抗SARS冠状病毒中和活性单克隆抗体的筛选及其结合位点分析

目的 建立能分泌具有中和活性的抗SARS-CoV单克隆抗体（McAb）细胞株，制备有中和活性的抗SARS-CoV MeAb，用于SARS-CoV感染的早期特异诊断和进行SARS-CoV结构蛋白的功能研究。方法 用灭活纯化sARS-c0V（BJ01株）免疫BALB／c小鼠，通过细胞融合技术，建立能稳定分泌SAILS病毒MeAb的杂交瘤细胞系，然后用中和试验进一步筛选分泌具有中和活性的抗SARS-CoV MeAb细胞株。利用SARS-CoV的S和N蛋白的不同长度肽段通过EusA鉴定McAb的特异结合区域，分析S和N蛋白不同区域诱导产生抗体的能力和特性。结果 建立了12株能稳定分泌抗SARS-CoV McAb的杂交瘤细胞株，间接免疫荧光法检测抗体效价在1：320～1：20 480之间，其中6株具有较好的中和SARS-CoV的能力。具有中和活性的McAb中，3株是针对S蛋白的，2株是针对N蛋白的。其中抗S蛋白的中和抗体活性比抗N蛋白的中和抗体活性高，另外1株可能是针对SARS-CoV的其他结构蛋白的。进一步对6株抗S蛋白的McAb的特异抗原结合表位分析，发现其中3株结合位点在S蛋白第12～311氨基酸之间，2株在第310～535氨基酸之间，后者中和效价高于前者，另1株是针对S2蛋白的，SARS病毒的受体结合区正位于第310～535氨基酸这一区段。具有中和活性的McAb通过间接免疫荧光、ELISA、酶标免疫组化法和胶体金方法对SARS病毒进行检测，都显示出高度的特异性和良好亲和力。结论 成功制备了具中和活性的抗SARS-CoV单克隆抗体，并分别测定了McAb对S蛋白和N蛋白的特异抗原结合活性，初步确定了S蛋白的中和表位。为今后SARS病毒的特异诊断、结构蛋白的功能分析和重组疫苗的研制奠定了较好的基础。     

Ⅰ型登革病毒NS1抗原捕获ELISA的建立和初步临床诊断应用

目的以登革病毒特异性非结构蛋白1（NS1）单克隆抗体为基础建立Ⅰ型登革病毒（DEN1）抗原检测的酶联免疫吸附（ELISA）法，并探索从病人早期血清样品中检测DEN1-NS1的可行性。方法利用已制备的抗DEN1-NS1单克隆抗体（单抗），进行多种抗体组合配对优化模式的分析，建立双抗体夹心抗原捕获ELISA，以469份健康人血清样品确定cut off值，检测DEN1感染患者急性期血清样品。结果对多种抗体组合反复筛选，最终确立了最佳的包被单抗和酶标测定单抗，建立了抗体夹心捕获DEN1-NS1抗原的酶联免疫测定方法，能特异检测DEN1，与其他血清型登革病毒不发生交叉反应。检测16例临床确诊DEN1感染病人急性期血清样品，15例呈特异的抗原反应阳性。结论成功建立了DEN1-NS1抗原捕获ELISA并应用于临床血清样品的检测，为登革热的早期实验室诊断提供技术方法。     

免疫磁性海藻酸钠载药纳米微球的制备与评价

靶向治疗系统是目前研究的热点,用微乳化-离子交联方法制备包覆阿霉素的碳包铁/海藻酸钠复合纳米微球,以水溶性碳二亚胺为交联剂,将载药微球与单抗Hab18连接,制备出了免疫磁性药物纳米微球.对该免疫磁性微球的理化性能进行了表征,同时检测了免疫磁性微球中抗体的活性和免疫磁性微球与靶细胞的体外结合情况,结果表明,免疫磁性药物纳米微球平均粒径约为171.2nm,外观为球型,铁含量为14.6%,载药量为10.8%,且具有强磁响应性和长时间药物缓释效果.同时在体外该微球能够与靶细胞特异性结合.这种免疫磁性药物纳米微球有望成为一种优良的靶向肿瘤药物载体.     

泰素抑制内皮细胞管道组装功能的机理研究

目的体外实验研究显示低浓度泰素具有抑制血管内皮细胞组装形成管道的能力。本研究探索泰素这种作用的机理。方法体外培养的人脐静脉血管内皮细胞(HumanUmbilicalVeinEn-dothelialCell,HUVEC)加入低浓度泰素,观察HUVEC的细胞形态,荧光染色检测HUVEC细胞内actin的表达情况。在体外管道形成试验中检测抗TLR-4(Tolllikereceptor-4)抗体对泰素抑制HUVEC管道组装能力的拮抗作用。结果实验结果发现低浓度泰素可使体外培养的HUVEC形态向间质细胞转化。荧光染色发现泰素可抑制HUVEC细胞actin表达。而对其他细胞无类似作用。采用TLR-4抗体可拮抗泰素抑制HUVEC管道形成的作用。结论低浓度泰素通过TLR-4抑制HUVEC细胞内actin的表达,使内皮细胞形态向间质细胞转化,从而抑制内皮细胞组装血管的能力。泰素的这种作用具有血管内皮细胞特异性。     

抗独特型疫苗在肿瘤免疫治疗中的研究现状及前景

恶性肿瘤的治疗已有很多进展,但微小残留病灶仍难以被现行的化疗、放疗、手术等方案彻底清除。如果应用肿瘤免疫治疗激发机体免疫监视系统,消灭残存肿瘤细胞,有可能彻底治愈肿瘤。肿瘤特异性主动免疫治疗研究已有几十年历史,其中抗独特型抗体由于能模拟肿瘤抗原打破机体对肿瘤的免疫耐受而越来越受到人们的重视,成为肿瘤免疫治疗的新途径。     

Comparative study of monoclonal antibody B72.3 and gross cystic disease fluid protein-15 as markers of apocrine carcinoma of the breast

Gross cystic disease fluid protein-15 (GCDFP-15) is a commonly used apocrine marker; however, its expression was recently found to decrease in infiltrating, larger, or metastasizing apocrine carcinomas of the breast. In the breast, monoclonal antibody (MAb) B72.3 has been reported to be useful as an apocrine marker although it is used for that purpose much less frequently than GCDFP-15. In the search for a more consistent apocrine marker, immunoreactivity for MAb B72.3 was examined in apocrine carcinomas at different stages and compared with GCDFP-15. 47 of 51 apocrine carcinomas (92%) and 9 of 62 ordinary carcinomas (15%) were MAb B72.3 positive, while 39 of 51 apocrine carcinomas (76%) and 13 of 62 ordinary carcinomas (21%) were GCDFP-15 positive. Thus, both sensitivity and specificity were higher for MAb B72.3. Furthermore, unlike GCDFP-15, MAb B72.3 exhibited positivity irrespective of infiltrating status, tumor size, or metastatic status. There was no correlation between MAb B72.3-immunoreactivity and GCDFP-15-expression. The combined usage of MAb B72.3 with GCDFP-15 was useful to confirm the diagnosis of apocrine carcinoma, especially for advanced tumors, with only two cases being negative for both MAb B72.3 and GCDFP-15. Whether these two cases should be differentiated from ordinary apocrine carcinomas remains to be investigated.     

Qualification of a microfluidics-based electrophoretic method for impurity testing of monoclonal antibodies

In this work, we present a comprehensive evaluation of the Agilent Bioanalyzer, a microfluidics-based electrophoretic device that was used for impurity testing of a monoclonal antibody (mAb). We compared the system to SDS-PAGE, both operated under non-reducing conditions and found a significant improvement of accuracy for the Bioanalyzer. In addition, the latter exhibited a larger assay range and lower limit of quantitation (LOQ) based on a predefined total error limit of ±30%. However, during method qualification applying a three-factor nested design with two operators performing duplicate measurements per day, each on 4 different days, we observed unpredictable recurring quantitative outliers using the chip-based system. In-depth analysis on multiple runs with various chip lots confirmed the above finding and indicated that most likely on-chip dye labeling and/or post-column background fluorescence elimination are not compatible with the large size of the intact antibody as similar findings were observed for myosin used as upper marker for time correction. Interestingly, after reducing the intact antibody into light and heavy chain, we resolved the outlier issue. Eventually, requalification of the micro-fabricated analytical device under reducing conditions revealed only 1 out of 32 quality control samples (QCs) exceeding the ±30% total error limits.     

Effect of the C3a-Receptor Antagonist SB 290157 on Anti-OVA Polyclonal Antibody–Induced Arthritis

It was investigated whether the C3a-receptor antagonist (C3aRA) SB 290157 was involved in the suppression of anti-OVA pAb–induced arthritis because it is well known that anaphylatoxin C3a plays a crucial role in the development of an effective inflammatory response during complement activation. Anti-OVA pAb–induced arthritis was induced in DBA/1J mice by administration of anti-OVA pAb 0.5 h prior to intra-articular (i.a.) injection of OVA (0 h). Two peaks of joint swelling were observed at 0.5 and 3 h. The role of C3aRA in arthritis was investigated by injection of SB 290157 at concentrations of 10 and 30 mg/kg at 0 and 2 h. The antagonist was able to reduce joint swelling only at 3 h, and about 50% inhibition of joint swelling was observed with the concentration of 30 mg/kg. The C3 level was significantly decreased at 3 h compared with naïve mice showing complement consumption. Furthermore, the C3 activation was observed and increased corresponding to the graded concentration of anti-OVA pAb. The results also revealed that the C3aRA was able to reduce the expression of IL-1β in synovial tissue. Taken together, the results suggested that C3aRA may be effective in the inhibition of arthritis.