Deane M, Norton J D
Department of Haematology, Royal Free Hospital School of Medicine, London.
Eur J Immunol. 1990 Oct;20(10):2209-17. doi: 10.1002/eji.1830201009.
During B cell development, immunoglobulin heavy chain (IgH) variable region (VH) genes are rearranged and expressed in a programmed manner and accumulating evidence suggests recurrent utilization of developmentally restricted VH genes in malignant B lymphoid populations. We have used polymerase chain reaction gene amplification in conjunction with a panel of VH family-specific amplimers to directly compare the repertoire of VH region rearrangement in mature, CD5+ B cell chronic lymphocytic leukemia with that in immature, CD5 B lineage acute lymphoblastic leukemia. The results revealed a diverse pattern of VH family utilization common to both disease groups in which VH regions most proximal to the IgH joining locus were preferentially rearranged relative to their family sizes with recurrent utilization of several known developmentally restricted VH genes in close to germ-line configuration. These results indicate that biased VH family usage is independent of tumor cell phenotype in B lineage leukemias. This bias may reflect similar stages or compartments in normal B lymphopoiesis from which diverse types of B cell malignancy may arise. Moreover, since blast cells in acute lymphoblastic leukaemia do not express functional immunoglobulin, we infer that the tumor cell-associated VH family repertoire is determined through antigen-independent mechanisms.
在B细胞发育过程中,免疫球蛋白重链(IgH)可变区(VH)基因以程序化方式进行重排和表达,越来越多的证据表明,恶性B淋巴细胞群体中发育受限的VH基因会被反复利用。我们使用聚合酶链反应基因扩增技术,并结合一组VH家族特异性扩增引物,直接比较成熟的CD5+B细胞慢性淋巴细胞白血病与未成熟的CD5+B系急性淋巴细胞白血病中VH区重排的情况。结果显示,两个疾病组中VH家族利用模式多样,其中相对于家族大小,最靠近IgH连接位点的VH区优先重排,且几个已知的发育受限VH基因以接近种系的构型被反复利用。这些结果表明,在B系白血病中,VH家族使用的偏向性与肿瘤细胞表型无关。这种偏向性可能反映了正常B淋巴细胞生成中相似的阶段或区室,不同类型的B细胞恶性肿瘤可能由此产生。此外,由于急性淋巴细胞白血病中的原始细胞不表达功能性免疫球蛋白,我们推断肿瘤细胞相关的VH家族谱是通过抗原非依赖机制决定的。