Expression of the recombination-activating genes in extrafollicular lymphocytes but no apparent reinduction in germinal center reactions in human tonsils
Expression of the recombination-activating genes in extrafollicular lymphocytes but no apparent reinduction in germinal center reactions in human tonsils
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DOI：
10.1182/blood.v99.2.531
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发表时间：
2002-01-15
期刊：
影响因子：
20.3
通讯作者：
Niedobitek, G
中科院分区：
文献类型：
--
作者：
Meru, N;Jung, A;Niedobitek, G
淋巴细胞中的V（D）J重组由2个重组激活基因RAG 1和RAG 2介导，RAG 1和RAG 2在骨髓和胸腺中的淋巴细胞发育期间表达。根据RAGs在生殖中心B细胞中再表达的研究结果，分别采用原位杂交和免疫组织化学方法检测了RAGs和末端脱氧核苷酸转移酶（TdT）在人淋巴组织中的表达。在这里，它表明，RAGs和TdT没有重新诱导在germinal中心的反应。然而，RAG（+）/TdT（+）细胞经常出现在扁桃体的滤泡外区域，主要在淋巴组织和纤维支架之间的边界处。表型分析表明这些细胞是B细胞。最后，我们发现RAG（+）/TdT（+）细胞在扁桃体中比在其他外周淋巴组织中更常见。这可能反映了RAG（+）/TdT（+）细胞的流入增加，这是该部位较高抗原刺激的结果。或者，这一观察结果可能表明，扁桃体是淋巴细胞个体发生的一个额外的网站。（血。2002;99：531-537）（C）2002年由美国血液学会。
V(D)J recombination in lymphocytes is mediated by 2 recombination-activating genes, RAG1 and RAG2, which are expressed during lymphocyte development in bone marrow and thymus. Prompted by studies reporting re-expression of the RAGs in germinal center B cells, the expression of RAGs and terminal deoxynucleotidyl transferase (TdT) in human lymphoid tissues was examined using in situ hybridization and immunohistochemistry, respectively. Here it is shown that RAGs and TdT are not reinduced in germinal center reactions. However, RAG(+)/TdT(+) cells are frequently present in extrafollicular areas of tonsils mainly at the boundary between lymphoid tissue and fibrous scaffold. Phenotypic analyses suggest that these cells are B cells. Finally, it is shown that RAG(+)/TdT(+) cells are found more frequently in tonsils than in other peripheral lymphoid tissues. This may reflect an increased influx of RAG(+)/TdT(+) cells as a result of higher antigenic stimulation at this site. Alternatively, this observation may indicate that the tonsils are an additional site of lymphocyte ontogeny. (Blood. 2002;99:531-537) (C) 2002 by The American Society of Hematology.