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Analysis of Cellular Response and Gamma Interferon Synthesis in Bronchoalveolar Lavage Fluid and Lung Homogenate of Mice Infected with Pneumocystis carinii
Author(s) -
Ishimine Tomohiko,
Kawakami Kazuyoshi,
Nakamoto Atsushi,
Saito Atsushi
Publication year - 1995
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1995.tb02167.x
Subject(s) - pneumocystis carinii , bronchoalveolar lavage , biology , cytokine , lung , interferon gamma , immunology , cd8 , microbiology and biotechnology , immune system , medicine , human immunodeficiency virus (hiv) , pneumocystis jirovecii
The cellular and cytokine responses in the lungs of mice infected with Pneumocystis carinii were examined on both lung homogenates and bronchoalveolar lavage (BAL) fluids. In the lungs of infected mice, the number of P. carinii cysts rapidly decreased by day 7, then started to increase with a peak on day 14, and thereafter decreased gradually. When the presence of P. carinii was examined at the DNA level by dot blot hybridization, a similar clearance curve was obtained, and the organisms were shown to be completely eliminated on day 28. In the late phase of infection, leukocytes, mainly lymphocytes, increased in number when analyzed on lung homogenates, while no significant increase of inflammatory cells was observed in BAL fluids. An accumulation of both CD4 + and CD8 + T cells and an increase of activated T cells expressing IL‐2Rα were observed in lung homogenates of the infected mice. In addition, a considerable amount of IFN‐γ was detected in lung homogenates, but not in BAL fluids. These data indicate that lung homogenates are more suitable than BAL fluids for the analysis of cellular and cytokine responses in the lungs of mice infected with P. carinii . To define the involvement of IFN‐γ in host defense against P. carinii , the effect of this cytokine on the killing activity of macrophages against P. carinii was examined in vitro . IFN‐γ was found to augment this activity by increasing nitric oxide synthesis of the macrophages. Thus, it is suggested that IFN‐γ plays an important role in the protection of mice from P. carinii infection.