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为分析多发性骨髓瘤 (multiplemyeloma,MM )细胞对免疫球蛋白重链基因可变区 (VH)基因家族的取用 ;根据VH 基因突变特点 ,揭示MM细胞的起源。以重链基因可变区 (VH1 VH6 )基因家族特异性引物 ,用PCR法扩增骨髓瘤细胞系CZ 1细胞和 98例MM患者外周血单个核细胞VH 基因片段 ,纯化后的PCR产物和pMD18 T载体连接并转化JM10 9细菌 ,经克隆鉴定后 ,目的DNA片段用末端双脱氧法测定DNA序列 ,和其对应的胚系基因序列比较。结果表明MM细胞对各VH 基因家族的取用顺序为VH3>VH1>VH4 >VH2 >VH5 >VH6 ;MM细胞VH 基因互补决定区 (CDR )氨基酸替换性突变 (R突变 ) /氨基酸静寂性突变 (S突变 )等于 9 6 7,而骨架区 (FR )R/S等于 0 87,而且随着疾病的进展 ,IgVH 基因并不发生进一步的突变。结论是MM前体细胞在进行VDJ基因重排时 ,对VH 基因家族的取用和基因家族相对大小有关 ;MM细胞可能起源于已经发生抗原选择和体细胞突变的B记忆细胞或前浆细胞。
To analyze the access of immunoglobulin heavy chain variable region (VH) gene family to multiple myeloma (MM) cells and reveal the origin of MM cells according to the characteristics of VH gene mutation. The VH gene fragment of peripheral blood mononuclear cells of myeloma cell line CZ 1 and 98 cases of MM were amplified by PCR using the VH1 VH6 gene family-specific primers. The purified PCR product and pMD18 T vector and transformed into JM109 bacteria. After identification of the clones, the DNA sequence of the target DNA fragment was determined by terminal dideoxy method and compared with its corresponding germline gene sequence. The results showed that MM cells had VH3> VH1> VH4> VH2> VH5> VH6 accessions for each VH gene family; amino acid substitution mutation (R mutation) / amino acid silencing mutation S mutation is equal to 9 6 7, while the framework region (FR) R / S is equal to 0 87, and as the disease progresses, IgVH gene does not undergo further mutation. The conclusion is that MM precursor cells are associated with relative gene family size when MM precursor cells undergo VDJ rearrangement. MM cells may originate from B memory cells or pruritus cells that have undergone antigenic selection and somatic mutation.