Alt F W, Enea V, Bothwell A L, Baltimore D
Cell. 1980 Aug;21(1):1-12. doi: 10.1016/0092-8674(80)90109-9.
Two cloned lambda 1-producing myelomas (HOPC-1, MOPC-104E) contain rearranged kappa genes and levels of mature-sized kappa RNA comparable to those found in kappa-producing myeloma cells. Another lambda 1-producing myeloma tumor line (HOPC-2020) and a lambda 1-containing B cell leukemia line (BCL1) also contain significant levels of kappa RNA. One lambda 11-producing line (MOPC-315) contains no detectable kappa RNA, but it also has no kappa genes in the embryonic configuration. kappa-related proteins are not detectable in the lambda 1-producing lines by standard procedures, but by sensitive methods at least two lines contain kappa protein fragments. The MOPC-104E line produces both a 14.5K kappa fragment that is not readily detectable because of its low rate of synthesis and short half-life (T 1/2 less than 5 min), and a major 16.5K protein that lacks kappa cross reactivity but is demonstrable by translation of purified MOPC-104E kappa RNA. The HOPC-1 kappa RNA also encodes a short-lived 14K kappa fragment. The MPC-11 line, which produces a mature kappa RNA and protein as well as an 800 base kappa fragment RNA and kappa protein fragment, has both kappa alleles rearranged, one apparently aberrantly between J and C kappa. Two different kappa RNA species, one the same size as the MPC-11 kappa fragment RNA, frequently are present in kappa RNA-containing Abelson murine leukemia virus-transformed lymphoid cells as well as in 18 and 19 day murine fetal liver. For light chains, neither allelic nor isotype exclusion is generally evident in myeloma and lymphoma cells; rather both produce only a single functional light chain. Models of light chain activation must explain restriction by considering the functional properties of the light chain rather than light chain gene expression.
两个产生λ1的克隆骨髓瘤（HOPC - 1、MOPC - 104E）含有重排的κ基因，且成熟大小的κRNA水平与产生κ的骨髓瘤细胞中的水平相当。另一个产生λ1的骨髓瘤肿瘤系（HOPC - 2020）和一个含λ1的B细胞白血病系（BCL1）也含有显著水平的κRNA。一个产生λ11的系（MOPC - 315）未检测到κRNA，但它也没有处于胚胎构型的κ基因。通过标准程序在产生λ1的系中检测不到κ相关蛋白，但通过敏感方法至少有两个系含有κ蛋白片段。MOPC - 104E系产生一种14.5K的κ片段，由于其合成速率低和半衰期短（T1/2小于5分钟）而不易检测到，以及一种主要的16.5K蛋白，该蛋白缺乏κ交叉反应性，但通过纯化的MOPC - 104E κRNA翻译可证明其存在。HOPC - 1 κRNA也编码一种半衰期短的14K κ片段。MPC - 11系产生成熟的κRNA和蛋白以及一个800碱基的κ片段RNA和κ蛋白片段，其两个κ等位基因均重排，其中一个显然在Jκ和Cκ之间异常重排。两种不同的κRNA种类，其中一种与MPC - 11 κ片段RNA大小相同，经常出现于表达κ的阿贝尔逊鼠白血病病毒转化的淋巴细胞以及18至19天的鼠胎肝中。对于轻链，等位基因排斥和同型排斥在骨髓瘤和淋巴瘤细胞中通常都不明显；相反，两者都只产生单一功能性轻链。轻链激活模型必须通过考虑轻 链的功能特性而非轻链基因表达来解释限制现象。
