Knight K L, Barrington R A
Department of Microbiology and Immunology, Loyola University at Chicago, Maywood, Illinois 60153, USA.
Immunol Rev. 1998 Apr;162:37-47. doi: 10.1111/j.1600-065x.1998.tb01427.x.
Rabbits have helped elucidate one of the major immunologic puzzles, namely the genetic control of antibody diversity. The primary IgH antibody repertoire in rabbits is dominated by B cells that use the same germline VH-gene segment in VDJ gene rearrangements. The VDJ genes of essentially all B lymphocytes undergo somatic diversification within the first few weeks of the rabbit's life. Such diversification occurs both by a somatic gene conversion-like mechanism as well as by somatic hyperpointmutation. The diversification that occurs early in ontogeny takes place in gut-associated lymphoid tissues and potentially depends on external factors such as microbial antigens. Few, if any, new B lymphocytes develop in adult rabbits and we discuss how the antibody repertoire is maintained throughout life. Finally, we discuss the molecular mechanism of somatic gene conversion of Ig genes, including the possibility that this involves the use of RAD51, an enzyme required for gene conversion-mediated mating type switch in yeast.
兔子有助于阐明主要的免疫学谜题之一，即抗体多样性的遗传控制。兔子的主要免疫球蛋白重链（IgH）抗体库由在VDJ基因重排中使用相同种系VH基因片段的B细胞主导。基本上所有B淋巴细胞的VDJ基因在兔子生命的最初几周内都会经历体细胞多样化。这种多样化通过类似体细胞基因转换的机制以及体细胞超突变发生。个体发育早期发生的多样化发生在肠道相关淋巴组织中，并且可能取决于外部因素，如微生物抗原。成年兔子中几乎没有新的B淋巴细胞发育，我们将讨论抗体库如何在整个生命过程中得以维持。最后，我们讨论免疫球蛋白基因体细胞基因转换的分子机制，包括这可能涉及使用RAD51的可能性，RAD51是酵母中基因转换介导的交配型转换所需的一种酶。
