T Cell-Dependent Activation of Macrophages and Enhancement of Their Phagocytic Activity in the Lungs of Mice Inoculated with Heat-Killed Cryptococcus neoformans: Involvement of IFN-γ and Its Protective Effect against Cryptococcal Infection
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- KAWAKAMI Kazuyoshi
- First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus
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- KOHNO Shigeru
- Second Department of Internal Medicine, Nagasaki University School of Medicine
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- KADOTA Jun-ichi
- Second Department of Internal Medicine, Nagasaki University School of Medicine
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- TOHYAMA Masaki
- First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus
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- TERUYA Katsuji
- First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus
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- KUDEKEN Norifumi
- First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus
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- SAITO Atsushi
- First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus
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- HARA Kohei
- Second Department of Internal Medicine, Nagasaki University School of Medicine
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Abstract
Previous investigations have demonstrated that macrophages play a critical role in the first-line cellular defense mechanism against infection with Cryptococcus neoformans. In the present study, to elucidate the way in which anticryptococcal activity of macrophages is regulated at the site of infection, pulmonary intraparenchymal macrophages were directly analyzed for expression of their surface molecules and their phagocytic activities against the organism, and the effects of depletion of T cells and endogenous IFN-γ in vivo on these parameters were examined. In the lungs of mice intratracheally inoculated with heat-killed C. neoformans, macrophages were activated, as indicated by augmented expression of MHC class II, intercellular adhesion molecule-1 (ICAM-1) and Fc receptor (FcR), and about two-thirds of macrophages were found to have ingested an average of 3.77±0.12 yeast cells per macrophage. In mice depleted of both CD4+ and CD8+ T cells by injecting the specific monoclonal antibodies (mAbs) or anti-IFN-γ mAb, not only augmentation of the expression of macrophage activation markers but also phagocytosis of C. neoformans was significantly reduced. These results suggest that anticryptococcal activity of macrophages is regulated by IFN-γ endogenously produced by T cells. Additionally, treatment with IFN-γ were shown to significantly prolong the survival time of mice infected with viable C. neoformans. Additionally, preimmunization with heat-killed C. neoformans significantly prolonged the survival time of mice which received the following infection.
Journal
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- MICROBIOLOGY and IMMUNOLOGY
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MICROBIOLOGY and IMMUNOLOGY 39 (2), 135-143, 1995-02-20
Center For Academic Publications Japan
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Details 詳細情報について
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- CRID
- 1571698599321789056
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- NII Article ID
- 10005004008
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- NII Book ID
- AA00738350
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- ISSN
- 03855600
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- Text Lang
- en
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- Data Source
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- CiNii Articles