Expression of 3G11 epitope defines subpopulations of regulatory T cells with different suppressive potency

Distinct Role of IL-27 in Immature and LPS-Induced Mature Dendritic Cell-Mediated Development of CD4+ CD127+3G11+ Regulatory T Cell Subset

Interleukin-27 (IL-27) plays an important role in regulation of anti-inflammatory responses and autoimmunity; however, the molecular mechanisms of IL-27 in modulation of immune tolerance and autoimmunity have not been fully elucidated. Dendritic cells (DCs) play a central role in regulating immune responses mediated by innate and adaptive immune systems, but regulatory mechanisms of DCs in CD4⁺ T cell-mediated immune responses have not yet been elucidated. Here we show that IL-27 treated mature DCs induced by LPS inhibit immune tolerance mediated by LPS-stimulated DCs. IL-27 treatment facilitates development of the CD4⁺ CD127⁺3G11⁺ regulatory T cell subset in vitro and in vivo. By contrast, IL-27 treated immature DCs fail to modulate development of the CD4⁺CD127⁺3G11⁺ regulatory T cell sub-population in vitro and in vivo. Our results suggest that IL-27 may break immune tolerance induced by LPS-stimulated mature DCs through modulating development of a specific CD4⁺ regulatory T cell subset mediated by 3G11 and CD127. Our data reveal a new cellular regulatory mechanism of IL-27 that targets DC-mediated immune responses in autoimmune diseases such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE).

LPS-treated bone marrow-derived dendritic cells induce immune tolerance through modulating differentiation of CD4+ regulatory T cell subpopulations mediated by 3G11 and CD127

Intravenous transfer of LPS-treated bone marrow-derived dendritic cells blocks development of autoimmunity induced by CD4⁺ T cells in vivo. However, cellular mechanisms of dendritic cell-mediated immune tolerance have not yet been fully elucidated. Here, we report that there are two new subpopulations of CD4⁺CD25⁺FoxP3⁺GITR⁺ regulatory T cells (CD127⁺3G11⁺ and CD127⁺3G11^- cells). LPS-treated dendritic cells facilitate development of CD4⁺CD127⁺3G11^- regulatory T cells but inhibit that of CD4⁺CD127⁺3G11⁺ regulatory T cells. LPS-induced tolerogenic dendritic cells may cause immune tolerance through modulating balance of different subsets of CD4⁺ regulatory T cells mediated by CD127 and 3G11. Our results imply a new potential cellular mechanism of dendritic cell-mediated immune tolerance.

3G11 expression in CD4+ T cell-mediated autoimmunity and immune tolerance

3G11 is a sialylated carbohydrate epitope of the disialoganglioside molecule expressed on mouse CD4(+) T cells. Recent research showed that 3G11 expression is related to the modulation of T cell function, i.e., 3G11(-) T cells exhibit anergic/Treg characteristics and efficiently inhibit autoimmunity in the central nervous system. The relationship between 3G11 expression and immune tolerance is summarized in this literature review.