Tsubh cells have long been divided into two subsets, Tsubh1 and Tsubh2; however, recently, Tsubh17 and inducible regulatory T (iTreg) cells were identified as new Tsubh cell subsets. Although Tsubh1- ...and Tsubh2-polarizing cytokines have been shown to suppress Tsubh17 and iTreg development, transcriptional regulation of Tsubh17 and iTreg differentiation by cytokines remains to be clarified. In this study, we found that expression of the growth factor independent 1 (Gfi1) gene, which has been implicated in Tsubh2 development, was repressed in Tsubh17 and iTreg cells compared with Tsubh1 and Tsubh2 lineages. Gfi1 expression was enhanced by the IFN-γ/STAT1 and IL-4/STAT6 pathways, whereas it was repressed by the transforming growth factor-β1 stimulation at the promoter level. Over-expression of Gfi1 strongly reduced IL-17A transcription in the EL4 T cell line, as well as in primary T cells. This was due to the blockade of recruitment of retinoid-related orphan receptor γt to the IL-17A promoter. In contrast, IL-17A expression was significantly enhanced in Gfi1-deficient T cells under Tsubh17-promoting differentiation conditions as compared with wild-type T cells. In contrast, the impacts of Gfi1 in iTregs were not as strong as in Tsubh17 cells. Taken together, these data strongly suggest that Gfi1 is a negative regulator of Tsubh17 differentiation, which represents a novel mechanism for the regulation of Tsubh17 development by cytokines.
The cytokine, transforming growth factor-beta1 (TGF-beta1), converts naive T cells into regulatory T cells that prevent autoimmunity. However, in the presence of interleukin (IL)-6, TGF-beta1 has ...also been found to promote differentiation into IL-17-producing helper T (Th17) cells that are deeply involved in autoimmunity and inflammation. However, it has not been clarified how TGF-beta1 and IL-6 determine such a distinct fate. Here we found that a master regulator for Th17, retinoic acid-related orphan receptor gammat (RORgammat), was rapidly induced by TGF-beta1 regardless of the presence of IL-6. IL-6 reduced Foxp3 expression, and overexpression of Foxp3 in a T cell line resulted in a strong reduction of IL-17A expression. We have characterized the IL-17A promoter and found that RORgammat binding is sufficient for activation of the minimum promoter in the HEK 293T cells. RORgammat-mediated IL-17A promoter activation was suppressed by forced expression of Foxp3. Foxp3 directly interacted with RORgammat through exon 2 region of Foxp3. The exon 2 region and forkhead (FKH) domain of Foxp3 were necessary for the suppression of RORgammat-mediated IL-17A promoter activation. We propose that induction of Foxp3 is the mechanism for the suppression of Th17 and polarization into inducible Treg.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The cytokine, transforming growth factor-β1 (TGF-β1), converts naive T cells into regulatory T cells that prevent autoimmunity.
However, in the presence of interleukin (IL)-6, TGF-β1 has also been ...found to promote differentiation into IL-17-producing
helper T (Th17) cells that are deeply involved in autoimmunity and inflammation. However, it has not been clarified how TGF-β1
and IL-6 determine such a distinct fate. Here we found that a master regulator for Th17, retinoic acid-related orphan receptor
γt (RORγt), was rapidly induced by TGF-β1 regardless of the presence of IL-6. IL-6 reduced Foxp3 expression, and overexpression
of Foxp3 in a T cell line resulted in a strong reduction of IL-17A expression. We have characterized the IL-17A promoter and found that RORγt binding is sufficient for activation of the minimum promoter in the HEK 293T cells. RORγt-mediated
IL-17A promoter activation was suppressed by forced expression of Foxp3. Foxp3 directly interacted with RORγt through exon 2 region
of Foxp3. The exon 2 region and forkhead (FKH) domain of Foxp3 were necessary for the suppression of RORγt-mediated IL-17A promoter activation. We propose that induction of Foxp3 is the mechanism for the suppression of Th17 and polarization into
inducible Treg.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Conventional PCR-based genotyping is useful for forensic testing but cannot be used to determine parental origins of alleles in DNA specimens. Here we describe a novel method of combined conventional ...genotyping and PIA typing (parentally imprinted allele typing) at a minisatellite region upstream from the H19 locus. The PIA typing uses two sets of primers and DNA digested with methylation-sensitive Hha I enzyme. The first amplification produces only the methylated fragment of paternal H19 allele, and the second detects polymorphism in the minisatellite. Hence, this distinguishes paternal and maternal alleles by difference in the DNA methylation. Furthermore, the polymorphism in this polymorphic locus was examined using 199 unrelated Japanese and 171 unrelated Germans, their polymorphism information content being 0.671 and 0.705, respectively. Feasibility of this typing is demonstrated for six families, and the usefulness is shown by application to paternity testing.
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