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Updated: Jun 25, 2025

Visualization of IL-22-expressing Lymphocytes Using Reporter Mice
Published on: January 25, 2017
IL-33 controls IL-22-dependent antibacterial defense by modulating the microbiota
Ivo Röwekamp1, Laura Maschirow1, Anne Rabes1
1Department of Infectious Diseases, Respiratory Medicine and Critical Care, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin 13353, Germany.
Interleukin-33 (IL-33) negatively regulates IL-22 production, enhancing resistance to Streptococcus pneumoniae lung infections. Genetic and environmental factors influencing gut microbiota impact pneumonia susceptibility.
Area of Science:
- Immunology
- Microbiology
- Genetics
Background:
- Interleukin-22 (IL-22) is crucial for mucosal defense against infections.
- Regulation of IL-22 production remains incompletely understood.
- Streptococcus pneumoniae causes lung infections, including pneumonia.
Purpose of the Study:
- To investigate the role of IL-33 in regulating IL-22 production and its impact on Streptococcus pneumoniae lung infection.
- To explore the genetic and environmental factors influencing this immune response.
Main Methods:
- Studied mice lacking IL-33 or its receptor ST2 (IL-1RL1) during S. pneumoniae infection.
- Analyzed single-nucleotide polymorphisms in IL33 and IL1RL1 in human pneumonia patients.
- Investigated the role of innate lymphoid cells (ILCs) and gut microbiota.
Main Results:
- Mice lacking IL-33 or ST2 showed increased resistance to S. pneumoniae.
- Genetic variations in IL33 and IL1RL1 were associated with human pneumococcal pneumonia.
- IL-33 negatively regulated IL-22 production in ILCs, independent of ILC2s, IL-4, and IL-13.
- The effect of IL-33 was modulated by housing conditions and gut microbiota.
Conclusions:
- IL-33 negatively regulates IL-22-mediated antibacterial defense against S. pneumoniae.
- Gut microbiota composition, influenced by genetic and environmental factors, plays a key role in pneumonia susceptibility.
- Highlights bidirectional crosstalk between the innate immune system and gut microbiota.
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