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素的来源已经并且仍然存在相当大的不确定性。不确定各种要素是否始终发挥着特定的防御功能，或者是否将它们从其他机体角色中选拔出来以形成粗暴的天真曲目，然后随着添加组合机制变得更加复杂。关于人类天真的抗体库的当前大小的估计，也有广泛的争议，其数量从实验得出的数字到1000万个成员，再到理论组合计算得出的不同序列，则超过一万亿个成员或更多。 。在这个数字频谱的两端都有一些相关的问题。在下限时，可能会质疑，这是否不足以抵抗所有潜在的带有抗原的病原体。从上限来看，问题要简单得多：在有意义的时间范围内，任何人如何询问如此大量的带有抗体的B细胞？这篇综述评估了适应性免疫系统的进化方面，这些计算导致了较大的库值估计，一些实验证据指向了一个更受限制的库，其变异似乎源自趋同的“结构和特异性特征”，并且包括支持它的理论模型。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。