Rooney J W, Dubois P M, Sibley C H
Department of Genetics (SK-50), University of Washington, Seattle 98195.
Eur J Immunol. 1991 Dec;21(12):2993-8. doi: 10.1002/eji.1830211214.
In B lymphocytes, cross-linking of surface IgM activates changes in both the cell cycle and differentiation. In normal B cells and B cell tumors, many stimuli induce the activation of NF-kappa B and its translocation from the cytoplasm to the nucleus. In this study we sought to determine if cross-linking of surface IgM led to the activation of NF-kappa B. Our results show that activation of B cells by cross-linking anti-IgM antibodies activated NF-kappa B in the murine B lymphoid cell lines 70Z/3 and M12, and in the dense fraction of splenic cells. The activation of NF-kappa B required optimal doses of anti-IgM antibodies and took 5 to 10 min to reach maximal levels. Cross-linking of IgM has also been shown to activate protein kinases including protein kinase C (PKC). To test whether PKC activation was required for NF-kappa B translocation, we treated 70Z/3 cells for 18 h with phorbol 12-myristate 13-acetate, a procedure which depletes these cells of functional PKC. This treatment did not abrogate the nuclear translocation of NF-kappa B following anti-IgM cross-linking. These results indicate that the nuclear translocation of NF-kappa B is rapidly induced by surface IgM cross-linking and that this activation appears to use a pathway which does not require PKC.
在B淋巴细胞中，表面IgM的交联可激活细胞周期和分化的变化。在正常B细胞和B细胞肿瘤中，许多刺激可诱导NF-κB的激活及其从细胞质向细胞核的转位。在本研究中，我们试图确定表面IgM的交联是否会导致NF-κB的激活。我们的结果表明，通过交联抗IgM抗体激活B细胞可在小鼠B淋巴细胞系70Z/3和M12以及脾细胞的致密部分中激活NF-κB。NF-κB的激活需要最佳剂量的抗IgM抗体，并且需要5到10分钟才能达到最大水平。IgM的交联也已被证明可激活包括蛋白激酶C（PKC）在内的蛋白激酶。为了测试PKC激活是否是NF-κB转位所必需的，我们用佛波醇12-肉豆蔻酸酯13-乙酸酯处理70Z/3细胞18小时，该过程使这些细胞耗尽功能性PKC。这种处理并没有消除抗IgM交联后NF-κB的核转位。这些结果表明，表面IgM交联可迅速诱导NF-κB的核转位，并且这种激活似乎使用了一条不需要PKC的途径。
