Nomura J, Inui S, Yamasaki T, Kataoka S, Maeda K, Nakanishi K, Sakaguchi N
Department of Immunology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan.
Immunol Lett. 1995 Mar;45(3):195-203. doi: 10.1016/0165-2478(95)00006-q.
To study the activation and differentiation of murine B cells, we prepared a hybridoma secreting monoclonal antibody, LB429, which can directly induce the proliferation of murine B cells in vitro. LB429 recognizes a B cell specific surface molecule of 45 kDa. It recognizes an epitope of murine CD40 produced as a soluble fusion protein with glutathione S-transferase. LB429 stains COS-7 transfectant with murine CD40 cDNA and mature B-cell lines but does not stain pre-B cell lines. Two color staining demonstrated that the epitope recognized with LB429 appears on the surface of B220+ cells of spleen and bone marrow. LB429 can induce a strong proliferation of murine B cells from spleen in the absence of initial triggering with anti-IgM antibody or with anti-IgM antibody + IL-4. LB429 induced the cell size enlargement and the cell cycle transition of resting B cells as well as lipopolysaccharide (LPS). LB429 and LPS stimulate B cells synergistically in vitro by accumulating 44.7% of cells in S/G2/M phases of cell cycle. However, stimulation of spleen B cells with LB429 resulted in the increase of sIgM high+ sIgD(high)+ B cells, in contrast LPS showed the proliferation of both sIgM(high)+ sIgD(high)+ B cells and sIgM(low)+ sIgD(high)+ B cells. These results suggested that LB429 and LPS cause the proliferation of B cells through different stimulatory pathways. This anti-mouse CD40 antibody (LB429) is a very useful reagent to study the activation and differentiation of B cells in vitro.
为了研究小鼠B细胞的激活和分化，我们制备了一种分泌单克隆抗体LB429的杂交瘤，该抗体可在体外直接诱导小鼠B细胞增殖。LB429识别一种45 kDa的B细胞特异性表面分子。它识别与谷胱甘肽S-转移酶形成可溶性融合蛋白的小鼠CD40的一个表位。LB429可使转染了小鼠CD40 cDNA的COS-7细胞以及成熟B细胞系染色，但不能使前B细胞系染色。双色染色表明，LB429识别的表位出现在脾脏和骨髓中B220+细胞的表面。在没有抗IgM抗体或抗IgM抗体+IL-4初始触发的情况下，LB429可诱导来自脾脏的小鼠B细胞强烈增殖。LB429诱导静息B细胞的细胞大小增大和细胞周期转变，脂多糖（LPS）也有此作用。LB429和LPS在体外通过使44.7%的细胞积累在细胞周期的S/G2/M期而协同刺激B细胞。然而，用LB429刺激脾脏B细胞导致sIgM高+sIgD（高）+B细胞增加，相比之下，LPS显示sIgM（高）+sIgD（高）+B细胞和sIgM（低）+sIgD（高）+B细胞均增殖。这些结果表明，LB429和LPS通过不同的刺激途径导致B细胞增殖。这种抗小鼠CD40抗体（LB429）是研究体外B细胞激活和分化的非常有用的试剂。
