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Control of amino-acid transport by antigen receptors coordinates the metabolic reprogramming essential for T cell differentiation.

Sinclair LV, Rolf J, Emslie E, Shi YB, Taylor PM, Cantrell DA - Nat. Immunol. (2013)

Bottom Line: T cells responded to antigen by upregulating expression of many amino-acid transporters, but a single System L ('leucine-preferring system') transporter, Slc7a5, mediated uptake of LNAAs in activated T cells.The metabolic catastrophe caused by loss of Slc7a5 reflected the requirement for sustained uptake of the LNAA leucine for activation of the serine-threonine kinase complex mTORC1 and for expression of the transcription factor c-Myc.Control of expression of the System L transporter by pathogens is thus a critical metabolic checkpoint for T cells.

View Article: PubMed Central - PubMed

Affiliation: Division of Cell Signalling and Immunology, University of Dundee, Dundee, UK.

ABSTRACT
T lymphocytes must regulate nutrient uptake to meet the metabolic demands of an immune response. Here we show that the intracellular supply of large neutral amino acids (LNAAs) in T cells was regulated by pathogens and the T cell antigen receptor (TCR). T cells responded to antigen by upregulating expression of many amino-acid transporters, but a single System L ('leucine-preferring system') transporter, Slc7a5, mediated uptake of LNAAs in activated T cells. Slc7a5- T cells were unable to metabolically reprogram in response to antigen and did not undergo clonal expansion or effector differentiation. The metabolic catastrophe caused by loss of Slc7a5 reflected the requirement for sustained uptake of the LNAA leucine for activation of the serine-threonine kinase complex mTORC1 and for expression of the transcription factor c-Myc. Control of expression of the System L transporter by pathogens is thus a critical metabolic checkpoint for T cells.

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System L amino acid transport in CD8+ T cellsThe data show 3H-phenylalanine uptake (c.p.m.) per 106 cells in (a) OT-I TCR transgenic lymph node cells cultured with IL-7 or stimulated with SIINFEKL for 4h (p=0.0147 )or 20 h p<0.0001. (b) Purified CD8+ T cells from Listeria-infected mice, 3 days post infection, and from uninfected mice. (c) Effector CTLs exposed to 20 ng/ml IL-2, 1.25 ng/ml IL-2 or medium alone for 20 h. (d) Phenylalanine flux (rate of Phe uptake) of IL-2 maintained CTLs in the presence of 10 mM cold amino acids; Phe, Lys, Asp or Leu, or in the presence of 10 mM of BCH or MeAIB. Data is from a minimum of 3 experiments done in triplicates (a, c and d), data in b is from 6 mice, 1 experiment.
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Figure 1: System L amino acid transport in CD8+ T cellsThe data show 3H-phenylalanine uptake (c.p.m.) per 106 cells in (a) OT-I TCR transgenic lymph node cells cultured with IL-7 or stimulated with SIINFEKL for 4h (p=0.0147 )or 20 h p<0.0001. (b) Purified CD8+ T cells from Listeria-infected mice, 3 days post infection, and from uninfected mice. (c) Effector CTLs exposed to 20 ng/ml IL-2, 1.25 ng/ml IL-2 or medium alone for 20 h. (d) Phenylalanine flux (rate of Phe uptake) of IL-2 maintained CTLs in the presence of 10 mM cold amino acids; Phe, Lys, Asp or Leu, or in the presence of 10 mM of BCH or MeAIB. Data is from a minimum of 3 experiments done in triplicates (a, c and d), data in b is from 6 mice, 1 experiment.

Mentions: Naïve CD8+ T cells did not effectively take up 3H-labeled phenylalanine, a large neutral amino acid that is transported via System L amino acid transporters (Fig. 1a). However, TCR triggering of CD8+ T cells with cognate peptide induced a substantial increase in phenylalanine transport (Fig. 1a). Effector CD8+ T cells from mice immunized with Listeria also showed enhanced phenylalanine transport compared to naïve T cells (Fig. 1b). TCR-primed CD8+ T cells cultured in IL-2 clonally expand and differentiate to cytotoxic T cells (CTLs). CTLs cultured in IL-2 had enhanced phenylalanine uptake; the removal of IL-2 or the exposure of cells to limiting IL-2 concentrations caused CTLs to decrease phenylalanine uptake (Fig. 1c). 3H-phenylalanine uptake by CTLs can be competed by unlabeled leucine but not by basic amino acids such as lysine or by the acidic amino acid aspartic acid (Fig. 1d). Moreover, treatment of CTLs with 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), an inhibitor of System L amino acid transporters, blocked the influx of phenylalanine in CTLs, whereas treatment with the MeIAB, a System A amino acid transport inhibitor, did not (Fig. 1d). Thus, activated effector T cells increase System L amino acid transporter activity.


Control of amino-acid transport by antigen receptors coordinates the metabolic reprogramming essential for T cell differentiation.

Sinclair LV, Rolf J, Emslie E, Shi YB, Taylor PM, Cantrell DA - Nat. Immunol. (2013)

System L amino acid transport in CD8+ T cellsThe data show 3H-phenylalanine uptake (c.p.m.) per 106 cells in (a) OT-I TCR transgenic lymph node cells cultured with IL-7 or stimulated with SIINFEKL for 4h (p=0.0147 )or 20 h p<0.0001. (b) Purified CD8+ T cells from Listeria-infected mice, 3 days post infection, and from uninfected mice. (c) Effector CTLs exposed to 20 ng/ml IL-2, 1.25 ng/ml IL-2 or medium alone for 20 h. (d) Phenylalanine flux (rate of Phe uptake) of IL-2 maintained CTLs in the presence of 10 mM cold amino acids; Phe, Lys, Asp or Leu, or in the presence of 10 mM of BCH or MeAIB. Data is from a minimum of 3 experiments done in triplicates (a, c and d), data in b is from 6 mice, 1 experiment.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672957&req=5

Figure 1: System L amino acid transport in CD8+ T cellsThe data show 3H-phenylalanine uptake (c.p.m.) per 106 cells in (a) OT-I TCR transgenic lymph node cells cultured with IL-7 or stimulated with SIINFEKL for 4h (p=0.0147 )or 20 h p<0.0001. (b) Purified CD8+ T cells from Listeria-infected mice, 3 days post infection, and from uninfected mice. (c) Effector CTLs exposed to 20 ng/ml IL-2, 1.25 ng/ml IL-2 or medium alone for 20 h. (d) Phenylalanine flux (rate of Phe uptake) of IL-2 maintained CTLs in the presence of 10 mM cold amino acids; Phe, Lys, Asp or Leu, or in the presence of 10 mM of BCH or MeAIB. Data is from a minimum of 3 experiments done in triplicates (a, c and d), data in b is from 6 mice, 1 experiment.
Mentions: Naïve CD8+ T cells did not effectively take up 3H-labeled phenylalanine, a large neutral amino acid that is transported via System L amino acid transporters (Fig. 1a). However, TCR triggering of CD8+ T cells with cognate peptide induced a substantial increase in phenylalanine transport (Fig. 1a). Effector CD8+ T cells from mice immunized with Listeria also showed enhanced phenylalanine transport compared to naïve T cells (Fig. 1b). TCR-primed CD8+ T cells cultured in IL-2 clonally expand and differentiate to cytotoxic T cells (CTLs). CTLs cultured in IL-2 had enhanced phenylalanine uptake; the removal of IL-2 or the exposure of cells to limiting IL-2 concentrations caused CTLs to decrease phenylalanine uptake (Fig. 1c). 3H-phenylalanine uptake by CTLs can be competed by unlabeled leucine but not by basic amino acids such as lysine or by the acidic amino acid aspartic acid (Fig. 1d). Moreover, treatment of CTLs with 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), an inhibitor of System L amino acid transporters, blocked the influx of phenylalanine in CTLs, whereas treatment with the MeIAB, a System A amino acid transport inhibitor, did not (Fig. 1d). Thus, activated effector T cells increase System L amino acid transporter activity.

Bottom Line: T cells responded to antigen by upregulating expression of many amino-acid transporters, but a single System L ('leucine-preferring system') transporter, Slc7a5, mediated uptake of LNAAs in activated T cells.The metabolic catastrophe caused by loss of Slc7a5 reflected the requirement for sustained uptake of the LNAA leucine for activation of the serine-threonine kinase complex mTORC1 and for expression of the transcription factor c-Myc.Control of expression of the System L transporter by pathogens is thus a critical metabolic checkpoint for T cells.

View Article: PubMed Central - PubMed

Affiliation: Division of Cell Signalling and Immunology, University of Dundee, Dundee, UK.

ABSTRACT
T lymphocytes must regulate nutrient uptake to meet the metabolic demands of an immune response. Here we show that the intracellular supply of large neutral amino acids (LNAAs) in T cells was regulated by pathogens and the T cell antigen receptor (TCR). T cells responded to antigen by upregulating expression of many amino-acid transporters, but a single System L ('leucine-preferring system') transporter, Slc7a5, mediated uptake of LNAAs in activated T cells. Slc7a5- T cells were unable to metabolically reprogram in response to antigen and did not undergo clonal expansion or effector differentiation. The metabolic catastrophe caused by loss of Slc7a5 reflected the requirement for sustained uptake of the LNAA leucine for activation of the serine-threonine kinase complex mTORC1 and for expression of the transcription factor c-Myc. Control of expression of the System L transporter by pathogens is thus a critical metabolic checkpoint for T cells.

Show MeSH
Related in: MedlinePlus