190CT3多肽调节白血病细胞增殖分化的实验研究

白血病抑制因子（LIF）是一种多效性细胞因子,作用于多种细胞组织发挥不同的生物学作用。其生物学效应依赖于其结合靶细胞膜上的LIF受体a亚基（gp190）,与8亚基（gp130）形成异源性二聚体,从而激活下游信号转导通路。LIF因子可通过激活JAK-STAT和RAS-MAPK途径,调节白血病细胞的增殖分化。我们根据gp190细胞内区功能域设计了小分子-190CT3,     

白血病抑制因子受体与血病细胞U937内促分裂原活化蛋白激 …

探讨人白血病细胞系Ｕ９３７白血病抑制因子（ＬＩＦ）受体α亚基和另一亚基ｇｐ１３０细胞内区与促分裂原活化蛋白激酶（ＭＡＰＫ）的关系,旨在研究白血病细胞增殖和分化的机制。用基因重组技术将两基因细胞内区互换以构成两嵌合体受体（１９０／１３０,１３０／１９０）并分别在Ｕ９３７表达,其与野生受体竞争性结合白血病抑制因子,用免疫组化和免疫印迹法分析受体细胞内区形成同源性二聚体（１９０ｃｙｔ－１９０ｃｙｔ,１３     

白血病抑制因子受体与白血病细胞U937内促分裂原活化蛋白激酶的关系

探讨人白血病细胞系U937白血病抑制因子 (LIF)受体α亚基和另一亚基gp130细胞内区与促分裂原活化蛋白激酶 (MAPK)的关系 ,旨在研究白血病细胞增殖和分化的机制。用基因重组技术将两基因细胞内区互换以构成两嵌合体受体 (190 130 ,130 190 )并分别在U937表达 ,其与野生受体竞争性结合白血病抑制因子 ,用免疫组化和免疫印迹法分析受体细胞内区形成同源性二聚体(190cyt 190cyt,130cyt 130cyt)后的细胞状况和细胞内MAPK的水平。结果表明 ,转染pE190 130后用LIF作用 6h ,U937细胞MAPK表达量增加 ,MAPK形成的二聚体较明显 ,细胞增殖较快 ;而另一嵌合体受体与α亚基形成 190cyt 190cyt时U937细胞MAPK的表达无变化 ,二聚体不明显。说明LIF受体中gp130亚基的细胞内区参与了MAPK的激活及白血病U937细胞增殖信号的传递。     

人白血病抑制因子(hLIF)在昆虫细胞Sf9中表达

白血病抑制因子(LIF)是一种作用广泛的细胞因子,它促进小鼠白血病M_1细胞分化并抑制其增殖,所以把它命名为白血病抑制因子。随着研究的不断深入,人们了解到它还具有抑制胚胎干细胞的分化,抑制脂蛋白脂酶的活性,促进骨吸收,引起血小板增加,刺激肝细胞合成急性反应蛋白,以及参与胚胎发育、促进神经肌肉的生长和维持垂体功能等作用。 本研究用PCR扩增pLXSN-hLIF中的LIF结构序列。经HindⅢ和BamHⅠ插入质粒     

人白血病抑制因子基因LIF的克隆、真核表达及活性检测

白血病抑制因子 (LIF)是一种多功能细胞因子 ,在生物发育及维持正常生理功能中发挥着重要的作用。以成人血细胞的总RNA为模板 ,利用RT PCR方法从成人外周血细胞中扩增人白血病抑制因子 ,而后将其克隆到真核表达载体pcDNA3,在哺乳动物细胞中成功表达。将分泌到细胞培养基中的LIF因子收集 ,通过LIF信号转导通路下游蛋白质STAT3磷酸化水平的检测、EMSA实验以及荧光酶报告系统检测 ,发现其具有激活STAT3信号通路的生物学活性。同时 ,[3H] TdR参入实验的结果也表明 ,所表达LIF因子能显著抑制鼠骨髓白血病细胞系M1的增殖。     

睫状神经营养因子受体

睫状神经营养因子是一种能够促进感觉、交感和运动神经元存活和分化的细胞因子．睫状神经营养因子受体复合物由三个亚基组成,α亚基是睫状神经营养因子的结合蛋白,它不是跨膜蛋白,而是通过GPI键锚在细胞膜上;信号传递体的两个亚基分别是gp130和LIFRβ．随状神经营养因子受体复合物的形成是一个有序过程、Jak／Tyk家族的激活与细胞内信号传导有关．     

白血病抑制因子受体细胞内区对HL-60细胞表达CD14和CD15的影响

观察白血病抑制因子 (LIF)受体gp190亚基完整的细胞内区和gp190胞内区C末端片段(190CT)对人白血病系HL 6 0表达CD14、CD15的影响 ,进一步了解LIF引发白血病细胞增殖抑制和分化的关系 .用基因重组技术将LIF另一亚基gp130的细胞内区换成gp190的细胞内区 ,用PCR技术扩增gp190细胞内区C末端的一个多肽的编码序列 ,构成嵌合体受体基因 130 /190及 190CT片段 ,并分别在HL 6 0细胞表达 .用免疫组化和流式细胞术检测分析在LIF的诱导下 ,HL 6 0细胞表达CD14、CD15的水平 .转染pcDNA130 /190的HL 6 0细胞 ,CD15表达量明显增高 ;转染pcDNA190CT的细胞 ,CD15的表达量降低 ;但 2组细胞的CD14表达量均较低且水平接近 .LIF可能诱导HL 6 0细胞向粒细胞而不向单核细胞分化 ,该效应是由gp190亚基细胞内区介导的 ,而gp190C末端片段可干扰LIFα受体介导的信号传导效应 .     

白细胞介素12研究进展

白细胞介素１２（ＩＬ－１２）是近年新发现的一种细胞因子,主要来源于Ｂ淋巴细胞系。它是目前发现的细胞因子中唯一由异二聚体组成的因子,两亚基的分子量分别为４０ｋＤ和３５ｋＤ。两亚基的基因定位于不同的染色体上。ＩＬ－２具有多种生物学效应,只存在单一亲和力的膜受体。对ＩＬ－１２的研究将有助于确定其在抗肿瘤和抗感染免疫中的重要作用。     

鲤鱼SOCS-4基因克隆、鉴定及表达模式分析

细胞因子是调节机体免疫和神经内分泌功能的生物活性物质,其信号的激发、放大和持续在时间和空间上都受到严格调控。细胞因子信号传导抑制因子(Suppressorof cytokine signaling,SOCS)是细胞因子信号通路的负调节因子,通过负反馈抑制细胞因子的信号传递,防止过度的信号反应干扰机体代谢平衡和细胞功能。在哺乳动物中,SOCS系统对生长激素(GH)、表皮生长因子     

IL－6受体结构与功能的研究进展

IL-6是一个多功能的细胞因子,其生物学作用在很大程度上受IL-6受体(IL-6R)结构和功能的影响.IL-6R由两条多肽链组成,即配体结合链gp80和信号传导链gp130.它们在结构和功能上既有分工又有合作.两种亚基组成的高亲和力IL-6R是介导细胞效应所必需的.IL-6Rα中的造血功能区属于造血因子受体超家族成员,它决定着结合IL-6的能力.然而gp130则是多种细胞因子共用的信号传递分子,其胞内段含有与酪氨酸激酶活化有关的保守成分.IL-6+IL-6R复合物通过诱导gp130的聚合来活化胞内的多种激酶分子和转录因子并最终导致有关基因的表达.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.