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Interferon γ Eliminates Responding Cd4 T Cells during Mycobacterial Infection by Inducing Apoptosis of Activated Cd4 T Cells
In Mycobacterium bovis Bacille Calmette-Guérin (BCG)-infected wild-type mice, there was a large expansion of an activated (CD44(hi)) splenic CD4 T cell population followed by a rapid contraction of this population to normal numbers. Contraction of the activated CD4 T cell population in wild-type mic...
Autores principales: | , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
2000
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1887703/ https://www.ncbi.nlm.nih.gov/pubmed/10880532 |
Sumario: | In Mycobacterium bovis Bacille Calmette-Guérin (BCG)-infected wild-type mice, there was a large expansion of an activated (CD44(hi)) splenic CD4 T cell population followed by a rapid contraction of this population to normal numbers. Contraction of the activated CD4 T cell population in wild-type mice was associated with increased apoptosis of activated CD4 T cells. In BCG-infected interferon (IFN)-γ knockout (KO) mice, the activated CD4 T cell population did not undergo apoptosis. These mice accumulated large numbers of CD4(+)CD44(hi) T cells that were responsive to mycobacterial antigens. Addition of IFN-γ to cultured splenocytes from BCG-infected IFN-γ KO mice induced apoptosis of activated CD4 T cells. IFN-γ–mediated apoptosis was abolished by depleting adherent cells or Mac-1(+) spleen cells or by inhibiting nitric oxide synthase. Thus, IFN-γ is essential to a regulatory mechanism that eliminates activated CD4 T cells and maintains CD4 T cell homeostasis during an immune response. |
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