Cutting edge: CD8+CD122+ regulatory T cells produce IL-10 to suppress IFN-gamma production and proliferation of CD8+ T cells.
We recently identified CD8+CD122+ regulatory T cells that directly control CD8+ and CD4+ cells without intervention of APCs. In this study, we investigated the effector mechanism of CD8+CD122+ regulatory T cells by using an in vitro regulation system. The profile of cytokine expression revealed that IL-10 was predominantly produced by CD8+CD122+ cells, whereas other cytokines were similarly expressed in CD8+CD122+ cells and CD8+CD122- cells. Suppression of both proliferation and IFN-gamma production by CD8+CD122- cells by CD8+CD122+ cells was blocked by adding anti-IL-10 Ab to the culture but not by adding anti-TGF-beta Ab. When IL-10 was removed from the conditioned medium from CD8+CD122+ cells, the conditioned medium no longer showed regulatory activity. Finally, CD8+CD122+ cells from IL-10-deficient mice had no regulatory activity in vitro and reduced regulatory activity in vivo. Our results clearly indicate that IL-10 is produced by CD8+CD122+ cells and mediates the regulatory activity of these cells.
Endharti
Agustina Tri
AT
Department of Immunology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Rifa'I
Muhaimin
M
Shi
Zhe
Z
Fukuoka
Yukari
Y
Nakahara
Yoshio
Y
Kawamoto
Yoshiyuki
Y
Takeda
Kozue
K
Isobe
Ken-Ichi
K
Suzuki
Haruhiko
H
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D007371:Interferon-gamma / Q000276:immunology*; D016753:Interleukin-10 / Q000096:biosynthesis / Q000172:deficiency / Q000276:immunology*; D051379:Mice; D015375:Receptors, Interleukin-2 / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
D017077:Culture Media, Conditioned; D016207:Cytokines; D015375:Receptors, Interleukin-2; D016753:Interleukin-10; D007371:Interferon-gamma