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Updated: Jun 22, 2026
07:42
Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
Published on: June 29, 2011
c-Maf increases apoptosis in peripheral CD8 cells by transactivating Caspase 6
Siying Peng1, Hailong Wu, Yin-Yuan Mo
1Department of Medical Microbiology, Southern Illinois University School of Medicine, Springfield, 62794, USA.
Immunology
|May 30, 2009
Summary
Cellular muscular aponeurotic fibrosarcoma (c-Maf) increases CD8 cell apoptosis by directly activating Caspase 6. This finding reveals a new mechanism for regulating CD8 cell death and survival in immune responses.
Area of Science:
- Immunology
- Molecular Biology
- Cell Death Pathways
Background:
- Cellular muscular aponeurotic fibrosarcoma (c-Maf) influences T-cell function, including CD4 cell apoptosis via Bcl-2.
- Reduced CD8 cell numbers in c-Maf transgenic mice suggest a role for c-Maf in CD8 cell survival.
Purpose of the Study:
- To investigate the role of c-Maf in CD8 cell apoptosis.
- To identify the molecular mechanisms by which c-Maf regulates CD8 cell death.
Main Methods:
- Analysis of c-Maf transgenic mice and T cells.
- Real-time reverse transcription-polymerase chain reaction (RT-PCR) to assess gene expression.
- Luciferase reporter assays and site-directed mutagenesis to study gene regulation.
- Chromatin immunoprecipitation (ChIP) to detect protein-DNA binding.
- Measurement of caspase activity and cytochrome c release.
Main Results:
- c-Maf enhances CD8 cell apoptosis independently of IL-4 and Bcl-2.
- Caspase 6 is upregulated in c-Maf transgenic CD8 cells, indicating it as a novel c-Maf target gene.
- A functional c-Maf recognition element (MARE) in the Caspase 6 gene mediates c-Maf binding and transactivation.
- Caspase 6, 3, 7, and 8 activities, along with cytochrome c release, are increased in CD8 cells from c-Maf transgenic mice upon T-cell receptor engagement.
Conclusions:
- c-Maf directly transactivates Caspase 6, increasing CD8 cell sensitivity to apoptosis.
- This mechanism provides a novel pathway for c-Maf-mediated regulation of CD8 cell apoptosis.
- Findings contribute to understanding T-cell homeostasis and immune regulation.
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