深低温储皮后其抗原性改变的免疫学研究

以人皮和豚鼠皮新鲜及－１９６℃冷冻皮片匀浆做为抗原，研制出兔抗人和豚鼠的新鲜及－１９６℃冷冻皮片匀浆的可溶性蛋白高效价的免疫血清，并通过免疫电泳、火箭免疫电泳、免疫火箭扩散电泳及单相免疫扩散电泳等不同免疫学电泳的检测，分别对新鲜皮片及－１９６℃冷冻皮片抗原性改变的这一现象进行探讨与研究。结果表明：人皮、豚鼠皮其新鲜皮片的抗原成份、抗原决定簇及抗原量均显著高于相应的－１９６℃冷冻组皮片，因而证实了通过深低温冷冻的皮片其抗原性低于新鲜皮片的论断。     

HBV重组抗原表位抗原性的研究

目的 在外源抗原表位表达载体系统中构建并表达HBV抗原表位,并对其抗原性进行研究.方法 人工合成编码HBV "a"抗原决定簇表位中24个氨基酸(S124-147)的寡核苷酸序列,克隆入外源抗原表位表达载体系统FHV-RNA2-I3位点,构建重组质粒,在原核pET系统(BL21细胞)中表达.以表达产物为包被抗原对其抗原性进行研究.结果 嵌和蛋白与抗-HBs血清可发生特异性结合反应.结论 在外源抗原表位表达系统中表达的HBV抗原表位具有良好的抗原性.     

N-Glycosylation contributes to the limited cross-reactivity between hemagglutinin neuraminidase proteins of human parainfluenza virus type 4A and 4B

cDNAs encoding human parainfluenza virus type 4B (hPIV-4B) hemagglutinin neuraminidase (HN) protein were cloned and the nucleotide sequences were determined. A high degree of identity (81.4%) was observed between the nucleotide sequences of hPIV-4A and -4B HN proteins, and an 87.3% identity was found between the deduced amino acid sequences. This degree of identity is considered to be greater than immunological similarity between hPIV-4A and -4B HN proteins determined using monoclonal antibodies. To elucidate the causes of the antigenic difference between HN proteins of hPIV-4A and -4B, we constructed three cDNAs of hPIV-4B HN whose potential N-glycosylation sites were partially or completely the same as in hPIV-4A HN cDNA. We compared the antigenicity of the expressed wild-type and mutant proteins, and found that the antigenicities of the mutant hPIV-4B HN proteins were more similar to the hPIV-4A HN protein than to the non-mutant hPIV-4B HN protein. This study indicated that the antigenic diversity between hPIV-4A and -4B was partly caused by deletion or creation of glycosylation sites, showing that the point mutations resulting in deletion or creation of glycosylation sites is one of the initial steps leading to the division of virus into subtypes. Received: 21 January 2000     

Antigenicity of the HCV HVR1 Peptide Analyzed by Computer Modeling

It is important to develop the HCV vaccines in China, be cause 11% 14% of patients with acute and choric hepati tis in this country are infected by HCV, and most of themare infected with Ⅱ/1b and Ⅲ/2a[1]. There are evi dences to indicate that a high variable region 1 (HVR1)exists in the terminal of E2 protein and contains some lin ear epitopes of B cells. Anti HCV antibodies can protectthe sensitive cells from infection by HCV[2 4]. We in tended to get some evidences for designing so…     

肾综合征出血热疫苗后备毒株的分离和生物学特性研究

目的从肾综合征出血热(HFRS)疫区阳性鼠肺中分离汉坦病毒(HV),并对分离到的病毒进行型别鉴定和生物学特性研究,为HFRS疫苗后备毒种库的建立打下基础。方法疫区阳性鼠肺研磨液接种长爪沙鼠分离病毒,并将分离到的HV经乳沙鼠脑内连续传代,采用直接免疫荧光法和酶联免疫吸附试验,检查毒株的型别,研究传代后毒株的繁殖特性、病毒滴度和抗原滴度。结果从疫区32份阳性鼠肺中分离到9株HV,经单克隆直接荧光血清检查6株为汉滩病毒株,3株为汉城病毒株,经乳沙鼠脑内连续传代,其中4株毒株的病毒滴度和抗原滴度较高,汉滩和汉城毒株的病毒和抗原滴度最高分别达106.50、106.00和1∶5120、1∶5120。结论4株毒株的病毒滴度和抗原滴度均较高,可作为HFRS疫苗后备毒种的筛选毒株。     

肾综合征出血热疫苗后备筛选毒株在Vero细胞上的适应传代及其抗原性研究

〔目的〕将肾综合征出血热疫苗后备毒株适应于Vero细胞 ,观察病变情况 ,并对其抗原性和繁殖特性进行研究。〔方法〕将新分离的汉坦病毒ZJ2、ZJ4、ZJ7株和汉城病毒ZJ5株在Vero细胞上进行连续传代 ,采用间接免疫荧光法(IFA)、反向被动血凝试验 (RPHA) ,研究传代后毒株的病毒滴度、抗原量以及细胞的病变情况 ,同时将传代后的病毒接种敏感动物 ,观察动物的发病情况和毒株的繁殖特性。〔结果〕经过 5次连续传代 ,四株病毒在Vero细胞上均显示出良好的适应性 ,从第二代开始病毒滴度稳定在 6.0 0LgTCID5 0 ml以上 ,第五代时最高达 7.5 0LgTCID5 0 ml ,第三代毒株抗原量均已达到 1:12 8,ZJ7株抗原量最高时达 1:768,四株毒株感染Vero细胞 ,连续观察 12d不见细胞产生病变 ,第五代细胞病毒液接种敏感动物 ,9d后动物发病甚至死亡。〔结论〕四株病毒已适应于Vero细胞 ,且具有病毒滴度高、毒力强和抗原性良好的特性 ,是Vero细胞肾综合征出血热灭活疫苗良好的后备筛选毒株。     

重组结核分枝杆菌特异性分泌抗原融合蛋白的活性鉴定及初步应用

目的：融合表达结核分枝杆菌分泌蛋白CFP10-ESAT-6或ESAT-6-CFP10，研究其免疫学特性，为结核病的血清学诊断提供物质基础。方法：将一个柔性的氨基酸“接头”插入原核表达载体pET32c（＋）中，构建pET32c（＋）-linker。PCR法扩增CFP10、ESAT-6基因。将CFP10克隆入改建的载体pET32e（＋）的linker前，ESAT-6克隆入linker后，构建CFP10-ESAT-6融合基因；或将ESAT-6克隆入改建的载体pET32c（＋）的linker前，CFP10克隆入linker后，构建ESAT-6-CFP10融合基因，分别转化大肠杆菌XL1-blue，抽提质粒，酶切鉴定；在大肠杆菌B121中表达，通过Western blot分析其抗原性。结果：两个目的基因分别被按顺序成功克隆入载体pET32c（＋）的linker前或后。重组质粒pET32c（＋）-CFP10-ESAT-6或pET32c（＋）-ESAT-6-CFP10靶基因的测序结果与预计序列完全一致。融合蛋白在B121菌中高效表达。Western blot分析表明，融合蛋白与活动性肺结核患者血清能发生特异性免疫反应。结论：成功地构建了多抗原基因DNA质粒；pET32e（＋）-CFP10-ESAT-6或pET32c（＋）-ESAT-6-CFP10质粒在B121菌中能高效表达rCFP10-ESAT-6或rESAT-6-CFP10融合蛋白，该蛋白兼具CFP10和ESAT-6两种蛋白的抗原性。本研究为rCFP10-ESAT-6或rESAT-6-CFP10融合蛋白在结核病血清学诊断中应用奠定了基础。     

Relevance of O-acetyl and phosphoglycerol groups for the antigenicity of Streptococcus pneumoniae serotype 18C capsular polysaccharide

Capsular polysaccharides are important virulence factors of Streptococcus pneumoniae. The polysaccharide has been used as a component of vaccines against pneumococcal diseases either as plain polysaccharide or better conjugated to a protein. The last one is the vaccine of choice to target child protection. The immune responses depend on several polysaccharide physicochemical properties that can be affected during either purification or modification in the case of conjugate vaccines. In serotype 18C, the repeating unit has a complex structure having a branched pentasaccharide with two apparently labile subtituents: glycerol-phosphate and O-acetyl group. The loss of these groups may potentially reduce the ability of the 18C polysaccharide to induce the desired immune response. Therefore, the relationship of both groups with the antigenicity and immunogenicity of 18C capsular polysaccharide is explored. It is shown that glycerol-phosphate must be preserved for conserving adequate antigenicity of the 18C capsular polysaccharide. At the same time, it was proved that O-acetyl groups do not play any role for the antigenicity and immunogenicity.     

同种异体BMSCs、ADSCs移植后的抗原性差异

目的　探讨骨髓来源间充质干细胞（MSCs from bone marrow, BMSCs）与脂肪来源间充质干细胞(Adipose tissue-derived MSCs,ADSCs)体内移植后的抗原性差异。 方法 体外培养WKY大鼠BMSCs、ADSCs,经成骨诱导后植入wistar大鼠桡骨缺损区,分别于植入后1、2、4、8周进行缺损区HE染色,于1、2、4、8周免疫组化检测缺损区IL-2、TGF-β、TNF-α、CD4、CD8,采用ELISA法检测脾细胞培养液上清IL-2、TGF-β、TNF-α的含量。 结果 BMSCs、ADSCs移植术后1～2周有少量淋巴细胞、白细胞浸润,IL-2、TGF-β、TNF-α、CD4、CD8蛋白少量表达;二者比较差异无显著性。 结论 BMSCs、ADSCs体内移植后所致的抗原性无显著性差异。     

刚地弓形虫磷酸甘油酸变位酶2基因片段克隆、表达及抗原性分析

目的克隆、表达刚地弓形虫(Toxoplasma gondii)磷酸甘油酸变位酶2(TgPGAM2)基因片段,并分析其抗原性。方法提取弓形虫RH株速殖子总RNA,逆转录合成cDNA。PCR扩增TgPGAM2基因。扩增产物经双酶切后连接入pET30a(+)载体,重组质粒转化大肠埃希菌(E.coli)DH5α,阳性菌落经PCR和双酶切鉴定,并测序。将测序正确的重组质粒pET30a(+)-TgPGAM2转化至E.coli BL21并加入异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)结合考马斯亮蓝染色检测表达产物。以兔抗弓形虫血清为一抗,蛋白质印迹(Western blotting)分析重组蛋白的抗原性。结果PCR扩增产物约为750 bp。菌落PCR、双酶切和测序结果显示,重组质粒pET30a(+)-TgPGAM2构建成功。SDS-PAGE结果显示,经IPTG诱导获得相对分子质量(Mr)约30 000的可溶性重组蛋白。Western blotting分析证实其能被兔抗弓形虫血清识别。结论刚地弓形虫RH株TgPGAM2基因片段可在原核表达系统中表达,且该可溶性重组蛋白具有抗原性。