抗磷酸胆碱B细胞κ链V基因经基因置换重排至Jκ下游区的研究  

ANTI PC B CELL κ CHAIN V GENE CAN BE FURTHER REARRANGED TO DOWNSTREAM J κ BY GENE REPLACEMENT

作　　者：郭卫星[1,2] 赵温利[1,2] 方燕 田志刚 

机构地区：[1]美国康奈尔大学病理系 [2]山东省医学科学院基础所

出　　处：《免疫学杂志》1997年第3期161-163,共3页Immunological Journal

摘　　要：为探讨外来抗原——磷酸胆碱（ＰＣ）激发的抗体反应中是否存在基因置换的调节机制，采用酶联免疫吸附试验（ＥＬＩＳＡ）、序列分析及Ｓｏｕｔｈｅｒｎ杂交对三种来自抗ＰＣＢ细胞单抗的重、轻链进行了分析。结果显示：①三种单抗具有相同的重、轻链Ｖ（Ｄ）Ｊ表型及ＶＨ与ＶＬ拼接顺序，提示三者源于共同的Ｂ细胞前体。②在２４－１Ｂ１０和２４－１Ｂ１１杂交瘤的抗体轻链中，Ｖκ区与Ｊκ２相连；而在２４－２Ｂ２中Ｖκ区与Ｊκ５相连，Ｓｏｕｔｈｅｒｎ杂交提示后者经过进一步的基因置换而发生了重排。③２４－２Ｂ２与硝基苯酚磷酸胆碱（ＮＰＰＣ）的亲和力分别比２４－１Ｂ１０和２４－１Ｂ１１高４倍和１３倍。推测抗原选择是Ｂ细胞克隆进一步重排的驱动力。To explore if gene replacement occurs in antibody responses to exogenous antigen,phosphocholine(PC),a panel of three monoclonal antibodies (mAb)derived from anti PC B cells were analyzed for their heavy and light chain gene usage.All three mAbs displayed the same heavy chain V(D) J configuration.The junctional sequences were also identical in both V H and V L,indicating they originated from a common B cell progenitor.Howe ver, two hybridoma light chain(24 1B10 and 24 1B11)V κ region joined to J κ 2,while in the third one,24 2B2,had V κ/J κ5 combination.A distinct size fragment detected by Southern analysis indicated that 24 2B2 have undergone further editing,or rearrangement by gene replacement from a duplicated upstream V κ.Based on the fact that 24 2B2 binds nitrophonolphosphocholine(NPPC) 4 and 13 times higher than 24 1B10 and 24 1B11 respectively,we postulate that antigen selection could be the driving force for this B cell clone to undergo further rearrangement.

关 键 词：基因重排 磷酸胆碱 单克隆抗体 DNA 

分 类 号：R392.11[医药卫生—免疫学]