Hirata Y, Sugie A, Matsuda A, Matsuda S, Koyasu S. TAK1-JNK axis mediates survival signal through Mcl1 stabilization in activated T cells.
THE JOURNAL OF IMMUNOLOGY 2013;
190:4621-6. [PMID:
23547112 DOI:
10.4049/jimmunol.1202809]
[Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
TAK1, a member of MAPK kinase kinase (MAPKK-K) family, can activate JNK, p38 MAPK, and NF-κB signaling pathways. Although targeted gene disruption studies have demonstrated that TAK1 plays a critical role in T cell functions, precise functions of downstream mediators remain elusive. We used the chemical compound LL-Z1640-2, which preferentially suppressed MAPK activation but not NF-κB signal downstream of TAK1. LL-Z1640-2 blocked TCR-induced T cell proliferation and activation, confirming that a TAK1-mediated MAPK signal is essential for T cell activation. LL-Z1640-2 induced apoptosis of activated mouse splenic T cells in a caspase- and caspase-activated DNase-dependent manner. TAK1-JNK pathway, which is activated downstream of IL-2R, induced the phosphorylation of antiapoptotic protein Mcl1 in activated T cells, resulting in the stabilization of Mcl1 protein. Our data uncover that among signal transduction pathways downstream of TAK1, JNK mediates a survival program through Mcl1 stabilization downstream of IL-2R in activated T cells and that blockade of TAK1-JNK pathway can eliminate activated T cells by apoptosis.
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