检索结果-南通市图书馆

The actin cytoskeleton coordinates the signal transduction and antigen processing functions of the B cell antigen receptor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Biology 2013年第5期8卷 475-485页

作者： Chaohong LIU Margaret K. FALLEN Heather MILLER Arpita UPADHYAYA wenxia song Department of Cell Biology & Molecular Genetics University of Maryland College Park MD 20742 USA Department of Physics University of Maryland College Park MD 20742 USA Division of Immunology Children's Hospital of Chongqing Medical University Chongqing 400014 China

The B cell antigen receptor （BCR） is the sensor on the B cell surface that surveys foreign molecules （antigen） in our bodies and activates B cells to generate antibody responses upon encountering cognate antigen. The binding of antigen to the BCR induces signaling cascades in the cytoplasm, which provides the first signal for B cell activation. Subsequently, BCRs internalize and target bound antigen to endosomes, where antigen is processed into T cell recognizable forms. T helper cells generate the second activation signal upon binding to antigen presented by B cells. The optimal activation of B cells requires both signals, thereby depending on the coordination of BCR signaling and antigen transport functions. Antigen binding to the BCR also induces rapid remodeling of the cortical actin network of B cells. While being initiated and controlled by BCR signaling, recent studies reveal that this actin remodeling is critical for both the signaling and antigen processing functions of the BCR, indicating a role for actin in coordinating these two pathways. Here we will review previous and recent studies on actin reorganization during BCR activation and BCR- mediated antigen processing, and discuss how actin remodeling translates BCR signaling into rapid antigen uptake and processing while providing positive and negative feedback to BCR signaling.

关键词： actin cytoskeleton endocytosis signal transduction receptor

Foil-like receptor agonists induce apoptosis in mouse 3-cell lymphoma cells by altering NF-κB activation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2013年第4期10卷 360-372页

作者： Nandini Arunkumar Chaohong Liu Haiying Hang wenxia song Department of Cell Biology & Molecular Genetics University of Maryland College Park Maryland USA National Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China

Toll-like receptor 9 （TLR9） recognizes microbial DNA containing unmethylated cytosyl guanosyl （CpG） sequences, induces innate immune responses, and facilitates antigen-specific adaptive immunity. Recent studies report that in addition to stimulating innate immunity, TLR9 ligands induce apoptosis of TLR9 expressing cancer cells. To understand the mechanism of TLR9-induced apoptosis, we compared the effects of CpG containing oligodeoxynucleotides （CpG ODN） on a mouse B-cell lymphoma line, CH27, with those on mouse splenic B cells. CpG ODN inhibited constitutive proliferation and induced apoptosis in the CH27 B-cell lymphoma line. In contrast, CpG ODN-treated primary B cells were stimulated to proliferate and were rescued from spontaneous apoptosis. The induction of apoptosis required the ODNs to contain the CpG motif and the expression of TLR9 in lymphoma B cells. A decrease in Bcl-xl expression and an increase in Fas and Fas ligand expression accompanied lymphoma B-cell apoptosis. Treatment with the Fas ligand-neutralizing antibody inhibited CpG ODN-induced apoptosis. CpG ODN triggered a transient NF-κB activation in the B-cell lymphoma cell line, which constitutively expresses a high level of c-Myc, while CpG ODN induced sustained increases in NF-κB activation and c-Myc expression in primary B cells. Furthermore, an NF-κB inhibitor inhibited the proliferation of the CH27 B-cell lymphoma line. Our data suggest that the differential responses of lymphoma and primary B cells to CpG ODN are the result of differences in NF-KB activation. The impaired NF-KB activation in the CpG ODN-treated B-cell lymphoma cell line alters the balance between NF-κB and c-Myc, which induces Fas/Fas ligand-dependent apoptosis.

关键词： apoptosis lymphoma B cells NF-κB Toll-like receptor

Hyperactive PI3Kδ predisposes naive T cells to activation via aerobic glycolysis programs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2021年第7期18卷 1783-1797页

作者： Yanjun Jia Qiuyun Yang Yanping Wang Wenyan Li Xuemei Chen Tao Xu Zhirui Tian Minxuan Feng Liang Zhang Wenjing Tang Na Tian Lina Zhou wenxia song Xiaodong Zhao National Clinical Research for Child Health and Disorders Chongqing Key Laboratory of Child Infection and ImmunityMinistry of Education Key Laboratory of Child Development and DisordersChildren’s Hospital of Chongqing Medical UniversityChongqingChina National Clinical Research for Child Health and Disorders Chongqing Key Laboratory of PediatricsMinistry of Education Key Laboratory of Child Development and DisordersChildren’s Hospital of Chongqing Medical UniversityChongqingChina Department of Cell Biology and Molecular Genetics University of MarylandCollege ParkMDUSA

Activated phosphoinositide 3-kinaseδsyndrome(APDS)is an autosomal-dominant combined immunodeficiency disorder resulting from pathogenic gain-of-function(GOF)mutations in the PIK3CD *** with APDS display abnormal T cell ***,the mechanisms by which PIK3CD GOF contributes to this feature remain ***,with a cohort of children with PIK3CD GOF mutations from multiple regions of China and a corresponding CRISPR/Cas9 gene-edited mouse model,we reported that hyperactive PI3Kδdisrupted TNaive cell homeostasis in the periphery by intrinsically promoting the growth,proliferation,and activation of TNaive *** results showed that PIK3CD GOF resulted in loss of the quiescence-associated gene expression profile in naive T cells and promoted naive T cells to overgrow,hyperproliferate and acquire an activated functional *** PIK3CD GOF T cells exhibited an enhanced glycolytic capacity and reduced mitochondrial respiration in the resting or activated *** glycolysis abrogated the abnormal splenic T cell pool and reversed the overactivated phenotype induced by PIK3CD GOF in vivo and in *** results suggest that enhanced aerobic glycolysis is required for PIK3CD GOF-induced overactivation of naive T cells and provide a potential therapeutic approach for targeting glycolysis to treat patients with APDS as well as other immune disorders.

关键词： Primary immunodeficiency disorders Activated phosphoinositide3-kinaseδsyndrome PIK3CD Naive T cells Aerobic glycolysis

TCR diversity is selectively skewed in T-cell populations of Wiskott-Aldrich syndrome patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

TCR diversity is selectively skewed in T-cell populations of...

第九届全国免疫学学术大会

作者： Junfeng Wu Dawei Liu Wenwei Tu wenxia song Xiaodong Zhao Ministry of Education Key Laboratory of Child Development and Disorders Children's Hospital of Chongqing Medical University Department of Paediatrics & Adolescent Medicine LKS Faculty of Medicinethe University of Hong Kong Department of Cell Biology & Molecular Genetics University of MarylandCollege ParkMD 20742U.S.A

Background:Wiskott-Aldrich syndrome(WAS)is a severe disorder characterized by thrombocytopenia,eczema,immunodeficiency,and increased risk of autoimmune disease and lymphoid *** immunodeficiency caused by lack of WAS protein(WASP)expression has been mainly attributed to defective T-cell *** WAS mutations differentially influence the T cell receptor(TCR)diversity of different T-cell subsets is ***:We aimed to identify the degree and the pattern of skewing in the variable region of theβ-chain(Vβ)TCR repertoire in different T-cell subsets from patients with ***:The TCR repertoire diversity in total peripheral T cells,sorted CD4+and CD8+T cells,CD45RA+(CD45RA+CD45RO-)and CD45RO+(CD45RA-CD45RO+)CD4+and CD8+T cells from patients with WAS and age-matched healthy controls were analyzed and compared,using spectratyping,of complementarity-determining region3(CDR3);and the CDR3 region of TCRβtranscripts in CD45RA+CD4+and CD8+T cells,CD45RO+CD4+T cells,CD8+terminally differentiated effctor memory T cells(Temra)and naive CD8+T(CD8+CD45RO-CCR7+)cells from patients and controls were analyzed and compared by high-throughput sequencing(HTS).Results:The TCR repertoire diversity in CD45RO+CD4+T cells and CD8+Temra of WAS patients was significantly skewed,compared to that in age-matched ***:Our results indicate that WAS gene mutations selectively influence the repertoire development or expansion of CD45RO+(memory)CD4+T cells.

关键词： Wiskott-Aldrich syndrome TCR diversity CDR3 spectratyping high-throughput sequencing

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

用于激光频率参数测量的飞秒光学频率梳

仪器仪表学报 2024年第2期45卷 31-46页

作者：韩羿曹士英宋文霞左娅妮房芳中国计量科学研究院时间频率计量科学研究所北京100029 国家市场监管重点实验室(时间频率与重力计量基准) 北京100029

近年来随着光纤制造技术和飞秒激光技术的成熟,以掺铒(Er)光纤光学频率梳为代表的频率梳技术,逐步突破了光学频率测量领域,在长度测量、精密光谱分析、超低相位噪声微波频率产生、精密时间频率传递、温度测量等领域发挥出越来越重要的作... 详细信息

近年来随着光纤制造技术和飞秒激光技术的成熟,以掺铒(Er)光纤光学频率梳为代表的频率梳技术,逐步突破了光学频率测量领域,在长度测量、精密光谱分析、超低相位噪声微波频率产生、精密时间频率传递、温度测量等领域发挥出越来越重要的作用,已成为许多高端科研领域的基础性工具。但飞秒光学频率梳所解决的重要问题是对激光频率进行测量。本文主要面向激光频率参数测量的需求,研制基于掺Er光纤飞秒激光器的光学频率梳,在实现光学频率梳稳定运转的前提下,通过非线性光学频率变换技术,实现光谱范围从掺Er光纤光学频率梳的中心波长向各个待测激光波长的转换,并完成与多个不同波长激光的拍频信号探测。目前已验证的飞秒光梳可测频率范围为500~2000 nm;频率稳定度和准确度为10^(-16)量级;线宽为Hz量级。该指标满足了激光频率特性参数测量的需求,为激光绝对频率、频率漂移、线宽等参数的测量提供了基础性的测量工具。

关键词：光学频率梳频率测量拍频稳定度线宽绝对频率

断层破碎带大断面巷道围岩变形破坏机理及控制技术

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

煤炭与化工 2019年第10期42卷 21-24,28页

作者：宋文侠山西长平煤业有限责任公司

为了解决断层破碎带大断面巷道围岩控制的难题,结合长平矿4320回风措施巷的围岩地质条件,分析了断层破碎带巷道围岩破碎机理,提出了超前注浆加固+锚杆索支护+工字钢补强的围岩控制方案。试验表明,超前注浆加固可以改善围岩力学性能,提... 详细信息

为了解决断层破碎带大断面巷道围岩控制的难题,结合长平矿4320回风措施巷的围岩地质条件,分析了断层破碎带巷道围岩破碎机理,提出了超前注浆加固+锚杆索支护+工字钢补强的围岩控制方案。试验表明,超前注浆加固可以改善围岩力学性能,提高围岩刚度和强度;及时进行锚杆索加密支护和工字梁加固的主被动支护可有效控制巷道的有害变形。

关键词：断层破碎带大断面超前注浆锚杆支护工字梁加固

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

实现射孔器标准化提升产品质量

石油工业技术监督 2007年第5期23卷 17-19页

作者：宋文侠辽河石油勘探局测井公司辽宁盘锦124010

有枪身射孔器主要用于油气井的射孔．是聚能射孔器的一种，它是由聚能射孔弹、密封的钢管（射孔枪）、弹架、起爆传爆部件（或装置）等构成的射孔总成．是利用炸药爆轰的聚能效应产生的高温高压高速的聚能射流完成射孔作业的。在生产中... 详细信息

有枪身射孔器主要用于油气井的射孔．是聚能射孔器的一种，它是由聚能射孔弹、密封的钢管（射孔枪）、弹架、起爆传爆部件（或装置）等构成的射孔总成．是利用炸药爆轰的聚能效应产生的高温高压高速的聚能射流完成射孔作业的。在生产中聚能射孔器的性能直接关系着射孔的效果和射孔后对井下环境的影响和破坏，因此，对射孔器的穿透性能、射孔枪的变形（外径胀大、裂纹）、套管伤害（外径胀大、内毛刺高、裂纹等）就要有一个硬性的要求。

关键词：射孔器产品质量标准化聚能射孔弹穿透性能射孔作业聚能射流高温高压