Increased susceptibility for superinfection with Streptococcus pneumoniae during influenza virus infection is not caused by TLR7-mediated lymphopenia.

2.50
HDL Handle:
http://hdl.handle.net/10033/70593
Title:
Increased susceptibility for superinfection with Streptococcus pneumoniae during influenza virus infection is not caused by TLR7-mediated lymphopenia.
Authors:
Stegemann, Sabine; Dahlberg, Sofia; Kröger, Andrea; Gereke, Marcus; Bruder, Dunja; Henriques-Normark, Birgitta; Gunzer, Matthias
Abstract:
Influenza A virus (IAV) causes respiratory tract infections leading to recurring epidemics with high rates of morbidity and mortality. In the past century IAV induced several world-wide pandemics, the most aggressive occurring in 1918 with a death toll of 20-50 million cases. However, infection with IAV alone is rarely fatal. Instead, death associated with IAV is usually mediated by superinfection with bacteria, mainly Streptococcus pneumoniae. The reasons for this increased susceptibility to bacterial superinfection have not been fully elucidated. We previously demonstrated that triggering of TLR7 causes immune incompetence in mice by induction of lymphopenia. IAV is recognized by TLR7 and infections can lead to lymphopenia. Since lymphocytes are critical to protect from S. pneumoniae it has long been speculated that IAV-induced lymphopenia might mediate increased susceptibility to superinfection. Here we show that sub-lethal pre-infections of mice with IAV-PR8/A/34 strongly increased their mortality in non-lethal SP infections, surprisingly despite the absence of detectable lymphopenia. In contrast to SP-infection alone co-infected animals were unable to control the exponential growth of SP. However, lymphopenia forced by TLR7-triggering or antibody-mediated neutropenia did not increase SP-susceptibility or compromise the ability to control SP growth. Thus, the immune-incompetence caused by transient lympho- or leukopenia is not sufficient to inhibit potent antibacterial responses of the host and mechanisms distinct from leukodepletion must account for increased bacterial superinfection during viral defence.
Affiliation:
Otto-von-Guericke University, Institute of Molecular and Clinical Immunology, Magdeburg, Germany.
Citation:
Increased susceptibility for superinfection with Streptococcus pneumoniae during influenza virus infection is not caused by TLR7-mediated lymphopenia. 2009, 4 (3):e4840 PLoS ONE
Journal:
PloS one
Issue Date:
2009
URI:
http://hdl.handle.net/10033/70593
DOI:
10.1371/journal.pone.0004840
PubMed ID:
19290047
Type:
Article
Language:
en
ISSN:
1932-6203
Appears in Collections:
Publications of RG Immunoregulation (IREG)

Full metadata record

DC FieldValueLanguage
dc.contributor.authorStegemann, Sabine-
dc.contributor.authorDahlberg, Sofia-
dc.contributor.authorKröger, Andrea-
dc.contributor.authorGereke, Marcus-
dc.contributor.authorBruder, Dunja-
dc.contributor.authorHenriques-Normark, Birgitta-
dc.contributor.authorGunzer, Matthias-
dc.date.accessioned2009-06-16T12:52:36Z-
dc.date.available2009-06-16T12:52:36Z-
dc.date.issued2009-
dc.identifier.citationIncreased susceptibility for superinfection with Streptococcus pneumoniae during influenza virus infection is not caused by TLR7-mediated lymphopenia. 2009, 4 (3):e4840 PLoS ONEen
dc.identifier.issn1932-6203-
dc.identifier.pmid19290047-
dc.identifier.doi10.1371/journal.pone.0004840-
dc.identifier.urihttp://hdl.handle.net/10033/70593-
dc.description.abstractInfluenza A virus (IAV) causes respiratory tract infections leading to recurring epidemics with high rates of morbidity and mortality. In the past century IAV induced several world-wide pandemics, the most aggressive occurring in 1918 with a death toll of 20-50 million cases. However, infection with IAV alone is rarely fatal. Instead, death associated with IAV is usually mediated by superinfection with bacteria, mainly Streptococcus pneumoniae. The reasons for this increased susceptibility to bacterial superinfection have not been fully elucidated. We previously demonstrated that triggering of TLR7 causes immune incompetence in mice by induction of lymphopenia. IAV is recognized by TLR7 and infections can lead to lymphopenia. Since lymphocytes are critical to protect from S. pneumoniae it has long been speculated that IAV-induced lymphopenia might mediate increased susceptibility to superinfection. Here we show that sub-lethal pre-infections of mice with IAV-PR8/A/34 strongly increased their mortality in non-lethal SP infections, surprisingly despite the absence of detectable lymphopenia. In contrast to SP-infection alone co-infected animals were unable to control the exponential growth of SP. However, lymphopenia forced by TLR7-triggering or antibody-mediated neutropenia did not increase SP-susceptibility or compromise the ability to control SP growth. Thus, the immune-incompetence caused by transient lympho- or leukopenia is not sufficient to inhibit potent antibacterial responses of the host and mechanisms distinct from leukodepletion must account for increased bacterial superinfection during viral defence.en
dc.language.isoenen
dc.subject.meshAnimalsen
dc.subject.meshBronchoalveolar Lavage Fluiden
dc.subject.meshDisease Susceptibilityen
dc.subject.meshFemaleen
dc.subject.meshInfluenza A virusen
dc.subject.meshLymphopeniaen
dc.subject.meshMembrane Glycoproteinsen
dc.subject.meshMiceen
dc.subject.meshMice, Inbred C57BLen
dc.subject.meshOrthomyxoviridae Infectionsen
dc.subject.meshPneumonia, Pneumococcalen
dc.subject.meshStreptococcus pneumoniaeen
dc.subject.meshSuperinfectionen
dc.subject.meshToll-Like Receptor 7en
dc.titleIncreased susceptibility for superinfection with Streptococcus pneumoniae during influenza virus infection is not caused by TLR7-mediated lymphopenia.en
dc.typeArticleen
dc.contributor.departmentOtto-von-Guericke University, Institute of Molecular and Clinical Immunology, Magdeburg, Germany.en
dc.identifier.journalPloS oneen

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