Memory B cells are biased towards terminal differentiation: a strategy that may prevent repertoire freezing.
Memory B cells are biased towards terminal differentiation: a strategy that may prevent repertoire freezing.
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DOI：
10.1084/jem.186.6.931
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发表时间：
1997-09-15
期刊：
影响因子：
--
通讯作者：
Liu YJ
中科院分区：
文献类型：
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作者：
Arpin C;Banchereau J;Liu YJ
分离大量表面IgD+ CD 38 −初始和表面IgD− CD 38 −记忆B细胞使我们能够研究这两个群体之间的内在差异。在与IL-2和IL-10体外培养时，人CD 40激活的记忆B细胞比初始B细胞更容易终末分化为浆细胞，因为它们产生5 - 8倍的浆细胞和3 - 4倍的分泌免疫球蛋白。相比之下，幼稚B细胞产生大量未分化的B母细胞。完全抑制幼稚B细胞分化的饱和浓度的CD 40配体仅部分影响记忆B细胞的分化。记忆B细胞进行终末浆细胞分化的倾向可以解释广泛的额外滤泡浆细胞反应和有限的生发中心反应后，在体内观察到的二次免疫，这与在载体引发的动物的主要反应。记忆B细胞的这种独特特征可以赋予免疫系统两种重要的能力：（a）快速产生大量效应细胞以有效地消除病原体;和（B）防止一种特定记忆B细胞克隆的过度扩张和慢性积累，这种克隆将冻结可用的外周库。
Isolation of large numbers of surface IgD+CD38− naive and surface IgD−CD38− memory B cells allowed us to study the intrinsic differences between these two populations. Upon in vitro culture with IL-2 and IL-10, human CD40–activated memory B cells undergo terminal differentiation into plasma cells more readily than do naive B cells, as they give rise to five- to eightfold more plasma cells and three- to fourfold more secreted immunoglobulins. By contrast, naive B cells give rise to a larger number of nondifferentiated B blasts. Saturating concentrations of CD40 ligand, which fully inhibit naive B cell differentiation, only partially affect that of memory B cells. The propensity of memory B cells to undergo terminal plasma cell differentiation may explain the extensive extra follicular plasma cell reaction and the limited germinal center reaction observed in vivo after secondary immunizations, which contrast with primary responses in carrier-primed animals. This unique feature of memory B cells may confer two important capacities to the immune system: (a) the rapid generation of a large number of effector cells to efficiently eliminate the pathogens; and (b) the prevention of the overexpansion and chronic accumulation of one particular memory B cell clone that would freeze the available peripheral repertoire.