Protein Phosphatase 2A Promotes CD8+ T Cell Effector Function through the Augmentation of CD28 Costimulation
Protein phosphatase 2A (PP2A) is one of the most abundant serine/threonine phosphatases and plays critical roles in regulating cell fate and function. We previously showed that PP2A regulates the differentiation of CD4+ T cells and the development of thymocytes. Nevertheless, its role in CD8+ T cell...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Association for the Advancement of Science (AAAS)
2025-01-01
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| Series: | Research |
| Online Access: | https://spj.science.org/doi/10.34133/research.0545 |
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| Summary: | Protein phosphatase 2A (PP2A) is one of the most abundant serine/threonine phosphatases and plays critical roles in regulating cell fate and function. We previously showed that PP2A regulates the differentiation of CD4+ T cells and the development of thymocytes. Nevertheless, its role in CD8+ T cells remains elusive. By ablating the catalytic subunit α (Cα) of PP2A in CD8+ T cells, we revealed the essential role of PP2A in promoting the effector functions of CD8+ T cells. Notably, PP2A Cα-deficient CD8+ T cells exhibit reduced proliferation and decreased cytokine production upon stimulation in vitro. In vivo, mice lacking PP2A Cα in T cells displayed defective immune responses against lymphocytic choriomeningitis virus infection, associated with reduced CD8+ T cell expansion and decreased cytokine production. Consistently, the ablation of the PP2A Cα subunit in CD8+ T cells results in attenuated antitumor activity in mice. There is a notable decrease in the infiltration of PP2A Cα-deficient CD8+ T cells within the tumor microenvironment, and the cells that do infiltrate exhibit diminished effector functions. Mechanistically, PP2A Cα deficiency impedes CD28-induced AKT Ser473 phosphorylation, thus impairing CD8+ T cell costimulation signal. Collectively, our findings underscore the critical role of phosphatase PP2A as a propeller for CD28-mediated costimulation signaling in CD8+ T cell effector function by fine-tuning T cell activation. |
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| ISSN: | 2639-5274 |