Effects of heat treatment on the antigenicity of four milk proteins in milk protein concentrates

The effects of heat treatment on the antigenicity and potential allergenicity of α-Lactalbumin (α-LA), β-Lactoglobulin (β-LG), α-casein (α-CN), and β-casein (β-CN) in milk protein concentrates (MPCs) were investigated at temperatures in the range of 65–100°C for times from 10 to 30?min. The antigenicity and potential allergenicity of α-LA decreased significantly. The antigenicity of β-LG was sharply increased throughout the heat treatment, while the potential allergenicity decreased significantly only at 85°C and 100°C for 25?min. The antigenicity of α-CN and β-CN showed fluctuated changes, but were all lower than untreated sample. The α-CN potential allergenicity decreased when heated at 65°C and 70°C for 25?min. Compared with untreated sample, the potential allergenicity of β-CN increased sharply after heat treatment. The results showed that different proteins in the MPCs showed different sensitivities under heat treatment.     

Effect of Maillard reaction conditions on antigenicity of β-lactoglobulin and the properties of glycated whey protein during simulated gastric digestion

Response surface methodology was employed to study the effects of Maillard reaction conditions on the antigenicity of β-lactoglobulin (β-LG) in whey protein isolate (WPI) and to optimise the Maillard reaction conditions of WPI conjugate with oligoisomaltose under which the antigenicity of β-LG reduced to the minimum value. The antigenicity of β-LG and α-lactalbumin (α-LA) in natural and glycated WPI during simulated gastric digestion were investigated. The antigenicity of β-LG was reduced from 272.4 µg mL^?1 to 30.99 µg mL^?1 under the optimal Maillard reaction conditions. After 120 min simulated gastric digestion, the antigenicity of β-LG in natural and glycated WPI were 42.83 µg mL^?1 and 15.66 µg mL^?1, respectively. And the antigenicity of α-LA in natural and glycated WPI were 0.78 µg mL^?1 and 0.03 µg mL^?1, respectively.     

三种去污剂对红内期恶性疟原虫虫体抗原的影响

采用三种去污剂（ＮＰ－４０、十二烷基磺酸钠－ＳＤＳ和皂素－Ｓａｐｏｎｉｎ）加上多种蛋白酶抑制剂混合物制备红内期恶性疟原虫抗原，并使用ＥＬＩＳＡ法比较三种可溶性提取物的抗原性。结果发现，碳酸盐缓冲液包被虫体抗原比ＰＢＳ包被效果好。前者可增加抗原的吸附性。ＮＰ４０提取物仍然含有抗原性，尽管其抗原含量远远低于另两种提取物。ＮＰ４０－ＳＤＳ和Ｓａｐｏｎｉｎ－ＳＤＳ提取物对许多病例表现出抗原性差异。以上结果提示在用疟原虫虫体抗原作现场免疫学筛选时，最好用ＮＰ４０提取物、ＮＰ４０－ＳＤＳ提取物和Ｓａｐｏｎｉｎ－ＳＤＳ提取物作混合抗原以提高检测的敏感性。     

松黄蛋白组分的分离及抗原性的实验分析

目的：分析松黄蛋白抗原中致敏成分。方法：用硫酸铵沉淀、葡聚糖凝胶层析分离松黄蛋白质组分，以致敏大鼠腹腔肥大细胞组胺释放试验和被动皮肤过敏反应试验检测松黄蛋白组分的致敏活性。结果：松黄蛋白中含有３种抗原性不同的组分，组分Ⅱ是松黄主要抗原。结论：松黄蛋白中含有致敏组分，此蛋白组分具对热和酸碱不稳定的性质。     

浙江省近年来流感病毒株的抗原性及人群免疫状况分析

目的 为了解1998－1999年浙江省分离的流感病毒株的抗原性以及杭州市区人群对各类流感病毒的体液免疫力。方法 我们采用常规大量半加敏双向血凝抑制（HI）试验检测相应毒株的交叉HI滴度并计算相应的抗原比。用微量半加敏HI试验检测人群流感HI抗体滴度。结果 浙江省近2年来共分离到12株流感病毒代表株，其中11株为甲3（H3N2）亚型，1株为乙型。A3／浙防／10／98毒株与A3／汉防／359／95、A3悉尼／5／97、A3／沪防／1／98毒株的抗原比分别为1．4、4．0和16．0；A3／浙防／7／99毒株与上述3种标准毒株的抗原比分别为22．6、2．0和1．4。B／浙防／31／99毒株与B／京防／172／97和B／深防／12／97毒株的单向HI滴度分别为≥10240和40。杭州市区人群各型流感HI抗体阳性率为62．4％－100．0％，GMT在11．67－275．49之间。提示，除A3／浙防／10／98毒株抗原性类似于A3／汉防/359/95外，其余甲3亚型毒株的抗原性均类似于A3／沪防／1／98病毒。B型毒株抗原性属于巴拿马类病毒。结论 杭州市区人群对甲3亚型和B型巴拿马类毒株普遍具有HI抗体免疫力。     

乙型脑炎病毒SA14-14-2株NS1蛋白基因在原核细胞中的高效表达及其表达产物的抗原性分析

目的将乙型脑炎病毒NS1蛋白基因克隆至pET28-a( )表达载体,构建原核表达载体pET-NS1,并使该基因在E.coli中高效表达,为进一步研制乙脑早期诊断试剂奠定基础。方法根据GenBank中提供的乙型脑炎病毒SA14-14-2株全基因序列设计引物,通过反转录及巢式PCR方法扩增目的片段,测序后连接pET28-a( )载体,构建重组表达载体pET-NS1,转化大肠杆菌BL21(DE3)后,利用IPTG诱导获得高效表达。结果扩增出了1300bp的基因片段,与预期大小一致,测序后经Blast验证与已发表乙型脑炎病毒SA14-14-2株NS1蛋白基因序列同源性为100%,成功克隆至表达载体pET28-a( )并获得高效表达,表达产物分子量约为45kD,Western blot分析表明该表达产物具有良好抗原性。结论该表达产物的稳定高效表达及其抗原特异性为乙脑的诊断试剂开发提供了依据。     

ABO疑难血型鉴定与临床输血的研究

目的：研究ABO疑难血型,为安全输血提供质量保障。方法：采用血型血清学,对盐水介质正、反定型不合者用人血清鉴定,采用微柱凝集,吸收放散和血型物质的检测,在显微镜下观察红细胞的凝集状态,以准确判断ABO疑难血型。结果：成人2例被定为A3和Ax亚型;13例白血病抗原性减弱和3例异基因骨髓移植者在显微镜下鉴定为弱抗原A型（9）和B型（6）及AB（1）;高效价冷抗体3例,排除干扰后被定为AB（2）和O型（1）;心脏手术患儿血型抗体未形成30例,出生7d~3岁,分别被定为无抗体O型（16）,A型（8）,B型（6）。51例患者经盐水介质和Polybrine配血后输注,未发生溶血反应。结论：用微柱凝集、吸收放散和血型物质的检测,排除干扰后在显微镜下观察结果,能准确及时判断ABO疑难血型。     

河北省麻疹野病毒抗原性变异分析

目的了解河北省麻疹野病毒与疫苗株抗原性之间的差异,为制定加速控制和消除麻疹的策略和措施提供科学依据。方法用麻疹疫苗免疫后的初免人群血清与河北省分离的麻疹野病毒（Hebei07-4和Hebei08-1）和麻疹疫苗株沪191分别进行中和试验,分析中和抗体之间的差异。结果中和抗体的均数为Hebei07-4 1∶16.77、Hebei08-1 1∶17.51、沪191 1∶157.15,初免人群血清中和麻疹野病毒的能力明显低于疫苗株。结论河北省麻疹野病毒与麻疹疫苗株的抗原性之间存在差异。     

Impact of Maillard reaction conditions on the antigenicity of parvalbumin,the major allergen in grass carp

Impacts of the Maillard reaction conditions (maltose/parvalbumin weight ratio, reaction temperature and reaction time) on the antigenicity of parvalbumin (PV) were explored using response surface methodology. The model to predict the antigenicity of PVand an optimal reaction condition were obtained. In addition, the antigenicity, immunoglobulin E (IgE) binding ability and amino acid composition of PV-maltose were analysed. The reaction temperature showed a significant effect on the antigenicity of PV. The optimal reaction condition was: maltose/PV weight ratio was 2.04, reaction temperature was 67.15°C and reaction time was 74.25 h. The predicted antigenicity was 0.276 µg mL^?1 under these conditions, and the test antigenicity was 0.388 µg mL^?1. The IgE binding ability of PV-maltose was significantly suppressed after Maillard reaction. Therefore, Maillard reaction was an effective way to control the main allergen of grass carp.