- Expression of Fibronectin, Vitronectin, Surfactant-A and D in Interaction of Pneumocystis carinii and Alveolar Epithelial Cells in Pneumocystis carinii Pneumonia.
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Kun Young Kwon, Young June Jeon, Eun Sook Chang
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Korean J Pathol. 2000;34(9):625-635.
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Abstract
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- Both fibronectin and vitronectin bind to Pneumocystis carinii (P. carinii) and mediate the attachment of the organisms to respiratory epithelial cells. Surfactant A and D play a role in the interaction between P. carinii and host cells. In this study we examined the expression of fibronectin, vitronectin, surfactant-A and D in the interaction between P. carinii and alveolar epithelial cells by immunohistochemistry and pre-embedding immunoelectron microscopy. The experimental rat model of P. carinii pneumonia was induced by administration of low protein diet (8%) and drinking water containing dexamethasone (2 mg/liter) for 6 to 8 weeks. The primary antibodies for light and electron microscopic immunohistochemistries were monoclonal antibodies including fibronectin (1:100) and vitronectin (1:100), and polyclonal antibodies including surfactant A (1:50) and D (1:50), respectively.
Light microscopic immunohistochemistry for the fibronectin, vitronectin, surfactant-A and D showed strong expressions on the P. carinii and surface linings of type I alveolar epithelial cells. The electron microscopic immunohistochemistry of the fibronectin and vitronectin showed a strong immunoexpression along the surface pellicles and tubular extensions of P. carinii trophozoites, and surface membranes of the type I epithelial cells. The surfactant-A and D proteins showed a strong expression on the pellicles of P.
carinii and surface membranes of the type I epithelial cells, but a weak expression on the free-floating surfactant materials. In conclusions, the trophozoites of P.
carinii were mostly attached to type I epithelial cells. The fibronectin, vitronectin, surfactant-A and D were strongly expressed, and played an enhancing role in the binding between the P. carinii organisms and the type I alveolar epithelial cells.
- Expression of Surfactant-D Protein and TNF-alpha in the Interaction of Pneumocystis Carinii and Alveolar Macrophages in Pneumocystis Carinii Pneumonia.
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Kun Young Kwon, Kwan Kyu Park, Chang Kwon Park, Young June Jeon, Eun Sook Chang
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Korean J Pathol. 1999;33(9):684-694.
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Abstract
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- Alveolar macrophages participate in the host defense against P. carinii, but the mechanisms in degradation and clearance of the organism from lung has not been well established. We observed the transmission and scanning electron microscopic features and evaluated the expression of TNF-alpha and Surfactant-D in the interaction of P.
carinii with alveolar macrophages. Expression of TNF-alpha and Surfactant-D in the experimentally induced P. carinii pneumonia in rat was examined by immunohistochemistry and immunoelectron microscopy. Electron microscopically, the alveolar macrophages phagocytized trophozoites and cysts of P. carinii micro-organisms.
Immunohistochemically TNF-alpha was strongly expressed in the cytoplasms of alveolar macrophages. Postembedding immunogold labeling for Surfactant-D protein was expressed on the pellicles of trophozoites and cysts, P.
carinii micro-organisms in the cytoplasms of macrophages, free floating surfactant materials and multilamellar bodies of type II epithelial cells. We conclude that alveolar macrophages interacted with P. carinii micro-organisms respond with increased expression of TNF-alpha. TNF-alpha may bind to P.
carinii and exert a direct toxic effect upon the micro-organisms. Surfactant-D protein may augment binding of P. carinii to the alveolar macrophages and enhance the clearance of the micro-organisms.
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