Abstract
CD4+CD25+ and CD1d-restricted natural killer T (NKT) cells are thymus-derived self-reactive regulatory T cells that play a key role in the control of pathological immune responses. Little is known about functional cooperation between innate regulatory NKT cells and adaptive CD4+ CD25+ regulatory cells. Here we show that human CD4+V[alpha]24+V[beta]11+ (CD4+ NKT) cells isolated from peripheral blood by flow cytometric cell sorting secrete substantial amounts of IL-2 after stimulation with dendritic cells (DC) and [alpha]-Galactosylceramide. When cocultured with CD4+CD25+ cells, CD4+ NKT cells promoted moderate proliferation of CD4+CD25+ cells. The proliferation of CD4+CD25+ T cells was due to soluble IL-2 produced by activated CD4+ NKT cells. The expanded CD4+CD25+ cells remained anergic and retained their potent suppressive properties. These findings indicate that unlike conventional CD4+ and CD8+ T cells, which are susceptible to CD4+CD25+ regulatory cell suppression, NKT cells promote CD4+CD25+ regulatory cell proliferation. These data raise the possibility that NKT cells can function as helper cells to CD4+CD25+ regulatory T cells, thereby providing a link between the two naturally occurring populations of regulatory T cells. (C) 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
| Original language | English |
|---|---|
| Pages (from-to) | 1193 - 1200 |
| Number of pages | 8 |
| Journal | European Journal of Immunology |
| Volume | 35 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2005 |