Raji 细胞系特异性Fab噬菌体抗体库的构建及筛选

目的构建针对B细胞淋巴瘤Raji细胞系噬菌体抗体库并从中筛选出特异性的抗体。方法以Raji细胞免疫BALB/c小鼠,RT-PCR法从脾淋巴细胞中扩增抗体轻链к和重链Fd基因。经SacI/XbaI和XhoI/SpeI双酶切,依次克隆入噬菌体载体pComb3H-SS中,并电转化大肠杆菌XL1-Blue,以辅助噬菌体VCSM13进行超感染,构建B细胞淋巴瘤Raji细胞系特异性Fab噬菌体抗体库。以Raji细胞为抗原进行筛选,获得抗Raji细胞的抗体,通过ELISA法进行抗原结合活性的测定,并对所得阳性克隆进行基因测序分析。结果构建了容量为2.18×107的抗人B细胞淋巴瘤Raji细胞系的Fab噬菌体抗体库,并筛选获得了与Raji细胞系特异性识别结合的8株阳性克隆。对其中两个阳性克隆进行基因序列分析,结果显示其重链可变区、轻链可变区分别与免疫球蛋白基因库中已注册的鼠源性免疫球蛋白重链可变区和轻链可变区序列具有高度同源性。结论成功地构建Fab噬菌体抗体库并筛选出针对Raji细胞系膜抗原的抗体,为进一步研究B细胞淋巴瘤的免疫治疗提供了实验基础。

Construction and screening of the specific Fab phage antibody library against Raji cell strain

AIM: To construct and screen the specific Fab phage antibody library against human Raji cell strain in B-lymphoma. METHODS: BALB/c mice were immunized with Raji cells, and the antibody light chain kappa genes and heavy chain genes Fd from the spleen cells were amplified by RT-PCR. After restrictive digestion with Sac I/Xba I and Xho I/Spe I, the light chain kappa genes and heavy chain genes Fd were inserted into the phagemid vector pComb3H-SS successively and then electroporated into E.coli XL1-Blue. The specific Fab phage antibody library against Raji cell strain in human B-lymphoma was constructed by infection of helper phage VCSM13. The specific antibodies against Raji cells were obtained after selected with Raji cells. The binding activity with antigens was identified by ELISA and the positive clones were sequenced. RESULTS: The Fab phage antibody library with 2.18 x 10(7) volume was constructed and eight positive clones which specifically recognized Raji cell strain were isolated. Sequence analysis of the two positive clones showed that the variable heavy domains (VH) and variable light domains (VL) were highly homologous with the registered murine Ig heavy chain V region sequences and kappa light chain sequences, respectively. CONCLUSION: Fab phage antibody library was successfully constructed and specific antibodies against membrane antigens in Raji cells were obtained, which will provide an experimental foundation for the further investigation of B-lymphoma immunotherapy.