- Paper Report
- Open Access
Characterization of regulatory T cells in humans
- Fanny Monneaux1
© Biomed Central Ltd 2001
- Received: 25 July 2001
- Accepted: 25 July 2001
- Published: 25 July 2001
- regulatory T cells
Regulatory T cells with the ability to prevent or regulate autoimmune disease have been demonstrated in several different experimental systems (see Additional information ). Studies have shown that this potent CD4+ immunoregulatory T-cell population can be defined by expression of the interleukin (IL)-2 receptor a chain (CD25). CD4+ CD25+ T cells are anergic to stimulation via T-cell receptors and suppress proliferation of CD4+CD25- lymphocytes in vitro. This suppression was shown to be cytokine-independent but required cell-cell contact to be efficient. This study was undertaken to establish the existence of such T-cell populations in humans.
CD4+CD25+ T cells were purified from human thymus lymphocytes and peripheral blood lymphocytes (PBLs). As has been shown in mice, these cells proliferated poorly in response to mitogenic stimulation, and this defect was reversed by exogenous IL-2. CD4+CD25+ T cells expressed cytotoxic T lymphocyte associated antigen (CTLA)-4 and CD122 molecules, and suppressed proliferation of CD4+CD25- T cells in a dose-dependent manner. This suppression required direct interactions between CD4+CD25+ and CD4+CD25- T cells in vitro. Unstimulated thymic CD4+CD25+ T cells secreted IL-10 (not IL-2, IL-4 and interferon [IFN]-?), and suppressed secretion of IL-2, IL-4 and IFN-? by CD4+CD25+ T cells in co-culture experiments. Similar characteristics were found in CD4+CD25+ from PBLs, except that these cells produced similar levels of IL-4 when compared with CD4+CD25+ T cells.
T cell purification, FACS analysis, co-culture experiments
Sakaguchi S: Policing the regulators.
Nat Immunol 2001, 2:283-284.
Taams LS, Smith J, Rustin MH, Salmon M, Poulter LW, Akbar AN: Human anergic/suppressive CD4 + CD25 + T cells: a highly differentiated and apoptosis-prone population.
Eur J Immunol 2001, 31:1122-1131.