Kaji H, Parkhouse M E
J Immunol. 1975 Apr;114(4):1218-20.
Mouse myeloma tumors and some variants derived from them were labeled in vitro with tritiated leucine and the radioactive J chain was assayed in cell lysates by precipitation with an antiserum specific for mouse J chain. The major findings were: 1) J chain can be found in an IgG2b-secreting cells (MPC-11). These data, together with previous findings suggest that cells secreting all classes of IgG synthesize J chain, even though there is no apparent requirement for J chain in assembly of the IgG molecule. Hence production of J chain does not depend upon secretion of a polymeric immunoglobulin. 2) Intracellular J chain can be found in myeloma variants that do not produce heavy chains showing that production of J chain may not coordinately be linked to the synthesis of heavy chain. 3) J chain was found in cells synthesizing, but not secreting, immunoglobulin. Thus production of J chain is not linked to secretion of immunoglobulin. 4) J chain could not be detected in plasma cells that do not produce immunoglobulins. It was also not found in mouse leukemic cells, suggesting that production of J chain is probably linked in some way to immunoglobulin production.
用氚标记的亮氨酸在体外标记小鼠骨髓瘤肿瘤及其一些衍生变体，并用对小鼠J链特异的抗血清沉淀法测定细胞裂解物中的放射性J链。主要发现如下：1）在分泌IgG2b的细胞（MPC-11）中可发现J链。这些数据与先前的发现共同表明，分泌所有IgG类别的细胞都合成J链，尽管在IgG分子组装中对J链没有明显需求。因此，J链的产生并不依赖于聚合免疫球蛋白的分泌。2）在不产生重链的骨髓瘤变体中可发现细胞内J链，这表明J链的产生可能与重链的合成没有协同联系。3）在合成但不分泌免疫球蛋白的细胞中发现了J链。因此，J链的产生与免疫球蛋白的分泌没有联系。4）在不产生免疫球蛋白的浆细胞中未检测到J链。在小鼠白血病细胞中也未发现J链，这表明J链的产生可能在某种程度上与免疫球蛋白的产生相关。
