• 1
    Strauss, L., Bergmann, C., Gooding, W., Johnson, J. T. and Whiteside, T. L., The frequency and suppressor function of CD4+CD25highFoxp3+ T cells in the circulation of patients with squamous cell carcinoma of the head and neck. Clin. Cancer Res. 2007. 13: 63016311.
  • 2
    Kryczek, I., Wu, K., Zhao, E., Wei, S., Vatan, L., Szeliga, W., Huang, E. et al., IL-17+ regulatory T cells in the microenvironments of chronic inflammation and cancer. J. Immunol. 2011. 186: 43884395.
  • 3
    Gounaris, E., Blatner, N. R., Dennis, K., Magnusson, F., Gurish, M. F., Strom, T. B., Beckhove, P. et al., T-regulatory cells shift from a protective anti-inflammatory to a cancer-promoting proinflammatory phenotype in polyposis. Cancer Res. 2009. 69: 54905497.
  • 4
    Sakaguchi, S., Miyara, M., Costantino, C. M. and Hafler, D. A., FOXP3+ regulatory T cells in the human immune system. Nat. Rev. Immunol. 2010. 10: 490500.
  • 5
    Sakaguchi, S., Wing, K., Onishi, Y., Prieto-Martin, P. andYamaguchi, T., Regulatory T cells: how do they suppress immune responses? Int. Immunol. 2009. 21: 11051111.
  • 6
    Bindea, G., Mlecnik, B., Fridman, W. H. and Galon, J., The prognostic impact of anti-cancer immune response: a novel classification of cancer patients. Semin. Immunopathol. 2011. 33: 335340.
  • 7
    Bergmann, C., Strauss, L., Zeidler, R., Lang, S. and Whiteside, T. L., Expansion of human T regulatory type 1 cells in the microenvironment of cyclooxygenase 2 overexpressing head and neck squamous cell carcinoma. Cancer Res. 2007. 67: 88658873.
  • 8
    Zhou, X., Bailey-Bucktrout, S., Jeker, L. T. and Bluestone, J. A., Plasticity of CD4(+) FoxP3(+) T cells. Curr. Opin. Immunol. 2009. 21: 281285.
  • 9
    Borsellino, G., Kleinewietfeld, M., Di Mitri, D., Sternjak, A., Diamantini, A., Giometto, R., Hopner, S. et al., Expression of ectonucleotidase CD39 by Foxp3+ Treg cells cells: hydrolysis of extracellular ATP and immune suppression. Blood 2007. 110: 12251232.
  • 10
    Deaglio, S., Dwyer, K. M., Gao, W., Friedman, D., Usheva, A., Erat, A., Chen, J. F. et al., Adenosine generation catalyzed by CD39 and CD73 expressed on regulatory T cells mediates immune suppression. J. Exp. Med. 2007. 204: 12571265.
  • 11
    Dwyer, K. M., Hanidziar, D., Putheti, P., Hill, P. A., Pommey, S., McRae, J. L., Winterhalter, A. et al., Expression of CD39 by human peripheral blood CD4+ CD25+ T cells denotes a regulatory memory phenotype. Am. J. Transplant. 2010. 10: 24102420.
  • 12
    Schuler, P. J., Harasymczuk, M., Schilling, B., Lang, S. and Whiteside, T. L., Separation of human CD4+CD39+ T cells by magnetic beads reveals two phenotypically and functionally different subsets. J. Immunol. Methods 2011. 369: 5968.
  • 13
    Moncrieffe, H., Nistala, K., Kamhieh, Y., Evans, J., Eddaoudi, A., Eaton, S. andWedderburn, L. R., High expression of the ectonucleotidase CD39 on T cells from the inflamed site identifies two distinct populations, one regulatory and one memory T-cell population. J. Immunol. 2010. 185: 134143.
  • 14
    Zhou, L., Chong, M. M. and Littman, D. R., Plasticity of CD4 + T-cell lineage differentiation. Immunity 2009. 30: 646655.
  • 15
    Ndhlovu, L. C., Leal, F. E., Eccles-James, I. G., Jha, A. R., Lanteri, M., Norris, P. J., Barbour, J. D. et al., A novel human CD4+ T-cell inducer subset with potent immunostimulatory properties. Eur. J. Immunol. 2010. 40: 134141.
  • 16
    Schenk, U., Frascoli, M., Proietti, M., Geffers, R., Traggiai, E., Buer, J., Ricordi, C. et al., ATP inhibits the generation and function of regulatory T cells through the activation of purinergic P2X receptors. Sci. Signal 2011. 4: ra12.
  • 17
    Ohta, A. and Sitkovsky, M., Role of G-protein-coupled adenosine receptors in downregulation of inflammation and protection from tissue damage. Nature 2001. 414: 916920.
  • 18
    Whiteside, T. L., Mandapathil, M. andSchuler, P., The role of the adenosinergic pathway in immunosuppression mediated by human regulatory T cells (Treg cells). Curr. Med. Chem. 2011. 18: 52175223.
  • 19
    Zhou, X., Bailey-Bucktrout, S. L., Jeker, L. T., Penaranda, C., Martinez-Llordella, M., Ashby, M., Nakayama, M. et al., Instability of the transcription factor Foxp3 leads to the generation of pathogenic memory T cells in vivo. Nat. Immunol. 2009. 10: 10001007.
  • 20
    Bailey-Bucktrout, S. L. and Bluestone, J. A., Regulatory T cells: stability revisited. Trends Immunol. 2011. 32: 301306.
  • 21
    Kryczek, I., Zhao, E., Liu, Y., Wang, Y., Vatan, L., Szeliga, W., Moyer, J. et al.,Human TH17 cells are long-lived effector memory cells. Sci. Transl. Med. 2011. 3: 104ra100.
  • 22
    Schulze Zur Wiesch, J., Thomssen, A., Hartjen, P., Toth, I., Lehmann, C., Meyer-Olson, D., Colberg, K. et al., Comprehensive analysis of frequency and phenotype of T regulatory cells in HIV infection: CD39 expression of FoxP3+ T regulatory cells correlates with progressive disease. J. Virol. 2011. 85: 12871297.
  • 23
    Law, J. P., Hirschkorn, D. F., Owen, R. E., Biswas, H. H., Norris, P. J. and Lanteri, M. C., The importance of Foxp3 antibody and fixation/permeabilization buffer combinations in identifying CD4+CD25+Foxp3+ regulatory T cells. Cytometry A. 2009. 75: 10401050.