Int Immunol. 2004 Feb;16(2):249-56
Zhang X, Koldzic DN, Izikson L, Reddy J, Nazareno RF, Sakaguchi S, Kuchroo VK, Weiner HL.
Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA Department of Immunopathology, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan.
CD25(+)CD4(+) regulatory T cells inhibit the activation of autoreactive T cells in vitro and in vivo, and suppress organ-specific autoimmune diseases.
The mechanism of CD25(+)CD4(+) T cells in the regulation of experimental autoimmune encephalomyelitis (EAE) is poorly understood.
To assess the role of CD25(+)CD4(+) T cells in EAE, SJL mice were immunized with myelin proteolipid protein (PLP)(139-151) to develop EAE and were treated with anti-CD25 mAb.
Treatment with anti-CD25 antibody following immunization resulted in a significant enhancement of EAE disease severity and mortality.
There was increased inflammation in the central nervous system (CNS) of anti-CD25 mAb-treated mice.
Anti-CD25 antibody treatment caused a decrease in the percentage of CD25(+)CD4(+) T cells in blood, peripheral lymph node (LN) and spleen associated with increased production of IFN-gamma and a decrease in IL-10 production by LN cells stimulated with PLP(130-151) in vitro.
In addition, transfer of CD25(+)CD4(+) regulatory T cells from naive SJL mice decreased the severity of active EAE.
In vitro, anti-CD3-stimulated CD25(+)CD4(+) T cells from naive SJL mice secreted IL-10 and IL-10 soluble receptor (sR) partially reversed the in vitro suppressive activity of CD25(+)CD4(+) T cells.
CD25(+)CD4(+) T cells from IL-10-deficient mice were unable to suppress active EAE.
These findings demonstrate that CD25(+)CD4(+) T cells suppress pathogenic autoreactive T cells in actively induced EAE and suggest they may play an important natural regulatory function in controlling CNS autoimmune disease through a mechanism that involves IL-10.