Protein phosphatase 2A catalytic subunit ß suppresses PMA/ionomycin-induced T-cell activation by negatively regulating PI3K/Akt signaling.
FEBS J
; 289(15): 4518-4535, 2022 08.
Article
em En
| MEDLINE
| ID: mdl-35068054
ABSTRACT
The precise regulation of the T-cell activation process is critical for overall immune homeostasis. Although protein phosphatase 2A (PP2A) is required for T-cell development and function, the role of PPP2CB, which is the catalytic subunit ß isoform of PP2A, remains unknown. In the present study, using a T cell-specific knockout mouse of PPP2CB (PPP2CBfl/fl Lck-Cre+ ), we demonstrated that PPP2CB was dispensable for T-cell development in the thymus and peripheral lymphoid organs. Furthermore, PPP2CB deletion did not affect T-cell receptor (TCR)-induced T-cell activation or cytokine-induced T-cell responses; however, it specifically enhanced phorbol myristate acetate (PMA) plus ionomycin-induced T-cell activation with increased cellular proliferation, elevated CD69 and CD25 expression, and enhanced cytokine production (inteferon-γ, interleukin-2 and tumor necrosis factor). Mechanistic analyses suggested that the PPP2CB deletion enhanced activation of the phosphoinositide 3-kinase/Akt signaling pathway and Ca2+ flux following stimulation with PMA plus ionomycin. Moreover, the specific PI3K inhibitor rescued the augmented cell activation in PPP2CB-deficient T cells. Using mass spectrometry-based phospho-peptide analysis, we identified potential substrates of PPP2CB during PMA plus ionomycin-induced T-cell activation. Collectively, our study provides evidence of the specific role of PPP2CB in controlling PMA plus ionomycin-induced T-cell activation.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação Linfocitária
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Linfócitos T
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Fosfatidilinositol 3-Quinases
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Proteínas Proto-Oncogênicas c-akt
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Proteína Fosfatase 2
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article