T helper cell fate specified by kinase-mediated interaction of T-bet with GATA-3

Hwang, Eun Sook,Laurie H. Glimcher 이화여자대학교 세포신호전달연구센터 2005 고사리 세포신호전달 심포지움 Vol. No.7

Specification of mammalian cell lineage requires both gene activation and silencing. The decision of a T helper progenitor lymphocyte to differentiate into either a Th1 or Th2 effector cell depends on the action of two opposing transcription factors, T-bet and GATA-3, which reciprocally activate and silence Th1 and Th2 genetic programs. While the activation of Th-selective cytokine genes by T-bet and GATA-3 has been well studied, the mechanisms by which these factors repress the development of the opposing lineage remain obscure. We report that T-bet represses Th2 lineage commitment by an ITK regulated interaction with GATA-3. Upon T cell receptor signaling, T-bet is phosphorylated at residue Y525 by the TCR-activated Tec kinase, ITK, a posttranslational modification required for optimal T-bet mediated repression of Th2 cytokines. The mechanism of such repression is an ITK-mediated interaction between phosphorylated T-bet and GATA-3, resulting in interference with GAT A-3 binding to DNA. These results provide a novel function for tyrosine phosphorylation of a transcription factor in specifying alternate fates of a common progenitor cell.

Amelioration of neurodegenerative diseases by cell death-induced cytoplasmic delivery of humanin

Park, T.Y.,Kim, S.H.,Shin, Y.C.,Lee, N.H.,Lee, R.K.C.,Shim, J.H.,Glimcher, L.H.,Mook-Jung, I.,Cheong, E.,Kim, W.K.,Honda, F.,Morio, T.,Lim, J.S.,Lee, S.K. Elsevier Science Publishers 2013 Journal of controlled release Vol.166 No.3

Inhibition of the early intracellular event that triggers neurodegenerative cascades and reversal of neuronal cell death are essential for effective treatment of Alzheimer's disease (AD). In this study, a novel therapeutic for AD, a transducible humanin with an extended caspase-3 cleavage sequence (tHN-C3), was developed and showed multiple mechanisms of therapeutic action. These included targeted delivery of anti-apoptotic protein humanin through the blood-brain barrier (BBB) to neuronal cells, specific inhibition of caspase-3 activation to inhibit the early triggering of AD progression, and delivery of humanin into the cytoplasm of neuronal cells undergoing apoptosis where it exerts its anti-apoptotic functions effectively. The tHN-C3 prevented neuronal cell death induced by H<SUB>2</SUB>O<SUB>2</SUB>, or soluble Aβ<SUB>42</SUB>, via Bax binding. In animal models of AD induced by amyloid beta, in Tg2576 mice, and in the rat middle cerebral artery occlusion model of stroke, tHN-C3 effectively prevented neuronal cell death, inflammatory cell infiltration into the brain, and improved cognitive memory. The therapeutic effectiveness of tHN-C3 was comparable to that of Aricept, a clinically approved drug for AD treatment. Therefore, tHN-C3 may be a new remedy with multiple therapeutic functions targeting the early and late stages of neurodegeneration in AD and other brain injuries.

Restoration of T-box–containing protein expressed in T cells protects against allergen-induced asthma

Park, Jung Won,Min, Hyun Jung,Sohn, Jung Ho,Kim, Joo Young,Hong, Jeong Ho,Sigrist, Kirsten S.,Glimcher, Laurie H.,Hwang, Eun Sook Elsevier 2009 The journal of allergy and clinical immunology Vol.123 No.2

<P><B>Background</B></P><P>A T<SUB>H</SUB>1-specific transcription factor, T-box–containing protein expressed in T cells (T-bet), controls the production of both T<SUB>H</SUB>1 and T<SUB>H</SUB>2 cytokines in T<SUB>H</SUB> cell differentiation by means of distinct mechanisms. T-bet–deficient mice overproduce T<SUB>H</SUB>2 cytokines and have spontaneous airway inflammation.</P><P><B>Objectives</B></P><P>We tested whether T-bet overexpression could protect against the development or progression of asthma.</P><P><B>Methods</B></P><P>We generated a T cell–specific and inducible line of T-bet–transgenic mice on a T-bet–deficient genetic background and used it to study the function of T-bet in an ovalbumin (OVA)–induced asthma model.</P><P><B>Results</B></P><P>Induction of T-bet in a T cell–specific manner in an OVA model of asthma concomitant with OVA injection prevented airway hyperresponsiveness, eosinophilic and lymphocytic inflammation, and IL-5 and IL-13 production in bronchoalveolar lavage fluid and also reduced serum IgE and T<SUB>H</SUB>2 cytokine production by peripheral T cells. Even when T-bet expression was induced during later stages of asthma progression, T-bet overexpression still attenuated airway hyperresponsiveness and goblet cell hyperplasia, as well as T<SUB>H</SUB>2 cytokine production.</P><P><B>Conclusions</B></P><P>Our results suggest that T-bet expression in T cells can prevent the initiation of airway inflammation and progression of chronic inflammation and might be extrapolated to human asthma.</P>

Crystal structure of the DNA binding domain of the transcription factor T-bet suggests simultaneous recognition of distant genome sites

Liu, Ce Feng,Brandt, Gabriel S.,Hoang, Quyen Q.,Naumova, Natalia,Lazarevic, Vanja,Hwang, Eun Sook,Dekker, Job,Glimcher, Laurie H.,Ringe, Dagmar,Petsko, Gregory A. National Academy of Sciences 2016 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.113 No.43

<P>The transcription factor T-bet (Tbox protein expressed in T cells) is one of the master regulators of both the innate and adaptive immune responses. It plays a central role in T-cell lineage commitment, where it controls the T(H)1 response, and in gene regulation in plasma B-cells and dendritic cells. T-bet is a member of the Tbox family of transcription factors; however, T-bet coordinately regulates the expression of many more genes than other Tbox proteins. A central unresolved question is how T-bet is able to simultaneously recognize distant Tbox binding sites, which may be located thousands of base pairs away. We have determined the crystal structure of the Tbox DNA binding domain (DBD) of T-bet in complex with a palindromic DNA. The structure shows a quaternary structure in which the T-bet dimer has its DNA binding regions splayed far apart, making it impossible for a single dimer to bind both sites of the DNA palindrome. In contrast to most other Tbox proteins, a single T-bet DBD dimer binds simultaneously to identical half-sites on two independent DNA. A fluorescence-based assay confirms that T-bet dimers are able to bring two independent DNA molecules into close juxtaposition. Furthermore, chromosome conformation capture assays confirm that T-bet functions in the direct formation of chromatin loops in vitro and in vivo. The data are consistent with a looping/synapsing model for transcriptional regulation by T-bet in which a single dimer of the transcription factor can recognize and coalesce distinct genetic elements, either a promoter plus a distant regulatory element, or promoters on two different genes.</P>

Post-translational control of T cell development by the ESCRT protein CHMP5

Adoro, Stanley,Park, Kwang Hwan,Bettigole, Sarah E,Lis, Raphael,Shin, Hee Rae,Seo, Heewon,Kim, Ju Han,Knobeloch, Klaus-Peter,Shim, Jae-Hyuck,Glimcher, Laurie H NATURE AMERICA INC 2017 NATURE IMMUNOLOGY Vol.18 No.7

<P>The acquisition of a protective vertebrate immune system hinges on the efficient generation of a diverse but self-tolerant repertoire of T cells by the thymus through mechanisms that remain incompletely resolved. Here we identified the endosomal-sorting-complex-required-for-transport (ESCRT) protein CHMP5, known to be required for the formation of multivesicular bodies, as a key sensor of thresholds for signaling via the T cell antigen receptor (TCR) that was essential for T cell development. CHMP5 enabled positive selection by promoting post-selection thymocyte survival in part through stabilization of the pro-survival protein Bcl-2. Accordingly, loss of CHMP5 in thymocyte precursor cells abolished T cell development, a phenotype that was 'rescued' by genetic deletion of the pro-apoptotic protein Bim or transgenic expression of Bcl-2. Mechanistically, positive selection resulted in the stabilization of CHMP5 by inducing its interaction with the deubiquitinase USP8. Our results thus identify CHMP5 as an essential component of the post-translational machinery required for T cell development.</P>

Restoration ofT-box-containing protein expressed in T cells protects against allergen-induced asthma

Eun Sook, Hwang,Jung Won, Park,Hyun Jung, Min,Jung Ho, Sohn,Joo Young, Kim,Jeong Ho, Hong,Kirsten S. Sigrist,Laurie H. Glimcher 이화여자대학교 약학연구소 2010 藥學硏究論文集 Vol.- No.20

BACKGROUND: A T(H)1-specific transcription factor, T-box-containing protein expressed in T cells (T-bet), controls the production of both T(H)1 and T(H)2 cytokines in T(H) cell differentiation by means of distinct mechanisms. T-bet-deficient mice overproduce T(H)2 cytokines and have spontaneous airway inflammation. OBJECTIVES: We tested whether T-bet overexpression could protect against the development or progression of asthma. METHODS: We generated a T cell-specific and inducible line of T-bet-transgenic mice on a T-bet-deficient genetic background and used it to study the function of T-bet in an ovalbumin (OVA)-induced asthma model. RESULTS: Induction of T-bet in a T cell-specific manner in an OVA model of asthma concomitant with OVA injection prevented airway hyperresponsiveness, eosinophilic and lymphocytic inflammation, and IL-5 and IL-13 production in bronchoalveolar lavage fluid and also reduced serum IgE and T(H)2 cytokine production by peripheral T cells. Even when T-bet expression was induced during later stages of asthma progression, T-bet overexpression still attenuated airway hyperresponsiveness and goblet cell hyperplasia, as well as T(H)2 cytokine production. CONCLUSIONS: Our results suggest that T-bet expression in T cells can prevent the initiation of airway inflammation and progression of chronic inflammation and might be extrapolated to human asthma.

Administration of BMP2/7 in utero partially reverses Rubinstein-Taybi syndrome-like skeletal defects induced by Pdk1 or Cbp mutations in mice.

Shim, Jae-Hyuck,Greenblatt, Matthew B,Singh, Anju,Brady, Nicholas,Hu, Dorothy,Drapp, Rebecca,Ogawa, Wataru,Kasuga, Masato,Noda, Tetsuo,Yang, Sang-Hwa,Lee, Sang-Kyou,Rebel, Vivienne I,Glimcher, Laurie American Society for Clinical Investigation 2012 The Journal of clinical investigation Vol.122 No.1

<P>Mutations in the coactivator CREB-binding protein (CBP) are a major cause of the human skeletal dysplasia Rubinstein-Taybi syndrome (RTS); however, the mechanism by which these mutations affect skeletal mineralization and patterning is unknown. Here, we report the identification of 3-phosphoinositide-dependent kinase 1 (PDK1) as a key regulator of CBP activity and demonstrate that its functions map to both osteoprogenitor cells and mature osteoblasts. In osteoblasts, PDK1 activated the CREB/CBP complex, which in turn controlled runt-related transcription factor 2 (RUNX2) activation and expression of bone morphogenetic protein 2 (BMP2). These pathways also operated in vivo, as evidenced by recapitulation of RTS spectrum phenotypes with osteoblast-specific Pdk1 deletion in mice (Pdk1osx mice) and by the genetic interactions observed in mice heterozygous for both osteoblast-specific Pdk1 deletion and either Runx2 or Creb deletion. Finally, treatment of Pdk1osx and Cbp+/- embryos with BMPs in utero partially reversed their skeletal anomalies at birth. These findings illustrate the in vivo function of the PDK1-AKT-CREB/CBP pathway in bone formation and provide proof of principle for in utero growth factor supplementation as a potential therapy for skeletal dysplasias.</P>