结核分枝杆菌4种抗原的基因克隆、表达、纯化和抗原性初步检测

目的:克隆38kD、ESAT-6、CFP10和MPT64等4种结核分枝杆菌抗原基因,利用大肠杆菌表达系统分别表达重组蛋白,纯化并初步评价其抗原性。方法:通过PCR方法从结核分枝杆菌H37Rv株基因组中扩增38kD、ESAT-6、CFP10和MPT64抗原的基因,连接入pBVIL1表达载体,在大肠杆菌HB101株中进行表达,以间接ELISA方法初步评价其抗原性。结果:获得了结核分枝杆菌抗原38kD、ESAT-6、CFP10和MPT64的基因,并在大肠杆菌中进行了高效表达,初步验证所纯化获得的抗原具有良好的抗原性。结论:pBVIL1表达载体可以高效表达多种结核分枝杆菌抗原,38kD、ESAT-6和CFP10抗原均可作为结核病血清学诊断的候选抗原。     

重组恶性疟原虫DNA质粒免疫小鼠制备单克隆抗体

用恶性疟原虫MSP131基因片段的重组质粒DNA直接免疫BALB/c小鼠,诱导产生体液,免疫后取脾细胞与SP2/0小鼠骨髓瘤细胞在PEG1450作用下进行融合,获得了2株能分泌抗恶性疟原虫MSP131单克隆抗体的小鼠杂交瘤细胞株9H9和8A2。用酶联免疫吸附试验检测,小鼠腹水抗体滴度最高为1∶10 000。经免疫球蛋白类型和亚类鉴定,2株杂交瘤细胞株均为IgG\-1\.蛋白免疫印迹试验表明,此单克隆抗体与MSP1\|31蛋白抗原有特异免疫反应,证明通过质粒DNA直接免疫小鼠可制备特异性单克隆抗体。     

P2X7受体短肽单克隆抗体的制备及鉴定

旨在制备与鉴定鼠抗P2X7受体的蛋白单克隆抗体.以人P2X7受体的胞外段制备短肽作为抗原,皮下注射免疫Balb/c小鼠.分离小鼠脾脏B淋巴细胞与骨髓瘤细胞融合并培养,挑选阳性杂交瘤细胞,扩大培养,制备和鉴定P2X7其生物学效应.结果显示,获得1株稳定分泌抗人P2X7受体的单克隆抗体的杂交瘤细胞株,所分泌的单抗类型重链为IgG1,轻链为κ;该株杂交瘤细胞腹水效价为1∶6.4×104;传30代及液氮中保存6个月,抗体效价稳定;Western blotting检测证明该单抗与人细胞表面的P2X7受体蛋白特异地结合.所制备的抗人P2X7受体的单克隆抗体具有高度的特异性及稳定性,为针对P2X7受体为靶点的抗体药物的开发应用、疾病的辅助诊断奠定了基础.     

伪狂犬病病毒单克隆抗体制备及特征分析

目的:制备伪狂犬病病毒(PRV)单克隆抗体,为PVR防控奠定基础。方法:用PRV疫苗毒株Bartha-k61免疫小鼠,取免疫小鼠脾脏B淋巴细胞与SP2/0细胞融合,用酶联免疫吸附实验筛选阳性杂交瘤细胞并制备腹水,用病毒中和实验检测单克隆抗体(腹水)对PRV的中和作用。结果:通过细胞融合,共得到11株针对PRV的杂交瘤细胞。中和实验结果显示,无论是对于PRV弱毒株Bartha-k61还是强毒株AV25,2株杂交瘤细胞产生的腹水都表现为明显的中和效应;但2株单抗的中和能力不同,其中1株杂交瘤细胞腹水的中和效价为1∶16~1∶32,另1株的效价为1∶4。交叉反应显示,11株单克隆抗体中,2株与单纯性疱疹病毒存在明显的免疫反应,1株与猴B病毒的gD蛋白存在明显交叉反应。结论:制备了PRV的单克隆抗体,并获得了对PRV具有中和作用的单克隆抗体,以及能与其他疱疹病毒交叉反应的单克隆抗体。     

建兰花叶病毒单克隆抗体的制备及检测应用

用建兰花叶病毒(Cymbidium mosaic virus,CymMV)免疫的BALB/C鼠脾细胞与SP2/0鼠骨髓瘤细胞融合,经筛选克隆,获得3株能稳定传代并分泌抗CymMV单克隆抗体(McAb)的杂交瘤细胞(2C6、5B7和12G9),分别制备它们的单抗腹水。其中5B7和12G92株单克隆抗体腹水间接ELISA效价达10-6,3株单抗的抗体类型及亚类均为IgG1,轻链均为κ链。利用单克隆抗体建立了抗原包被间接ELISA(ACP-ELISA)检测CymMV的方法。蝴蝶兰病叶作1∶10240倍稀释、提纯CymMV病毒浓度为4.87ng/mL(每孔的病毒绝对量为0.487ng)时,该方法仍能检测到病毒。利用ACP-ELISA方法检测了田间样品,发现CymMV在兰花上发病很普遍。     

人突触小体相关蛋白25单克隆抗体的制备及初步鉴定

目的:制备抗人突触小体相关蛋白25(SNAP25)的鼠源单克隆抗体。方法:利用大肠杆菌表达SNAP25蛋白,纯化后免疫BALB/c小鼠制备杂交瘤细胞,筛选针对SNAP25的阳性杂交瘤细胞株,鉴定抗体亚型;用杂交瘤细胞株制备腹水单抗,纯化后利用SDS-PAGE检测抗体纯度。结果:表达并纯化得到纯度大于90%的SNAP25蛋白,免疫小鼠后经2轮筛选得到12株阳性杂交瘤细胞株,其中抗体重链包括IgG1、IgG2型,轻链大部分为κ链;选择具有相对较高抗原结合活性的14号杂交瘤细胞株制备腹水,纯化后得到纯度大于90%的抗体。结论:获得1株高纯度的针对SNAP25的鼠源单克隆抗体,为肉毒毒素的检测奠定了基础。     

抗猪PD-L1单克隆抗体的制备与其生物学特性鉴定

本研究旨在制备抗猪PD-L1单克隆抗体(monoclonal antibody,m Ab),有助于阻断猪PD-1/PD-L1通路逆转免疫功能。免疫原为猪PD-L1胞外区重组蛋白,雌性BALB/c鼠为免疫动物,用淋巴细胞杂交瘤技术将鼠骨髓瘤细胞NS0和免疫BALB/c鼠脾细胞融合,ELISA法筛选及多次克隆化培养,筛选抗猪PD-L1 mAb的杂交瘤细胞株。成功制备1株能稳定分泌抗猪PD-L1的mAb的杂交瘤细胞株3B5,Ig亚型为IgG1,细胞上清和腹水效价分别为1:1×2~(10)和1:1.024×10~5,ELISA和Western-blotting结果表明该株单抗能特异性识别猪重组PD-L1蛋白,流式细胞术结果表明该单抗可以与猪PBMC上PD-L1蛋白有效结合,成功制备了1株分泌抗猪PD-L1单克隆抗体的杂交瘤细胞株3B5,为检测猪PD-L1蛋白表达水平及猪PD-1通路在猪传染性疾病中的致病机制提供有力的检测工具。     

抗FLAG标签单克隆抗体的制备、鉴定及初步应用

用碳化二亚胺法合成FLAG完全抗原,利用杂交瘤技术制备出5株分泌抗FLAG标签单克隆抗体的杂交瘤细胞株。经鉴定,腹水效价均高于1：106 ,且5株单抗与其它融合蛋白标签无交叉反应性,并在免疫亲和层析实验中取得了满意的效果,为含标签的融合蛋白的纯化和研究应用提供了重要的工具。     

番茄花叶病毒单克隆抗体的制备及检测应用

用番茄花叶病毒(ToMV)免疫的BAL B/c鼠脾细胞与SP2/0鼠骨髓瘤细胞融合,经筛选克隆,获得4株能稳定传代并分泌抗ToMV单克隆抗体(Mab)的杂交瘤细胞,其中2株能同时检测ToMV和烟草花叶病毒(TMV),各单克隆抗体腹水ELLSA效价在1∶32 000～1∶1 024 000之间。经TASELISA测定,4株单克隆抗体检测病汁液的稀释度均能达到1∶2 000倍以上。4株单克隆抗体与其他病毒无交叉反应。Westernblot分析表明,其中两株与ToMV176kD的外壳蛋白亚基有特异反应,而另两株无反应,推测它们是针对构象决定簇的抗体。     

百合无症病毒单克隆抗体的制备及检测应用

用百合无症病毒(Lilysymptomlessvirus,LSV)免疫的BALBC鼠脾细胞与SP20鼠骨髓瘤细胞融合,经筛选克隆,获得4株能稳定传代并分泌抗LSV单克隆抗体(MAb)的杂交瘤细胞(2A2、5H9、5H2和5E12),并分别制备它们的单抗腹水。4株单克隆抗体腹水间接ELISA效价达10-6,5H9和5E12的抗体类型及亚类均为IgG1,而2A2和5H2均为IgG3,4株单克隆抗体的轻链均为κ链。利用单克隆抗体建立了抗原包被间接ELISA(ACP-ELISA)检测LSV的方法。病叶作1300倍稀释、提纯LSV病毒浓度为18ngmL(每孔的病毒绝对量为1.8ng)时,该方法仍能检测到病毒。利用ACP-ELISA检测了田间样品,发现LSV在百合上发病很普遍。     

人IL-12与结核分枝杆菌抗原ESAT-6联合基因疫苗的免疫效果观察

人白细胞介素12(IL-12)与结核分枝杆菌免疫优势抗原ESAT-6真核表达质粒联合基因免疫,诱导免疫应答效果观察。近交系BALB/c小鼠,随机分组:A组(生理盐水对照)、B组(pcDNA3.1空质粒对照)、C组(BCG对照)、D组(pcESAT-6)和E组(pcIL-12 pcESAT-6)。B、D、E质粒免疫组小鼠分别于胫前肌肌肉注射布比卡因(7.5g/L)和质粒的混和物(1∶4,100μL,含质粒70μg/次),A组小鼠肌肉注射生理盐水和布比卡因的混和物(1∶4,100μL),均间隔2周免疫一次,共免疫3次;末次免疫时,C组小鼠皮下注射BCG菌液,0.3mL/只,含106CFU/mL。末次免疫后14d和28d,各组小鼠分别取血分离血清用于总IgG测定,同时分离脾细胞,经TB-PPD刺激后检测脾细胞增殖(XTT比色法)活性和脾细胞培养上清液中γ干扰素(IFN-γ)、白介素4(IL-4)分泌水平。pcESAT-6质粒DNA单独免疫(D组)或与pcIL-12质粒DNA联合免疫(E组),均能诱导小鼠产生特异性抗体,且抗体水平在末次加强免疫后14~28d逐渐增加;但pcIL-12与pcESAT-6联合免疫后,特异性抗体水平较pcESAT-6单独免疫增加不明显(P<0.05)。C、D、E组免疫小鼠脾细胞体外经TB-PPD刺激后,E组小鼠特异性淋巴细胞增殖活性和IFN-γ分泌水平明显强于C组和D组(P<0.05),而IL-4分泌水平相互间未发现明显差异。末次加强免疫后14~28d,E组小鼠脾细胞增殖活性维持在较高水平,而C组小鼠脾细胞增殖活性先低后高,D组则先高后低;IFN-γ诱生水平,E组最高,C组次之,D组最低。pcIL-12与pcESAT-6质粒DNA联合免疫后能刺激机体产生强烈的细胞免疫和稳定的体液免疫,在动物体内诱发的细胞免疫较ESAT-6或BCG单独免疫时均有明显增加并维持较长时间,此外联合免疫后诱导的体液免疫也较BCG免疫有明显增加。     

Control of M. tuberculosis ESAT-6 secretion and specific T cell recognition by PhoP

Analysis of mycobacterial strains that have lost their ability to cause disease is a powerful approach to identify yet unknown virulence determinants and pathways involved in tuberculosis pathogenesis. Two of the most widely used attenuated strains in the history of tuberculosis research are Mycobacterium bovis BCG (BCG) and Mycobacterium tuberculosis H37Ra (H37Ra), which both lost their virulence during in vitro serial passage. Whereas the attenuation of BCG is due mainly to loss of the ESAT-6 secretion system, ESX-1, the reason why H37Ra is attenuated remained unknown. However, here we show that a point mutation (S219L) in the predicted DNA binding region of the regulator PhoP is involved in the attenuation of H37Ra via a mechanism that impacts on the secretion of the major T cell antigen ESAT-6. Only H37Ra "knock-ins" that carried an integrated cosmid with the wild-type phoP gene from M. tuberculosis H37Rv showed changes in colony morphology, increased virulence, ESAT-6 secretion, and induction of specific T cell responses, whereas other H37Ra constructs did not. This finding established a link between the PhoP regulator and ESAT-6 secretion that opens exciting new perspectives for elucidating virulence regulation in M. tuberculosis.     

天然产物莪术醇单克隆抗体的制备

为制备小分子化合物莪术醇的单克隆抗体,先将莪术醇(curcumol)与载体蛋白牛血清蛋白(BSA)偶联形成完全抗原,用基质辅助激光解吸飞行时间质谱法(MALDI-TOF-MS)鉴定莪术醇人工抗原的偶联率,然后采用杂交瘤技术获得杂交瘤株,并对其进行小鼠腹水的制备与纯化.结果表明:莪术醇半抗原与载体的偶联比为19.6,单克...     

Performance of recombinant ESAT-6 antigen (ML0049) for detection of leprosy patients

AIMS: The study was aimed to evaluate the Mycobacterium leprae recombinant early secreted antigenic target-6 (rESAT-6) for its serological performance in leprosy patients. METHODS AND RESULTS: Employing enzyme-linked immunosorbent assay (ELISA), serum samples were tested for prevalence of immunoglobulin G antibodies against M. leprae rESAT-6. The results revealed that the sensitivity of the assay for smear-positive leprosy patients was 82.4% (14 of 17) while for smear-negative patients it was 19.4% (six of 31). Interestingly, the performance of ESAT-6-based assay was statistically comparable with anti-phenolic glycolipid-I antibody-detecting ELISA, a most widely studied serological assay in leprosy. Regarding specificity, none of the 48 controls was positive indicating that antibody response to ESAT-6 was highly specific. Moreover, a high concordance between bacterial index and anti-ESAT-6 antibody-detecting assay was noted. CONCLUSIONS: Recombinant ESAT-6 seems to be a potential serological reagent for detection of M. leprae infection. SIGNIFICANCE AND IMPACT OF THE STUDY: ESAT-6 serology may have utility for (i) early diagnosis, particularly, of highly infectious form (multibacillary, MB) of leprosy, (ii) monitoring the response in smear-positive leprosy patients during the course of the chemotherapy, (iii) classification of leprosy patients into MB and paucibacillary groups for treatment purpose. Hence, further research on these lines is warranted.     

Characterization of monoclonal antibodies to O-antigen of lipopolysaccharide of Actinobacillus pleuropneumoniae serotype 2 and their use in the classification of field isolates

Abstract Monoclonal antibodies (mAbs) against Actinobacillus pleuropneumoniae serotype 2 (reference strain Shope 4226 and field isolate F46) were produced. Twelve hybridoma clones were selected against both strains, and all the antibodies secreted were found to be reactive with whole-cell antigen of the homologous strain in ELISA, whereas only one mAb was reactive in slide agglutination test. The predominant antibody classes were IgG2b and IgG3, although IgG1 and IgM were also obtained. Immunoblot assay showed that mAbs could recognize a ladder band profile which is in accordance with the O-antigen of lipopolysaccharide. Most of the epitopes involved were resistant to proteinase K and also to boiling in the presence of sodium dodecyl sulfate and reducing conditions, but they were sensitive to periodic acid. The 12 mAbs recognized neither reference strains of the remaining A. pleuropneumoniae serotypes nor other taxonomically related Gram-negative organisms. The suitability of mAbs for serotyping of field isolates was also examined, and a high correlation (97.4%) was found between the results previously established by indirect hemagglutination with polyclonal rabbit sera and those obtained by ELISA with mAbs. The panel of mAbs described in this study was found to be extremely useful for identifying field isolates belonging to serotype 2 and could be used as a complementary serotyping method.     

Production and characterisation of monoclonal antibodies to the principle sonicate antigens of Porphyromonas gingivalis w50

Abstract Protein antigens from whole cell sonicates of Porphyromonas gingivalis W50, previously shown to be discriminatory antigens for patients with adult periodontitis, were purified using SDS-PAGE. Electroeluted proteins were used to immunize mice for the production of monoclonal antibodies (mAbs). A combination of enzyme-linked immunosorbent assay (ELISA) and Western blotting were used to screen hybridoma supernatants for mAbs. MAbs were successfully raised against M _r 115 000, M _r 55 000 and M _r 47 000 antigens together with a second M _r 55 000 polypeptide which was a contaminant of the M _r 55 000 antigen. No immunological cross-reactivity was found between these four proteins. The mAbs were used to examine the distribution of these antigens among fifteen P. gingivalis strains together with related oral bacteria using immunostaining of dot blots and Western blots. The antigens were confined to P. gingivalis with the M _r 115 000 and M _r 47 000 antigens being present in all strains tested . The distribution of the M _r 55 000 antigens were slightly more restricted: one M _r 55 000 (outer membrane location) was present in nine of the fifteen P. gingivalis strains tested, while the other M _r 55 000 (location unknown) was only absent from one strain. Whole cell ELISA demonstrated that the M _r 115 000 and the outer membrane M _r 55 000 antigen possess epitopes which are located on the surface of the bacterium.     

Detection of early secretory antigenic target-6 antibody for diagnosis of tuberculosis in non-human primates

Tuberculosis is one of the most economically devastating, zoonotic infections of captive non-human primates. The limitations of the tuberculin skin test, which is currently used to diagnose tuberculosis in living non-human primates, make it necessary to find new, simple, and economical diagnostic methods. We describe use of an enzyme-linked immunoassay to detect IgG antibodies against early secretory antigenic target (ESAT)-6, a small protein secreted by virulent tubercle bacilli, in paired (pre- and post-outbreak) sera from 57 non-human primates involved in an outbreak of Mycobacterium bovis infection in a research colony. Of 25 animals with tuberculosis lesions at necropsy, 22 (88%) had high serum levels of the ESAT-6 antibody. The ESAT-6 antibody was found in 16% (5/32) of post-outbreak sera from animals in which tuberculosis could not be confirmed at necropsy. The strong association between the ESAT-6 antibody and tuberculosis in non-human primates documented in this study, together with the robustness of the serologic assay, make the ESAT-6 ELISA a valuable tool for diagnosis of tuberculosis in captive non-human primates.     

空肠弯曲菌FlaA单克隆抗体的制备与鉴定

【目的】原核表达空肠弯曲菌鞭毛蛋白FlaA,并制备其单克隆抗体。【方法】克隆目的基因并将其构建到pET30a(+)和pGEX-6p-1表达载体,分别以变复性纯化后的rHis-FlaA、rGST-FlaA蛋白为免疫原和检测原进行杂交瘤细胞的筛选。采用间接ELISA法测定细胞上清和单抗腹水效价,Dot-ELISA、Western blot分析单抗特异性。【结果】成功构建pET30a(+)-flaA和pGEX-6p-1-flaA重组原核表达质粒,并融合表达rHis-FlaA和rGST-FlaA蛋白,Western blot试验显示天然蛋白多抗血清能与体外表达的蛋白呈现特异性反应,表明表达蛋白具有免疫原性。筛选获得3株稳定分泌抗FlaA的单克隆杂交瘤细胞株,分别命名为2D12、5E12、6A9,其Ig亚类分别为IgG2a、IgG1、IgG1,腹水效价分别为1∶102400,1∶102400和1∶51200;Western blot试验显示,3株单抗均能与表达rHis-FlaA重组蛋白的细菌发生特异性反应;Dot-ELISA试验表明,3株单抗均能与不同来源的空肠弯曲菌分离株发生特异性反应。【结论】本研究制备的单克隆抗体有较高特异性,具有良好的应用价值。为进一步研究空肠弯曲菌鞭毛蛋白的生物学特性、致病机理,以及建立快速检测技术奠定基础。     

Immunoenzyme analysis of adenovirus hexons. Indication and characteristics of rabbit and mouse antibodies against hexons

An enzyme-linked immunosorbent assay (ELISA) was developed for analysis of rabbit and mouse IgG antibodies specific to adenoviral hexon. The anti-hexon antibodies were detected by capture with purified hexon coated onto polystyrene microtiter plates and visualizing them by respective anti-IgG horseradish peroxidase conjugates. In the sera from hyperimmunized rabbits and mice as well as in the mouse ascite fluids the ELISA procedure revealed primarily type-specific (epsilon) and genus-specific (alpha) antigenic determinants in hexon but not those of intermediate specificities.