Moutsopoulos H M, Boehm-Truitt M, Kassan S S, Chused T M
J Immunol. 1977 Nov;119(5):1639-44.
We have developed a highly specific and sensitive "two-site" immunoradiometric assay for murine IgM in which antigen bound to immobilized antibody reacts with affinity-purified radiolabeled antibody. We utilized the sensitivity of this assay to study the rate of IgM secretion in short-term cultures by spleen cells from the autoimmune strains, New Zealand Black (NZB) and New Zealand Black by New Zealand White F1 hybrid (BW), and from normal (C57BL/6, DBA/2, NZW) mice. The temperature dependence of IgM secretion in short-term cultures, its pentameric structure, and the similar viability of NZB and normal strain spleen cells indicate that active IgM synthesis is being measured. We observed that the splenic B lymphocytes of NZB and BW mice, in contrast to normal strains, produce IgM in vitro at birth. By 6 to 8 weeks of age NZB and BW spleen cells produce 40 times more IgM than spleen cells from normal strains of mice. The IgM produced in vitro by splenic lymphocytes from NZB and BW mice is not absorbed by synegeneic or allogeneic thymocytes or erythrocytes.
我们已经开发出一种针对小鼠IgM的高度特异性和敏感性的“双位点”免疫放射分析方法，其中与固定化抗体结合的抗原与亲和纯化的放射性标记抗体发生反应。我们利用该分析方法的敏感性，研究了来自自身免疫品系新西兰黑鼠（NZB）、新西兰黑鼠与新西兰白鼠的F1杂交种（BW）以及正常（C57BL/6、DBA/2、NZW）小鼠的脾细胞在短期培养中IgM的分泌速率。短期培养中IgM分泌的温度依赖性、其五聚体结构以及NZB和正常品系脾细胞相似的活力表明，所测量的是活性IgM合成。我们观察到，与正常品系相比，NZB和BW小鼠的脾B淋巴细胞在出生时就在体外产生IgM。到6至8周龄时，NZB和BW脾细胞产生的IgM比正常品系小鼠的脾细胞多40倍。NZB和BW小鼠脾淋巴细胞在体外产生的IgM不会被同基因或异基因胸腺细胞或红细胞吸收。
