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Hirji N, Lin TJ, Bissonnette E, Belosevic M, Befus AD. Mechanisms of Macrophage Stimulation Through CD8: Macrophage CD8α and CD8β Induce Nitric Oxide Production and Associated Killing of the Parasite Leishmania major. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.12.6004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Prior studies demonstrated that rat macrophages express CD8, which differs from T lymphocyte CD8 within the ligand binding domain. We investigated whether stimulation of macrophage CD8 could induce mediator release and regulate host defense. Cross-linking either CD8α (OX8, 5 μg/ml) or CD8β (341, 10 μg/ml) stimulated nitric oxide (NO) production, which correlated with an up-regulation of inducible NO synthase protein. Cell signaling inhibitors were used to elucidate the pathways of CD8α and CD8β stimulation. Genistein (broad spectrum protein tyrosine kinase inhibitor, 10 μg/ml), PP1 (src family kinase inhibitor, 5 μg/ml), polymyxin B (protein kinase C (PKC) inhibitor, 100 μg/ml), and Ro 31-8220 (PKC inhibitor, 1 μM) significantly inhibited anti-CD8α- and anti-CD8β-stimulated NO production and inducible NO synthase up-regulation, suggesting that tyrosine kinase(s) (src family) and PKC are involved in CD8 signaling. In addition, cross-linking CD8α stimulated NO-dependent macrophage killing of the parasite Leishmania major. For the first time, this work demonstrates that the β-chain of macrophage CD8, in addition to the α-chain, can regulate mediator release. These results further illustrate the importance of this molecule and support our previous data demonstrating differences between macrophage and T lymphocyte CD8. Additional studies on the signaling mechanisms and possible ligand(s) for macrophage CD8 will lead to a greater understanding of inflammation and host defense.
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Affiliation(s)
| | | | | | - Miodrag Belosevic
- †Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Le Q, Daniel R, Chung SW, Kang AD, Eisenstein TK, Sultzer BM, Simpkins H, Wong PMC. Involvement of C-Abl Tyrosine Kinase in Lipopolysaccharide- Induced Macrophage Activation. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.7.3330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
LPS endotoxin-induced macrophage activation is recognized to be important in both nonspecific immunity and endotoxin-induced sepsis when excessive macrophage stimulation occurs. In this study, we showed that reduction of c-Abl in macrophages prevented LPS-induced growth arrest, nitric oxide production and TNF-α secretion by ANA-1 macrophages. These cells continued to grow but later underwent apoptosis. Reduction of c-Abl in these cells led to reduced c-Abl kinase activity associated with Ran, which recently has been shown to be an LPS-responsive gene product. Our data suggest that c-Abl tyrosine kinase is one of the intermediates downstream of the initial signal transduction event related to activation of macrophages by LPS.
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Affiliation(s)
- Quan Le
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Rene Daniel
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Siu-Wah Chung
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Anthony D. Kang
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Toby K. Eisenstein
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Barnet M. Sultzer
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Henry Simpkins
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | - Peter M. C. Wong
- Fels Institute for Cancer Research and Molecular Biology, Departments of Pathology and Laboratory Medicine, Biochemistry, and Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
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