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Corsini B, Aguinagalde L, Ruiz S, Domenech M, Antequera ML, Fenoll A, García P, García E, Yuste J. Immunization with LytB protein of Streptococcus pneumoniae activates complement-mediated phagocytosis and induces protection against pneumonia and sepsis. Vaccine 2016; 34:6148-6157. [PMID: 27840016 DOI: 10.1016/j.vaccine.2016.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/06/2016] [Accepted: 11/02/2016] [Indexed: 01/12/2023]
Abstract
The cell wall glucosaminidase LytB of Streptococcus pneumoniae is a surface exposed protein involved in daughter cell separation, biofilm formation and contributes to different aspects of the pathogenesis process. In this study we have characterized the antibody responses after immunization of mice with LytB in the presence of alhydrogel as an adjuvant. Enzyme-linked immunosorbent assays measuring different subclasses of immunoglobulin G, demonstrated that the antibody responses to LytB were predominantly IgG1 and IgG2b, followed by IgG3 and IgG2a subclasses. Complement-mediated immunity against two different pneumococcal serotypes was investigated using sera from immunized mice. Immunization with LytB increased the recognition of S. pneumoniae by complement components C1q and C3b demonstrating that anti-LytB antibodies trigger activation of the classical pathway. Phagocytosis assays showed that serum containing antibodies to LytB stimulates neutrophil-mediated phagocytosis against S. pneumoniae. Animal models of infection including invasive pneumonia and sepsis were performed with two different clinical isolates. Vaccination with LytB increased bacterial clearance and induced protection demonstrating that LytB might be a good candidate to be considered in a future protein-based vaccine against S. pneumoniae.
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Affiliation(s)
- Bruno Corsini
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Leire Aguinagalde
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Susana Ruiz
- Centro de Investigaciones Biológicas (CIB-CSIC), 28040 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain
| | - Mirian Domenech
- Centro de Investigaciones Biológicas (CIB-CSIC), 28040 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain
| | - María Luisa Antequera
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Asunción Fenoll
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Pedro García
- Centro de Investigaciones Biológicas (CIB-CSIC), 28040 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain
| | - Ernesto García
- Centro de Investigaciones Biológicas (CIB-CSIC), 28040 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain
| | - Jose Yuste
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain.
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