Klaus G G, Hawrylowicz C M, Holman M, Keeler K D
Immunology. 1984 Dec;53(4):693-701.
Intact (IgG) rabbit anti-immunoglobulin antibodies are generally not mitogenic for mouse B cells but, on the contrary, inhibit proliferation induced by either F(ab')2 anti-Ig or by lipopolysaccharide. We show here, however, that IgG anti-Ig activates mouse B cells, since it causes B cells to depolarize, to enlarge and to express increased levels of Ia antigens. In the continuing presence of IgG anti-Ig, B cells do not synthesise DNA. However, if cells cultured with IgG antibody are then washed, they start to proliferate earlier in response to F(ab')2 anti-Ig, i.e. they have become primed. We therefore conclude that IgG anti-Ig is an example of a 'step-one activator' for mouse B cells, which drives resting B cells out of Go, but actively prevents the cells from progressing into S. The latter effect appears to result from cross-linking of surface Ig and Fc receptors on B cells, although the mechanism is, as yet, unknown.
完整的（IgG）兔抗免疫球蛋白抗体通常对小鼠B细胞无促有丝分裂作用，但相反，它会抑制由F（ab'）2抗Ig或脂多糖诱导的增殖。然而，我们在此表明，IgG抗Ig可激活小鼠B细胞，因为它会导致B细胞去极化、体积增大并表达更高水平的Ia抗原。在持续存在IgG抗Ig的情况下，B细胞不会合成DNA。然而，如果用IgG抗体培养的细胞随后被洗涤，它们会更早地开始对F（ab'）2抗Ig作出增殖反应，即它们已被致敏。因此，我们得出结论，IgG抗Ig是小鼠B细胞“第一步激活剂”的一个例子，它驱使静止的B细胞离开G0期，但积极阻止细胞进入S期。后一种效应似乎是由于B细胞表面Ig和Fc受体的交联所致，尽管其机制尚不清楚。
