香菇多糖对小鼠骨髓树突状细胞表型和功能的影响

通过研究香菇多糖(Lentinan,LNT)对小鼠骨髓源树突状细胞(bone marrow dendritic cells,BMDCs)功能调节的机制,进一步阐明香菇多糖的免疫活性。本实验将BMDCs分成脂多糖(LPS)阳性对照组、LNT处理组和RPMI1640空白对照组,应用酸性磷酸酶活性检测、流式细胞仪检测技术、吞噬实验、酶联免疫吸附试验检测各组BMDCs表型和功能的各种指标。结果显示,LNT(50μg/mL)处理组BMDCs酸性磷酸酶活性降低;BMDCs吞噬能力比RPMI1640空白对照组明显下降;BMDCs表面MHCⅡ、CD40、CD83、CD80、CD86和DEC205的表达增加;BMDCs白细胞介素12(IL-12)、白细胞介素10(IL-10)和肿瘤坏死因子-α(TNF-α)的表达增加。证明了适宜浓度的LNT可以促进BMDCs表型及功能的成熟。     

小胶质细胞的培养及鉴定

目的:获得高纯度培养原代小胶质细胞的方法并检测Notch信号通路相关分子在小胶质细胞的表达情况。方法:取胎鼠利用反复机械振摇纯化分离小胶质细胞;利用流式细胞仪,根据CD11b及MHCII的表达水平对分离的小胶质细胞纯度进行鉴定;利用qPCR及琼脂糖凝胶电泳检测小胶质细胞中Notch通路相关分子的表达情况。结果:利用5只胎鼠采取反复机械振摇的方法可较稳定的获得1.1×106个的小胶质细胞,流式细胞术结果显示细胞纯度高达97.77%,并在小胶质细胞中检测到Notch相关分子的表达。结论:利用胎鼠反复机械振摇法可以获得较高纯度及产量的小胶质细胞,小胶质细胞表达Notch信号通路。     

丙酮酸脱氢酶激酶抑制剂促进食管鳞状细胞癌PD-L1的表达

目的 探讨丙酮酸脱氢酶激酶（pyruvate dehydrogenase kinase, PDHK）抑制剂对食管鳞状细胞癌（esophageal squamous cell carcinoma, ESCC）中PD-L1表达的影响及其可能的分子机制。方法 Western blot和qRT-PCR检测PD-L1表达水平，流式细胞术和免疫荧光染色检测细胞膜上PD-L1的表达，SRB法检测细胞增殖，基因芯片数据及hTFtarget数据库预测PD-L1基因启动子区域结合的转录因子。结果 PDHK抑制剂浓度依赖性上调ESCC细胞中PD-L1表达，同时在该浓度范围内PDHK抑制剂对ESCC细胞增殖无显著影响；基因芯片数据及hTFtarget数据库预测PDHK抑制剂可能通过转录因子NFATc1促进ESCC细胞中PD-L1的转录表达。结论 PDHK抑制剂促进食管鳞状细胞癌表达PD-L1，转录因子NFATc1可能参与该过程。     

甘草甜素对树突状细胞表型及生物学功能的影响

培养小鼠髓系DC2．4细胞,加入LPS（阳性对照组）或甘草甜素,用扫描电镜观察DC的超微结构、流式细胞仪检测DC表面分子MHCII、CD86及CD40的表达、4-氨基安替比林（4-AAP）比色检测DC内酸性磷酸酶活性、ELISA方法检测DC培养上清中IL—12的浓度,体外刺激淋巴细胞增殖实验检测DC对同种异体T淋巴细胞的刺激能力。结果表明,与对照组相比,甘草甜素刺激后,DC表面树突状突起增多,表面分子MHCⅡ、CD86及CD40表达增加,酸性磷酸酶活性下降,培养上清中IL-12浓度升高,刺激同种异体T淋巴细胞的能力也明显增强。结果表明,甘草甜素能够促进小鼠髓系DC2.4表型及功能的成熟。     

MHC II类分子表达调控的研究进展

MHCII类分子提呈经过加工的抗原给CD4 T淋巴细胞 ,在诱发免疫反应中起重要作用。MHCII类分子不正常表达会引起严重的免疫缺陷疾病 ,如裸淋巴细胞综合征 (BLS)等。目前已识别出四种不同的MHCII调控基因。这些基因分别编码RFXANK、RFX5、RFXAP和CIITA。其中 ,前三个是RFX复合物的亚基 ,RFX是一种结合于所有MHCII类基因启动子上的泛式表达的因子。CIITA是MHCII类分子表达的主要调控因子 ,其严密调控的表达模式决定了MHCII类分子表达的细胞特异性 ,及能否被诱导且在何种水平上表达。本文着重介绍近年来国内外对MHCII类分子表达及其调控研究的新进展     

成人外周血来源树突状细胞体外诱导培养动态监测

目的:分析体外诱导培养树突状细胞(dendritic cells,DCs)表面分子及成熟度的动态变化;方法:利用流式细胞仪(fluorescence activated cell sorter,FACS)检测分析DCs表面成熟标志分子CD83和T细胞辅助分子CD58、CD54、CD40、CD80、CD86、HLA-DR、HLA-ABC表达水平;结果:体外诱导培养5 d细胞即高表达DCs标志分子CD11c,细胞成熟度与细胞表面T细胞辅助分子的表达水平随培养天数的增加有一定提高,但显著低于大肠杆菌LPS刺激的DCs;结论:诱导培养6 d DCs表型为CD83 low、CD58low、CD54 low、CD40 low、CD80 low、CD86 low、HLA-DRhigh、HLA-ABChigh,为不成熟DCs.     

小胶质细胞的培养及鉴定

目的：获得高纯度培养原代小胶质细胞的方法并检测Notch信号通路相关分子在小胶质细胞的表达情况。方法：取胎鼠利用反复机械振摇纯化分离小胶质细胞;利用流式细胞仪,根据CDllb及MHCII的表达水平对分离的小胶质细胞纯度进行鉴定：利用qPCR及琼脂糖凝胶电泳检测小胶质细胞中Notch通路相关分子的表达情况。结果：利用5只胎鼠采取反复机械振摇的方法可较稳定的获得1．1x10‘个的小胶质细胞,流式细胞术结果显示细胞纯度高达97．77％,并在小胶质细胞中检测到Notch相关分子的表达。结论：利用胎鼠反复机械振摇法可以获得较高纯度及产量的小胶质细胞,小胶质细胞表达Notch信号通路。     

过表达IDO的骨髓间充质干细胞分泌外泌体下调树突状细胞免疫促进分子表达和上调Treg细胞数量

目的探讨过表达吲哚胺2, 3-双加氧酶(indoleamine 2, 3-dioxy genase, IDO)大鼠骨髓间充质干细胞(bone marrow mesenchy mal stem cells, BMSCs))分泌外泌体(exosome, ES)的免疫抑制调节作用。方法构建过表达IDO大鼠骨髓间充质干细胞提取分泌的外泌体做为实验组,将空载体大鼠骨髓间充质干细胞、大鼠骨髓间充质干细胞分泌的外泌体做为对照组,将实验组及对照组分泌的外泌体分别与树突状细胞(DC细胞)、T细胞体外共培养48h后采用流式细胞检测DC细胞表面免疫调节分子表达及T细胞亚群分子标志物表达,同时采用RT-PCR检测DC细胞中IDO表达量。结果过表达IDO的BMSCs分泌的外泌体与DC细胞共培养使DC细胞CD40、CD86、CD80、MHCII、CD45RA+CD45RB、OX62等免疫促进分子表达率降低,而CD274表达率升高,同时DC细胞中IDO表达量增多;而过表达IDO的BMSCs分泌的外泌体与T细胞共培养组使T细胞亚群中的Treg细胞数量增加,CD4阳性T细胞变化无规律性,但CD8阳性T细胞减少。结论过表达IDO-BMSCs分泌的外泌体可通过抑制DC活性和上调Treg细胞数量,产生免疫抑制作用。     

Snail基因修饰对骨髓基质干细胞骨架结构稳定作用及促迁移和对无血清培养诱导细胞凋亡的保护作用研究

转录因子Snail是调控肿瘤细胞迁徙转移的重要调控分子,基于干细胞与肿瘤细胞分子机制的重叠性,提出通过借鉴肿瘤细胞迁移的相关机制以用于提高骨髓基质干细胞向缺氧受损组织迁移能力的假设和研究思路,探讨Snail基因在人骨髓基质干细胞(MSCs)中的转染和表达情况,及转染后对基质干细胞促迁移作用、骨架结构的稳定作用及对无血清培养诱导细胞凋亡的保护作用。密度梯度离心法及细胞体外培养分离纯化人骨髓MSCs,脂质体法将重组表达载体pCAGGSneo-Snail-HA转染MSCs,G418筛选稳定表达,流式细胞仪检测MSCs表面抗原,采用免疫荧光染色技术检测转染后MSCs报告基因HA及目的基因Snail表达,Transwell细胞迁移实验和Western-blot评估细胞迁移能力和检测有关细胞信号转导通路分子水平变化,荧光染色分析细胞骨架,Sub-G1凋亡峰流式细胞仪检测细胞凋亡率并评估细胞抗凋亡能力。经流式细胞仪选择检测分离纯化扩增MSCs表面分子特点为CD34(-)/CD29( ),Snail及报告基因在转染后MSCs呈阳性表达,Snail质粒转染MSCs(MSCs-Sna)较对照空质粒转染MSCs(MSCs-neo)细胞迁移率增加(P<0.05),PI-3K信号通路特异性抑制剂Wortmannin能显著抑制此迁移率的增加,无血清培养72h后,MSCs-Sna凋亡率较MSCs-neo低(P<0.05)。经Snail基因转染,MSCs迁移能力、骨架结构的稳定性及在无血清培养环境中抗凋亡能力增加。     

LAG-3敲除加重免疫性肝损伤

目的：探究淋巴细胞活化基因-3(lymphocyte-activation gene 3, LAG-3)在免疫性肝损伤中的作用及机制。方法：采用尾静脉注射伴刀豆球蛋白A(Concanavalin A, Con A)诱导小鼠急性免疫性肝损伤模型;流式细胞术、实时定量PCR检测肝脏内免疫细胞LAG-3表达;利用LAG-3敲除小鼠研究LAG-3对Con A诱导的免疫性肝损伤的影响,于Con A注射后不同时间点收取外周血,检测血清ALT、AST、细胞因子水平;收集肝脏组织样本进行苏木精-伊红染色(hematoxylin-eosin staining, HE染色)并统计肝脏组织坏死面积;流式细胞术检测肝内细胞分群、T细胞活化;实时定量PCR检测炎症相关基因的表达;酵母双杂交筛选LAG-3相互作用蛋白质。结果：Con A诱导肝脏免疫细胞LAG-3表达增加;LAG-3敲除加重Con A所致小鼠血清转氨酶水平升高、肝脏坏死面积增大、炎症消除延迟;LAG-3敲除不影响Con A诱导的肝内免疫细胞浸润;LAG-3敲除抑制调节性T细胞扩增及IL-10表达;MHCII辅助分子CD74与LAG-3存在蛋白质相互...     

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.