IL-18 contributes to host resistance against infection with Cryptococcus neoformans in mice with defective IL-12 synthesis through induction of IFN-γ production by NK cells

Kazuyoshi Kawakami, Yoshinobu Koguchi, Mahboob Hossain Qureshi, Akiko Miyazato, Satomi Yara, Yuki Kinjo, Yoichiro Iwakura, Kiyoshi Takeda, Shizuo Akira, Masashi Kurimoto, Atsushi Saito

Research output: Contribution to journalArticle

113 Citations (Scopus)

Abstract

The aim of this study was to examine the contribution of IL-18 in host defense against infection caused by Cryptococcus neoformans in mice with defective IL-12 production. Experiments were conducted in mice with a targeted disruption of the gene for IL-12p40 subunit (IL-12p40(-/-) mice). In these mice, host resistance was impaired, as shown by increased number of organisms in both lungs and brains, compared with control mice. Serum IFN-γ was still detected in these mice at a considerable level (20-30% of that in control mice). The host resistance was moderately impaired in IL-12p40(-/-) mice compared with IFN-γ(-/-) mice. Neutralizing anti-IFN-γ mAb further increased the lung burdens of organisms. In addition, treatment with neutralizing anti-IL-18 Ab almost completely abrogated the production of IFN- γ and also impaired the host resistance. Host resistance in IL-12p40(-/-) IL-18(-/-) mice was more profoundly impaired than in IL-12p40(-/-) mice. Administration of IL-12 as well as IL-18 increased the serum levels of IFN-γ and significantly restored the reduced host resistance. Spleen cells obtained from infected IL-12p40(-/-) mice did not produce any IFN-γ upon restimulation with the same organisms, while those from infected and IL-12- treated mice produced IFN-γ. In contrast, IL-18 did not show such effect. Finally, depletion of NK cells by anti-asialo GM1 Ab mostly abrogated the residual production of IFN-γ in IL-12p40(-/-) mice. Our results indicate that IL-18 contributes to host resistance to cryptococcal infection through the induction of IFN-γ production by NK cells, but not through the development of Th1 cells, under the condition in which IL-12 synthesis is deficient.

Original languageEnglish
Pages (from-to)941-947
Number of pages7
JournalJournal of Immunology
Volume165
Issue number2
DOIs
Publication statusPublished - 2000 Jul 15
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Fingerprint Dive into the research topics of 'IL-18 contributes to host resistance against infection with Cryptococcus neoformans in mice with defective IL-12 synthesis through induction of IFN-γ production by NK cells'. Together they form a unique fingerprint.

  • Cite this