Schroeder H W, Hillson J L, Perlmutter R M
Howard Hughes Medical Institute, University of Washington, Seattle 98195.
Science. 1987 Nov 6;238(4828):791-3. doi: 10.1126/science.3118465.
Diversification of the antibody repertoire in mammals results from a series of apparently random somatically propagated gene rearrangement and mutational events. Nevertheless, it is well known that the adult repertoire of antibody specificities is acquired in a developmentally programmed fashion. As previously shown, rearrangement of the gene segments encoding the heavy-chain variable regions (VH) of mouse antibodies is also developmentally ordered: the number of VH gene segments rearranged in B lymphocytes of fetal mice is small but increased progressively after birth. In this report, human fetal B-lineage cells were also shown to rearrange a highly restricted set of VH gene segments. In a sample of heavy-chain transcripts from a 130-day human fetus the most frequently expressed human VH element proved to be closely related to the VH element most frequently expressed in murine fetal B-lineage cells. These observations are important in understanding the development of immunocompetence.
哺乳动物抗体库的多样化源于一系列明显随机的体细胞传播的基因重排和突变事件。然而，众所周知，成年抗体特异性库是以发育程序方式获得的。如先前所示，编码小鼠抗体重链可变区（VH）的基因片段的重排也是按发育顺序进行的：胎儿小鼠B淋巴细胞中重排的VH基因片段数量很少，但出生后逐渐增加。在本报告中，人类胎儿B系细胞也被证明重排了一组高度受限的VH基因片段。在一名130天大的人类胎儿的重链转录本样本中，最常表达的人类VH元件被证明与小鼠胎儿B系细胞中最常表达的VH元件密切相关。这些观察结果对于理解免疫能力的发展很重要。
