Muraguchi A, Kehrl J H, Butler J L, Fauci A S
J Immunol. 1984 Jan;132(1):176-80.
We have previously demonstrated that in vivo activated normal human B cells reflected differential sensitivity on the basis of cell size to either an activation signal delivered by anti-mu or a proliferative signal delivered by a monoclonal B cell growth factor (BCGF) produced by a human T-T hybridoma. In this manuscript, we have shown that by using an in vitro co-culture system of stimulation with anti-mu and BCGF, purified small (resting) B cells could be induced by anti-mu stimulation to express functionally active BCGF acceptor sites concomitant with RNA synthesis and cell enlargement. We have demonstrated that purified small B cells could be activated to increase both cell size and RNA synthesis within 8 hr of anti-mu stimulation. DNA synthesis by anti-mu-stimulated B cells began at 36 to 44 hr from initial stimulation only when BCGF was added to the culture. In addition, large B cells that had been incubated with anti-mu for 24 to 48 hr manifested significant incorporation of [3H]thymidine if BCGF was added to cultures. These data strongly suggest that anti-mu may induce the G0 phase B cells into the G1 phase and that BCGF may then push at least a subset of these G1 phase-B cells into the S phase. This experimental system may provide a useful model of normal human B cell activation and proliferation and may allow a more precise delineation of each phase of this cascade in the B cell repertoire.
我们之前已经证明，体内活化的正常人B细胞基于细胞大小，对由抗μ传递的激活信号或由人T-T杂交瘤产生的单克隆B细胞生长因子（BCGF）传递的增殖信号表现出不同的敏感性。在本论文中，我们表明，通过使用抗μ和BCGF刺激的体外共培养系统，纯化的小（静止）B细胞可被抗μ刺激诱导表达功能活性BCGF受体位点，同时伴随着RNA合成和细胞增大。我们已经证明，纯化的小B细胞在抗μ刺激8小时内可被激活，从而增加细胞大小和RNA合成。仅当向培养物中添加BCGF时，抗μ刺激的B细胞的DNA合成才在初始刺激后36至44小时开始。此外，如果向培养物中添加BCGF，与抗μ孵育24至48小时的大B细胞表现出显著的[3H]胸苷掺入。这些数据强烈表明，抗μ可能将G0期B细胞诱导进入G1期，然后BCGF可能将这些G1期B细胞的至少一个亚群推进到S期。该实验系统可能提供一个正常人B细胞激活和增殖的有用模型，并可能允许更精确地描绘B细胞库中这一级联反应的每个阶段。
