Glucose and glutamine fuel protein O-GlcNAcylation to control T cell self-renewal and malignancy

Sustained glucose and glutamine transport are essential for activated T lymphocytes to support ATP and macromolecule biosynthesis. We now show that glutamine and glucose also fuel an indispensible dynamic regulation of intracellular protein O-GlcNAcylation at key stages of T cell development, transformation and differentiation. Glucose and glutamine are precursors of UDP-GlcNAc, a substrate for cellular glycosyltransferases. Immune activated T cells contained higher concentrations of UDP-GlcNAc and increased intracellular protein O-GlcNAcylation controlled by the enzyme O-GlcNAc glycosyltransferase as compared to naïve cells. We identified Notch, the T cell antigen receptor and c-Myc as key controllers of T cell protein O-GlcNAcylation, via regulation of glucose and glutamine transport. Loss of O-GlcNAc transferase blocked T cell progenitor renewal, malignant transformation, and peripheral T cell clonal expansion. Nutrient-dependent signaling pathways regulated by O-GlcNAc glycosyltransferase are thus fundamental for T cell biology

TC-PTP regulates the IL-7 transcriptional response during murine early T cell development

Cytokines play a critical role in directing the discrete and gradual transcriptional changes that define T cell development. The interleukin-7 receptor (IL-7R), via its activation of the JAK-STAT pathway, promotes gene programs that change dynamically as cells progress through T cell differentiation. The molecular mechanism(s) directing differential gene expression downstream of the IL-7R are not fully elucidated. Here, we have identified T cell protein tyrosine phosphatase (TC-PTP), also known as PTPN2, as a negative regulator of IL-7R-STAT signaling in T cell progenitors, contributing to both the quantitative and qualitative nature of STAT-gene targeting. Novel genetic strategies used to modulate TC-PTP expression demonstrate that depletion of TC-PTP expression heightens the phosphorylation of STAT family members, causing aberrant expression of an interferon-response gene profile. Such molecular re-programming results in deregulation of early development checkpoints culminating in inefficient differentiation of CD4CD8 double positive cells. TC-PTP is therefore shown to be required to safeguard the dynamic transcriptome necessary for efficient T cell differentiation.Canadian Institute of Health Research (grant MOP-62887) and from the Canadian Leukemia and Lymphoma Society; Medical Research Council (UK) and Newcastle University Medical School; the Japan Society for the Promotion of Science through the WPI-IFReC Research Program and a KAKENHI grant; the Kishimoto Foundation; and the ETH Zurich–Japan Science and Technology Agency (ETHZ-JST) Japanese-Swiss Cooperative Program.Peer Reviewe

Single-cell analysis of thymocyte differentiation: identification of transcription factor interactions and a major stochastic component in αβ\alpha\beta-lineage commitment.

International audienceT cell commitment and $\alpha\beta$/$\gamma\delta$ lineage specification in the thymus involves interactions between many different genes. Characterization of these interactions thus requires a multiparameter analysis of individual thymocytes. We developed two efficient single-cell methods: (i) the quantitative evaluation of the co-expression levels of nine different genes, with a plating efficiency of 99-100% and a detection limit of 2 mRNA molecules/cell; and (ii) single-cell differentiation cultures, in the presence of OP9 cells transfected with the thymus Notch1 ligand DeltaL4. We show that during T cell commitment, Gata3 has a fundamental, dose-dependent role in maintaining Notch1 expression, with thymocytes becoming T-cell-committed when they co-express Notch1, Gata3 and Bc11b. Of the transcription factor expression patterns studied here, only that of Bcl11b was suggestive of a role in Pu1 down-regulation. Individual thymocytes became $\alpha\beta$$\gamma\delta$-lineage-committed at very different stages (from the TN2a stage onwards). However, 20% of TN3 cells are not $\alpha\beta$/$\gamma\delta$ lineage committed and TN4 cells comprise two main subpopulations with different degrees of maturity. The existence of a correlation between differentiation potential and expression of the pre-TCR showed that 83% of $\alpha\beta$-committed cells do not express the pre-TCR and revealed a major stochastic component in $\alpha\beta$-lineage specification

Flip the coin: IL-7 and IL-7R in health and disease

Copyright © 2019, The Author(s), under exclusive licence to Springer Nature America, Inc.The cytokine IL-7 and its receptor, IL-7R, are critical for T cell and, in the mouse, B cell development, as well as differentiation and survival of naive T cells, and generation and maintenance of memory T cells. They are also required for innate lymphoid cell (ILC) development and maintenance, and consequently for generation of lymphoid structures and barrier defense. Here we discuss the central role of IL-7 and IL-7R in the lymphoid system and highlight the impact of their deregulation, placing a particular emphasis on their 'dark side' as promoters of cancer development. We also explore therapeutic implications and opportunities associated with either positive or negative modulation of the IL-7-IL-7R signaling axis.J.T.B. is funded by the consolidator grant ERC CoG-648455 from the European Research Council, under the European Union’s Horizon 2020 research and innovation programme, and the FAPESP/20015/2014 and PTDC/MEC-HEM/31588/2017 grants from Fundação para a Ciência e a Tecnologia, Portugal; S.K.D. is funded by the intramural program of the US National Cancer Institute, National Institutes of Health, and the Children’s Cancer Foundation; B.S. is funded by the MRC (United Kingdom) under U117573801 and MR/P011225/1.info:eu-repo/semantics/publishedVersio