Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, United Kingdom.
J Immunol. 2012 Dec 15;189(12):5773-85. doi: 10.4049/jimmunol.1103720. Epub 2012 Nov 16.
Plasma cells (PCs), the terminal effectors of humoral immunity, are short-lived unless supported by niche environments in which they may persist for years. No model system has linked B cell activation with niche function to allow the in vitro generation of long-lived PCs. Thus, the full trajectory of B cell terminal differentiation has yet to be investigated in vitro. In this article, we describe a robust model for the generation of polyclonal long-lived human PCs from peripheral blood B cells. After a proliferative plasmablast phase, PCs persist in the absence of cell division, with viability limited only by elective culture termination. Conservative predictions for PC life expectancy are 300 d, but with the potential for significantly longer life spans for some cells. These long-lived PCs are preferentially derived from memory B cells, and acquire a CD138(high) phenotype analogous to that of human bone marrow PCs. Analysis of gene expression across the system defines clusters of genes with related dynamics and linked functional characteristics. Importantly, genes in these differentiation clusters demonstrate a similar overall pattern of expression for in vitro and ex vivo PCs. In vitro PCs are fully reprogrammed to a secretory state and are adapted to their secretory load, maintaining IgG secretion of 120 pg/cell/day in the absence of XBP1 mRNA splicing. By establishing a set of conditions sufficient to allow the development and persistence of mature human PCs in vitro, to our knowledge, we provide the first platform with which to sequentially explore and manipulate each stage of human PC differentiation.
浆细胞（PCs）是体液免疫的终末效应器，除非在支持其生存多年的龛位环境中，否则其寿命很短。目前尚无模型系统将 B 细胞激活与龛位功能联系起来，以允许在体外生成长寿的 PCs。因此，B 细胞终末分化的完整轨迹尚未在体外进行研究。在本文中，我们描述了一种从外周血 B 细胞生成多克隆长寿人 PCs 的稳健模型。在增殖性浆母细胞阶段之后，PCs 在没有细胞分裂的情况下持续存在，其生存能力仅受选择性培养终止的限制。PC 预期寿命的保守预测为 300 天，但有些细胞的寿命可能显著延长。这些长寿 PCs 主要来源于记忆 B 细胞，并获得类似于人类骨髓 PCs 的 CD138（高）表型。对整个系统的基因表达分析定义了具有相关动力学和关联功能特征的基因簇。重要的是，这些分化簇中的基因在体外和体内 PCs 中表现出相似的总体表达模式。体外 PCs 被完全重编程为分泌状态，并适应其分泌负荷，在没有 XBP1 mRNA 剪接的情况下，每天每细胞分泌 120pg IgG。通过建立一套足以允许成熟人类 PCs 在体外发育和持续存在的条件，据我们所知，我们首次提供了一个平台，可用于依次探索和操纵人类 PC 分化的每个阶段。
