The conventional view on T cell development posits that signals from the same T cell receptor (TCR) determines both positive and negative selection as well as lineage choice into mature CD4+ helper and CD8+ cytotoxic cells. The precise mechanism how this is achieved is still under dispute but it has been proposed that either quantitative or qualitative differences in TCR signaling would account for the different outcomes of lineage choice. In contrast to such views, here we show that TCR signaling alone is not sufficient to determine cell fate of developing thymocytes, and that CD4/CD8 lineage choice requires additional cues by cytokines such as interleukin-7 (IL-7). Using conditional deletion of immediate downstream signaling molecules of the IL-7 receptor, we demonstrate that IL-7 induced cytokine signals are required for CD8 lineage choice and for the differentiation into mature CD8+ cytotoxic T cells in vivo. Our data establish a previously unappreciated role for in vivo IL-7 and other gamma c-cytokines in CD8 lineage commitment of immature thymocytes, which is consistent with the kinetic signaling model of T cell lineage choice.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIABC011111-05
Application #
8552986
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
5
Fiscal Year
2012
Total Cost
$357,064
Indirect Cost
Name
National Cancer Institute Division of Basic Sciences
Department
Type
DUNS #
City
State
Country
Zip Code
Takada, Kensuke; Van Laethem, Francois; Xing, Yan et al. (2015) TCR affinity for thymoproteasome-dependent positively selecting peptides conditions antigen responsiveness in CD8(+) T cells. Nat Immunol 16:1069-76
Pobezinsky, Leonid A; Etzensperger, Ruth; Jeurling, Susanna et al. (2015) Let-7 microRNAs target the lineage-specific transcription factor PLZF to regulate terminal NKT cell differentiation and effector function. Nat Immunol 16:517-24
Tai, Xuguang; Singer, Alfred (2014) Basis of Treg development in the thymus. Cell Cycle 13:501-2
Van Laethem, François; Tikhonova, Anastasia N; Pobezinsky, Leonid A et al. (2013) Lck availability during thymic selection determines the recognition specificity of the T cell repertoire. Cell 154:1326-41
Tai, Xuguang; Erman, Batu; Alag, Amala et al. (2013) Foxp3 Transcription Factor Is Proapoptotic and Lethal to Developing Regulatory T Cells unless Counterbalanced by Cytokine Survival Signals. Immunity :
Tai, Xuguang; Van Laethem, Francois; Pobezinsky, Leonid et al. (2012) Basis of CTLA-4 function in regulatory and conventional CD4(+) T cells. Blood 119:5155-63
Adoro, Stanley; Park, Jung-Hyun; Singer, Alfred (2012) Coreceptor gene "imprinting:" a genetic solution to a developmental dilemma in T cells. Cell Cycle 11:833-4
Tikhonova, Anastasia N; Van Laethem, François; Hanada, Ken-ichi et al. (2012) αβ T cell receptors that do not undergo major histocompatibility complex-specific thymic selection possess antibody-like recognition specificities. Immunity 36:79-91
Van Laethem, François; Tikhonova, Anastasia N; Singer, Alfred (2012) MHC restriction is imposed on a diverse T cell receptor repertoire by CD4 and CD8 co-receptors during thymic selection. Trends Immunol 33:437-41
Gegonne, Anne; Tai, Xuguang; Zhang, Jinghui et al. (2012) The general transcription factor TAF7 is essential for embryonic development but not essential for the survival or differentiation of mature T cells. Mol Cell Biol 32:1984-97

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