用于人乳腺癌病理检测的抗人ARD1单克隆抗体的制备

hARD1蛋白是一个乙酰基转移酶,催化蛋白质N末端的乙酰化。前期的研究发现hARD1的高表达可能作为乳腺癌的一个指标。为了制备在乳腺肿瘤组织中特异识别的抗hARD1的单克隆抗体,将纯化的全长hARD1/Histag融合蛋白(1~235aa)免疫Balb/c小鼠,获得了8个稳定的阳性单克隆细胞株,酶联免疫吸附测定(ELISA)结果表明,所得抗体的轻链均为κ型,重链为3种亚型:IgG1、IgG2a和IgG2b。在不同肿瘤组织样本中进行抗体特异性筛选,获得一个在乳腺肿瘤组织中具有相对特异性的抗hARD1单克隆抗体,为进一步将抗hARD1的单克隆抗体应用于乳腺癌的病理诊断奠定基础,同时也为进一步研究hARD1在肿瘤发生中的作用提供了重要的工具。     

RNA recognition by a human antibody against brain cytoplasmic 200 RNA

Diverse functional RNAs participate in a wide range of cellular processes. The RNA structure is critical for function, either on its own or as a complex form with proteins and other ligands. Therefore, analysis of the RNA conformation in cells is essential for understanding their functional mechanisms. However, no appropriate methods have been established as yet. Here, we developed an efficient strategy for panning and affinity maturation of anti-RNA human monoclonal antibodies from a naïve antigen binding fragment (Fab) combinatorial phage library. Brain cytoplasmic 200 (BC200) RNA, which is also highly expressed in some tumors, was used as an RNA antigen. We identified MabBC200-A3 as the optimal binding antibody. Mutagenesis and SELEX experiments showed that the antibody recognized a domain of BC200 in a structure- and sequence-dependent manner. Various breast cancer cell lines were further examined for BC200 RNA expression using conventional hybridization and immunoanalysis with MabBC200-A3 to see whether the antibody specifically recognizes BC200 RNA among the total purified RNAs. The amounts of antibody-recognizable BC200 RNA were consistent with hybridization signals among the cell lines. Furthermore, the antibody was able to discriminate BC200 RNA from other RNAs, supporting the utility of this antibody as a specific RNA structure-recognizing probe. Intriguingly, however, when permeabilized cells were subjected to immunoanalysis instead of purified total RNA, the amount of antibody-recognizable RNA was not correlated with the cellular level of BC200 RNA, indicating that BC200 RNA exists as two distinct forms (antibody-recognizable and nonrecognizable) in breast cancer cells and that their distribution depends on the cell type. Our results clearly demonstrate that anti-RNA antibodies provide an effective novel tool for detecting and analyzing RNA conformation.     

Specific lectins map the distribution of fibronectin and beta 1-integrin on living MDCK cells

The expression and dynamics of bound fibronectin and the sialylated integral membrane protein, beta 1-integrin, were analyzed on the apical membrane of living MDCK cells. Fibronectin was identified by its specific binding of fluorescent peanut agglutinin and sialylated beta 1-integrin by its binding of Sambucus nigra agglutinin. Confocal epifluorescence microscopy and laser scanning cytometry determined the distribution and abundance of binding sites of the two fluorescently labeled lectins. Both fibronectin and beta 1-integrin were restricted to specific regions uniformly distributed over the entire apical surface. Apical-surface fibronectin binding varied much more between cells than did the expression of beta 1-integrin. Sialylated beta 1-integrin colocalized >92% with membrane microplicae while fibronectin was unrelated to these surface structures. This lack of colocalization of the proteins was confirmed by double-labeling experiments. From the maturation dependence of the fibronectin-binding capacity and the differences in protein turnover times, it was evident that fibronectin did not bind to sialylated beta 1-integrin. Furthermore, desialylation of beta 1-integrin uncovered additional fibronectin receptors on the apical membrane. We conclude that these lectins permit tracking of two membrane-associated glycoproteins in living cells and that fibronectin binds only to desialylated beta 1-integrin on MDCK cells.     

Comprehensive studies on subcellular localizations and cell death-inducing activities of eight GFP-tagged apoptosis-related caspases

By using green fluorescent protein fusion, we investigated the subcellular localization of all the caspases that have been cloned from humans and implicated in the execution of apoptosis. We divided these caspases into three groups according to subcellular localization. The first group includes caspase-1, -3, -6, -7, and -9, which are expressed mainly in the cytoplasm with various levels of nuclear localization depending on the cell type. The second group has a single member, caspase-2, which is primarily localized in the nucleus. The nuclear localization was demonstrated to be mediated by a nuclear localization signal near the NH(2)-terminus of the prodomain. The third group includes caspase-8 and -10, which have a cytoplasmic distribution. These two members have potent, rapid cell death-inducing activity and are prone to make aggregates when overexpressed. Their prodomains formed marked fibrous structures in the cytoplasm whose localization seemed distinct from organelles or cytoskeletons. None of the GFP-caspases examined in this study showed a predominant mitochondrial localization as has been reported for some caspases.     

MConfocal Fluorescence Microscopy of Urokinase Plasminogen Activator Receptor and Cathepsin D in Human MDA-MB-231 Breast Cancer Cells Migrating in Reconstituted Basement Membrane

Using confocal fluorescence microscopy with a monoclonal antibody, we have localized the receptor for urokinase plasminogen activator (uPAR) in MDA-MB-231 human breast cancer cells migrating into a reconstituted basement membrane. Patchy and polarized uPAR immunoreactivity was found at the cell membrane, and strong staining was found both in the ruffled border or leading edge of the cells and at pseudopodia penetrating into the membrane. Intracellular uPAR staining was localized in the paranuclear region and in rounded granule-like structures: some of these were identified as lysosomes by double staining for uPAR and the lysosomal enzyme cathepsin D. Urokinase plasminogen activator (uPA) activity has previously been shown to play a role in migration of cells into basement membranes, and it has been proposed that uPAR also is involved in this process. uPA is known to be internalized and degraded after complex formation with the inhibitor PAI-1. Lysosomal uPAR immunoreactivity may result from concomitant internalization of the receptor.     

鸡Toll样受体21单克隆抗体的研制及其初步应用

【目的】研制鸡Toll样受体21(chTLR21)单克隆抗体,考察禽致病性大肠杆菌(APEC)及高致病性禽流感病毒(HPAIV)感染鸡组织中的chTLR21蛋白的表达情况。【方法】以人工合成的多肽免疫原chTLR21(203–225aa)与KLH偶联蛋白免疫6周龄BALB/c小鼠,以多肽免疫原chTLR21 (203–225 aa)与BSA偶联蛋白作为检测抗原,通过间接ELISA技术筛选阳性杂交瘤细胞株,同时,采用间接免疫荧光技术(IFA)检测单克隆抗体的荧光反应性;上述单克隆抗体用于chTLR21在鸡巨噬细胞(HD11)中的定位;在APEC O1血清型E516菌株、HPAIV H5N6亚型毒株感染35日龄SPF鸡模型中,应用获得的单克隆抗体以免疫印迹(Western blotting)和免疫组化(IHC)方法检测感染鸡组织中chTLR21的表达情况。【结果】建立了间接ELISA检测方法,确定最适抗原包被浓度为2.5μg/mL,最适血清稀释度为1:6400。经ELISA、IFA筛选,获得4株阳性杂交瘤细胞株,分别命名为1G3、2C10、3B6和4F11。上述单克隆抗体亚类分别为IgG2...     

Compartmentalization of membrane trafficking,glucose transport,glycolysis, actin,tubulin and the proteasome in the cytoplasmic droplet/Hermes body of epididymal sperm

Discovered in 1909 by Retzius and described mainly by morphology, the cytoplasmic droplet of sperm (renamed here the Hermes body) is conserved among all mammalian species but largely undefined at the molecular level. Tandem mass spectrometry of the isolated Hermes body from rat epididymal sperm characterized 1511 proteins, 43 of which were localized to the structure in situ by light microscopy and two by quantitative electron microscopy localization. Glucose transporter 3 (GLUT-3) glycolytic enzymes, selected membrane traffic and cytoskeletal proteins were highly abundant and concentrated in the Hermes body. By electron microscope gold antibody labelling, the Golgi trafficking protein TMED7/p27 localized to unstacked flattened cisternae of the Hermes body, as did GLUT-3, the most abundant protein. Its biogenesis was deduced through the mapping of protein expression for all 43 proteins during male germ cell differentiation in the testis. It is at the terminal step 19 of spermiogenesis that the 43 characteristic proteins accumulated in the nascent Hermes body.     

东方蜜蜂微孢子虫一新型孢壁蛋白的基因克隆、 表达及亚细胞定位

【目的】微孢子虫(Microsporidia)孢壁在孢子构成及孢子侵染宿主过程中扮演重要的角色。本研究旨在鉴定获得的东方蜜蜂微孢子虫Nosema ceranae新型孢壁蛋白,并进行基因克隆和原核表达,明确其亚细胞定位。【方法】通过在线软件对东方蜜蜂微孢子虫新型孢壁蛋白AAJ76_1400036761序列进行生物信息学分析。利用PCR法获取目的片段并将其克隆至原核表达载体pCold II中,利用IPTG诱导表达重组蛋白并通过镍柱亲和层析法纯化目的蛋白。以获得的重组蛋白为抗原免疫小鼠制备多克隆抗体,通过间接免疫荧光技术和免疫胶体金定位技术对该蛋白进行亚细胞定位分析;利用蛋白质免疫印迹法检测该蛋白与东方蜜蜂微孢子虫几丁质壳的互作。【结果】在MicrosporidiaDB数据库中获得AAJ76_1400036761基因序列,基因全长681 bp,编码226个氨基酸;预测等电点为6.84,分子量为26.19 kD。SDS-PAGE电泳和Western blot结果表明AAJ76_1400036761重组蛋白能够在大肠杆菌Eescherichia coli Rosetta中高量表达。Western blot结果表明,制备的多克隆抗体能够特异地识别东方蜜蜂微孢子虫总蛋白中的AAJ76_1400036761,说明其在成熟东方蜜蜂微孢子虫中有表达。亚细胞定位结果显示,AAJ76_1400036761定位于东方蜜蜂微孢子虫孢壁上。重组蛋白AAJ76_1400036761能够与蜜蜂微孢子虫的几丁质壳结合。【结论】AAJ76_1400036761蛋白在东方蜜蜂微孢子虫成熟孢子中有表达;该蛋白定位于东方蜜蜂微孢子虫孢壁上,为东方蜜蜂微孢子虫新的孢壁蛋白。本研究为深入研究该蛋白的生物学功能奠定了基础。     

Localization of the fructose 1,6-bisphosphatase at the nuclear periphery

The localization of fructose 1,6-bisphosphatase (D-Fru-1,6-P₂-1-phosphohydrolase, EC 3.1.3.11) in rat kidney and liver was determined immunohistochemically using a polyclonal antibody raised against the enzyme purified from pig kidney. The immunohistochemical analysis revealed that the bisphosphatase was preferentially localized in hepatocytes of the periportal region of the liver and was absent from the perivenous region. Fructose-1,6-bisphosphatase was also preferentially localized in the cortex of the kidney proximal tubules and was absent in the glomeruli, loops of Henle, collecting and distal tubules, and in the renal medulla. As indicated by immunocytochemistry using light microscopy and confirmed with the use of reflection confocal microscopy, the enzyme was preferentially localized in a perinuclear position in the liver and the renal cells. Subcellular fractionation studies followed by enzyme activity assays revealed that a majority of the cellular fructose-1,6-bisphosphatase activity was associated to subcellular particulate structures. Overall, the data support the concept of metabolic zonation in liver as well as in kidney, and establish the concept that the Fructose-1,6-bisphosphatase is a particulate enzyme that can not be considered a soluble enzyme in the classical sense. © 1996 Wiley-Liss, Inc.     

Pro-apoptotic apoptosis protease-activating factor 1 (Apaf-1) has a cytoplasmic localization distinct from Bcl-2 or Bcl-x(L)

How Bcl-2 and its pro-survival relatives prevent activation of the caspases that mediate apoptosis is unknown, but they appear to act through the caspase activator apoptosis protease-activating factor 1 (Apaf-1). According to the apoptosome model, the Bcl-2-like proteins preclude Apaf-1 activity by sequestering the protein. To explore Apaf-1 function and to test this model, we generated monoclonal antibodies to Apaf-1 and used them to determine its localization within diverse cells by subcellular fractionation and confocal laser scanning microscopy. Whereas Bcl-2 and Bcl-x(L) were prominent on organelle membranes, endogenous Apaf-1 was cytosolic and did not colocalize with them, even when these pro-survival proteins were overexpressed or after apoptosis was induced. Immunogold electron microscopy confirmed that Apaf-1 was dispersed in the cytoplasm and not on mitochondria or other organelles. After the death stimuli, Bcl-2 and Bcl-x(L) precluded the release of the Apaf-1 cofactor cytochrome c from mitochondria and the formation of larger Apaf-1 complexes, which are steps that presage apoptosis. However, neither Bcl-2 nor Bcl-x(L) could prevent the in vitro activation of Apaf-1 induced by the addition of exogenous cytochrome c. Hence, rather than sequestering Apaf-1 as proposed by the apoptosome model, Bcl-2-like proteins probably regulate Apaf-1 indirectly by controlling upstream events critical for its activation.     

Electron microscopy evidence that cytoplasmic localization of the p16INK4A "nuclear" cyclin-dependent kinase inhibitor (CKI) in tumor cells is specific and not an artifact. A study in non-small cell lung carcinomas

It is well established that p16^INK4A protein acts as a cell cycle inhibitor in the nucleus. Therefore, cytoplasmic localization of p16 ^INK4A usually is disregarded by investigators as nonspecific. Three recent studies reported findings that differ from the current view concerning p16^INK4A immunohistochemical localization. All three demonstrated that breast and colon cancers expressing cytoplasmic p16^INK4 represent distinct biological subsets. We previously detected in a percentage of non-small cell lung carcinomas simultaneous nuclear and cytoplasmic p16^INK4A staining. In view of the reports concerning breast and colon carcinomas, we conducted an ultrastructural re-evaluation of our cases to clarify the specificity of p16^INK4A cytoplasmic expression. We observed p16 ^INK4A immunolocalization in both the nucleus and the cytoplasm of a proportion of tumor cells. Diffuse dense nuclear staining was detected in the nucleoplasm, whereas weaker granular immunoreactivity was observed in the cytoplasm near the rough endoplasmic reticulum. Negative tumor cells also were visible. In the tumor-associated stromal, cells p16^INK4A immunoreactivity was detected only in the nuclei. We have demonstrated that p16^INK4A cytoplasmic staining is specific and suggest that it represents a mechanism of p16^INK4A inactivation similar to that observed in other tumor suppressor genes.     

Construction, expression, purification and functional analysis of recombinant 6C6 immunotoxin to human breast-tumor cells

The 28 ku membrane protein is usually over-expressl m human bnasl bmast cancer and other tumor cells. licould be a larget for tumor therapy . By using genetie engineermg teehmgues.a 606 immunotoxin (sefv606-PE40) was construeted by joining the 606 single-chain antibdy (SeFv606) with the truncll Pseudonwnas exotoxin A (PE40), SeFv606 contains both the heavy and light-chnia variable domams of 606 monoelonal antibody. Which speeifieally ree-ognizes the 28 ku protein. The bacterial expression level og 606 imnmmotoxin is 3.3%. about 5.5 mg ml baeterial lysate.lsing singlc-step llisTrap (Nr2 chelating) column chronnetogaphy, the reeombinant peptide was obtained with a purit of 33.2%.This baeterial espressed 606 immunotosin binuls to MDA-231 human breast-tumer ccll surfaee and kill these cells with a median lethal dosage of 92 ngnd.     

三套荧光显微成像系统在光敏剂亚细胞定位研究中的应用比较

目的：对三套荧光显微成像系统在国产新型光敏剂HMME亚细胞定位研究中的应用特点及适用范围进行了比较与评价。方法：分别应用LSCM、CCD、ICCD荧光显微成像系统,选择特异性细胞器荧光探针Rhodamine-123、DIOC6(3)标记细胞内线粒体和内质网。采用细胞器-细胞荧光强度比值法,对HMME进行单细胞内分布的定性与定量研究。结果：LSCM和CCD成像系统能采集到浓度达到160μg／ml时的HMME的荧光图像,获得荧光探针图像信息显示所标记的细胞内线粒体和内质网平均荧光强度比值(J1/J2值)都明显高于细胞内J1/J2值。而ICCD成像系统只需HMME浓度为5μg/ml,荧光图像特点都呈胞浆中荧光强度较高且分布不均,细胞核区荧光较弱的中空现象。ICCD系统对细胞器探针荧光图像在空间分辨上不理想。结论：LSCM与CCD成像系统限于其探测灵敏度,对于弱荧光性光敏剂,适用于其高孵育浓度条件下的亚细胞定位研究。二者获得的结果相一致：孵育24h,HMME在鼠肺内皮细胞线粒体和内质网有分布而几乎不进入细胞核。ICCD成像系统可不受孵育浓度条件的限制,实现光敏剂极微弱荧光的有效探测,但空间分辨率较低。     

Cell density-dependent nuclear/cytoplasmic localization of NORPEG (RAI14) protein

NORPEG (RAI14), a developmentally regulated gene induced by retinoic acid, encodes a 980 amino acid (aa) residue protein containing six ankyrin repeats and a long coiled-coil domain [Kutty et al., J. Biol. Chem. 276 (2001), pp. 2831-2840]. We have expressed aa residues 1-287 of NORPEG and used the recombinant protein to produce an anti-NORPEG polyclonal antibody. Confocal immunofluorescence analysis showed that the subcellular localization of NORPEG in retinal pigment epithelial (ARPE-19) cells varies with cell density, with predominantly nuclear localization in nonconfluent cells, but a cytoplasmic localization, reminiscent of cytoskeleton, in confluent cultures. Interestingly, an evolutionarily conserved putative monopartite nuclear localization signal (P(270)KKRKAP(276)) was identified by analyzing the sequences of NORPEG and its orthologs. GFP-NORPEG (2-287 aa), a fusion protein containing this signal, was indeed localized to nuclei when expressed in ARPE-19 or COS-7 cells. Deletion and mutation analysis indicated that the identified nuclear localization sequence is indispensable for nuclear targeting.     

茶尺蠖水通道蛋白EoAQP1的cDNA克隆、多克隆抗体制备及亚细胞定位

【目的】水通道蛋白(aquaporin,AQP)是一种广泛存在于哺乳动物、植物和微生物中的跨膜转运蛋白,它在细胞水分运输、离子选择透过性和渗透压平衡等过程中发挥着重要的作用。本研究旨在分析茶尺蠖Ectropis obliqua Prout水通道蛋白AQP1的基因特性,在制备多克隆抗体的基础上了解其亚细胞定位分布。【方法】采用同源克隆方法并结合RACE技术克隆茶尺蠖AQP1的基因全长,通过生物信息学网站和软件分析茶尺蠖AQP1的生物学信息;通过实时荧光定量PCR技术(qRT-PCR)检测茶尺蠖AQP1在不同发育阶段和6龄幼虫不同组织中的相对表达量;通过原核表达、镍柱纯化并免疫新西兰兔制备了茶尺蠖AQP1的多克隆抗体;通过荧光显微镜观测了茶尺蠖AQP1在黑腹果蝇Drosophila melanogaster胚胎细胞S2中的定位分布,并利用多克隆抗体进行了Western blot验证。【结果】克隆并鉴定了茶尺蠖AQP1全长,将其命名为Eo AQP1(Gen Bank登录号:KT819587),Eo AQP1 c DNA全长1 826 bp,含有780 bp开放阅读框,编码259个氨基酸。系统进化树和氨基酸序列同源性比对表明,Eo AQP1在鳞翅目昆虫中高度保守。跨膜结构和水分渗透模拟表明,Eo AQP1具有经典的水分渗透模型。qRT-PCR结果表明,Eo AQP1在不同发育时期和6龄幼虫不同组织中均有表达且差异显著。亚细胞定位结果表明,Eo AQP1以圆形颗粒状成群聚集于细胞膜周边,而在细胞膜、核膜和细胞质等处均不表达。多克隆抗体Western blot检测结果表明,Eo AQP1多克隆抗体特异性较好,可用于后续相关实验。【结论】获得了Eo AQP1的c DNA序列,明确了Eo AQP1的生物学特征,阐明了Eo AQP1的时空表达特性,成功制备了Eo AQP1多克隆抗体,初步了解了Eo AQP1的亚细胞定位,为进一步研究Eo AQP1的水分渗透机理奠定了分子基础。     

Survival of human monoclonal anti-Rho (D) antibodies in the rhesus monkey.

In vivo half-life of a 125I-labeled human anti-D monoclonal antibody (mAb) and that of 131I-labeled Rho-GAM was assessed in a rhesus monkey injected simultaneously with both reagents. The half-life of the mAb was 7.9 days, compared to 17 days of Rho-GAM. Survival of the second dose of mAb, given 34 days after the first injection, was identical to that of the first dose, thus showing that the human mAb did not elicit an immune response. The in vitro produced human mAbs appear to be an alternative, unlimited source of anti-D antibodies for possible use in prevention of feto-maternal Rh immunization.     

Distribution of Epitopes of Trypanosoma cruzi Amastigotes During the Intracellular Life Cycle within Mammalian Cells

ABSTRACT. In this study we have examined the distribution of epitopes defined by monoclonal antibodies raised against Trypanosoma cruzi amastigotes during the intraceullar life cycle of the parasite. We have raised monoclonal antibodies towards amastigote forms and performed preliminary immunochemical characterization of their reactivities. MAB 1D9, 3G8, 2B7, 3B9, and 4B9, and 4B9 react with carbohydrate epitopes of the parasite major surface glycoprotein—Ssp-4 defined by MAB 2C2 [5]: MAB 4B5 reacts with a noncarbohydrate epitope in all developmental stages of the parasite, and MAB 3B2 also detects a noncarbohydrate epitope preferentially in T. cruzi flagellared forms. Vero cells infected with tissue culture-derived trypomastigotes of clone D11 (G strain) were fixed at different times during the intraceullular proliferation of parasites, and processed for immjno-electron microscopy and confocal immunoflurescence with the different monoclonal antibodies. We observed that while the surface distribution of MAB 2C2 and 4B9 epitopes was uniform throughout the cycle, MAB 1D9, 3G8, and 2B7 reacted with cytoplasmic membrance-bound compartments of the amastigotes. MAB 3B9 displayed a unique surface dentate pattern in some amastigotes. MAB 4B5 recognized a curved-shaped structure at the flagellar pocket region in some intracellular amastigotes and localized to the membrane in dividing forms. In intracellular trypomastigotes, MAB 4B5 also displayed a punctate pattern near the flagellar pocket.