First Author | Hoyer KK | Year | 2005 |
Journal | J Immunol | Volume | 175 |
Issue | 2 | Pages | 864-73 |
PubMed ID | 16002684 | Mgi Jnum | J:100696 |
Mgi Id | MGI:3589315 | Doi | 10.4049/jimmunol.175.2.864 |
Citation | Hoyer KK, et al. (2005) T cell leukemia-1 modulates TCR signal strength and IFN-gamma levels through phosphatidylinositol 3-kinase and protein kinase C pathway activation. J Immunol 175(2):864-73 |
abstractText | A signaling role for T cell leukemia-1 (TCL1) during T cell development or in premalignant T cell expansions and mature T cell tumors is unknown. In this study, TCL1 is shown to regulate the growth and survival of peripheral T cells but not precursor thymocytes. Proliferation is increased by TCL1-induced lowering of the TCR threshold for CD4(+) and CD8(+) T cell activation through both PI3K-Akt and protein kinase C-MAPK-ERK signaling pathways. This effect is submaximal as CD28 costimulation coupled to TCL1 expression additively accelerates dose-dependent T cell growth. In addition to its role in T cell proliferation, TCL1 also increases IFN-gamma levels from Th1-differentiated T cells, an effect that may provide a survival advantage during premalignant T cell expansions and in clonal T cell tumors. Combined, these data indicate a role for TCL1 control of growth and effector T cell functions, paralleling features provided by TCR-CD28 costimulation. These results also provide a more detailed mechanism for TCL1-augmented signaling and help explain the delayed occurrence of mature T cell expansions and leukemias despite tumorigenic TCL1 dysregulation that begins in early thymocytes. |