Bovkun L A, Peremislov V V, Nayakshin A M, Belousov E S, Mechetina L V, Aasted B, Taranin A V
Institute of Cytology and Genetics, Novosibirsk, Russia.
Eur J Immunol. 1993 Aug;23(8):1929-34. doi: 10.1002/eji.1830230830.
The ratio of kappa and lambda chains of immunoglobulins varies significantly from one species to another. It has previously been thought that lambda was only type expressed in mink. We tested mink immunoglobulin light chains using two monoclonal antibodies G80 and G88. It has been shown that G80 and G88 specifically recognize two antigenically different subpopulations of the light chains. Immunochemical analysis of these subpopulations separated by affinity chromatography suggested that they represent lambda and kappa types of light chains, respectively. Screening of a mink cDNA library with monoclonal antibody G88 resulted in the isolation of clone pIGK-1 containing kappa chain-encoding sequence. The cDNA insert of pIGK-1 included most of the V segment, as well as the J, C and 3' untranslated sequences. Mink V kappa sequence shown the highest homology with the human V kappa II subgroup genes (76-79%). Mink C kappa sequence was 53-63% homologous to C kappa of other species. The striking feature of mink C kappa chain is the presence of glutamine in the C-terminal position. Southern blot analysis suggested that mink haploid genome has one C kappa gene and multiple V kappa genes. The kappa:lambda chain ratio in the 12 minks studied was, on the average, 46:54. The same ratio was observed for the kappa- and lambda-producing cells in the mesenteric lymph nodes. The five previously identified mink light chain allotypes were assigned to the lambda chains, thereby confirming that lambda chains in this species are additionally subdivided into several subtypes.
免疫球蛋白的κ链和λ链比例在不同物种之间存在显著差异。以前人们认为λ链是水貂中唯一表达的类型。我们使用两种单克隆抗体G80和G88检测了水貂免疫球蛋白轻链。结果表明，G80和G88特异性识别轻链的两个抗原性不同的亚群。对通过亲和层析分离的这些亚群进行免疫化学分析表明，它们分别代表λ链和κ链类型。用单克隆抗体G88筛选水貂cDNA文库，得到了包含κ链编码序列的克隆pIGK-1。pIGK-1的cDNA插入片段包括大部分V片段，以及J、C和3'非翻译序列。水貂Vκ序列与人VκII亚组基因具有最高的同源性（76-79%）。水貂Cκ序列与其他物种的Cκ序列同源性为53-63%。水貂Cκ链的显著特征是在C末端位置存在谷氨酰胺。Southern印迹分析表明，水貂单倍体基因组有一个Cκ基因和多个Vκ基因。在所研究的12只水貂中，κ:λ链的平均比例为46:54。在肠系膜淋巴结中产生κ链和λ链的细胞也观察到相同的比例。先前鉴定的5种水貂轻链同种异型被归为λ链，从而证实该物种中的λ链还可进一步细分为几个亚型。
