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
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
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.
