Fuschiotti P, Fitts M G, Pospisil R, Weinstein P D, Mage R G
Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
J Immunol. 1997 Jan 1;158(1):55-64.
The appendix of young rabbits is a site of primary heavy chain variable region-gene diversification and B cell selection. Appendix cells from 6- to 9-wk-old rabbits were stained and sorted for surface CD43 and IgM. We found that the CD43+IgM- and double-negative CD43-IgM- cells contained RAG1 transcripts and RAG2 protein. The presence of RAG gene products in appendix raised the possibility that pro-/pre-B cells were present in young rabbit appendix. Although an early suggestion that RAG2 plays a role in variable region-gene diversification by gene conversion in chicken bursa was not supported by studies of RAG2 protein in this tissue, we produced anti-rabbit RAG2 Abs to determine whether RAG2 protein was present in rabbit appendix, where cells that recently underwent gene conversion are found. We detected RAG2 protein in the four subpopulations of rabbit appendix lymphocytes, distinguished by surface CD43 and IgM markers. The appearance of RAG gene products during different stages of B cell maturation may reflect the function of the young rabbit appendix as a site of both B cell development and diversification.
幼兔的阑尾是重链可变区基因初次多样化和B细胞选择的场所。对6至9周龄兔子的阑尾细胞进行染色，并根据表面CD43和IgM进行分选。我们发现CD43 + IgM-细胞和双阴性CD43-IgM-细胞含有RAG1转录本和RAG2蛋白。阑尾中存在RAG基因产物，这增加了幼兔阑尾中存在前B细胞/前B细胞的可能性。尽管早期有观点认为RAG2通过鸡法氏囊中基因转换在可变区基因多样化中起作用，但该组织中RAG2蛋白的研究并未支持这一观点，我们制备了抗兔RAG2抗体，以确定RAG2蛋白是否存在于兔阑尾中，因为在兔阑尾中可以找到最近经历基因转换的细胞。我们在兔阑尾淋巴细胞的四个亚群中检测到了RAG2蛋白，这些亚群通过表面CD43和IgM标记来区分。RAG基因产物在B细胞成熟的不同阶段出现，这可能反映了幼兔阑尾作为B细胞发育和多样化场所的功能。
