Expression of recombination-activating gene in mature peripheral T cells in Peyer's patch
Expression of recombination-activating gene in mature peripheral T cells in Peyer's patch
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DOI：
10.1093/intimm/dxg040
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发表时间：
2003-03-01
影响因子：
4.4
通讯作者：
Taniguchi, M
中科院分区：
文献类型：
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作者：
Kondo, E;Wakao, H;Taniguchi, M
活化基因（RAG）1和2是T和B细胞抗原受体基因重排所必需的。为了研究RAG基因在胸腺和骨髓以外的外周淋巴器官中的表达，我们建立了在RAG 2基因座中敲入绿色荧光蛋白（GFP）基因的小鼠（RAG 2-GFP小鼠）。在杂合RAG 2-GFP小鼠的胸腺和骨髓中，正如预期的那样，在发育T和B细胞的适当阶段检测到GFP表达。有趣的是，在外周淋巴器官中，发现派伊尔集合淋巴结中只有一部分Thy-1.2（+）细胞是GFP（+）。GFP（+）细胞表达高水平的表面TCR β和CD 3，表明具有重排的TCR α的成熟T细胞。然而，它们表现出活化/记忆表型，即CD 45 RB（低）、CD 69（高）、CD 44（高）和CD 62 L（低），并且属于表达未成熟发育淋巴细胞特征性c-kit、IL-7 R和pT α的CD 4（+）CD 8（+）群体。此外，RAG（+）派尔集合淋巴结T细胞似乎是胸腺起源的，这是通过它们的CD 8 α表达来判断的。这些结果表明，有一部分成熟的T细胞表达RAG基因的派伊尔氏集合淋巴结，这意味着一个潜在的次级重排的TCR胸腺外组织。
Recombination-activating gene (RAG) 1 and 2 are essential for the gene rearrangement of antigen receptors of both T and B cells. To investigate RAG gene expression in peripheral lymphoid organs other than the thymus and bone marrow, we established mice in which a green fluorescent protein (GFP) gene is knocked-in the RAG2 gene locus (RAG2-GFP mice). In the thymus and bone marrow of heterozygous RAG2-GFP mice, as expected, GFP expression was detected in the appropriate stages of developing T and B cells. Interestingly, only a fraction of Thy-1.2(+) cells in the Peyer's patch were found to be GFP(+) amongst the peripheral lymphoid organs. The GFP(+) cells expressed high levels of surface TCRbeta and CD3, suggesting mature T cells with rearranged TCRalphabeta. However, they showed activated/memory phenotypes, i.e. CD45RB(low), CD69(high), CD44(high) and CD62L(low), and belonged to a CD4(+)CD8(+) population expressing c-kit, IL-7R and pTalpha characteristic of immature developing lymphocytes. Moreover, RAG(+) Peyer's patch T cells seem to be of thymic origin as judged by their expression of CD8alphabeta. These results show that there exists a fraction of mature T cells expressing RAG genes in the Peyer's patch, implying a potential for a secondary rearrangement of TCR in extrathymic tissues.