抗ICAM-1单克隆抗体的制备与特性鉴定

目的:制备有生物学活性的抗人细胞间黏附分子-1(ICAM-1)单克隆抗体(mAb)并进行特性鉴定。方法:以纯品ICAM-1为抗原免疫BALB/c小鼠4次。采用杂交瘤技术,经3次亚克隆筛选稳定分泌抗人ICAM-1 mAb的杂交瘤细胞株。采用动物体内诱生的方法大量制备mAb。以protein G对其进行纯化后,用间接ELISA法测定mAb的效价并鉴定其Ig亚类。用Western blot鉴定mAb的特异性。结果:筛选出4株可稳定分泌抗人ICAM-1 mAb的杂交瘤细胞株,分别命名为B9株、F1株、C11株和D6株。4株mAb的Ig亚类均为IgG1。4株mAb培养上清的效价均为1∶1 000;腹水的效价B9株与D6株为1∶2×105,F1株与C11株为1∶4×105。纯化后mAb的蛋白浓度为1.2 g/L,均可与ICAM-1特异性结合。结论:成功制备出效价高、特异性良好的4株抗ICAM-1 mAb,为进一步研究ICAM-1的生物学功能和临床应用奠定了基础。     

抗人LSECtin单克隆抗体的制备与初步鉴定

目的:制备抗肝脏、淋巴结窦内皮细胞C型凝集素(LSECtin)单克隆抗体(mAb),并进行特性鉴定。方法:采用原核表达的LSECtin免疫BALB/c小鼠,以间接ELISA法筛选分泌特异性mAb的杂交瘤细胞,采用蛋白印迹、间接免疫荧光、流式细胞术和免疫组化染色法鉴定mAb的特异性。结果:共获得8株可稳定分泌mAb的杂交瘤细胞株。mAb的Ig亚类均为IgG,效价达1∶106~1∶107。这些mAb均可识别转染3T3细胞膜上的人LSECtin,6株mAb可特异识别肝脏窦内皮细胞。结论:成功地制备8株抗LSECtin的mAb,经免疫印迹、流式细胞术和免疫组化染色检测,这些mAb的特异性良好,为研究LSECtin的功能提供了有力的试剂。     

抗KDR胞内区(KDR-CD)单克隆抗体的制备和鉴定

目的:研制特异性针对肿瘤新生血管内皮细胞生长因子受体(或含激酶插入区受体)胞内区(KDR-CD)的特异性单克隆抗体(mAb).方法:以谷胱甘肽转硫酶耦联的KDR-CD(GST-KDR-CD)可溶性融合蛋白免疫BALB/c小鼠,采用杂交瘤技术制备分泌抗KDR-CD mAb的杂交瘤细胞;用间接ELISA法测定其亲和力、亚类,Western blot检测其特异性.结果:获得1株稳定分泌抗KDR-CD mAb的杂交瘤细胞株,命名为2B8H2A5;它分泌的抗体亚类为IgG1,к型轻链,而且亲和力强、特异性高.结论:成功获得能分泌抗KDR-CD mAb杂交瘤细胞,为以后将该mAb改造成小分子酪氨酸激酶抑制剂,使其能进入细胞内与受体KDR-CD特异性结合并阻断血管内皮细胞生长因子强大的生物学功能奠定了重要的基础.     

活体电穿孔法辅助HE4基因免疫小鼠制备单克隆抗体

目的:采用电穿孔辅助DNA免疫方法制备小鼠抗人附睾蛋白4(HE4)单克隆抗体(mAb)并对其生物学特性进行鉴定。方法:利用逆转录多聚酶链反应(RT-PCR)从卵巢癌患者组织中获得人HE4基因编码序列,将其亚克隆至pPICZαA表达载体中并测序鉴定。采用活体电穿孔法免疫BALB/c小鼠。单抗制备采用B淋巴细胞杂交瘤技术进行细胞融合,经多次克隆化培养,筛选出特异分泌鼠抗人HE4mAb的杂交瘤细胞株。采用Westernblot,Ig亚型分析和mAb表位分析等对mAb的生物学特性进行鉴定。结果:获得2株持续、稳定分泌鼠抗人HE4mAb的杂交瘤细胞株,命名为1-7-C和3-12-C。ELISA和Westernblot结果均显示本实验获得的2株mAb能够特异识别有天然构象的HE4蛋白,2株mAb的Ig亚类均为IgM,轻链均为λ链。结论:成功地构建了pPICZαA-HE4表达载体,并获得2株鼠抗人HE4杂交瘤,其所分泌的抗体能特异地识别HE4蛋白。     

抗人DcR3单克隆抗体的研制及其鉴定

目的:制备抗人DcR3单克隆抗体(mAb),并鉴定其特异性.方法:纯化的His-DcR3融合蛋白免疫小鼠,应用淋巴细胞杂交瘤技术制备抗人DcR3 mAb并进行纯化,纯化后的抗体经Western blot和ELISA方法鉴定其特异性、Ig亚型和效价.结果:获得5株稳定分泌抗DcR3 mAb的杂交瘤细胞,均属IgG1亚型,其腹水抗体效价为1×10-5 ～1×10-7,Western blot显示5株细胞分泌的mAb均可识别DcR3蛋白,其中1株(1B1)可与SW480细胞成分反应.结论:成功建立稳定分泌抗人DcR3 mAb的杂交瘤细胞株,其分泌的抗体特异性强、效价高,为研究DcR3在组织中的表达、分布及研制ELISA试剂盒奠定基础.     

抗血型M、N及抗血型糖蛋白A/B单克隆抗体的制备及其特性鉴定

目的:制备抗血型M、N及抗血型糖蛋白A/B(GPA/GPB)的单克隆抗体(mAb),并进行特性鉴定。方法:用人“O”型血红细胞作为免疫源,免疫BALB/c小鼠。采用淋巴细胞杂交瘤技术制备mAb,用谱红细胞筛选阳性克隆;采用直接、间接血凝试验检测杂交瘤细胞培养上清及腹水中mAb的效价。分别用快速定性试纸和酶处理红细胞检测mAb的Ig亚类及抗原表位。用Western blot鉴定抗GPA/GPB mAb的特异性。结果:获得4株分泌抗M、1株抗N及3株抗GPA/GPB mAb的杂交瘤细胞株。杂交瘤细胞培养上清mAb的效价介于1×2-4~1×2-8之间,腹水mAb的效价在1×2-7~1×2-12之间。除1株mAb 1C1C9C4为IgM外,其他7株mAb均为IgG。通过杂交瘤细胞培养上清与谱红细胞的反应格局,结合mAb抗原表位的检测,确定4株和1株mAb可分别特异性结合于GPA的M、N抗原表位;另3株mAb 6D7C9、7C9H4和7C9G11与“O”型血红细胞膜的Western blot结果显示,均可结合GPA、GPB蛋白。结论:成功地建立了4株分泌抗M、1株分泌抗N及3株分泌抗GPA/GPB mAb的杂交瘤细胞株,可用于MNSs血型系统的研究及鉴定,并为制备双功能抗体用于病毒、肿瘤疾病的诊断和治疗打下了坚实的基础。     

抗RAET1G2单克隆抗体的研制和初步鉴定

目的:制备鼠源抗RAET1G2单克隆抗体,并对其特异性进行鉴定。方法:以原核表达的RAET1G2蛋白为抗原免疫BALB/c小鼠,运用B淋巴细胞杂交瘤技术制备抗RAET1G2单克隆抗体;用免疫双扩散方法鉴定Ig亚类;Western blot鉴定单克隆抗体的特异性。结果:获得了4株可分泌特异性抗RAET1G2抗体的杂交瘤细胞株7A11、9C6、10F9和12F8,Ig亚类均为IgG1。结论:制备的杂交瘤细胞株能稳定分泌特异性的抗RAET1G2抗体,并且所分泌的单克隆抗体都能识别天然的RAET1G蛋白,为进一步研究游离性的RAETlG2分子与肿瘤进展的关系以及分析各种肿瘤细胞表面的RAET1G表达情况创造了条件。     

抗人HPPCn单克隆抗体的制备及鉴定

目的:制备高灵敏度的抗人HPPCn单克隆抗体(mAb),以用于HPPCn的功能研究及其疾病相关性研究。方法:用重组蛋白免疫雌性BALB/c小鼠,采用常规杂交瘤技术进行细胞融合,经ELISA法进行阳性克隆筛选、通过有限稀释法进行亚克隆,获得稳定分泌抗人HPPCn mAb的细胞株。采用间接ELISA、Western blot、Ig亚类快速定性试纸分析法等鉴定抗体的生物学特性;通过细胞免疫荧光实验观察了HPPCn蛋白的细胞定位。通过噬菌体肽库技术分析抗体所识别的抗原表位。结果:得到了1株稳定分泌抗人HPPCn抗体的杂交瘤细胞株,命名为W2-D5。经Ig亚类分析确定,该细胞株分泌的抗体属于IgG1亚类。间接ELISA检测表明,该抗体检测HPPCn的极限为0.1μg/L;Western blot结果显示,该抗体能特异性识别HPPCn。细胞免疫荧光实验,证实了HPPCn蛋白定位在细胞核。通过肽库筛选及表位分析认为,该抗体识别的表位可能为HPPCn7-13(IHLELRN)。结论:成功地获得了抗人HPPCn的特异性mAb。     

ERCC1的表达纯化及其单克隆抗体的制备

目的:表达纯化ERCC1蛋白并制备其单克隆抗体(mAb).方法:克隆并原核表达ERCC1蛋白, 其氨基端带有6-His标签.纯化后的蛋白免疫BALB/c小鼠, 经融合、筛选制备特异性mAb.结果:成功表达了ERCC1蛋白.SDS-PAGE显示所表达蛋白的相对分子质量(Mr)约为37 000.获得了1 株稳定分泌抗ERCC1抗体的杂交瘤细胞株(6F8), 其分泌的mAb的Ig亚类(型)为IgG2b.ELISA检测, 对应腹水mAb的效价为1∶ 1.5×106.Western blot结果显示抗ERCC1 mAb具有良好的特异性.结论:成功地表达纯化ERCC1蛋白并制备了1株抗ERCC1 mAb.     

鼠抗人CD28分子单克隆抗体的研制及生物学特性研究

目的 制备鼠抗人CD28分子的单克隆抗体（mAb),研究其在T细胞的活化、增殖及信号传导中的作用。方法 以小鼠淋巴瘤细胞转染人CD28基因的细胞株（CD28-T）为免疫原,采用B淋巴细胞杂交瘤技术,获取分泌特异性mAb的杂交瘤细胞株,以体内诱生法生产腹水,并以免疫亲和层析法对其纯化,以快速定性试纸法鉴定mAb的Ig亚类,竞争抑制法分析mAb识别的抗原表位,3H-TdR掺入法研究mAb对T细胞的刺激效应,结果 成功地获得了5株分泌特异性抗入CD28mAb的杂交瘤细胞株,鉴定的1株（克隆18G8）属IgG2a,腹水效价（流式细胞仪分析）达1：2400以上,该mAb能60%阻断标准鼠抗入CD28抗体与相应抗原的结合,提示其识别的抗原表位与标准mAb不完全相同,mAb18G8可取代B7-1分子介导的协同刺激信号,促进人外周血T细胞增殖（ST=7）。结论 18G8是12株功能性mAb,具有重要的研究和应用价值。     

Cell extracts of Candida albicans block adherence of the organisms to endothelial cells.

Cell extracts of Candida albicans were fractionated by concanavalin A affinity chromatography. Eluted mannosylated proteins (fraction II) and nonbinding, nonmannosylated proteins (fraction I) were collected and assayed directly for inhibition of adherence of C. albicans to endothelium. Fraction II blocked blastospore adherence to endothelial cells. Fraction I blocked both blastospore and germ tube adherence to endothelial cells. Monoclonal antibody OKM-1 (anti-CR3) and an anti-C. albicans monoclonal antibody, CA-A (anti-CR2), reacted in Western blots with proteins from fraction I, suggesting the presence of the CR2- and CR3-like proteins that have been previously identified on C. albicans germ tubes.     

The presumptive identification of Candida albicans with germ tube induced by high temperature

For direct identification of Candida albicans from other Candida species, the chlamydospore formation and the mycelial transition induced by high temperature and by sera were examined in 198 Candida isolates. The germ tubes of C. albicans developed early at 30 min in high temperature-induction, but at 60 min in serum-induction. C. albicans generated germ tubes well at concentrations lower than 2 x 10(7) cells/ml, but the germ tube formation was markedly restrained at concentrations higher than 4 x 10(7) cells/ml. In a serum-free, yeast extract-peptone-dextrose (YEPD) medium, C. albicans grew as a yeast form at 30 degrees C and as a mycelial form at 35-42 degrees C. Mycelial development was maximal at 37 degrees C in serum and at 39 degrees C in YEPD. Germ tubes were formed within 30 min in YEPD at 39 degrees C, but after 60 min in serum at 37 degrees C. Our examination showed that the 39 degrees C-induced germ tube formation tests were very reliable (sensitivity 100%, specificity 100%) at discerning C. albicans from other Candida species. These results suggest that the high temperature-induced germ tube formation testing could be a useful identification method of C. albicans in clinical laboratories.     

Critical role of germ tube formation in the pathogenesis of candidal vaginitis.

A variant strain of Candida albicans incapable of hyphal production at 37 degrees C was used to study the role of germ tube formation in the pathogenesis of experimental vaginal candidiasis in rats. No difference was observed in the in vitro adherence at 25 degrees C of blastoconidia of the variant strain to vaginal epithelial cells when compared with the parent wild-type, germ tube-producing strain and multiple clinical isolates of C. albicans. However, after exposure to conditions favoring germ tube production, the adherence of the variant strain to epithelial cells was significantly less than that of germinated strains (P less than 0.01). In vivo animal studies revealed that the variant strain was less likely to result in vaginal colonization and infection than the wild-type strain and the other clinical isolates. Furthermore, infection, when established, was milder, often transient, and with significantly lower titers of cultured vaginal microorganisms obtained by lavage. Electron microscopic studies confirmed the failure of the variant strain to produce hyphae in vivo. The capacity of C. albicans to produce hyphae appears to be an important but nonessential virulence factor in the pathogenesis of candidal vaginitis.     

Involvement of alpha(v)beta3 integrin-like receptor and glycosaminoglycans in Candida albicans germ tube adhesion to vitronectin and to a human endothelial cell line

The present study was undertaken to investigate the expression of alpha(v)beta3 and alpha(v)beta5 integrin-like vitronectin receptors (VNRs) on Candida albicans germ tube and their involvement in its adhesion to vitronectin (VN) and human endothelial cells. By immunofluorescence and FACS analysis, several monoclonal antibodies directed against human alpha(v) or beta3 integrin subunit or alpha(v)beta3 and alpha(v)beta5 heterodimers, positively stained C. albicans germ tubes. C. albicans germ tubes specifically adhered (45-50%) to VN and this adhesion was markedly inhibited by RGD-, but not RGE-containing peptides. Adhesion of C. albicans germ tubes to VN was strongly inhibited by anti-alphav, anti-beta3 or anti-alpha(v)beta3, but not by alpha(v)beta5 monoclonal antibody. C. albicans germ tube adhesion to VN was also inhibited by glycosaminoglycans (GAGs) such as heparin or chondroitin sulphate. Finally, we show that C. albicans germ tubes adhere to the human EA.hy 926 endothelial cell line. This adhesion is markedly blocked by anti-beta3 monoclonal antibody, GRGDSP peptide or heparin, and is completely abolished by their combination. Overall these results indicate that C. albicans germ tube adherence to VN and to a human endothelial cell line is mediated by alpha(v)beta3, but not by alpha(v)beta5-like integrin, and depends on GAGs which may act by regulating alpha(v)beta3 integrin-like/VN adhesive interaction.     

Effect of pH, carbon source and K+ on the Na+-inhibited germ tube formation of Candida albicans.

The effect of pH, carbon source and K+ on the Na+ -inhibited germ tube formation of the pathogenic fungus Candida albicans was examined in the arginine-phosphate modified (APM) medium. All C. albicans cells formed germ tubes in APM medium at pH 5.0-9.0. Na+ inhibited germ tube formation in a concentration dependent manner ranging from 0.2 to 1.0 M, and was further influenced by the pH of the medium. The inhibitory effect of Na+ was lowest at pH 8.0, and germ tube formation ceased at 1.0 M Na+ for any pH (4.0-9.0). At pH > or = 6.0, non-germ tube-forming cells did not show yeast growth; whereas at pH < or = 5.0, Na+ inhibited only germ tube formation but did not inhibit yeast growth. The inhibitory effect of Na+ was stronger in glucose medium than in galactose medium as carbon source. K+, at 0-0.8 M, had almost no effect on germ tube formation. However, in the presence of Na+, a very low concentration of K+ (0.5 mM) was able to release the cells from Na+ arrest and produced an increase in the rate as well as the percentage of germ tube formation. Intracellular Na+/K+ ratios increased with the increase in extracellular Na+ concentration, whereas the ratios decreased and remained within nontoxic levels when the extracellular K+ concentration was increased.     

Lysis of hybridoma cells bearing anti-clonotypic surface immunoglobulin by clonotype-expressing alloreactive cytotoxic T cells

A B cell hybridoma (Désiré-1) was derived which secreted and expressed at its cell surface immunoglobulin (Ig) specific for the antigen-specific T cell receptor (Ti) of an H-2Kb-specific alloreactive cytotoxic T lymphocyte (CTL) clone (KB5-C20). It was found that the CTL clone could lyse hybridoma Désiré-1, whereas it could not lyse hybridoma which expressed surface Ig (sIg) binding to other cell surface structures of clone KB5-C20 such as the H-2Kk molecule. Blocking of CTL-target cell interactions using monoclonal antibodies (mAb) indicated that the CTL-target cell interaction was inhibited with appropriate anti-H-2 mAb and by anti-Lyt-2 mAb when CTL-H-2Kb interaction was involved but not when CTL-sIg interaction was involved. The two types of interactions were inhibited by anti-LFA-1 mAb. The involvement of the CTL-Ti structure was necessary to obtain a lytic interaction between CTL and target cells, but a major histocompatibility complex product on the target cells did not need to be involved. Comparison of CTL-target cell inhibition with cold target cells or with anti-clonotypic mAb indicated that the Ti-sIg cellular interaction was of much higher apparent affinity than the Ti-H-2Kb cellular interaction. These results further suggest potential regulatory effects of CTL-B cell cross-idiotypic interactions.     

A monoclonal antibody directed against a Candida albicans cell wall mannoprotein exerts three anti-C. albicans activities

Antibodies are believed to play a role in the protection against Candida albicans infections by a number of mechanisms, including the inhibition of adhesion or germ tube formation, opsonization, neutralization of virulence-related enzymes, and direct candidacidal activity. Although some of these biological activities have been demonstrated individually in monoclonal antibodies (MAbs), it is not clear if all these anti-C. albicans activities can be displayed by a single antibody. In this report, we characterized a monoclonal antibody raised against the main target of salivary secretory immunoglobulin A in the cell wall of C. albicans, which exerts three anti-C. albicans activities: (i) inhibition of adherence to HEp-2 cells, (ii) inhibition of germination, and (iii) direct candidacidal activity. MAb C7 reacted with a proteinic epitope from a mannoprotein with a molecular mass of >200 kDa predominantly expressed on the C. albicans germ tube cell wall surface as well as with a number of antigens from Candida lusitaniae, Cryptococcus neoformans, Aspergillus fumigatus, and Scedosporium prolificans. MAb C7 caused a 31.1% inhibition in the adhesion of C. albicans to HEp-2 monolayers and a 55.3% inhibition in the adhesion of C. albicans to buccal epithelial cells, produced a 38.5% decrease in the filamentation of C. albicans, and exhibited a potent fungicidal effect against C. albicans, C. lusitaniae, Cryptococcus neoformans, A. fumigatus, and S. prolificans, showing reductions in fungal growth ranging from 34.2 to 88.7%. The fungicidal activity showed by MAb C7 seems to be related to that reported by antibodies mimicking the activity of a killer toxin produced by the yeast Pichia anomala, since one of these MAbs also reacted with the C. albicans mannoprotein with a molecular mass of >200 kDa. Results presented in this study support the concept of a family of microbicidal antibodies that could be useful in the treatment of a wide range of microbial infections when used alone or in combination with current antimicrobial agents.     

In vitro effect of fibrinogen on Candida albicans germ tube formation

Pseudohyphae formation by Candida albicans blastoconidia, as seen in vaginal smears, is a phenotypical change commonly assumed to mean fungal invasiveness, i.e. not mere colonization. C. albicans forms germ tubes in vitro in the presence of serum. In our search for inhibitory components of germ tube formation, we decided to study fibrinogen. The inhibition of germ tube formation by clinical isolates of C. albicans was evaluated in the presence of serial concentrations of fraction I, type IV and fraction I, type Is of fibrinogen from bovine plasma. Fibrinogen showed a dose-dependent, pH-independent inhibitory effect on the germ tube formation by C. albicans.     

抗KDR单克隆抗体的制备

目的：研制针对肿瘤新生血管内皮细胞生长因子受体（KDR）的特异性单克隆抗体（mAb）。方法：以谷胱甘肽转硫酶耦联的KDR（GST-KDR）可溶性融合蛋白免疫BALB／c小鼠,采用杂交瘤技术制备分泌抗KDRmAb的杂交瘤细胞。结果：获得1株稳定分泌抗KDRmAb的杂交瘤细胞株,命名为3E9B2G11。结论：成功获得能分泌抗KDRmAb杂交瘤细胞,为以后将该mAb改造成小分子酪氨酸激酶抑制剂,使其能进入细胞内与受体KDR特异性结合并阻断血管内皮细胞生长因子的强大生物学功能奠定了重要基础。     

Antifungal activity of Lavandula angustifolia essential oil against Candida albicans yeast and mycelial form.

The antifungal activity of the essential oil of Lavandula angustifolia Mill. (lavender oil) and its main components, linalool and linalyl acetate, was investigated against 50 clinical isolates of Candida albicans (28 oropharyngeal strains, 22 vaginal strains) and C. albicans ATCC 3153. Growth inhibition, killing time and inhibition of germ tube formation were evaluated. The chemical composition of the essential oil was determined by gas chromatography and mass spectrometry. Lavender oil inhibited C. albicans growth: mean minimum inhibitory concentration (MIC) of 0.69% (vol./vol.) (vaginal strains) and 1.04% (oropharyngeal strains); mean MFC of 1.1% (vaginal strains) and 1.8% (oropharyngeal strains). Linalool was more effective than essential oil: mean MIC of 0.09% (vaginal strains) and 0.29% (oropharyngeal strains); mean MFC of 0.1% (vaginal strains) and 0.3% (oropharyngeal strains). Linalyl acetate was almost ineffective. Lavender oil (2%) killed 100% of the C. albicans ATCC 3153 cells within 15 min; linalool (0.5%) killed 100% of the cells within 30 s. The essential oil inhibited germ tube formation (mean MIC of 0.09%), as did the main components (MIC of 0.11% for linalool and 0.08% for linalyl acetate). Both the essential oil and its main components inhibited hyphal elongation of C. albicans ATCC 3153 (about 50% inhibition at 0.016% with each substance). Lavender oil shows both fungistatic and fungicidal activity against C. albicans strains. At lower concentrations, it inhibits germ tube formation and hyphal elongation, indicating that it is effective against C. albicans dimorphism and may thus reduce fungal progression and the spread of infection in host tissues.