Sustained Id2 regulation of E proteins is required for terminal differentiation of effector CD8+ T cells.

CD8+ T cells responding to infection differentiate into a heterogeneous population composed of progeny that are short-lived and participate in the immediate, acute response and those that provide long-lasting host protection. Although it is appreciated that distinct functional and phenotypic CD8+ T cell subsets persist, it is unclear whether there is plasticity among subsets and what mechanisms maintain subset-specific differences. Here, we show that continued Id2 regulation of E-protein activity is required to maintain the KLRG1hi CD8+ T cell population after lymphocytic choriomeningitis virus infection. Induced deletion of Id2 phenotypically and transcriptionally transformed the KLRG1hi "terminal" effector/effector-memory CD8+ T cell population into a KLRG1lo memory-like population, promoting a gene-expression program that resembled that of central memory T cells. Our results question the idea that KLRG1hi CD8+ T cells are necessarily terminally programmed and suggest that sustained regulation is required to maintain distinct CD8+ T cell states

Signal-induced Brd4 release from chromatin is essential for its role transition from chromatin targeting to transcriptional regulation

Bromodomain-containing protein Brd4 is shown to persistently associate with chromosomes during mitosis for transmitting epigenetic memory across cell divisions. During interphase, Brd4 also plays a key role in regulating the transcription of signal-inducible genes by recruiting positive transcription elongation factor b (P-TEFb) to promoters. How the chromatin-bound Brd4 transits into a transcriptional regulation mode in response to stimulation, however, is largely unknown. Here, by analyzing the dynamics of Brd4 during ultraviolet or hexamethylene bisacetamide treatment, we show that the signal-induced release of chromatin-bound Brd4 is essential for its functional transition. In untreated cells, almost all Brd4 is observed in association with interphase chromatin. Upon treatment, Brd4 is released from chromatin, mostly due to signal-triggered deacetylation of nucleosomal histone H4 at acetylated-lysine 5/8 (H4K5ac/K8ac). Through selective association with the transcriptional active form of P-TEFb that has been liberated from the inactive multi-subunit complex in response to treatment, the released Brd4 mediates the recruitment of this active P-TEFb to promoter, which enhances transcription at the stage of elongation. Thus, through signal-induced release from chromatin and selective association with the active form of P-TEFb, the chromatin-bound Brd4 switches its role to mediate the recruitment of P-TEFb for regulating the transcriptional elongation of signal-inducible genes.National Natural Science Foundation of China[30930046, 30670408, 81070307]; Natural Science Foundation of Fujian[C0210005, 2010J01231]; Science Planning Program of Fujian Province[2009J1010, 2010J1008]; National Foundation for fostering talents of basic science[J1030626

Transcriptional repressor ZEB2 promotes terminal differentiation of CD8⁺ effector and memory T cell populations during infection

ZEB2 is a multi-zinc-finger transcription factor known to play a significant role in early neurogenesis and in epithelial-mesenchymal transition-dependent tumor metastasis. Although the function of ZEB2 in T lymphocytes is unknown, activity of the closely related family member ZEB1 has been implicated in lymphocyte development. Here, we find that ZEB2 expression is up-regulated by activated T cells, specifically in the KLRG1(hi) effector CD8(+) T cell subset. Loss of ZEB2 expression results in a significant loss of antigen-specific CD8(+) T cells after primary and secondary infection with a severe impairment in the generation of the KLRG1(hi) effector memory cell population. We show that ZEB2, which can bind DNA at tandem, consensus E-box sites, regulates gene expression of several E-protein targets and may directly repress Il7r and Il2 in CD8(+) T cells responding to infection. Furthermore, we find that T-bet binds to highly conserved T-box sites in the Zeb2 gene and that T-bet and ZEB2 regulate similar gene expression programs in effector T cells, suggesting that T-bet acts upstream and through regulation of ZEB2. Collectively, we place ZEB2 in a larger transcriptional network that is responsible for the balance between terminal differentiation and formation of memory CD8(+) T cells

Multi-layered epigenetic control of T cell fate decisions

CD8 + T cells are a central component of the adaptive immune system. Upon infection, a naive CD8 + T cell will differentiate into a heterogeneous population of effector T cells composed of terminal-effector and memory-precursor CD8 + T cells. Terminal-effector T cells rapidly decay after pathogens are eradicated while memory-precursor T cells survive during the contraction phase to become memory T cells, providing long-term protection from reinfection. Similar to the heterogeneity of effector T cells, memory T cells can also be divided into central-memory, effector-memory and tissue-resident memory subsets based on trafficking, location, proliferation potential and cytotoxic function. These memory subsets collaborate together to enhance the pathogen clearance and vaccine efficacy. The differentiation of a naive CD8 + T cell into a specific effector or memory subset is influenced by cell-extrinsic environmental signals and cell-intrinsic factors including transcription factors (TFs), epigenetic modification and chromatin organization. Considerable advances have been made to identify key TFs that regulate these T cell fate decisions. However, the TF-mediated transcriptional network responsible for specific subset differentiation and how epigenetic modifications and chromatin configuration modulate CD8 + T cell fate determination is still largely unknown. To address these questions, we deciphered epigenetic landscapes in effector and memory CD8 + T cells in response to bacterial infection by characterizing the genome-wide histone modification, chromatin accessibility and transcriptional program. Integrative analysis of epigenomics data showed that subset-specific enhancers established by key TFs foreshadow the specific lineage differentiation. To better identify cruicial TFs from multilayered epigenetic landscapes, we developed a webpage ranking-based algorithm (PageRank) to rank the importance of TFs from transcriptional network and identified a novel function of two TFs: YY1 and Nr3c1 to regulate terminal-effector and memory-precursor subset differentiation, respectively. By leveraging the PageRank analysis and chromatin accessibility data, we developed a computational screen to predict key TFs for tissue-resident memory T cell differentiation. Combining this approach with shRNA functional screen, we identified the role of Runx3 in programming tissue-residency signatures in non-lymphoid tissues and tumors. Finally, we discovered a novel role for the genome organizer CTCF in CD8 + T cell fate decisions illustrating the impact of chromatin organization on effector and memory T cell differentiation. Taken together, we uncovered a multi-layered regulation of chromatin state, accessibility and organization, that influences T cell fate decisions by fine-tuning transcriptional circuits. We further constructed a computational framework that integrates these high-dimensional data, facilitating identification of key transcriptional regulators and providing valuable biological insights

Multi-layered epigenetic control of T cell fate decisions

CD8 + T cells are a central component of the adaptive immune system. Upon infection, a naive CD8 + T cell will differentiate into a heterogeneous population of effector T cells composed of terminal-effector and memory-precursor CD8 + T cells. Terminal-effector T cells rapidly decay after pathogens are eradicated while memory-precursor T cells survive during the contraction phase to become memory T cells, providing long-term protection from reinfection. Similar to the heterogeneity of effector T cells, memory T cells can also be divided into central-memory, effector-memory and tissue-resident memory subsets based on trafficking, location, proliferation potential and cytotoxic function. These memory subsets collaborate together to enhance the pathogen clearance and vaccine efficacy. The differentiation of a naive CD8 + T cell into a specific effector or memory subset is influenced by cell-extrinsic environmental signals and cell-intrinsic factors including transcription factors (TFs), epigenetic modification and chromatin organization. Considerable advances have been made to identify key TFs that regulate these T cell fate decisions. However, the TF-mediated transcriptional network responsible for specific subset differentiation and how epigenetic modifications and chromatin configuration modulate CD8 + T cell fate determination is still largely unknown. To address these questions, we deciphered epigenetic landscapes in effector and memory CD8 + T cells in response to bacterial infection by characterizing the genome-wide histone modification, chromatin accessibility and transcriptional program. Integrative analysis of epigenomics data showed that subset-specific enhancers established by key TFs foreshadow the specific lineage differentiation. To better identify cruicial TFs from multilayered epigenetic landscapes, we developed a webpage ranking-based algorithm (PageRank) to rank the importance of TFs from transcriptional network and identified a novel function of two TFs: YY1 and Nr3c1 to regulate terminal-effector and memory-precursor subset differentiation, respectively. By leveraging the PageRank analysis and chromatin accessibility data, we developed a computational screen to predict key TFs for tissue-resident memory T cell differentiation. Combining this approach with shRNA functional screen, we identified the role of Runx3 in programming tissue-residency signatures in non-lymphoid tissues and tumors. Finally, we discovered a novel role for the genome organizer CTCF in CD8 + T cell fate decisions illustrating the impact of chromatin organization on effector and memory T cell differentiation. Taken together, we uncovered a multi-layered regulation of chromatin state, accessibility and organization, that influences T cell fate decisions by fine-tuning transcriptional circuits. We further constructed a computational framework that integrates these high-dimensional data, facilitating identification of key transcriptional regulators and providing valuable biological insights

Comprehensive analysis of gravity and magnetic anomalies in Jinniu volcanic basin for prediction of ore deposits

The middle and lower reaches of the Yangtze River is an important iron, copper, gold and other polymetallic metallogenic belt in China. The southern part of the Yangtze River is the southeast Hubei ore concentration area. As an important source of iron and copper deposits in China, several iron-rich copper deposits are concentrated in this area. The Jinniu volcanic basin is located in the southeastern Hubei ore concentration area. The basin has the ore potential of iron, copper, gold and other polymetallic deposits with the similar metallogenic conditions of other mining areas in this metallogenic belt. However, the basin has a thick overlying strata of magnetic rock and sedimentary rock, which increases the difficulty of ore prospecting. Therefore, it is necessary to strengthen the application of technologies for improving the effect of ore prediction. In the adjacent ore concentration areas, the prospecting work mainly focuses on gravity and magnetic data and combined with other geophysical data for comprehensive analysis, which lays a good foundation for the study of structural characteristics and the guidance of prospecting prediction. These previous works has proved that by comprehensive analysis and interpretation of high-precision gravity and magnetic data combined with other geophysical data, the tectonic framework characteristics, buried rocks and physical property distribution of the study area can be extracted, so as to infer the tectonic characteristics of the basin and its basement and put forward prospecting prediction. For the lack of systematic research and demand for prospecting in Jinniu volcanic basin, based on measured and collected geological and geophysical data, comprehensive analysis and interpretation of gravity and magnetic data combined with MT data were carried out. The techniques of linear signal extraction, multi-scale analysis, inversion and resistivity imaging, etc., were utilized to estimate the depth of the basin basement, delineate volcanic mechanism and buried rocks, and speculate fractures, basin boundary, and some areas of prospecting prospect. The such research has the guidance or reference significance for the basic geological survey and deep ore prediction in this area

NMR and theoretical study on the coordination interaction between peroxovanadium( V) complexes and 5-amino-1,10-phenanthroline

Hunan Provincial Natural Science Foundation of China [14JJ7049]; Scientific Research Fund of Hunan Provincial Education Department [12K101]; State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University [201309]; Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan ProvinceTo understand the coordination modes and the solution structure of 5-amino-1,10-phenanthroline (5-NH2-phen), the coordination reaction between peroxovanadium(V) complex [OV(O-2)(2)(D2O)](-)/[OV(O-2)(2)(HOD)](-) and 5-NH2-phen has been investigated by multinuclear (H-1, C-13, and V-51) magnetic resonance with variable temperature NMR, COSY, and HSQC. The experimental results indicate a pair of isomers in solution, which are attributed to different coordination modes between vanadium and 5-NH2-phen. The solution structures of these newly formed peroxovanadate species were proposed based on experimental NMR information and confirmed by theoretical calculations. Moreover, the results of density functional calculations indicate that solvation plays an important role in these interactions

Study on the interaction between carbonyl-fused N-confused porphyrin and bovine serum albumin by spectroscopic techniques

The interaction between carbonyl-fused N-confused porphyrin (CF-NCP) and bovine serum albumin (BSA) was investigated by fluorescence and ultraviolet-visible (UV-Vis) spectroscopy. The results indicated that CF-NCP has strong ability to quench the intrinsic fluorescence of BSA by forming complexes. The binding constants (Ka), binding sites (n) were obtained. The corresponding thermodynamic parameters (ΔH, ΔS and ΔG) of the interaction system were calculated at three different temperatures. The results revealed that the binding process is spontaneous, and the acting force between CF-NCP and BSA were mainly electrostatic forces. According to Forster non-radiation energy transfer theory, the binding distance between CF-NCP and BSA was calculated to be 4.37 nm. What is more, the conformation of BSA was observed from synchronous fluorescence spectroscopy. ? 2014 Elsevier Inc. All rights reserved

The complete mitochondrial genomes of Cynomys leucurus and C. ludovicianus (Rodentia: Sciuridae)

The mitochondrial genomes of the white - tailed praire dog Cynomys leucurus and black-tailed prairie dog C. ludovicianus (Rodentia: Sciuridae) are circular molecules of 16,454 bp and 16,466 bp in length, respectively, containing 37 genes as in other Rodentia species. The A + T content of the overall base composition of the H-strand is 63.0% and 62.6% for C. leucurus and C. ludovicianus, respectively. The control region of the C. leucurus and C. ludovicianus mt genome is 1012 bp in length, and the A + T content of this region is 63.5% and 62.0%, respectively. Nucleotide sequence divergence of the mt genome (p distance) between C. leucurus and C. ludovicianus was 4.0%

Sustained Id2 regulation of E proteins is required for terminal differentiation of effector CD8+ T cells.

CD8+ T cells responding to infection differentiate into a heterogeneous population composed of progeny that are short-lived and participate in the immediate, acute response and those that provide long-lasting host protection. Although it is appreciated that distinct functional and phenotypic CD8+ T cell subsets persist, it is unclear whether there is plasticity among subsets and what mechanisms maintain subset-specific differences. Here, we show that continued Id2 regulation of E-protein activity is required to maintain the KLRG1hi CD8+ T cell population after lymphocytic choriomeningitis virus infection. Induced deletion of Id2 phenotypically and transcriptionally transformed the KLRG1hi "terminal" effector/effector-memory CD8+ T cell population into a KLRG1lo memory-like population, promoting a gene-expression program that resembled that of central memory T cells. Our results question the idea that KLRG1hi CD8+ T cells are necessarily terminally programmed and suggest that sustained regulation is required to maintain distinct CD8+ T cell states