Wirths Stefan, Lanzavecchia Antonio
Institute for Research in Biomedicine, Bellinzona, Switzerland.
Eur J Immunol. 2005 Dec;35(12):3433-41. doi: 10.1002/eji.200535364.
The exact identification of B cell subsets is instrumental to understand their dynamics under physiological and pathological conditions. Human memory B cells are currently identified according to the expression of CD27, which is absent on naive B cells. We report here that the ATP-binding cassette (ABC)B1 transporter is exclusively present on mature CD27- naive B cells, while it is absent in CD27+ memory B cells and in a heterogeneous subset of CD27- cells that comprise both switch memory and transitional B cells. Thus, ABCB1 activity precisely discriminates naive from transitional and all memory B cells. Using this improved method to discriminate human B cell subsets, and Ki67 staining to identify recently divided cells, we show that in both cord blood and adult peripheral blood, mature naive B cells are quiescent while transitional B cells and memory B cells have a high in vivo turnover.
准确识别B细胞亚群有助于了解它们在生理和病理条件下的动态变化。目前人类记忆B细胞是根据CD27的表达来识别的，而初始B细胞上不存在CD27。我们在此报告，ATP结合盒（ABC）B1转运蛋白仅存在于成熟的CD27阴性初始B细胞上，而在CD27阳性记忆B细胞以及包含转换记忆B细胞和过渡性B细胞的CD27阴性细胞异质亚群中不存在。因此，ABCB1活性精确地区分了初始B细胞与过渡性B细胞以及所有记忆B细胞。利用这种改进的方法区分人类B细胞亚群，并通过Ki67染色识别最近分裂的细胞，我们发现，在脐带血和成人外周血中，成熟初始B细胞处于静止状态，而过渡性B细胞和记忆B细胞在体内有很高的更新率。
