Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high p...Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F（ab＇）z fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic （anti-ld） responses. Antigen-specific elution method was used for panning private anti-ld VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay （ELISA）. Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.展开更多
The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes ...The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes of the VHIV and VHIII families, respectively. The former 2 VH segments were in germline configuration. A common VH segment, with the best similarity of 90.1 % to the published VHIII germline genes, was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs. This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHIII gene. All these polyreactive mAbs displayed a large NDN region (VH-D-JH junction). The entire H chain V regions of these polyreactive mAbs are unusually basic. The analysis of the charge properties of these mAbs as well as those of other poly- and mono- reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites (CDRs), may be an important structural feature involved in antibody polyreactivity.展开更多
It is well established that all camelids have unique antibodies circulating in their blood.Unlike antibodies from all other species,these special antibodies are devoid of light chains,and are composed of a heavy chain...It is well established that all camelids have unique antibodies circulating in their blood.Unlike antibodies from all other species,these special antibodies are devoid of light chains,and are composed of a heavy chain homodimer.These so-called heavy-chain antibodies(HCAbs)are expressed after a V-D-J rearrangement and require dedicated constant gamma genes. An immune response is raised in these HCAbs following a classical immunization protocol.These HCAbs are easily purified from serum,and their antigen-binding fragment interacts with parts of the target that are less antigenic to conventional antibodies.The antigen binding site of the dromedary HCAb comprises one single domain,referred to as VHH or nanobody(Nb),therefore,a strategy was designed to clone the Nb repertoire of an immunized dromedary and to select the Nb with specificity for our target antigens.The monoclonal Nb is produced well in bacteria,is very stable and highly soluble,and it binds the antigen with high affinity and specificity.Currently,the recombinant Nb has been developed successfully for research purposes, as a probe in biosensors,to diagnose infections,or to treat diseases such as cancer or trypanosomiasis.展开更多
构建双峰驼天然重链抗体可变区(VHH)酵母双杂交文库,并对文库质量进行鉴定。采集未经免疫的6月龄雌性双峰驼外周血、骨髓、脾和淋巴结,并从外周血中分离淋巴细胞。抽提总RNA,反转录为cDNA,用2对引物经过2轮PCR扩增得到400bp左右的双峰驼...构建双峰驼天然重链抗体可变区(VHH)酵母双杂交文库,并对文库质量进行鉴定。采集未经免疫的6月龄雌性双峰驼外周血、骨髓、脾和淋巴结,并从外周血中分离淋巴细胞。抽提总RNA,反转录为cDNA,用2对引物经过2轮PCR扩增得到400bp左右的双峰驼VHH片段。根据Clontech公司Mate&PlateTMlibrary construction system使用手册,将带有同源臂的VHH片段与线性化的pGADT7-Rec质粒共转化Y187酵母感受态细胞,转化产物涂布SD/-Leu平板,30℃倒置培养3~5d后,收集平板上的所有克隆,即为双峰驼天然重链抗体可变区酵母双杂交文库。对文库的滴度、重组效率及多样性进行鉴定。结果显示,本研究构建的双峰驼天然重链抗体可变区酵母双杂交文库库容为2.07×107,滴度为7.6×108cfu·mL-1。随机挑取47个独立克隆进行菌落PCR鉴定,43个含有VHH片段,重组率为91.5%;选取其中19个测序,均为独立克隆,且多样性好。该研究成功构建双峰驼天然重链抗体可变区酵母双杂交文库,且文库质量满足要求,为进一步获得特定抗原的VHH奠定了基础。展开更多
目的 获得鼠抗人精浆蛋白 m Ab重链 Fd段基因 ,并将其转染到 He L a细胞进行表达 .方法 从分泌抗人精浆蛋白 m Ab的杂交瘤细胞系 E4 B7中提取总 RNA,用 RT- PCR法获取重链 Fd段 c DNA.将其克隆入真核表达载体 pc D-NA3,用脂质体转染...目的 获得鼠抗人精浆蛋白 m Ab重链 Fd段基因 ,并将其转染到 He L a细胞进行表达 .方法 从分泌抗人精浆蛋白 m Ab的杂交瘤细胞系 E4 B7中提取总 RNA,用 RT- PCR法获取重链 Fd段 c DNA.将其克隆入真核表达载体 pc D-NA3,用脂质体转染法转染 He L a细胞 ,并用免疫荧光染色方法检测重链 Fd段的表达 .结果 从分泌抗人精浆蛋白的鼠m Ab杂交瘤细胞系 E4 B7中克隆出了重链 Fd段基因 ,序列测定表明 ,VH 与鼠免疫球蛋白 MUSIGHAEI同源性最高 .将含重链 Fd段基因的真核表达载体 pc DNA3- E4 B7Fd中转染He L a细胞后 ,在 He L a细胞中检测到了重链 Fd段的表达 .结论 获得了序列正确的重链 Fd段基因 ,它在 He L a细胞中可以成功地表达 ,为进一步构建和表达 Fab奠定基础 .展开更多
[目的]探讨抗心肌肌凝蛋白重链自身抗体(AMCHA)IgG亚类的产生与腹主动脉缩窄术后大鼠左室功能的关系。[方法]应用腹主动脉缩窄术建立慢性心力衰竭(CHF)大鼠模型,测定血流动力学变化,计算左心室重量/体重(LVW/BW)比值;以合成的大鼠心肌...[目的]探讨抗心肌肌凝蛋白重链自身抗体(AMCHA)IgG亚类的产生与腹主动脉缩窄术后大鼠左室功能的关系。[方法]应用腹主动脉缩窄术建立慢性心力衰竭(CHF)大鼠模型,测定血流动力学变化,计算左心室重量/体重(LVW/BW)比值;以合成的大鼠心肌肌凝蛋白重链部分肽段(1135-1150氨基酸残基)为包被抗原,采用间接ELISA方法检测大鼠血清中心肌肌凝蛋白重链自身抗体(MCHA)IgG亚类的水平及动态变化。[结果]CHF大鼠手术组与假手术组相比左室压力上升和下降最大速率降低(+dp/dtm ax:2103.91±606.89 vs 3196.64±383.29;-dp/dtm ax:-1709.60±460.96 vs-2762.64±514.42,P<0.01),左室舒张末压升高(LVEDP:17.49±8.33 vs-5.69±1.19,P<0.01)、左室收缩压升高(LVSP:131.67±25.14 vs 111.98±4.63,P<0.05)、左心室重量/体重比值升高(LVW/BW:3.04±0.44 vs 2.57±0.20,P<0.01),术后1~2周,IgG1、IgG2 a和IgG2b自身抗体...展开更多
基金supported by a grant from the National Basic Research Program of China(2013CB127804)the National Natural Science Funds(31171696,China)the Research Program of the State Key Laboratory of Food Science and Technology,Nanchang University(SKLF-MB-201002)
文摘Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F（ab＇）z fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic （anti-ld） responses. Antigen-specific elution method was used for panning private anti-ld VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay （ELISA）. Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.
文摘The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes of the VHIV and VHIII families, respectively. The former 2 VH segments were in germline configuration. A common VH segment, with the best similarity of 90.1 % to the published VHIII germline genes, was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs. This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHIII gene. All these polyreactive mAbs displayed a large NDN region (VH-D-JH junction). The entire H chain V regions of these polyreactive mAbs are unusually basic. The analysis of the charge properties of these mAbs as well as those of other poly- and mono- reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites (CDRs), may be an important structural feature involved in antibody polyreactivity.
文摘It is well established that all camelids have unique antibodies circulating in their blood.Unlike antibodies from all other species,these special antibodies are devoid of light chains,and are composed of a heavy chain homodimer.These so-called heavy-chain antibodies(HCAbs)are expressed after a V-D-J rearrangement and require dedicated constant gamma genes. An immune response is raised in these HCAbs following a classical immunization protocol.These HCAbs are easily purified from serum,and their antigen-binding fragment interacts with parts of the target that are less antigenic to conventional antibodies.The antigen binding site of the dromedary HCAb comprises one single domain,referred to as VHH or nanobody(Nb),therefore,a strategy was designed to clone the Nb repertoire of an immunized dromedary and to select the Nb with specificity for our target antigens.The monoclonal Nb is produced well in bacteria,is very stable and highly soluble,and it binds the antigen with high affinity and specificity.Currently,the recombinant Nb has been developed successfully for research purposes, as a probe in biosensors,to diagnose infections,or to treat diseases such as cancer or trypanosomiasis.
文摘构建双峰驼天然重链抗体可变区(VHH)酵母双杂交文库,并对文库质量进行鉴定。采集未经免疫的6月龄雌性双峰驼外周血、骨髓、脾和淋巴结,并从外周血中分离淋巴细胞。抽提总RNA,反转录为cDNA,用2对引物经过2轮PCR扩增得到400bp左右的双峰驼VHH片段。根据Clontech公司Mate&PlateTMlibrary construction system使用手册,将带有同源臂的VHH片段与线性化的pGADT7-Rec质粒共转化Y187酵母感受态细胞,转化产物涂布SD/-Leu平板,30℃倒置培养3~5d后,收集平板上的所有克隆,即为双峰驼天然重链抗体可变区酵母双杂交文库。对文库的滴度、重组效率及多样性进行鉴定。结果显示,本研究构建的双峰驼天然重链抗体可变区酵母双杂交文库库容为2.07×107,滴度为7.6×108cfu·mL-1。随机挑取47个独立克隆进行菌落PCR鉴定,43个含有VHH片段,重组率为91.5%;选取其中19个测序,均为独立克隆,且多样性好。该研究成功构建双峰驼天然重链抗体可变区酵母双杂交文库,且文库质量满足要求,为进一步获得特定抗原的VHH奠定了基础。
文摘目的 获得鼠抗人精浆蛋白 m Ab重链 Fd段基因 ,并将其转染到 He L a细胞进行表达 .方法 从分泌抗人精浆蛋白 m Ab的杂交瘤细胞系 E4 B7中提取总 RNA,用 RT- PCR法获取重链 Fd段 c DNA.将其克隆入真核表达载体 pc D-NA3,用脂质体转染法转染 He L a细胞 ,并用免疫荧光染色方法检测重链 Fd段的表达 .结果 从分泌抗人精浆蛋白的鼠m Ab杂交瘤细胞系 E4 B7中克隆出了重链 Fd段基因 ,序列测定表明 ,VH 与鼠免疫球蛋白 MUSIGHAEI同源性最高 .将含重链 Fd段基因的真核表达载体 pc DNA3- E4 B7Fd中转染He L a细胞后 ,在 He L a细胞中检测到了重链 Fd段的表达 .结论 获得了序列正确的重链 Fd段基因 ,它在 He L a细胞中可以成功地表达 ,为进一步构建和表达 Fab奠定基础 .
文摘[目的]探讨抗心肌肌凝蛋白重链自身抗体(AMCHA)IgG亚类的产生与腹主动脉缩窄术后大鼠左室功能的关系。[方法]应用腹主动脉缩窄术建立慢性心力衰竭(CHF)大鼠模型,测定血流动力学变化,计算左心室重量/体重(LVW/BW)比值;以合成的大鼠心肌肌凝蛋白重链部分肽段(1135-1150氨基酸残基)为包被抗原,采用间接ELISA方法检测大鼠血清中心肌肌凝蛋白重链自身抗体(MCHA)IgG亚类的水平及动态变化。[结果]CHF大鼠手术组与假手术组相比左室压力上升和下降最大速率降低(+dp/dtm ax:2103.91±606.89 vs 3196.64±383.29;-dp/dtm ax:-1709.60±460.96 vs-2762.64±514.42,P<0.01),左室舒张末压升高(LVEDP:17.49±8.33 vs-5.69±1.19,P<0.01)、左室收缩压升高(LVSP:131.67±25.14 vs 111.98±4.63,P<0.05)、左心室重量/体重比值升高(LVW/BW:3.04±0.44 vs 2.57±0.20,P<0.01),术后1~2周,IgG1、IgG2 a和IgG2b自身抗体...
