Individual Sea Urchin Coelomocytes Undergo Somatic Immune Gene Diversification
Individual Sea Urchin Coelomocytes Undergo Somatic Immune Gene Diversification
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DOI：
10.3389/fimmu.2019.01298
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发表时间：
2019-06-06
影响因子：
7.3
通讯作者：
Smith, L. Courtney
中科院分区：
文献类型：
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作者：
Oren, Matan;Rosental, Benyamin;Smith, L. Courtney
有颌脊椎动物的适应性免疫反应是以体细胞特异性免疫受体基因多样化的能力为标志的。基因片段的体细胞重组和超突变用于产生广泛的T和B细胞受体库。相比之下，无颌脊椎动物利用基于拷贝选择的独特多样化系统来组装其可变淋巴细胞受体。迄今为止，很少有证据表明，体细胞免疫基因多样化已在无脊椎动物物种的报道。在这里，我们表明，SpTransformer（SpTrf;以前的Sp185/333）免疫效应基因家族成员从单个体腔细胞从紫色海胆经历体细胞多样化的基因缺失，复制，和收购单核苷酸多态性的手段。虽然来自单个海胆的精子细胞具有相同的SpTrf基因库，但来自同一海胆的两个不同体腔细胞亚群的单细胞在SpTrf基因库中表现出显着的变化。此外，来自单个体腔细胞的高度多样性的基因序列都是符合读框的，这表明驱动这些体细胞变化的未知机制涉及用于表达生产性SpTrf转录物的严格选择或校正过程。总之，我们的研究结果推断体细胞免疫基因多样化的策略在无脊椎动物。
The adaptive immune response in jawed vertebrates is marked by the ability to diversify somatically specific immune receptor genes. Somatic recombination and hypermutation of gene segments are used to generate extensive repertoires of T and B cell receptors. In contrast, jawless vertebrates utilize a distinct diversification system based on copy choice to assemble their variable lymphocyte receptors. To date, very little evidence for somatic immune gene diversification has been reported in invertebrate species. Here we show that the SpTransformer (SpTrf; formerly Sp185/333) immune effector gene family members from individual coelomocytes from purple sea urchins undergo somatic diversification by means of gene deletions, duplications, and acquisitions of single nucleotide polymorphisms. While sperm cells from an individual sea urchin have identical SpTrf gene repertoires, single cells from two distinct coelomocyte subpopulations from the same sea urchin exhibit significant variation in the SpTrf gene repertoires. Moreover, the highly diverse gene sequences derived from single coelomocytes are all in-frame, suggesting that an unknown mechanism(s) driving these somatic changes involve stringent selection or correction processes for expression of productive SpTrf transcripts. Together, our findings infer somatic immune gene diversification strategy in an invertebrate.