antibody elicited by the immunization of humans with pneumococcal surface protein A (PspA) can passively protect mice from infection. However, robust in vitro functional assays for antibody to PspA are not available to predict the protective capacity of immune serum. For polysaccharide based vaccines, a standardized opsonophagocytosis killing assay (OPKA) is used. Antibody to PspA, however, does not work well in the standard OPKA. The present studies take advantage of past observations that phagocytosis is more efficient on tissue surfaces than in solution. In a modified surface killing assay (MSKA), monoclonal antibody to PspA, in the presence of complement, opsonized pneumococci for killing by phagocytes on an agar surface. Five monoclonal antibodies to PspA were tested; three demonstrated increased amounts of killing compared to the diluent control and protected mice by passive protection against type 3 pneumococci. The two antibodies that were not functional in the MSKA also failed to protect mice. Thus, an MSKA might be useful as a functional assay for immunity to PspA.
Collapse
|
19
|
Modified opsonization, phagocytosis, and killing assays to measure potentially protective antibodies against pneumococcal surface protein A. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1549-58. [PMID: 23925886 DOI: 10.1128/cvi.00371-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The standard opsonophagocytosis killing assay (OPKA) for antibodies to pneumococcal capsular polysaccharide was modified to permit an evaluation of the protection-mediating antibodies to pneumococcal surface protein A (PspA). We found that by increasing the incubation time with the complement and phagocytes from 45 min to 75 min, the protective activity was readily detected. In another modification, we used a capsule type 2 target strain that expressed PspA but not pneumococcal surface protein C (PspC). With these modifications separately or in combination, rabbit antisera to the recombinant α-helical or proline-rich domains of PspA mediated >50% killing of the target strain. The ability of normal human sera to mediate the killing of pneumococci in this modified OPKA correlated with their levels of antibodies to PspA and their ability to protect mice against fatal infection with a type 3 strain. Passive protection of mice against pneumococci and killing in the modified OPKA were lost when normal human sera were adsorbed with recombinant PspA (rPspA) on Sepharose, thus supporting the potential utility of the modified OPKA to detect protective antibodies to PspA. In the standard OPKA, monoclonal antibodies to PspA were strongly protective in the presence of subprotective amounts of anti-capsule. Thus, the currently established high-throughput OPKA for antibodies to capsule could be modified in one of two ways to permit an evaluation of the opsonic efficacy of antibodies to PspA.
Collapse
|
20
|
Darrieux M, Goulart C, Briles D, Leite LCDC. Current status and perspectives on protein-based pneumococcal vaccines. Crit Rev Microbiol 2013; 41:190-200. [DOI: 10.3109/1040841x.2013.813902] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
21
|
Phenotypic and molecular characterization of optochin-resistant Streptococcus pneumoniae isolates from Brazil, with description of five novel mutations in the ATPC gene. J Clin Microbiol 2013; 51:3242-9. [PMID: 23884994 DOI: 10.1128/jcm.01168-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Optochin (Opt) susceptibility is used largely for the identification of Streptococcus pneumoniae in diagnostic laboratories. Opt-resistant (Opt(r)) S. pneumoniae isolates have been reported, however, indicating the potential for misidentification of this important pathogen. Point mutations in the atpC gene have been associated with the emergence of Opt(r) S. pneumoniae, but data on the characterization of such atypical variants of S. pneumoniae are still limited. The present report describes the results of a polyphasic approach to identifying and characterizing 26 Opt(r) S. pneumoniae isolates recovered from patients or carriers living in Brazil. Sixteen isolates consisted of heterogeneous populations, and 10 isolates were homogeneously Opt(r). The isolates had different serotypes and antimicrobial susceptibility profiles. They also presented diverse genetic characteristics, as indicated by pulsed-field gel electrophoresis (PFGE), multilocus variable-number tandem-repeat analysis (MLVA), and pspA gene typing. Except for Opt MICs (4- to 64-fold higher among Opt(r) variants), Opt(r) and Opt-susceptible (Opt(s)) subpopulations originating from the same culture had identical characteristics. Sequencing of the atpC gene of the Opt(r) variants revealed 13 different nucleotide changes distributed among eight different codons. Changes in codon 49 were the most frequent, suggesting that this might be a hot spot for optochin resistance-conferring mutations. On the other hand, five novel types of mutations in the atpC gene (Met13Ile, Gly18Ser, Gly20Ala, Ala31Val, and Ala49Gly) were identified. In silico prediction modeling indicated that the atpC gene mutations corresponded to alterations in the transmembrane region of the ATPase, leading to a higher hydrophobicity profile in α-helix 1 and to a lower hydrophobicity profile in α-helix 2.
Collapse
|
22
|
Ferreira DM, Neill DR, Bangert M, Gritzfeld JF, Green N, Wright AKA, Pennington SH, Bricio-Moreno L, Bricio Moreno L, Moreno AT, Miyaji EN, Wright AD, Collins AM, Goldblatt D, Kadioglu A, Gordon SB. Controlled human infection and rechallenge with Streptococcus pneumoniae reveals the protective efficacy of carriage in healthy adults. Am J Respir Crit Care Med 2013; 187:855-64. [PMID: 23370916 DOI: 10.1164/rccm.201212-2277oc] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
RATIONALE The immunological and protective role of pneumococcal carriage in healthy adults is not known, but high rates of disease and death in the elderly are associated with low carriage prevalence. OBJECTIVES We employed an experimental human pneumococcal carriage model to investigate the immunizing effect of a single carriage episode. METHODS Seventy healthy adults were challenged, and of those with carriage, 10 were rechallenged intranasally with live 6B Streptococcus pneumoniae up to 11 months after clearance of the first carriage episode. Serum and nasal wash antibody responses were measured before and after each challenge. MEASUREMENTS AND MAIN RESULTS A total of 29 subjects were experimentally colonized. No subjects were colonized by experimental rechallenge, demonstrating the protective effect of initial carriage against subsequent infection. Carriage increased both mucosal and serum IgG levels to pneumococcal proteins and polysaccharide, resulting in a fourfold increase in opsonophagocytic activity. Importantly, passive transfer of postcarriage sera from colonized subjects conferred 70% protection against lethal challenge by a heterologous strain in a murine model of invasive pneumococcal pneumonia. These levels were significantly higher than the protection conferred by either precarriage sera (30%) or saline (10%). CONCLUSIONS Experimental human carriage resulted in mucosal and systemic immunological responses that conferred protection against recolonization and invasive pneumococcal disease. These data suggest that mucosal pneumococcal vaccination strategies may be important for vulnerable patient groups, particularly the elderly, who do not sustain carriage.
Collapse
Affiliation(s)
- Daniela M Ferreira
- Respiratory Infection Group, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Muchnik L, Adawi A, Ohayon A, Dotan S, Malka I, Azriel S, Shagan M, Portnoi M, Kafka D, Nahmani H, Porgador A, Gershoni JM, Gershoni JM, Morrison DA, Mitchell A, Tal M, Ellis R, Dagan R, Nebenzahl YM. NADH oxidase functions as an adhesin in Streptococcus pneumoniae and elicits a protective immune response in mice. PLoS One 2013; 8:e61128. [PMID: 23577197 PMCID: PMC3620118 DOI: 10.1371/journal.pone.0061128] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 03/08/2013] [Indexed: 11/18/2022] Open
Abstract
The initial event in disease caused by S. pneumoniae is adhesion of the bacterium to respiratory epithelial cells, mediated by surface expressed molecules including cell-wall proteins. NADH oxidase (NOX), which reduces free oxygen to water in the cytoplasm, was identified in a non-lectin enriched pneumococcal cell-wall fraction. Recombinant NOX (rNOX) was screened with sera obtained longitudinally from children and demonstrated age-dependent immunogenicity. NOX ablation in S. pneumoniae significantly reduced bacterial adhesion to A549 epithelial cells in vitro and their virulence in the intranasal or intraperitoneal challenge models in mice, compared to the parental strain. Supplementation of Δnox WU2 with the nox gene restored its virulence. Saturation of A549 target cells with rNOX or neutralization of cell-wall residing NOX using anti-rNOX antiserum decreased adhesion to A549 cells. rNOX-binding phages inhibited bacterial adhesion. Moreover, peptides derived from the human proteins contactin 4, chondroitin 4 sulfotraferase and laminin5, homologous to the insert peptides in the neutralizing phages, inhibited bacterial adhesion to the A549 cells. Furthermore, rNOX immunization of mice elicited a protective immune response to intranasal or intraperitoneal S. pneumoniae challenge, whereas pneumococcal virulence was neutralized by anti-rNOX antiserum prior to intraperitoneal challenge. Our results suggest that in addition to its enzymatic activity, NOX contributes to S. pneumoniae virulence as a putative adhesin and thus peptides derived from its target molecules may be considered for the treatment of pneumococcal infections. Finally, rNOX elicited a protective immune response in both aerobic and anaerobic environments, which renders NOX a candidate for future pneumococcal vaccine.
Collapse
Affiliation(s)
- Lena Muchnik
- Pediatric Infectious Disease Unit, Soroka University Medical Center, Beer Sheva, Israel
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Mukerji R, Mirza S, Roche AM, Widener RW, Croney CM, Rhee DK, Weiser JN, Szalai AJ, Briles DE. Pneumococcal surface protein A inhibits complement deposition on the pneumococcal surface by competing with the binding of C-reactive protein to cell-surface phosphocholine. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2012; 189:5327-35. [PMID: 23105137 PMCID: PMC3517878 DOI: 10.4049/jimmunol.1201967] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In the presence of normal serum, complement component C3 is deposited on pneumococci primarily via the classical pathway. Pneumococcal surface protein A (PspA), a major virulence factor of pneumococci, effectively inhibits C3 deposition. PspA's C terminus has a choline-binding domain that anchors PspA to the phosphocholine (PC) moieties on the pneumococcal surface. C-reactive protein (CRP), another important host defense molecule, also binds to PC, and CRP binding to pneumococci enhances complement C3 deposition through the classical pathway. Using flow cytometry of PspA(+) and PspA(-) strains, we observed that the absence of PspA led to exposure of PC, enhanced the surface binding of CRP, and increased the deposition of C3. Moreover, when the PspA(-) mutant was incubated with a pneumococcal eluate containing native PspA, there was decreased deposition of CRP and C3 on the pneumococcal surface compared with incubation with an eluate from a PspA(-) strain. This inhibition was not observed when a recombinant PspA fragment, which lacks the choline-binding region of PspA, was added to the PspA(-) mutant. Also, there was much greater C3 deposition onto the PspA(-) pneumococcus when exposed to normal mouse serum from wild-type mice as compared with that from CRP knockout mice. Furthermore, when CRP knockout mouse serum was replenished with CRP, there was a dose-dependent increase in C3 deposition. The combined data reveal a novel mechanism of complement inhibition by a bacterial protein: inhibition of CRP surface binding and, thus, diminution of CRP-mediated complement deposition.
Collapse
Affiliation(s)
- Reshmi Mukerji
- Department of Microbiology, University of Alabama at Birmingham
| | - Shaper Mirza
- University of Texas School of Public Health Division of Epidemiology Brownsville regional campus Brownsville TX
| | - Aoife M. Roche
- Department of Microbiology, School of Medicine, University of Pennsylvania
| | | | | | - Dong-Kwon Rhee
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Jeffrey N. Weiser
- Department of Microbiology, School of Medicine, University of Pennsylvania
| | - Alexander J. Szalai
- Department of Microbiology, University of Alabama at Birmingham
- Division of Immunology Department of Medicine, University of Alabama at Birmingham
| | - David E. Briles
- Department of Microbiology, University of Alabama at Birmingham
- Department of Pediatrics, University of Alabama at Birmingham
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| |
Collapse
|
25
|
The absence of PspA or presence of antibody to PspA facilitates the complement-dependent phagocytosis of pneumococci in vitro. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1574-82. [PMID: 22855389 DOI: 10.1128/cvi.00393-12] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Pneumococcal surface protein A (PspA) is a surface molecule on pneumococci that is required for full virulence in mouse models of infection. PspA has been reported to inhibit complement deposition on the pneumococcal surface. It has been assumed that this decreased complement deposition results in the inefficient phagocytosis of wild-type pneumococci. However, an effect of PspA on phagocytosis had not been shown. Our present studies demonstrated that a loss of PspA by capsular type 3 strains WU2 and A66.1 led to enhanced complement-dependent phagocytosis of the pneumococci by the mouse macrophage cell line J774A.1. This observation was made using human complement as well as mouse complement. Since this enhanced phagocytosis could be blocked by antibody to complement receptor CR3 on J774A.1, it was concluded that PspA's effect on phagocytosis was due to its effect on the amount of deposited complement, which in turn helped opsonize the pneumococci for phagocytosis. Since these studies included new independent mutants lacking PspA, the results provide solid confirmation of the previously reported effects of PspA on pneumococcal virulence and complement deposition. Finally, we showed that antibody to PspA, which is also known to enhance complement deposition, also enhances the phagocytosis of pneumococci in a largely complement-dependent manner.
Collapse
|
26
|
Shivshankar P. Modulation of bacterial pathogenesis by oppressive aging factors: insights into host-pneumococcal interaction strategies. ISRN INFLAMMATION 2012; 2012:267101. [PMID: 24049644 PMCID: PMC3765745 DOI: 10.5402/2012/267101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 03/20/2012] [Indexed: 01/20/2023]
Abstract
Streptococcus pneumonia, (Spn, the pneumococcus), is the leading cause of community-acquired pneumonia (CAP) and is responsible for 15–40% deaths in the elderly worldwide. A primed inflammatory status is a significant risk factor for the increased severity of infectious diseases among the elderly (≥65 years of age). Studies have shown that expression of host receptors that the pneumococci bind to invade the tissues are increased thereby increasing the susceptibility to pneumococcal challenge in aged mice. Cellular senescence, an age-related phenomenon that leads to cell cycle arrest may also contribute to increased inflammation in aged mice. Evidence of cellular senescence in aged lungs of humans and mice adds credits to the concept of inflammaging and enhanced bacterial ligands expression during aging. Furthermore, cell senescence has been shown to occur in age-associated lung pathologies such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) that may predispose the elderly to pathogenic assaults, including S. pneumoniae. This review highlights the aspects of: chronic inflammation in the aged population; contribution of cellular senescence to age-associated inflammation and their impact on host receptor expression; and, increased susceptibility of fibrosis and emphysematous lesions-bearing lungs to microbial infections.
Collapse
Affiliation(s)
- Pooja Shivshankar
- Division of Cardiology, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| |
Collapse
|
27
|
Mucosal immunization with an unadjuvanted vaccine that targets Streptococcus pneumoniae PspA to human Fcγ receptor type I protects against pneumococcal infection through complement- and lactoferrin-mediated bactericidal activity. Infect Immun 2011; 80:1166-80. [PMID: 22158740 DOI: 10.1128/iai.05511-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Targeting an antigen to Fc receptors (FcR) can enhance the immune response to the antigen in the absence of adjuvant. Furthermore, we recently demonstrated that intranasal immunization with an FcγR-targeted antigen enhances protection against a category A intracellular mucosal pathogen, Francisella tularensis. To determine if a similar strategy could be applied to the important pathogen Streptococcus pneumoniae, we used an improved mucosal FcR-targeting strategy that specifically targets human FcγR type I (hFcγRI). A humanized single-chain antibody component in which the variable domain binds to hFcγRI [anti-hFcγRI (H22)] was linked in a fusion protein with the pneumococcal surface protein A (PspA). PspA is known to elicit protection against pneumococcal sepsis, carriage, and pneumonia in mouse models when administered with adjuvants. Anti-hFcγRI-PspA or recombinant PspA (rPspA) alone was used to intranasally immunize wild-type (WT) and hFcγRI transgenic (Tg) mice in the absence of adjuvant. The hFcγRI Tg mice receiving anti-hFcγRI-PspA exhibited elevated S. pneumoniae-specific IgA, IgG2c, and IgG1 antibodies in serum and bronchoalveolar lavage fluid. Neither immunogen was effective in protecting WT mice in the absence of adjuvant, but when PspA was targeted to hFcγRI as the anti-hFcγRI-PspA fusion, enhanced protection against lethal S. pneumoniae challenge was observed in the hFcγRI Tg mice compared to mice given nontargeted rPspA alone. Immune sera from the anti-hFcγRI-PspA-immunized Tg mice showed enhanced complement C3 deposition on bacterial surfaces, and protection was dependent upon an active complement system. Immune serum also showed an enhanced bactericidal activity directed against S. pneumoniae that appears to be lactoferrin mediated.
Collapse
|
28
|
Carvalho RJ, Cabrera-Crespo J, Tanizaki MM, Gonçalves VM. Development of production and purification processes of recombinant fragment of pneumococcal surface protein A in Escherichia coli using different carbon sources and chromatography sequences. Appl Microbiol Biotechnol 2011; 94:683-94. [DOI: 10.1007/s00253-011-3649-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 09/28/2011] [Accepted: 10/17/2011] [Indexed: 11/24/2022]
|
29
|
Abstract
Pneumococcal meningitis continues to be associated with high rates of mortality and long-term neurological sequelae. The most common route of infection starts by nasopharyngeal colonization by Streptococcus pneumoniae, which must avoid mucosal entrapment and evade the host immune system after local activation. During invasive disease, pneumococcal epithelial adhesion is followed by bloodstream invasion and activation of the complement and coagulation systems. The release of inflammatory mediators facilitates pneumococcal crossing of the blood-brain barrier into the brain, where the bacteria multiply freely and trigger activation of circulating antigen-presenting cells and resident microglial cells. The resulting massive inflammation leads to further neutrophil recruitment and inflammation, resulting in the well-known features of bacterial meningitis, including cerebrospinal fluid pleocytosis, cochlear damage, cerebral edema, hydrocephalus, and cerebrovascular complications. Experimental animal models continue to further our understanding of the pathophysiology of pneumococcal meningitis and provide the platform for the development of new adjuvant treatments and antimicrobial therapy. This review discusses the most recent views on the pathophysiology of pneumococcal meningitis, as well as potential targets for (adjunctive) therapy.
Collapse
|
30
|
Kono M, Hotomi M, Hollingshead SK, Briles DE, Yamanaka N. Maternal immunization with pneumococcal surface protein A protects against pneumococcal infections among derived offspring. PLoS One 2011; 6:e27102. [PMID: 22073127 PMCID: PMC3205068 DOI: 10.1371/journal.pone.0027102] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Accepted: 10/10/2011] [Indexed: 11/25/2022] Open
Abstract
Pathogen-specific antibody plays an important role in protection against pneumococcal carriage and infections. However, neonates and infants exhibit impaired innate and adaptive immune responses, which result in their high susceptibility to pneumococci. To protect neonates and infants against pneumococcal infection it is important to elicit specific protective immune responses at very young ages. In this study, we investigated the protective immunity against pneumococcal carriage, pneumonia, and sepsis induced by maternal immunization with pneumococcal surface protein A (PspA). Mother mice were intranasally immunized with recombinant PspA (rPspA) and cholera toxin B subunit (CTB) prior to being mated. Anti-PspA specific IgG, predominantly IgG1, was present at a high level in the serum and milk of immunized mothers and in the sera of their pups. The pneumococcal densities in washed nasal tissues and in lung homogenate were significantly reduced in pups delivered from and/or breast-fed by PspA-immunized mothers. Survival after fatal systemic infections with various types of pneumococci was significantly extended in the pups, which had received anti-PspA antibody via the placenta or through their milk. The current findings strongly suggest that maternal immunization with PspA is an attractive strategy against pneumococcal infections during early childhood. (191 words)
Collapse
Affiliation(s)
- Masamitsu Kono
- Department of Otolaryngology-Head and Neck Surgery, Wakayama Medical University, Wakayama-city, Wakayama, Japan
| | - Muneki Hotomi
- Department of Otolaryngology-Head and Neck Surgery, Wakayama Medical University, Wakayama-city, Wakayama, Japan
- * E-mail:
| | - Susan K. Hollingshead
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - David E. Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Noboru Yamanaka
- Department of Otolaryngology-Head and Neck Surgery, Wakayama Medical University, Wakayama-city, Wakayama, Japan
| |
Collapse
|
31
|
Moffitt KL, Malley R. Next generation pneumococcal vaccines. Curr Opin Immunol 2011; 23:407-13. [PMID: 21514128 DOI: 10.1016/j.coi.2011.04.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 04/01/2011] [Accepted: 04/04/2011] [Indexed: 11/15/2022]
Abstract
Currently licensed pneumococcal vaccines are based on the generation of antibodies to the pneumococcal polysaccharide, of which there are more than 90 different types. While these vaccines are highly effective against the serotypes included, their high cost and limited serotype coverage limit their usefulness worldwide, particularly in low resource areas. Thus alternative or adjunctive options are being actively pursued. This review will present these various approaches, including variations of the polysaccharide-protein conjugate strategy, protein-based strategies, and whole cell pneumococcal vaccines. The immunological basis for these different approaches is discussed as well.
Collapse
Affiliation(s)
- Kristin L Moffitt
- Division of Infectious Diseases, Children's Hospital, Harvard Medical School, Boston, MA, United States
| | | |
Collapse
|
32
|
Ezoe H, Akeda Y, Piao Z, Aoshi T, Koyama S, Tanimoto T, Ishii KJ, Oishi K. Intranasal vaccination with pneumococcal surface protein A plus poly(I:C) protects against secondary pneumococcal pneumonia in mice. Vaccine 2011; 29:1754-61. [PMID: 21219977 DOI: 10.1016/j.vaccine.2010.12.117] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 12/07/2010] [Accepted: 12/23/2010] [Indexed: 11/18/2022]
Abstract
Effective pneumococcal vaccines are required for preventing secondary bacterial pneumonia, a life-threatening condition, during epidemics of influenza. We examined whether nasal administration of a low dose of pneumococcal surface protein A (PspA) plus polyinosinic-polycytidylic acid (poly(I:C)) could protect against a fatal secondary pneumococcal pneumonia after influenza A virus infection in mice. PspA-specific IgG but not IgA level was higher in the airways and blood of mice nasally administered a low dose of PspA plus poly(I:C) than in mice nasally administered PspA alone or poly(I:C) alone. Binding of PspA-specific IgG increased C3 deposition on the bacterial surface. The survival rate during secondary infection was higher in mice immunized with PspA plus poly(I:C) than in mice immunized with poly(I:C) alone. The significant reduction in bacterial density in the lung and blood was associated with increased survival of immunized mice with secondary pneumonia. Passive transfer of sera from mice immunized with PspA plus poly(I:C) increased the survival of mice infected with secondary pneumonia. Our data suggest that an intranasal PspA vaccine has promising protective effects against secondary pneumonia after influenza and that PspA-specific IgG plays a critical role in this protection.
Collapse
MESH Headings
- Adjuvants, Immunologic/administration & dosage
- Adjuvants, Immunologic/therapeutic use
- Administration, Intranasal
- Animals
- Bacterial Proteins/administration & dosage
- Bacterial Proteins/immunology
- Humans
- Immunization, Secondary/methods
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza, Human/complications
- Influenza, Human/immunology
- Influenza, Human/prevention & control
- Mice
- Mice, Inbred C57BL
- Pneumococcal Infections/etiology
- Pneumococcal Infections/immunology
- Pneumococcal Infections/prevention & control
- Pneumococcal Vaccines/administration & dosage
- Pneumococcal Vaccines/immunology
- Pneumonia, Pneumococcal/etiology
- Pneumonia, Pneumococcal/immunology
- Pneumonia, Pneumococcal/prevention & control
- Poly I-C/administration & dosage
- Poly I-C/immunology
- Poly I-C/therapeutic use
- Secondary Prevention/methods
Collapse
Affiliation(s)
- Hirokazu Ezoe
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Shao Z, Pan X, Li X, Liu W, Han M, Wang C, Wang J, Zheng F, Cao M, Tang J. HtpS, a novel immunogenic cell surface-exposed protein of Streptococcus suis, confers protection in mice. FEMS Microbiol Lett 2010; 314:174-82. [DOI: 10.1111/j.1574-6968.2010.02162.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
34
|
Serotype-related variation in susceptibility to complement deposition and opsonophagocytosis among clinical isolates of Streptococcus pneumoniae. Infect Immun 2010; 78:5252-61. [PMID: 20855517 DOI: 10.1128/iai.00739-10] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The polysaccharide capsule is a major virulence factor of Streptococcus pneumoniae; it affects complement resistance and shields the bacterium from phagocytes. Certain capsular serotypes appear to be better able to cause invasive disease than others. Serotypes 1 and 5 are common causes of invasive disease but are rarely isolated from healthy carriers, whereas serotypes 6B and 23F are more frequently isolated from carriage than invasive disease. We have recently shown that serotypes 6B and 19F differ in resistance to complement C3 deposition and opsonophagocytic killing. In this study we assessed the complement resistance and susceptibility to opsonophagocytosis of several other serotypes targeted by the pneumococcal conjugate vaccines. Clinical isolates of serotypes 1, 4, 5, 14, 18C, and 23F were tested along reference strains of corresponding capsular types. The concentration of anticapsular antibodies required for opsonophagocytic killing correlated inversely with C3 deposition on the serotype. Serotype 1 was the most resistant of the clinical isolates to C3 deposition and, along with serotypes 5 and 19F, required the highest concentration of capsule antibodies for opsonophagocytic killing, whereas serotype 23F was the most sensitive to opsonophagocytosis. Sensitivity to C3 deposition and opsonophagocytosis was associated with serotype-specific mortality of invasive pneumococcal disease, suggesting that the primary pathogens, such as serotypes 1 and 5, are more resistant to complement and require a higher concentration of capsule antibodies for opsonophagocytic killing than the opportunistic serotypes such as 6B and 23F, which are associated with a more severe disease outcome.
Collapse
|
35
|
Abstract
The pneumococcal histidine triad (Pht) proteins PhtA, PhtB, PhtD, and PhtE form a group of conserved pneumococcal surface proteins. Humans produce antibodies to Pht proteins upon exposure to pneumococcus, and immunization of mice has provided protective immunity against sepsis and pneumonia and reduced nasopharyngeal colonization. Pht proteins are candidates for inclusion in multicomponent pneumococcal protein vaccines. Their biological function in pneumococcal infections is not clear, but a role in complement inhibition has been suggested. We measured complement deposition on wild-type and Pht mutant strains in four genetic backgrounds: Streptococcus pneumoniae D39 (serotype 2) and R36A (unencapsulated derivative of D39) and strains of serotypes 3, 4, and 19F. PspA and PspC single and double mutants were compared to the wild-type and Pht-deficient D39 strains. Factor H binding was measured to bacterial cells, lysates, and protein antigens. Deletion of all four Pht proteins (Pht(-)) resulted in increased C3 deposition on the serotype 4 strain but not on the other strains. Pht antigens did not bind factor H, and deletion of Pht proteins did not affect factor H binding by bacterial lysates. The Pht(-) mutant serotype 4 strain bound slightly less factor H than the wild-type strain when binding was measured by flow cytometry. Pht proteins may play a role in immune evasion, but the mechanism of function is unlikely to be mediated by factor H binding. The relative contribution of Pht proteins to the inhibition of complement deposition is likely to be affected by the presence of other pneumococcal proteins and to depend on the genetic background.
Collapse
|
36
|
Immunization of mice with single PspA fragments induces antibodies capable of mediating complement deposition on different pneumococcal strains and cross-protection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:439-46. [PMID: 20089795 DOI: 10.1128/cvi.00430-09] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PspA is an important candidate for a vaccine with serotype-independent immunity against pneumococcal infections. Based on sequence relatedness, PspA has been classified into three families comprising six clades. We have previously addressed the cross-reactivity of antibodies against PspA fragments containing the N-terminal and proline-rich regions of PspA from clades 1 to 5 (PspA1, PspA2, PspA3, PspA4, and PspA5) by Western blot analysis and reported that anti-PspA4 and anti-PspA5 were able to recognize pneumococci expressing PspA proteins from all of the clades analyzed. We have now analyzed the functional capacity of these antibodies to bind and to mediate complement deposition on intact bacteria in vitro. Our results show that both PspA4 and PspA5 elicit antibodies that are able to bind and to mediate complement deposition efficiently on pneumococcal strains bearing PspA proteins from clades 1 to 5. Moreover, mice immunized with PspA4 and PspA5 were protected against an intranasal lethal challenge with strains expressing PspA proteins from the two major families. PspA4 and PspA5 are thus able to induce antibodies with a high degree of cross-reactivity in vitro, which is reflected in cross-protection of mice. We have also analyzed the contribution of the nonproline (NonPro) block within the conserved proline-rich region to the reactivity of anti-PspA antibodies, and the results indicate that N-terminal alpha-helical region, the blocks of proline repeats, and the NonPro region can influence the degree of cross-reactivity of antibodies to PspA.
Collapse
|
37
|
Maternal antibodies to pneumolysin but not to pneumococcal surface protein A delay early pneumococcal carriage in high-risk Papua New Guinean infants. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:1633-8. [PMID: 19776196 DOI: 10.1128/cvi.00247-09] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Immunization of pregnant women can be an efficient strategy to induce early protection in infants in developing countries. Pneumococcal protein-based vaccines may have the capacity to induce pneumococcal serotype-independent protection. To understand the potential of maternal pneumococcal protein-specific antibodies in infants in high-risk areas, we studied the placental transfer of naturally acquired antibodies to pneumolysin (Ply) and pneumococcal surface protein A family 1 and 2 (PspA1 and PspA2) in relation to onset of pneumococcal nasopharyngeal carriage in infants in Papua New Guinea (PNG). In this study, 76% of the infants carried Streptococcus pneumoniae in the upper respiratory tract within the first month of life, at a median age of 19 days. Maternal and cord blood antibody titers to Ply (rho = 0.824, P < 0.001), PspA1 (rho = 0.746, P < 0.001), and PspA2 (rho = 0.631, P < 0.001) were strongly correlated. Maternal pneumococcal carriage (hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.25 to 5.39) and younger maternal age (HR, 0.74; 95% CI, 0.54 to 1.00) were independent risk factors for early carriage, while higher cord Ply-specific antibody titers predicted a significantly delayed onset (HR, 0.71; 95% CI, 0.52 to 1.00) and cord PspA1-specific antibodies a significantly younger onset of carriage in PNG infants (HR, 1.57; 95% CI, 1.03 to 2.40). Maternal vaccination with a pneumococcal protein-based vaccine should be considered as a strategy to protect high-risk infants against pneumococcal disease by reducing carriage risks in both mothers and infants.
Collapse
|
38
|
Rohatgi S, Dutta D, Tahir S, Sehgal D. Molecular Dissection of Antibody Responses against Pneumococcal Surface Protein A: Evidence for Diverse DH-Less Heavy Chain Gene Usage and Avidity Maturation. THE JOURNAL OF IMMUNOLOGY 2009; 182:5570-85. [PMID: 19380805 DOI: 10.4049/jimmunol.0803254] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Bacterial/biosynthesis
- Antibodies, Bacterial/genetics
- Antibodies, Bacterial/metabolism
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/metabolism
- Antibody Affinity/genetics
- Antibody Diversity/genetics
- Bacterial Proteins/immunology
- Base Sequence
- Epitopes, B-Lymphocyte/metabolism
- Female
- Gene Deletion
- Gene Rearrangement, B-Lymphocyte, Heavy Chain/genetics
- Hybridomas
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Heavy Chains/metabolism
- Immunoglobulin Variable Region/genetics
- Immunoglobulin Variable Region/metabolism
- Membrane Proteins/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred CBA
- Molecular Sequence Data
- Multigene Family/immunology
- Streptococcus pneumoniae/immunology
Collapse
Affiliation(s)
- Soma Rohatgi
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | | | | | | |
Collapse
|
39
|
Streptococcus pneumoniae capsular serotype 19F is more resistant to C3 deposition and less sensitive to opsonophagocytosis than serotype 6B. Infect Immun 2008; 77:676-84. [PMID: 19047408 DOI: 10.1128/iai.01186-08] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The polysaccharide capsule is a major virulence mechanism of Streptococcus pneumoniae, shielding the bacterium from phagocytes. Capsule types may differ in their abilities to resist immune defense. Antibody-mediated complement activation and opsonophagocytosis are crucial in protection against pneumococcus. Conjugate vaccine trials suggest imperfect protection against 19F. We have previously shown that significantly more anti-19F than anti-6B antibody is needed for killing in the opsonophagocytic assay (OPA). In this study, we explored whether the amount of C3 deposited on serotype 6B and 19F pneumococcal strains reflects their sensitivity to opsonophagocytosis. We compared clinical 6B and 19F nasopharyngeal, middle ear, and blood isolates as well as reference OPA strains (n = 16) for their sensitivity to opsonophagocytosis and C3 deposition. Sixfold anticapsular antibody concentrations were required for 50% opsonophagocytic killing of 19F compared to that of 6B strains. Serotype 19F was more resistant to C3 deposition than 6B. Complement deposition and opsonophagocytosis were dependent on the concentration of anticapsular antibodies. Differences between pneumococcal serotypes in antibody-mediated protection may partly be explained by the abilities of the capsules to resist complement deposition. These findings support previous studies suggesting that higher antibody concentrations to the capsular polysaccharide are needed for protection against disease caused by serotype 19F than that caused by 6B.
Collapse
|