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Updated: Jul 20, 2026
Imaging of In Situ Interferon Gamma Production in the Mouse Spleen following Listeria monocytogenes Infection
Published on: July 16, 2019
Interleukin-18 protects splenectomized mice from lethal Streptococcus pneumoniae sepsis independent of
Noritsugu Kuranaga1, Manabu Kinoshita, Toshinobu Kawabata
1Department of Immunology and Microbiology, National Defense Medical College, Namiki 3-2, Tokorozawa 359-8513, Japan.
Abstract:
The mechanism of the susceptibility of splenectomized mice to Streptococcus pneumoniae infection and the therapeutic effect of interleukin (IL)-18 were investigated. We demonstrated that, although S. pneumoniae challenge induced IL-12 production, it did not induce either interferon (IFN)-gamma or IL-18 production in mice with or without a splenectomy. Liver mononuclear cells stimulated with heat-killed S. pneumoniae but not with viable S. pneumoniae produced IFN- gamma in vitro. However, IL-18 pretreatment recovered the low serum immunoglobulin (Ig) M levels in splenectomized mice and completely inhibited mortality after S. pneumoniae infection without any IFN-gamma up-regulation. Injection of IgM from noninfected control mice into splenectomized mice before infection confirmed the essential role that IgM plays against S. pneumoniae infection. Therefore, low serum IgM levels but not a low IFN-gamma response in splenectomized mice cause lethality in S. pneumoniae infection, and IL-18 pretreatment protects them from infection by increasing IgM levels before infection.
