The anti-apoptotic Bcl-2 family member Mcl-1 promotes T lymphocyte survival at multiple stages.
T lymphocyte development and function are tightly regulated by the intrinsic death pathway through members of the Bcl-2 family. Genetic studies have demonstrated that the Bcl-2 family member Mcl-1 is an important anti-apoptotic protein in the development of multiple cell types including T lymphocytes. However, the expression pattern and anti-apoptotic roles of Mcl-1 in T lymphocytes at different developmental stages remain to be fully determined. In this study, we examined the expression pattern of Mcl-1 in different populations of T cells at the single-cell level and found that Mcl-1 protein is constitutively expressed in all T cell populations and up-regulated upon TCR stimulation. We then investigated the role of Mcl-1 in the survival of these different populations by conditionally deleting Mcl-1 at various T cell stages. Our results show that Mcl-1 is required for the survival of double-negative and single-positive thymocytes as well as naive and activated T cells. Furthermore, we demonstrate that Mcl-1 functions together with Bcl-xL to promote double-positive thymocyte survival. Thus, Mcl-1 is a critical anti-apoptotic factor for the survival of T cells at multiple stages in vivo.
Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
Ivan
I
Dzhagalov
Alexis
A
Dunkle
You-Wen
YW
He
D000818:Animals; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
C579094:Mcl1 protein, mouse; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein