Expansion and de novo generation of potentially therapeutic regulatory T cells in patients with autoimmune hepatitis

Authors

  • Maria Serena Longhi,

    1. Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
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  • Francesca Meda,

    1. Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
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  • Pengyun Wang,

    1. Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
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  • Marianne Samyn,

    1. Department of Child Health, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
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  • Giorgina Mieli-Vergani,

    1. Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
    2. Department of Child Health, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
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  • Diego Vergani,

    1. Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
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    • These authors contributed equally to this work.

  • Yun Ma

    Corresponding author
    1. Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK
    • Institute of Liver Studies, King's College Hospital, Denmark Hill, London SE5 9RS, UK
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    • These authors contributed equally to this work.

    • fax: (44) 203-2993760.


  • Potential conflict of interest: Nothing to report.

Abstract

CD4+CD25+ regulatory T cells (T-regs) are central to the maintenance of immune tolerance and represent an immune intervention candidate in autoimmune hepatitis (AIH), a condition characterized by impaired T-reg number and function. We investigated whether T-regs can be expanded from the existing CD4+CD25+ T cell pool and generated de novo from CD4+CD25− T cells in AIH patients and healthy controls. Purified CD4+CD25+ and CD4+CD25− T cells from 24 patients with type 1 AIH and 22 healthy controls were cultured for up to 5 weeks with anti-CD3/anti-CD28 T cell expander and high-dose interleukin-2 (IL-2). Cell phenotypes, suppressor ability, forkhead winged/helix transcription factor box P3 (FOXP3) gene, and protein expression were assessed weekly by cytofluorimetry, proliferation assay, real-time polymerase chain reaction (PCR), and immunoblot. During culture, the number of CD4+CD25+ T cells derived from the existing T-reg pool (expanded T-regs) and generated de novo from CD4+CD25− T cells (newly generated T-regs) increased constantly up to week 4 in both healthy controls and, to a lesser extent, in AIH patients. Expanded T-regs retained conventional T-reg phenotype and, compared with baseline, demonstrated more vigorous suppressive function and increased FOXP3 gene and protein expression. Newly generated T-regs not only acquired T-reg phenotype but underwent greater growth and were more resistant to apoptosis than expanded T-regs. Their suppressive function augmented throughout culture, reaching a peak at week 4, preceded by a peak FOXP3 gene and protein expression at week 2. Suppressor function and FOXP3 expression of both expanded and newly generated T-regs were higher in normal controls than in AIH patients. Conclusion: Functionally enhanced T-regs can be expanded and generated de novo in patients with AIH. This finding may assist in reconstituting impaired immune regulation and restoring peripheral tolerance through T-reg infusion in this condition. (HEPATOLOGY 2008;47:581–591.)

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