Loss of surface immunoglobulin expression precedes B cell death by apoptosis in the bursa of Fabricius.
Loss of surface immunoglobulin expression precedes B cell death by apoptosis in the bursa of Fabricius.
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DOI：
10.1084/jem.181.1.105
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发表时间：
1995-01-01
期刊：
影响因子：
--
通讯作者：
Ratcliffe MJ
中科院分区：
文献类型：
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作者：
Paramithiotis E;Jacobsen KA;Ratcliffe MJ
绝大多数的淋巴细胞产生的鸡法氏囊每天不迁移到周边，但在原位死亡。通过电子显微镜观察到的DNA片段和大量浓缩的细胞核，可以很容易地检测到囊中的凋亡细胞。因此，大多数新产生的淋巴细胞通过程序性细胞死亡而死亡。我们发现，囊细胞分裂迅速，凋亡细胞来自快速分裂的前体。细胞凋亡的囊细胞的表型分析表明，细胞死亡不会发生在最成熟的囊细胞群，因此不是随机的。进入细胞周期S期的囊细胞表达高水平的表面IG。相比之下，体内细胞凋亡早期阶段的囊细胞表达极低至不可检测水平的表面IG，但通过重排IG基因的聚合酶链反应（PCR）检测明确证实为B谱系。在体外诱导经历凋亡的囊细胞表达高水平的表面IG，表明诱导凋亡本身并不诱导表面IG表达的丧失。因此，表面IG表达的损失之前，囊细胞凋亡在体内，这表明，表面IG的阈值水平的维持可能是鸡B淋巴细胞发育的持续进展的囊。
The vast majority of lymphocytes generated daily in the chicken bursa of Fabricius do not emigrate to the periphery but die in situ. Apoptotic cells in the bursa can be readily detected by the presence of fragmented DNA and by the large numbers of condensed cellular nuclei observed by electron microscopy. Consequently, most newly generated lymphocytes die by programmed cell death. We show that bursal cells divide rapidly and apoptotic cells are derived from rapidly dividing precursors. Analysis of the phenotype of bursal cells undergoing apoptosis demonstrated that cell death does not occur in the most mature bursal cell population and is therefore not random. High levels of surface Ig are expressed on bursal cells entering S phase of the cell cycle. In contrast, bursal cells in the early stages of apoptosis in vivo express very low to undetectable levels of surface Ig but were unequivocally confirmed as being of the B lineage by polymerase chain reaction (PCR) detection of rearranged Ig genes. Bursal cells induced to undergo apoptosis in vitro express high levels of surface Ig demonstrating that induction of apoptosis does not in itself induce a loss of surface Ig expression. Consequently, loss of surface Ig expression precedes bursal cell death by apoptosis in vivo, suggesting that maintenance of a threshold level of surface Ig may be a requirement for the continued progression of chicken B lymphocyte development in the bursa.