Jones Derek D, Wilmore Joel R, Allman David
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104.
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
J Immunol. 2015 Nov 15;195(10):4753-9. doi: 10.4049/jimmunol.1501365. Epub 2015 Oct 5.
Despite their critical role in long-term immunity, the life span of individual memory B cells remains poorly defined. Using a tetracycline-regulated pulse-chase system, we measured population turnover rates and individual t1/2 of pre-established Ag-induced Ig class-switched and IgM-positive memory B cells over 402 d. Our results indicate that, once established, both IgG-positive and less frequent IgM-positive memory populations are exceptionally stable, with little evidence of attrition or cellular turnover. Indeed, the vast majority of cells in both pools exhibited t1/2 that appear to exceed the life span of the mouse, contrasting dramatically with mature naive B cells. These results indicate that recall Ab responses are mediated by stable pools of extremely long-lived cells, and suggest that Ag-experienced B cells employ remarkably efficient survival mechanisms.
尽管个体记忆B细胞在长期免疫中发挥着关键作用，但其寿命仍未明确界定。我们使用四环素调控的脉冲追踪系统，在402天的时间里测量了预先建立的抗原诱导的Ig类别转换和IgM阳性记忆B细胞群体的更新率和个体半衰期。我们的结果表明，一旦建立，IgG阳性和较罕见的IgM阳性记忆群体都异常稳定，几乎没有损耗或细胞更新的迹象。事实上，这两个细胞库中的绝大多数细胞的半衰期似乎超过了小鼠的寿命，这与成熟的幼稚B细胞形成了鲜明对比。这些结果表明，回忆性抗体反应是由极其长寿的稳定细胞库介导的，并提示经历过抗原刺激的B细胞采用了非常有效的存活机制。
