The origins of the various elements in the human antibody repertoire have been and still are subject to considerable uncertainty. Uncertainty in respect of whether the various elements have always served a specific defense function or whether they were co-opted from other organismal roles to form a crude naïve repertoire that then became more complex as combinatorial mechanisms were added. Estimates of the current size of the human antibody naïve repertoire are also widely debated with numbers anywhere from 10 million members, based on experimentally derived numbers, to in excess of one thousand trillion members or more, based on the different sequences derived from theoretical combinatorial calculations. There are questions that are relevant at both ends of this number spectrum. At the lower bound it could be questioned whether this is an insufficient repertoire size to counter all the potential antigen-bearing pathogens. At the upper bound the question is rather simpler: How can any individual interrogate such an astronomical number of antibody-bearing B cells in a timeframe that is meaningful? This review evaluates the evolutionary aspects of the adaptive immune system, the calculations that lead to the large repertoire estimates, some of the experimental evidence pointing to a more restricted repertoire whose variation appears to derive from convergent 'structure and specificity features', and includes a theoretical model that seems to support it. Finally, a solution that may reconcile the size difference anomaly, which is still a hot subject of debate, is suggested.

中文翻译：

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了解人类抗体库。


人类抗体库中各种元件的起源一直且仍然存在相当大的不确定性。不确定的是，各种元素是否始终发挥特定的防御功能，或者它们是否从其他有机体角色中选择出来，形成一个原始的指令集，然后随着组合机制的添加而变得更加复杂。对人类抗体库当前规模的估计也受到广泛争论，从基于实验得出的数字的 1000 万成员到基于理论组合计算得出的不同序列的超过 1000 万亿个成员或更多。 。在这个数字范围的两端都有一些相关的问题。在下限，可能会质疑这是否不足以对抗所有潜在的携带抗原的病原体。在上限上，问题相当简单：任何人如何才能在有意义的时间范围内询问如此天文数字的携带抗体的 B 细胞？这篇综述评估了适应性免疫系统的进化方面、导致大量谱估计的计算、一些实验证据指出了更受限制的谱，其变异似乎源自趋同的“结构和特异性特征”，并包括似乎支持它的理论模型。最后，提出了一种可以解决尺寸差异异常的解决方案，这仍然是争论的热点话题。