Uhr J W, Vitetta E S
Natl Cancer Inst Monogr. 1978 May(48):295-300.
Murine lymphocytes were enzymatically radioiodinated and the class of immunoglobulin (isotype) on the cell surface was studied as a function of differentiation and ontogeny. The results indicate that IgM is the first isotype to appear and that IgD is subsequently acquired. A proportion of IgM-bearing cells also bear IgD. The acquisition of IgD does not appear to be under the influence of the thymus or of exposure to antigen. The observations suggest a sequence of differentiation steps in which B-cells first express IgM then acquire IgD (to become "double bearers"), and eventually lose IgM. The relationship of the IgD-bearing cells to the IgG-bearing memory cells has not yet been established. The implications of these findings with regard to function and genetic organization are discussed.
对小鼠淋巴细胞进行酶促放射性碘化处理，并研究细胞表面免疫球蛋白（同种型）类别随分化和个体发育的变化。结果表明，IgM是首先出现的同种型，随后获得IgD。一部分携带IgM的细胞也携带IgD。IgD的获得似乎不受胸腺或接触抗原的影响。这些观察结果提示了一个分化步骤序列，其中B细胞首先表达IgM，然后获得IgD（成为“双携带者”），最终失去IgM。携带IgD的细胞与携带IgG的记忆细胞之间的关系尚未确定。讨论了这些发现对功能和基因组织的意义。
