Article | Published:

Thymic selection threshold defined by compartmentalization of Ras/MAPK signalling

Naturevolume 444pages724729 (2006) | Download Citation



A healthy individual can mount an immune response to exogenous pathogens while avoiding an autoimmune attack on normal tissues. The ability to distinguish between self and non-self is called ‘immunological tolerance’ and, for T lymphocytes, involves the generation of a diverse pool of functional T cells through positive selection and the removal of overtly self-reactive thymocytes by negative selection during T-cell ontogeny. To elucidate how thymocytes arrive at these cell fate decisions, here we have identified ligands that define an extremely narrow gap spanning the threshold that distinguishes positive from negative selection. We show that, at the selection threshold, a small increase in ligand affinity for the T-cell antigen receptor leads to a marked change in the activation and subcellular localization of Ras and mitogen-activated protein kinase (MAPK) signalling intermediates and the induction of negative selection. The ability to compartmentalize signalling molecules differentially in the cell endows the thymocyte with the ability to convert a small change in analogue input (affinity) into a digital output (positive versus negative selection) and provides the basis for establishing central tolerance.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Starr, T. K., Jameson, S. C. & Hogquist, K. A. Positive and negative selection T cells. Annu. Rev. Immunol. 21, 139–176 (2003)

  2. 2

    Germain, R. N. The T cell receptor for antigen: signaling and ligand discrimination. J. Biol. Chem. 276, 35223–35226 (2001)

  3. 3

    Sebzda, E. et al. Positive and negative thymocyte selection induced by different concentrations of a single peptide. Science 263, 1615–1618 (1994)

  4. 4

    Ashton-Rickardt, P. G. et al. Evidence for a differential avidity model of T cell selection in the thymus. Cell 76, 651–663 (1994)

  5. 5

    Fontenot, J. D. & Rudensky, A. Y. A well adapted regulatory contrivance: regulatory T cell development and the Forkhead family transcription factor Foxp3. Nature Immunol. 6, 331–337 (2005)

  6. 6

    Sakaguchi, S. Naturally arising Foxp3-expressing CD25+CD4+ regulatory T cells in immunological tolerance to self and non-self. Nature Immunol. 6, 345–352 (2005)

  7. 7

    Leishman, A. J. et al. Precursors of functional MHC class I- or class II-restricted CD8αα+ T cells are positively selected in the thymus by agonist self-peptides. Immunity 16, 355–364 (2002)

  8. 8

    Yamagata, T., Mathis, D. & Benoist, C. Self-reactivity in thymic double-positive cells commits cells to a CD8αα lineage with characteristics of innate immune cells. Nature Immunol. 5, 597–605 (2004)

  9. 9

    Hogquist, K. A., Baldwin, T. A. & Jameson, S. C. Central tolerance: learning self-control in the thymus. Nature Rev. Immunol. 5, 772–782 (2005)

  10. 10

    McKeithan, T. W. Kinetic proofreading in T-cell receptor signal transduction. Proc. Natl Acad. Sci. USA 92, 5042–5046 (1995)

  11. 11

    Goldstein, B., Faeder, J. R. & Hlavacek, W. S. Mathematical and computational models of immune-receptor signalling. Nature Rev. Immunol. 4, 445–456 (2004)

  12. 12

    Alam, S. M. et al. T-cell receptor affinity and thymocyte positive selection. Nature 381, 616–620 (1996)

  13. 13

    Davis, M. M. et al. Ligand recognition by αβ T cell receptors. Annu. Rev. Immunol. 16, 523–544 (1998)

  14. 14

    Liu, C. P., Crawford, F., Marrack, P. & Kappler, J. T cell positive selection by a high density, low affinity ligand. Proc. Natl Acad. Sci. USA 95, 4522–4526 (1998)

  15. 15

    Williams, C. B., Engle, D. L., Kersh, G. J., Michael White, J. & Allen, P. M. A kinetic threshold between negative and positive selection based on the longevity of the T cell receptor–ligand complex. J. Exp. Med. 189, 1531–1544 (1999)

  16. 16

    Garcia, K. C. et al. CD8 enhances formation of stable T-cell receptor/MHC class I molecule complexes. Nature 384, 577–581 (1996)

  17. 17

    Wyer, J. R. et al. T cell receptor and coreceptor CD8αα bind peptide–MHC independently and with distinct kinetics. Immunity 10, 219–225 (1999)

  18. 18

    Zamoyska, R. et al. The influence of the Src-family kinases, Lck and Fyn, on T cell differentiation, survival and activation. Immunol. Rev. 191, 107–118 (2003)

  19. 19

    Daniels, M. A. et al. CD8 binding to MHC class I molecules is influenced by T cell maturation and glycosylation. Immunity 15, 1051–1061 (2001)

  20. 20

    van Leeuwen, J. E. & Samelson, L. E. T cell antigen-receptor signal transduction. Curr. Opin. Immunol. 11, 242–248 (1999)

  21. 21

    Alberola-Ila, J. & Hernandez-Hoyos, G. The Ras/MAPK cascade and the control of positive selection. Immunol. Rev. 191, 79–96 (2003)

  22. 22

    Werlen, G., Hausmann, B., Naeher, D. & Palmer, E. Signaling life and death in the thymus: timing is everything. Science 299, 1859–1863 (2003)

  23. 23

    Palmer, E. Negative selection—clearing out the bad apples from the T-cell repertoire. Nature Rev. Immunol. 3, 383–391 (2003)

  24. 24

    Bommhardt, U., Scheuring, Y., Bickel, C., Zamoyska, R. & Hunig, T. MEK activity regulates negative selection of immature CD4+CD8+ thymocytes. J. Immunol. 164, 2326–2337 (2000)

  25. 25

    Mariathasan, S. et al. Duration and strength of extracellular signal-regulated kinase signals are altered during positive versus negative thymocyte selection. J. Immunol. 167, 4966–4973 (2001)

  26. 26

    Dong, C., Davis, R. J. & Flavell, R. A. MAP kinases in the immune response. Annu. Rev. Immunol. 20, 55–72 (2002)

  27. 27

    Alam, S. M. et al. Qualitative and quantitative differences in T cell receptor binding of agonist and antagonist ligands. Immunity 10, 227–237 (1999)

  28. 28

    Hare, K. J., Jenkinson, E. J. & Anderson, G. CD69 expression discriminates MHC-dependent and -independent stages of thymocyte positive selection. J. Immunol. 162, 3978–3983 (1999)

  29. 29

    Hogquist, K. A. et al. T cell receptor antagonist peptides induce positive selection. Cell 76, 17–27 (1994)

  30. 30

    Savage, P. A., Boniface, J. J. & Davis, M. M. A kinetic basis for T cell receptor repertoire selection during an immune response. Immunity 10, 485–492 (1999)

  31. 31

    Crawford, F., Kozono, H., White, J., Marrack, P. & Kappler, J. Detection of antigen-specific T cells with multivalent soluble class II MHC covalent peptide complexes. Immunity 8, 675–682 (1998)

  32. 32

    Daniels, M. A. & Jameson, S. C. Critical role for CD8 in T cell receptor binding and activation by peptide/major histocompatibility complex multimers. J. Exp. Med. 191, 335–346 (2000)

  33. 33

    Rosette, C. et al. The impact of duration versus extent of TCR occupancy on T cell activation: a revision of the kinetic proofreading model. Immunity 15, 59–70 (2001)

  34. 34

    Potter, T. A., Rajan, T. V., Dick, R. F. & Bluestone, J. A. Substitution at residue 227 of H–2 class I molecules abrogates recognition by CD8-dependent, but not CD8-independent, cytotoxic T lymphocytes. Nature 337, 73–75 (1989)

  35. 35

    Harding, A., Tian, T., Westbury, E., Frische, E. & Hancock, J. F. Subcellular localization determines MAP kinase signal output. Curr. Biol. 15, 869–873 (2005)

  36. 36

    Mor, A. & Philips, M. R. Compartmentalized Ras/MAPK signaling. Annu. Rev. Immunol. 24, 771–800 (2006)

  37. 37

    Sommers, C. L., Samelson, L. E. & Love, P. E. LAT: a T lymphocyte adapter protein that couples the antigen receptor to downstream signaling pathways. BioEssays 26, 61–67 (2004)

  38. 38

    Gong, Q. et al. Disruption of T cell signaling networks and development by Grb2 haploid insufficiency. Nature Immunol. 2, 29–36 (2001)

  39. 39

    Dower, N. A. et al. RasGRP is essential for mouse thymocyte differentiation and TCR signaling. Nature Immunol. 1, 317–321 (2000)

  40. 40

    Rocks, O. et al. An acylation cycle regulates localization and activity of palmitoylated Ras isoforms. Science 307, 1746–1752 (2005)

  41. 41

    Werlen, G., Hausmann, B. & Palmer, E. A motif in the αβ T-cell receptor controls positive selection by modulating ERK activity. Nature 406, 422–426 (2000)

  42. 42

    Goldrath, A. W., Hogquist, K. A. & Bevan, M. J. CD8 lineage commitment in the absence of CD8. Immunity 6, 633–642 (1997)

  43. 43

    Hare, K. J., Jenkinson, E. J. & Anderson, G. In vitro models of T cell development. Semin. Immunol. 11, 3–12 (1999)

  44. 44

    Yachi, P. P., Ampudia, J., Gascoigne, N. R. & Zal, T. Nonstimulatory peptides contribute to antigen-induced CD8–T cell receptor interaction at the immunological synapse. Nature Immunol. 6, 785–792 (2005)

  45. 45

    Bivona, T. G. et al. Phospholipase Cγ activates Ras on the Golgi apparatus by means of RasGRP1. Nature 424, 694–698 (2003)

  46. 46

    Liu, X. et al. Restricting Zap70 expression to CD4+CD8+ thymocytes reveals a T cell receptor-dependent proofreading mechanism controlling the completion of positive selection. J. Exp. Med. 197, 363–373 (2003)

  47. 47

    McNeil, L. K., Starr, T. K. & Hogquist, K. A. A requirement for sustained ERK signaling during thymocyte positive selection in vivo. Proc. Natl Acad. Sci. USA 102, 13574–13579 (2005)

  48. 48

    Teixeiro, E. et al. T cell division and death are segregated by mutation of TCRβ chain constant domains. Immunity 21, 515–526 (2004)

  49. 49

    Teixeiro, E., Fuentes, P., Galocha, B., Alarcon, B. & Bragado, R. T cell receptor-mediated signal transduction controlled by the β chain transmembrane domain: apoptosis-deficient cells display unbalanced mitogen-activated protein kinases activities upon T cell receptor engagement. J. Biol. Chem. 277, 3993–4002 (2002)

  50. 50

    Anderson, G., Jenkinson, E. J., Moore, N. C. & Owen, J. J. MHC class II-positive epithelium and mesenchyme cells are both required for T-cell development in the thymus. Nature 362, 70–73 (1993)

Download references


We thank R. Clark and T. Potter for hospitality and for providing OT-I Rag-/-β2m-/- mice; S. Jameson for Kb plasmids; G. de Libero and A. Schrum for reading the manuscript; V. Jäggin for assistance with the Ca2+ flux analysis; and E. Wagner and W. Hänggi for animal husbandry. This work was supported by grants from Novartis, the Swiss National Science Foundation, the US Cancer Research Institute (to M.A.D. and K.H.), Hoffmann La Roche, and the NIH (to N.R.J.G.).

Author information


  1. Laboratory of Transplantation Immunology and Nephrology, Department of Research, University Hospital–Basel, Hebelstrasse 20, Basel, 4031, Switzerland

    • Mark A. Daniels
    • , Emma Teixeiro
    • , Barbara Hausmann
    • , Dominique Roubaty
    •  & Ed Palmer
  2. Pediatric Immunology, Center for Biomedicine and The University Children’s Hospital of Basel, Mattenstrasse 28, 4058, Basel, Switzerland

    • Jason Gill
    •  & Georg A. Holländer
  3. Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, California, 92037, La Jolla, USA

    • Kaisa Holmberg
    •  & Nicholas R. J. Gascoigne
  4. Department of Cell Biology & Neuroscience, Rutgers, The State University of New Jersey, Piscataway, 604 Allison Road, New Jersey, 08854-8082, USA

    • Guy Werlen
  5. Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road

    • Guy Werlen


  1. Search for Mark A. Daniels in:

  2. Search for Emma Teixeiro in:

  3. Search for Jason Gill in:

  4. Search for Barbara Hausmann in:

  5. Search for Dominique Roubaty in:

  6. Search for Kaisa Holmberg in:

  7. Search for Guy Werlen in:

  8. Search for Georg A. Holländer in:

  9. Search for Nicholas R. J. Gascoigne in:

  10. Search for Ed Palmer in:

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Corresponding author

Correspondence to Ed Palmer.

Supplementary information

  1. Supplementary Notes

    This file contains Supplementary Figures 1–4 and Supplementary Methods. (PDF 4447 kb)

About this article

Publication history




Issue Date


Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.