Kim K J, Dejoy S Q
Immunology. 1986 Sep;59(1):15-21.
We have examined the effect of concanavalin A (Con A), a conventionally known T-cell mitogen, on the induction of Ig secretion from BALB/c B lymphoid cell lines expressing membrane IgM (X16C8.5, BALENTL 17.7.2 and BCL1) or membrane IgG (A20 and M12.4). A20 tumour cells, but not other tumour cells, responded to Con A by secreting Ig as measured by the reverse plaque-forming cell (PFC) assay. Another typical T-cell mitogen, phytohaemagglutinin (PHA), did not have any effect on the differentiation of A20 tumour cells. The addition of NaN3 abolished the PFC formation, showing that IgG PFC formation of A20 tumour cells was due to the active synthesis of secreted IgG and not due to the shedding of mIgG. The increase in the biosynthesis of secreted IgG from A20 tumour cells by Con A was also observed by polyacrylamide gel electrophoresis. The ability of Con A to induce IgG secretion from A20 tumour cells was abolished by the addition of alpha-methylmannoside, confirming that Con A itself, and not some contaminating material in Con A, induced the maturation of A20 tumour cells. Con A was also shown to induce Ig secretion, but not proliferation, in a subset of normal B cells. Thus, we conclude that Con A does give a differentiation signal to a subset of B cells.
我们研究了伴刀豆球蛋白A（Con A），一种传统上已知的T细胞有丝分裂原，对表达膜IgM（X16C8.5、BALENTL 17.7.2和BCL1）或膜IgG（A20和M12.4）的BALB/c B淋巴细胞系诱导Ig分泌的影响。通过反向空斑形成细胞（PFC）测定法检测发现，A20肿瘤细胞而非其他肿瘤细胞对Con A有反应并分泌Ig。另一种典型的T细胞有丝分裂原，植物血凝素（PHA），对A20肿瘤细胞的分化没有任何影响。NaN3的添加消除了PFC的形成，表明A20肿瘤细胞的IgG PFC形成是由于分泌型IgG的活性合成，而非mIgG的脱落。通过聚丙烯酰胺凝胶电泳也观察到Con A使A20肿瘤细胞分泌型IgG的生物合成增加。添加α-甲基甘露糖苷可消除Con A诱导A20肿瘤细胞分泌IgG的能力，证实是Con A本身而非Con A中的某些污染物质诱导了A20肿瘤细胞的成熟。Con A还被证明可诱导一部分正常B细胞分泌Ig，但不诱导其增殖。因此，我们得出结论，Con A确实能向一部分B细胞发出分化信号。
