Skok J A, Brown K E, Azuara V, Caparros M L, Baxter J, Takacs K, Dillon N, Gray D, Perry R P, Merkenschlager M, Fisher A G
Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, Du Cane Road, London W12 ONN, UK.
Nat Immunol. 2001 Sep;2(9):848-54. doi: 10.1038/ni0901-848.
Individual B lymphocytes normally express immunoglobulin (Ig) proteins derived from single Ig heavy chain (H) and light chain (L) alleles. Allelic exclusion ensures monoallelic expression of Ig genes by each B cell to maintain single receptor specificity. Here we provide evidence that at later stages of B cell development, additional mechanisms may contribute to prioritizing expression of single IgH and IgL alleles. Fluorescent in situ hybridization analysis of primary splenic B cells isolated from normal and genetically manipulated mice showed that endogenous IgH, kappa and lambda alleles localized to different subnuclear environments after activation and had differential expression patterns. However, this differential recruitment and expression of Ig alleles was not typically seen among transformed B cell lines. These data raise the possibility that epigenetic factors help maintain the monoallelic expression of Ig.
单个B淋巴细胞通常表达源自单个免疫球蛋白（Ig）重链（H）和轻链（L）等位基因的Ig蛋白。等位基因排斥确保每个B细胞单等位基因表达Ig基因，以维持单一受体特异性。在此，我们提供证据表明，在B细胞发育的后期阶段，其他机制可能有助于优先表达单个IgH和IgL等位基因。对从正常和基因操作小鼠中分离的原代脾B细胞进行荧光原位杂交分析表明，内源性IgH、κ和λ等位基因在激活后定位于不同的核内亚环境，并具有不同的表达模式。然而，在转化的B细胞系中通常看不到Ig等位基因的这种差异募集和表达。这些数据增加了表观遗传因素有助于维持Ig单等位基因表达的可能性。
