登革4型病毒的单克隆抗体

用SP2/0小鼠骨髓瘤细胞与用登革4型病毒免疫的鼠脾细胞,在PEG—1000的作用下进行融合,获得了8株产生抗登革4型病毒单克隆抗体的杂交瘤细胞系。其中5株杂交瘤产生的抗体,对登革4型病毒具有荧光型特异性,1株对登革1型病毒有交叉反应;另2株对登革2型病毒有交叉反应。对上述8株杂交瘤分泌的抗体又进行了补体结合、空斑抑制中和及血凝抑制试验的鉴定,结果有2株是补体结合型特异,另4株有低度的中和活性。然后用3个荧光型特异的单克隆抗体对5个地方毒株进行试用的结果,进一步验证了它们的特异性。上述杂交瘤稳定传代7个月后,冻存于液氮中。     

产生抗登革4型病毒单克隆抗体杂交瘤细胞系的建立

用登革4型H241株病毒免疫的小鼠脾细胞与小鼠骨髓瘤细胞融合,获得了5个产生抗登革4型病毒单克隆抗体的杂交瘤细胞系。这些杂交瘤细胞的上清液及小鼠腹水抗体均用间接免疫荧光法检测。其中两个杂交瘤细胞系产生的抗体对登革4型病毒具有型特异性,它们的荧光抗体滴度分别为1:10,240～1:20,480和1:2,560。另两个细胞系产生的抗体对登革2型病毒有交叉;另1个对登革1型病毒有交叉。     

用单克隆抗体快速鉴定登革病毒

用登革病毒参考株免疫的BALB/C鼠的脾细胞与SP2/O鼠骨髓瘤细胞融合,成功地建立了分泌抗登革1～4型病毒单克隆抗体的杂交瘤31株。经免疫荧光交叉鉴定,其中17株杂交瘤的抗体是属登革型特异的。用4个型特异的单克隆抗体对国内分离的12令登革地方毒株进行了免疫荧光的快速鉴定,获得了高度敏感高度特异的结果。证明获得的单克隆抗体可以作为免疫荧光诊断制剂,提供登革热病原的快速鉴定应用。     

登革1型病毒的单克隆抗体

我们用SP2/0-Ag14小鼠骨髓瘤细胞与用登革1型病毒免疫的BALB/C小鼠脾细胞在融合剂PEG-1000的诱导下进行融合,获得了15株产生抗登革1型病毒单克隆抗体的杂交瘤细胞系。其中14株属登革病毒型特异,1株属登革病毒亚群特异,它们的荧光效价均在10,240以上。15株杂交瘤均无血凝活性,3株有补体结合活性。1D_4,1B_9的IgG亚类为IgG_1,1F_(11)为IgG_2a,轻链均为K型。1株杂交瘤(1D_4)的染色体数为87～115。用SDS-PAGE测定1D_4分子量,重链为54,000,轻链为24,000。15株杂交瘤连续传代3～6个月,冻存复苏后抗体水平未见下降。     

登革2型病毒单克隆抗体的制备与鉴定

用登革2型病毒参考株免疫的BALB/C小鼠脾细胞与SP2/0小鼠骨髓瘤细胞在PEG1000作用下进行融合,获得了10株分泌抗登革2型病毒单克隆抗体的杂交瘤。经间接免疫荧光鉴定,有4株杂交瘤产生的单克隆抗体对登革2型病毒是型特异的;2株对登革1型有交叉反应;1株对登革3型有交叉反应;1株对登革4型有交叉反应;另2株为黄病毒属特异的。经补体结合和血凝抑制试验鉴定,有2个单克隆抗体是黄病毒属血凝抑制特异的。这10个单克隆抗体对登革热的诊断是很有用的。     

人禽流感HSN1病毒HA1蛋白抗原表位及主要免疫功能区特征的研究

目的 确定人禽流感H5N1病毒HA1蛋白的单克隆抗体(McAb)抗识别表位及主要免疫功能区.方法 将16条人禽流感H5N1病毒HA1基因重叠片段克隆入真核表达载体pDisplay,构建表达HA1蛋白的重叠肽段重组质粒,转染HeLa细胞后制备细胞抗原片.利用灭活的H5N1病毒免疫BALB/C小鼠,制备病毒特异单克隆抗体(单抗)和多克隆抗体(多抗),采用间接免疫荧光法分析单抗、多抗与HA1肽段的反应性.确定HA1蛋白的单抗识别表位及主要免疫功能区.结果 成功克隆、表达了16条不同长度的H5N1肽段,并制备、获得30株分泌抗H5N1型禽流感病毒McAb的杂交瘤细胞株,其中18株为抗HA的单抗,18株中有6株单抗具有中和病毒活性.利用表达的H5N1肽段对单抗识别表位进行分析,初步确定3B5、3D1、3132、M6、M3等18株McAb识别表位区域分别位于氨基酸残基aa133-143、aa155-165、aa166-196、aa166-176、aa34-66及aa296-328之间,其中3B5、3D1、3B2、M6等McAb识别表位为序列依赖型表位,M3和M7等具有中和活性的McAb识别表位为构象性中和表位.结论 利用制备的H5N1病毒特异性McAb和表达的病毒HA1蛋白重叠肽抗原,初步确定了18株抗HA McAb的识别表位和HA1蛋白的主要免疫功能区,为进一步研究开发新型疫苗提供了重要理论依据.     

登革2型病毒PrM基因对不同型登革病毒复制的特异抑制作用

目的 :将我国登革 2型病毒PrM(D2 _PrM)基因导入甲病毒载体系统 ,探讨含正、反义PrM基因的重组病毒对不同血清型登革病毒复制的特异抑制作用。方法 :采用体外转录和电穿孔的方法 ,首先分别将构建的含正、反义PrM基因的重组质粒DNA和辅助载体DNA转录成RNA ,然后将这两种RNA共转染BHK细胞 ,进而包装成重组病毒颗粒。再将经激活的重组病毒感染宿主细胞 ,分别用不同型登革病毒攻击 ,然后通过免疫荧光法 ,观察对不同型登革病毒复制的抑制作用。结果 :含登革 2型正、反义PrM基因的重组甲病毒 ,不仅可完全抑制该型病毒在宿主细胞中的复制 ,而且对其他 3个型病毒的复制也具有不同程度的抑制作用。含反义PrM基因的重组病毒对 4个型登革病毒复制的抑制作用最强。结论 :登革 2型病毒的正、反义PrM基因在宿主细胞中通过重组甲病毒 ,可介导对登革 1～ 4型病毒复制的特异抑制作用     

产生抗登革4型病毒单克隆抗体杂交瘤细胞系的建立

登革热是东南亚地区由虫媒病毒引起的重要传染病之一。在登革病毒1—4型中,以4型病毒引起的病情最严重,出血型病例多,病死率高。我国在1978—1980年间,曾连续发生了登革热的暴发流行。在病原诊断中,用白纹伊蚊C6/36细胞大大提高了病毒分离率,但在鉴定分型中,因交叉反应明显造成困难。由于登革病毒具有型间和组间的共同抗原,故用一般的动物免疫血清或免疫腹水进行鉴定分型时,交叉反应难以克服。采用淋巴细胞杂交瘤技术,能够制备出对病毒单一抗原决定簇的单克隆抗体,可以很好地解决上述交叉问题。国外已有登革3型和2型病毒单克隆抗体的报导。为了平时和战时提供登革病毒型特异的诊断制剂,解决     

登革病毒单克隆抗体鉴定及其血清学性质观察

利用补体结合试验(CF)和血凝抑制试验(HI)对83份免疫荧光阳性的登革病毒单克隆抗体进行了鉴定,11份CF阳性,8份HI阳性。登革1型和4型病毒的单克隆抗体仅有CF活性,其中4F_7和4F_9滴度达到1:20480～1:40960,并且为CF型特异。而登革2型和3型病毒的单克隆抗体,则仅有HI活性,除3D_4为HI型特异外,其余均为HI属特异,与其他黄病毒属抗原有明显交叉。     

登革2型病毒包膜蛋白B区在大肠杆菌中的高效表达

目的：在大肠杆菌中对登革2型病毒包膜蛋白B区进行表达，为观察其抗原性和免疫原性奠定基础。方法：将通过PCR扩增的登革2型病毒包膜蛋白B区插入高效原核表达栽体pBAD／Topo ThioFusion，然后在大肠杆菌中利用阿拉伯糖进行诱导表达。时表达产物以免疲印迹和ELISA法进行检测。结果和结论：登革2型病毒包膜蛋白B区在大肠杆菌中的表达产物以可溶性形式存在，表达量约占细菌可溶性总蛋白的62％。表达产物可与登革2型病毒的特异多抗反应，但与登革1、3和4型病毒的特异多抗无交叉反应。登革2型病毒包膜蛋白B区可在大肠杆菌中以可溶性形式高效表达。     

抗Salmonella minnesota R_(595)菌脂多糖杂交瘤的建立及其抗体特性的初步鉴定

将煮沸致死的R_(595)菌体免疫BALB/C小鼠,取其脾细胞在PEG介导下与SP_(2/0)细胞融合,经筛选获得2个阳性孔2D_6、3H_4。将2D_6、3H_4阳性孔细胞克隆,传代最终获得8株能稳定分泌抗R_(595)内毒素单抗的杂交瘤株。经鉴定,杂交瘤细胞染色体数90余条,抗体效价(EL1SA法)10~4～10~5,2D_6B_1,2D_6E_7单抗的Ig类型为IgG_1,3H_42F_7、3H_42H_3单抗Ig类型为IgG2_b,轻链均为K链。类脂A抑制试验显示,单抗识别的表位为类脂A或KDO,表明抗体识别内毒素保守区域。间接EL1SA试验表明,抗体能与多种GNB交叉反应,提示抗体具广谱交叉反应性。玻片凝集试验显示,抗体仅能凝集R_(595)菌,不能凝集其它GNB菌。     

电击缓冲液对哺乳动物细胞电穿孔效率的影响

目的：提高哺乳动物细胞转染率,使非贴壁细胞和难转染细胞得到转染。方法：比较囝８种不同电击缓冲液条件下３种细胞的电穿孔效率。电击缓冲液包括细胞培养基如ＲＰＭＩ１６４０、ＤＭＥＭ、ＤＭＥＭ／Ｆ１２、磷酸缓冲液Ｋ－ＰＢＳ、ＨＢＳ、ＨｅＢｓ、ＰＢＳ及ｃｙｔｏｍｉｘ,３种细胞分别是贴壁生长的Ｖｅｒｏ细胞、半贴壁生长的Ｓｐ２／０细胞及悬浮生长的Ｎａｍａｌｗａ细胞。通过Ｘ－Ｇａｌ染色确定细胞转染率,通过锥虫蓝染     

抗莱氏无胆甾原体单克隆抗体杂交瘤细胞株的建立

本文采用浓缩提纯的莱氏无胆甾原体做为抗原,多途径免疫 BALB/C 小鼠,取脾细胞与 SP_2/O-Ag~(14)小鼠骨髓瘤细胞融合,建立了4株分泌抗莱氏无胆甾原体单克隆抗体杂交瘤细胞。分析了杂交瘤细胞的染色体,平均数为103条;制备了腹水抗体,经 APAAP 法(碱性磷酸酶—抗碱性磷酸酶桥联酶标显色技术)和 IFA 法检测,抗体效价在80～320之间;对免疫球蛋白亚类进行了鉴定,其抗体均为 IgM。上述细胞经3～4个月稳定传代后,冻存于液氮中。该单克隆抗体的制备对细胞培养中支原体污染的检出可能有重要意义。     

抗-HIV单克隆抗体的筛选与鉴定

我们用HIV抗体阳性者血浆包被聚苯乙烯条,加入纯化的HIV组织培养抗原,通过夹心ELISA法,筛选出3株能分泌抗HIV单克隆抗体杂交瘤细胞,传代稳定。培养上清经Western blot染色鉴定含有抗-HIV gag蛋白。夹心ELISA法测得杂交瘤细胞培养上清中单克隆抗体滴度达到1∶6400,接种BALB/C小鼠获腹水抗体效价为1∶2430000。实验表明,用此单克隆抗体检测HIV病人血清抗体敏感、特异、稳定、重复性好,是一种良好的试剂。     

抗大鼠HSP70蛋白单克隆抗体的制备及特性研究

目的制备大鼠HSP70蛋白单克隆抗体并对其性质进行研究。方法利用PCR技术扩增大鼠全长hsp70,插入表达质粒pET-28a,pMAL-c2x,诱导表达,采用亲和层析纯化融合蛋白;用HIS-HSP70融合蛋白免疫BALB/c小鼠,杂交瘤技术制备大鼠HSP70单克隆抗体;采用Western印迹和免疫组化方法对抗体性质进行鉴定,ELISA方法确定抗体的表型。结果亲和层析纯化HIS-HSP70蛋白纯度在97.6%,获得6株可稳定分泌抗HSP70mAb的杂交瘤细胞系;抗体的亚类均是IgG1类κ链的。Western印迹结果显示6株单抗均能识别天然的大鼠HSP70蛋白;免疫组化结果显示3株抗体可以识别组织的HSP70蛋白。结论成功获得6株有活性HSP70单克隆抗体,可以识别HSP70蛋白不同表位,为进一步研究HSP70单克隆抗体在疾病中的作用奠定基础。     

小鼠原发性肝癌短期诱导模型的建立和评价

目的用一个月的时间建立小鼠原发性肝癌模型。方法用二乙基亚硝胺（DEN）通过腹腔注射的方式对C57BL/6小鼠进行肝脏物理损伤和毒性诱导,再经过30%部分肝切除（PH）刺激肝再生,同时辅以二乙酰基芴（2-AAF）抑制肝实质细胞分裂,使DEN的毒性诱导作用直接作用于肝脏卵圆细胞（OVC）,诱导突变。结果 模型组存活8只（8/12）,将存活的各组小鼠通过放射免疫分析（R IA）、免疫组化（IHC）和免疫印迹（WB）方法鉴定短期诱导小鼠原发性肝癌建模是否成功,结果发现原发性肝癌的绝大多数指标明显改变。结论鉴定结果表明采用化学损伤结合部分肝切除方法,经过一个月时间成功诱导并建立了C57BL/6小鼠的原发性肝癌模型。     

抗A型肉毒毒素鼠源性单克隆抗体的制备和鉴定

目的：制备与鉴定抗A型肉毒神经毒素重链C端（ heavy chain of botulinum neurotoxin serotype A, BoNT／AHc）特异性鼠单克隆抗体。方法通过纯化BoNT／AHc抗原、免疫BALB／c小鼠并建立杂交瘤细胞以制备鼠单抗,用ELISA、Western印迹实验和抗体分型试剂盒进行分析鉴定,并通过ELISA检测鼠单抗与BoNT／AHc突变体结合,初步鉴定其在BoNT／AHc的结合表位。结果得到纯度较高的BoNT／AHc抗原,制备了4株特异性鼠单抗1A4、3H3、3H7、5H8。间接ELISA结果显示,单抗细胞上清效价均＞3．0×103;Western印迹检测结果显示,单抗均能与BoNT／AHc特异性结合;抗体亚型鉴定结果为1A4、3H7属于IgG1（Κ）,3H3属于IgM（Κ）,而5H8属于IgG2b （Κ）;叠加ELISA实验表明,4株单抗抗原识别表位相近;用ELISA检测单抗与BoNT／AHc突变体结合实验结果初步确定了4株单抗与BoNT／AHc的结合表位。结论对抗A型肉毒毒素鼠源性抗体完成了制备和鉴定,为肉毒毒素中和抗体的开发与阐明中和抗体的表位奠定了基础。     

Cell cycle checkpoint evasion and protracted cell cycle arrest in X-irradiated small-cell lung carcinoma cells

Purpose: To determine the longevity and dose-dependence of acute X-irradiation-induced cell cycle perturbations in a panel of seven small-cell lung carcinoma (SCLC) cell lines (CORL32B, COR-L51B, COR-L88B, COR-L96C, COR-L103, CORL266B, COR-L279), assessed for TP53 tumour suppressor gene status and showing characteristically long population doubling periods. Materials and methods: Cell lines were screened for abnormalities in TP53. Cell cycle arrest and nuclear fragmentation were determined by flow cytometry under culture conditions that minimized the propensity of SCLC cells to form multicellular aggregates. A faster growing SCLC cell line (NCI-H69) and two breast tumour cell lines were used as controls. Results: NCI-H69 and five of the COR-SCLC cell lines showed clear evidence of TP53 abnormalities and the cycle arrest responses of the breast tumour cell lines established the effects of TP53 mutation on G1/S checkpoint loss. All SCLC lines, at 24h after low dose irradiation, showed abrogation of the G1/S checkpoint together with a range of expression of a protracted G2/M delay. G2/M delay progressed in all panel cell lines up to 48h post-irradiation while NCI-H69 showed significant recovery for the dose range 75-600cGy. Only NCI-H69 and one panel line showed dose-dependent progression to complete nuclear DNA fragmentation. Conclusions: The culture method permits the measurement of cell cycle effects that reflect the TP53 status of SCLC cells. G1/S checkpoint failure, long-term radiation-induced G2 arrest, highly muted apoptotic responses and delayed recovery appear to be typical responses of the recently derived COR-SCLC lines. The results imply that low levels of unrepaired DNA damage, induced at clinically relevant doses, can persist for days in SCLC cells with long cell cycle traverse times, and can remain capable of checkpoint activation with implications for S phase-targeted therapies.     

Cell cycle checkpoint evasion and protracted cell cycle arrest in X-irradiated small-cell lung carcinoma cells.

PURPOSE: To determine the longevity and dose-dependence of acute X-irradiation-induced cell cycle perturbations in a panel of seven small-cell lung carcinoma (SCLC) cell lines (COR-L32B, COR-L51B, COR-L88B, COR-L96C, COR-L103, COR-L266B, COR-L279), assessed for TP53 tumour suppressor gene status and showing characteristically long population doubling periods. MATERIALS AND METHODS: Cell lines were screened for abnormalities in TP53. Cell cycle arrest and nuclear fragmentation were determined by flow cytometry under culture conditions that minimized the propensity of SCLC cells to form multicellular aggregates. A faster growing SCLC cell line (NCI-H69) and two breast tumour cell lines were used as controls. RESULTS: NCI-H69 and five of the COR-SCLC cell lines showed clear evidence of TP53 abnormalities and the cycle arrest responses of the breast tumour cell lines established the effects of TP53 mutation on G1/S checkpoint loss. All SCLC lines, at 24 h after low dose irradiation, showed abrogation of the G1/S checkpoint together with a range of expression of a protracted G2/M delay. G2/M delay progressed in all panel cell lines up to 48 h post-irradiation while NCI-H69 showed significant recovery for the dose range 75-600cGy. Only NCI-H69 and one panel line showed dose-dependent progression to complete nuclear DNA fragmentation. CONCLUSIONS: The culture method permits the measurement of cell cycle effects that reflect the TP53 status of SCLC cells. G1/S checkpoint failure, long-term radiation-induced G2 arrest, highly muted apoptotic responses and delayed recovery appear to be typical responses of the recently derived COR-SCLC lines. The results imply that low levels of unrepaired DNA damage, induced at clinically relevant doses, can persist for days in SCLC cells with long cell cycle traverse times, and can remain capable of checkpoint activation with implications for S phase-targeted therapies.     

Carbocyanine labeled LDL for optical imaging of tumors

RATIONALE AND OBJECTIVES: The purpose of this study was to define and characterize carbocyanine labeled low-density lipoprotein (LDL) to be used in the optical imaging of LDL receptor (LDLr)-overexpressing tumor models. MATERIALS AND METHODS: 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) was used to label LDL (DiI-LDL). Scatchard plots were generated to determine the maximum binding capacity B(max) and dissociation constants K(D) of DiI-LDL in B16 melanoma (B16) and hepatoblastoma G(2) (HepG(2)) cell lines. Selective uptake of DiI-LDL into both tumor cells and corresponding subcutaneous tumors in mice were demonstrated by confocal microscopy and three-dimensional Cryo-imaging, respectively. RESULTS: The labeling efficiency of DiI-LDL was 61 ng DiI/microg LDL protein (34 mol DiI/mol LDL protein). B(max) and K(D) for B16 cells were 6.311 ng LDL/mg cell protein and 60.38 microg protein/mL (117 nM), respectively. B(max) and K(D) were 7.573 ng LDL/mg cell protein and 26.79 microg protein/mL (52 nM) for HepG(2) cells, respectively. Confocal microscopic images showed specific uptake of DiI-LDL throughout the cytoplasm in the B16/HepG(2) cells. Cryo-imaging demonstrated preferential accumulations of DiI-LDL in the viable tumor regions of both B16 and HepG(2) tumors compared with their adjacent normal tissues and corresponding necrotic tumor regions. In addition, uptake of DiI-LDL by the HepG(2) tumor was much higher than that of the B16 tumor, consistent with the fact that the probe binding affinity for LDLrs of HepG(2) cells is 2.3 times that of B16 cells. CONCLUSION: This study suggested that carbocyanine labeled LDL could be used for optical imaging of tumors overexpressing LDLr.