Although anticapsular antibodies confer serotype-specific immunity to pneumococci, children increase their ability to clear colonization before these antibodies appear, suggesting involvement of other mechanisms. We previously reported that intranasal immunization of mice with pneumococci confers CD4+ T cell–dependent, antibody- and serotype-independent protection against colonization. Here we show that this immunity, rather than preventing initiation of carriage, accelerates clearance over several days, accompanied by neutrophilic infiltration of the nasopharyngeal mucosa. Adoptive transfer of immune CD4+ T cells was sufficient to confer immunity to naïve RAG1−/− mice. A critical role of interleukin (IL)-17A was demonstrated: mice lacking interferon-γ or IL-4 were protected, but not mice lacking IL-17A receptor or mice with neutrophil depletion. In vitro expression of IL-17A in response to pneumococci was assayed: lymphoid tissue from vaccinated mice expressed significantly more IL-17A than controls, and IL-17A expression from peripheral blood samples from immunized mice predicted protection in vivo. IL-17A was elicited by pneumococcal stimulation of tonsillar cells of children or adult blood but not cord blood. IL-17A increased pneumococcal killing by human neutrophils both in the absence and in the presence of antibodies and complement. We conclude that IL-17A mediates pneumococcal immunity in mice and probably in humans; its elicitation in vitro could help in the development of candidate pneumococcal vaccines.
Interleukin-17A Mediates Acquired Immunity to Pneumococcal Colonization
Ying-Jie Lu,J. Gross,D. Bogaert,A. Finn,L. Bagrade,Qibo Zhang,J. Kolls,Amit Srivastava,A. Lundgren,Sophie S. Forte,C. Thompson,Kathleen F. Harney,P. Anderson,M. Lipsitch,R. Malley
Published 2008 in PLoS Pathogens
ABSTRACT
PUBLICATION RECORD
- Publication year
2008
- Venue
PLoS Pathogens
- Publication date
2008-09-01
- Fields of study
Biology, Medicine
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- adoptive transfer
Experimental transfer of immune cells from one mouse to another to test whether they can convey protection.
Aliases: cell transfer
- antibodies and complement
Humoral immune factors included in the in vitro killing assays to assess whether IL-17A acts with or without them.
Aliases: antibody and complement
- cd4+ t cells
Helper T lymphocytes implicated here in mediating acquired immunity to pneumococcal colonization.
Aliases: CD4 T cells, helper T cells
- human neutrophils
Peripheral blood innate immune cells tested for pneumococcal killing activity in vitro.
Aliases: neutrophils
- il-17a
A pro-inflammatory cytokine measured after pneumococcal stimulation and tested for its effect on neutrophil-mediated killing.
Aliases: interleukin-17A
- il-17a receptor
The host receptor that mediates cellular responses to IL-17A signaling.
Aliases: IL-17RA
- il-4
A cytokine representing a Th2-associated immune pathway examined as a comparator in the protection experiments.
Aliases: interleukin-4
- immune cd4+ t cells
CD4+ T cells isolated from immunized animals and used as the transferred protective cell population.
Aliases: immune helper T cells
- interferon-γ
A cytokine representing a Th1-associated immune pathway examined as a comparator in the protection experiments.
Aliases: IFN-gamma, IFN-γ
- intranasal immunization
Delivery of vaccine material through the nasal route to induce mucosal immune responses.
Aliases: nasal immunization
- lymphoid tissue
Immune tissue from vaccinated mice used to measure cytokine expression after pneumococcal stimulation.
Aliases: lymphoid tissues
- neutrophil depletion
Experimental reduction of neutrophils used to test whether these cells are required for protection.
Aliases: neutrophil removal
- pneumococcal colonization
Carriage of Streptococcus pneumoniae in the nasopharyngeal mucosa.
Aliases: pneumococcal carriage, colonization
- rag1−/− mice
Mice deficient in recombination-activating gene 1 and therefore lacking mature B and T lymphocytes.
Aliases: RAG1 knockout mice, RAG1 deficient mice
- tonsillar cells
Cells isolated from human tonsillar tissue and stimulated with pneumococci to assess IL-17A induction.
Aliases: tonsil cells
REFERENCES
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