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Regulation and role of IFN-gamma in the innate resistance to infection with Chlamydia pneumoniae
- Source :
- Journal of immunology (Baltimore, Md. : 1950). 164(9)
- Publication Year :
- 2000
-
Abstract
- By using mice genomically lacking IFN-γR, IL-12, perforin, and recombination-activating gene-1 (RAG-1), we analyzed the regulation and importance of IFN-γ in the control of infection with Chlamydia pneumoniae. IL-12 participates in resistance of mice to C. pneumoniae, probably by regulating the protective levels of IFN-γ mRNA. In turn, IFN-γ is necessary for the increased IL-12p40 mRNA accumulation that occurs in lungs during infection with C. pneumoniae, suggesting a positive feedback regulation between these two cytokines. In experiments including RAG-1−/−/IFN-γR−/− mice we showed that IFN-γ produced by innate cells controls the bacterial load and is necessary for the increased accumulation of transcripts for enzymes controlling high output NO release (inducible NO synthase), superoxide production (gp-91 NADPH oxidase), and catalyzis of tryptophan (indoleamine 2,3-dioxygenase (IDO)), mechanisms probably related to bacterial killing. Adaptive immune reponses diminish the levels of IFN-γ and IL-12 mRNA and thereby the levels of inducible NO synthase, IDO, and gp91 NADPH oxidase trancripts. By using RAG-1−/−/perforin−/− mice, we excluded the overt participation of NK cell cytotoxicity in the control of C. pneumoniae. However, NK cells and probably other innate immune cells release IFN-γ during the bacterial infection.
- Subjects :
- Cytotoxicity, Immunologic
Genes, RAG-1
Immunology
G(M1) Ganglioside
Microbiology
chemistry.chemical_compound
Interferon-gamma
Mice
Immune system
medicine
Immunology and Allergy
Animals
Genetic Predisposition to Disease
Receptors, Interferon
Sequence Deletion
chemistry.chemical_classification
Mice, Knockout
Messenger RNA
Innate immune system
NADPH oxidase
Chlamydia
biology
Superoxide
Immune Sera
Chlamydia Infections
Chlamydophila pneumoniae
medicine.disease
Immunity, Innate
Killer Cells, Natural
Mice, Inbred C57BL
Enzyme
chemistry
Perforin
Injections, Intravenous
biology.protein
Immunosuppressive Agents
Subjects
Details
- ISSN :
- 00221767
- Volume :
- 164
- Issue :
- 9
- Database :
- OpenAIRE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Accession number :
- edsair.doi.dedup.....17849ecdd3225e50271ba2bd2f1c0973