A molecular network regulating the proinflammatory phenotype of human memory T lymphocytes
NATURE IMMUNOLOGY
Authors: Emming, Stefan; Bianchi, Niccolo; Polletti, Sara; Balestrieri, Chiara; Leoni, Cristina; Montagner, Sara; Chirichella, Michele; Delaleu, Nicolas; Natoli, Gioacchino; Monticelli, Silvia
Abstract
Understanding the mechanisms that modulate helper T lymphocyte functions is crucial to decipher normal and pathogenic immune responses in humans. To identify molecular determinants influencing the pathogenicity of T cells, we separated ex vivo-isolated primary human memory T lymphocytes on the basis of their ability to produce high levels of inflammatory cytokines. We found that the inflammatory, cytokine-producing phenotype of memory T lymphocytes was defined by a specific core gene signature and was mechanistically regulated by the constitutive activation of the NF-kappa B pathway and by the expression of the transcriptional repressor BHLHE40. BHLHE40 attenuated the expression of anti-inflammatory factors, including miR-146a, a negative regulator of NF-kappa B activation and ZC3H12D, an RNase of the Regnase-1 family able to degrade inflammatory transcripts. Our data reveal a molecular network regulating the proinflammatory phenotype of human memory T lymphocytes, with the potential to contribute to disease. Monticelli and colleagues analyze primary human CD4(+) T cells to interrogate gene expression regulatory pathways that distinguish GM-CSF+ pathogenic programs from noninflammatory programs. They identify the transcriptional repressor BHLHE40 as an enforcer of proinflammatory gene expression by suppressing the NF-kappa B inhibitor miR-146a and the RNase ZC3H12D.
Molecular and genetic characterization of partial masculinization in embryonic ovaries grafted into male nude mice
PLOS ONE
Authors: Miura, Kento; Harikae, Kyoko; Nakaguchi, Mayu; Imaimatsu, Kenya; Hiramatsu, Ryuji; Tomita, Ayako; Hirate, Yoshikazu; Kanai-Azuma, Masami; Kurohmaru, Masamichi; Ogura, Atsuo; Kanai, Yoshiakira
Abstract
In most of mammalian embryos, gonadal sex differentiation occurs inside the maternal uterus before birth. In several fetal ovarian grafting experiments using male host mice, an experimental switch from the maternal intrauterine to male-host environment gradually induces partial masculinization of the grafted ovaries even under the wild-type genotype. However, either host-derived factors causing or molecular basis underlying this masculinization of the fetal ovaries are not clear. Here, we demonstrate that ectopic appearance of SOX9-positive Sertoli cell-like cells in grafted ovaries was mediated by the testosterone derived from the male host. Neither Sox8 nor Amh activity in the ovarian tissues is essential for such ectopic appearance of SOX9-positive cells. The transcriptome analyses of the grafted ovaries during this masculinization process showed early downregulation of pro-ovarian genes such as Irx3, Nr0b1/Dax1, Emx2, and Fez1/Lzts1 by days 7-10 post-transplantation, and subsequent upregulation of several pro-testis genes, such as Bhlhe40, Egr1/2, Nr4a2, and Zc3h12c by day 20, leading to a partial sex reversal with altered expression profiles in one-third of the total numbers of the sex-dimorphic pre-granulosa and Sertoli cell-specific genes at 12.5 dpc. Our data imply that the paternal testosterone exposure is partially responsible for the sex-reversal expression profiles of certain pro-ovarian and protestis genes in the fetal ovaries in a temporally dependent manner.