Pure E, Isakson P C, Kappler J W, Marrack P, Krammer P H, Vitetta E S
J Exp Med. 1983 Feb 1;157(2):600-12. doi: 10.1084/jem.157.2.600.
In these studies we have determined the molecular weights of B cell growth factor (BCGF) (less than 20,000), and B cell differentiation factors (BCDF) that induce immunoglobulin M (IgM) secretion (BCDF mu) (30-60,000) and IgG secretion (BCDF gamma) (less than 20,000). Thus, the molecular weight of BCDF mu is distinct from that of BCGF and BCDF gamma; BCGF and BCDF gamma cannot be distinguished. In addition, BCGF, BCDF mu, and BCDF gamma are distinguishable by their presence or absence in different supernatants from a panel of mitogen-induced T cell clones. These results suggest that the three lymphokines are different. This conclusion is supported by their differential biological effect on B cells from adult and neonatal mice. Thus, treatment with anti-Ig induces B cells from adult mice to proliferate and this proliferation is sustained by BCGF. In contrast, even in the presence of BCGF, anti-Ig does not induce B cells from neonatal mice to proliferate. However, BCDF mu and BCDF gamma induce IgM and IgG secretion in B cells, respectively, from both adult and neonatal mice. Thus, mature B cells can both clonally expand and differentiate in response to anti-Ig, BCGF, and BCDF, whereas immature B cells can only differentiate. The poor response of neonatal B cells to anti-Ig and BCGF may partially explain the relative immunoincompetence of immature B cells.
在这些研究中，我们测定了B细胞生长因子（BCGF）（分子量小于20,000）以及诱导免疫球蛋白M（IgM）分泌的B细胞分化因子（BCDFμ）（分子量30 - 60,000）和诱导IgG分泌的B细胞分化因子（BCDFγ）（分子量小于20,000）的分子量。因此，BCDFμ的分子量与BCGF和BCDFγ不同；BCGF和BCDFγ无法区分。此外，BCGF、BCDFμ和BCDFγ可通过它们在一组丝裂原诱导的T细胞克隆的不同上清液中是否存在来区分。这些结果表明这三种淋巴因子是不同的。这一结论得到了它们对成年和新生小鼠B细胞的不同生物学效应的支持。因此，用抗Ig处理可诱导成年小鼠的B细胞增殖，且这种增殖由BCGF维持。相比之下，即使存在BCGF，抗Ig也不会诱导新生小鼠的B细胞增殖。然而，BCDFμ和BCDFγ分别诱导成年和新生小鼠B细胞分泌IgM和IgG。因此，成熟B细胞可响应抗Ig、BCGF和BCDF进行克隆性扩增和分化，而未成熟B细胞只能分化。新生B细胞对抗Ig和BCGF反应不佳可能部分解释了未成熟B细胞相对免疫无能的现象。
