Procopio A D, Allavena P, Ortaldo J R
J Immunol. 1985 Nov;135(5):3264-71.
Highly purified human large granular (LGL), depleted of any detectable contaminant T and B cells or monocytes, were found to be potent producers in vitro of a soluble B cell growth factor (BCGF) able to sustain proliferation of B cells activated by anti-mu. Activation by lectins (phytohemagglutinin, PHA, concanavalin A, Con A; and pokeweed mitogen, PWM) was required to induce the production of high levels of this BCGF from cultured LGL. Production of BCGF was also detected after the binding of LGL with natural killer (NK)-sensitive (K562) but not with NK-resistant (RL male 1) target cells. In contrast to T cells, LGL did not need the additional presence of accessory cells to reach optimal production of BCGF by 72 hr of culture. The subpopulation of LGL responsible for the production of BCGF had phenotypic characteristics associated with NK cells (3G8+, HNK1+/OKT11+, DR-, OKT3-, Leu-M1-), and separated cells with these markers exerted high levels of NK activity. Selective production of BCGF also was obtained from cytotoxic clones derived from LGL. A partial characterization of the LGL-derived BCGF was performed by gel filtration. BCGF activity was detected in fractions with estimated m.w. of 20,000 and 45,000. The LGL-derived BCGF activity was resistant to reduction with 2-mercaptoethanol and was stable at -20 degrees C for months. Conversely, heating (56 degrees C for 1 hr) or digestion with trypsin greatly reduced the LGL-derived BCGF activity. These findings strongly suggest that LGL including those with NK activity can play an important positive role in the early events of the B cell-mediated immune response.
高度纯化的人类大颗粒淋巴细胞（LGL），去除了任何可检测到的污染性T细胞、B细胞或单核细胞，被发现是一种可溶性B细胞生长因子（BCGF）的高效体外生产者，这种因子能够维持由抗μ激活的B细胞的增殖。需要通过凝集素（植物血凝素、PHA、刀豆球蛋白A、Con A；以及商陆丝裂原、PWM）激活，才能诱导培养的LGL产生高水平的这种BCGF。LGL与自然杀伤（NK）敏感（K562）但不与NK抗性（RL male 1）靶细胞结合后，也检测到了BCGF的产生。与T细胞不同，LGL在培养72小时达到BCGF的最佳产量时，不需要额外存在辅助细胞。负责产生BCGF的LGL亚群具有与NK细胞相关的表型特征（3G8 +、HNK1 + /OKT11 +、DR -、OKT3 -、Leu - M1 -），具有这些标志物的分离细胞表现出高水平的NK活性。从LGL衍生的细胞毒性克隆中也选择性地产生了BCGF。通过凝胶过滤对LGL衍生的BCGF进行了部分特性分析。在估计分子量为20,000和45,000的级分中检测到了BCGF活性。LGL衍生的BCGF活性对2 - 巯基乙醇的还原具有抗性，并且在-20℃下可稳定保存数月。相反，加热（56℃1小时）或用胰蛋白酶消化会大大降低LGL衍生的BCGF活性。这些发现强烈表明，包括具有NK活性的LGL在内，在B细胞介导的免疫反应的早期事件中可以发挥重要的积极作用。
